explain xkcd - User contributions [en]

Beret Guy

2024-12-06T18:41:10Z

The-Ergster:

{{Infobox character
| image = Beret_Guy.png
| imagesize = 200px
| caption = '
| first_appearance = [[167: Nihilism]]
}}

<noinclude>:''For a list of comics, see [[:Category:Comics featuring Beret Guy|Comics featuring Beret Guy]].''</noinclude>

'''Beret Guy''' is a [[stick figure]] character in [[xkcd]]. He is distinguished by his white beret. Like [[Black Hat]], he is one of the few xkcd characters who tends to represent the same character in each appearance. Randall has admitted that '''Beret Guy''' is his favorite character.

Beret Guy is a naïve optimist, though rarely a victim in the strip. He is a funny and borderline-cute character, usually appearing as the basis of a strip's joke. He enjoys philosophizing, often taking the role of the {{w|existentialist}}. He has a very surreal side to him, often thinking about or being involved in bizarre situations. He also is shown to take things literally too far, making things surreal.

He has been fascinated with bakeries as in [[434: xkcd Goes to the Airport]] and [[442: xkcd Loves the Discovery Channel]], in particular with {{w|scone}}s (see [[452: Mission]] as well as the title text of [[677: Asshole]] and [[1030: Keyed]].)

Beret Guy had a steady job as a bartender in three comics [[328: Eggs]], [[474: Turn-On]], and [[712: Single Ladies]]. However, in later comics, he quit his job to become a "business professional", according to [[1032: Networking]]. There are many comics where he has unusual, impossible, or completely unnecessary jobs, like in [[1117: My Sky]]. (See all comics about [[:Category:Beret Guy's Business|Beret Guy's Business]].) He makes a load of money from his work but has no apparent job other than "a business grown-up who makes business profits". He appears again, with his own "real building he found" in [[1293: Job Interview]]. In [[1493: Meeting]], his business returns again, this time with a name http://CompanyName.website/ yet no explanation of how it makes money from Sales, run by [[Ponytail]] ("Money keeps appearing, but we have no idea how or why"). At the time, somehow, it is still massively successful. As of [[1533: Antique Factory]] it seems Beret Guy has reorganized his business and branched out from his technology area of expertise and operates what he refers to as an antique factory. In reality, the "factory" is simply a room with furniture in it where Beret Guy waits for the items to age.

Beret Guy also seems to be able to, consciously or unconsciously, warp the fabric of reality - see a list of [[:Category:Strange powers of Beret Guy|his strange powers]]. In [[1099: Tuesdays]], he grows "endless wings" and in the aforementioned [[1293: Job Interview]], he seems to be pouring soup from an electrical socket, as well as in [[1486: Vacuum]], where he misinterprets quantum physics and manages to get unlimited power from a vacuum cleaner. In [[1490: Atoms]], he appears to have a supernatural ability to see individual atoms (or at least the atomic make-up of items) and his mother seems to have an unexplained amount of plutonium in her body. In [[1608: Hoverboard]] he is shown riding a torpedo launched from a {{w|Star Destroyer}} towards the rebel ship below. He shouts 'Horsey' and seems unaware of the destruction these torpedoes are causing. However, Beret Guy seems to have no doubt that these events are perfectly normal; in fact, he just seems to accept them as they are without question. Beret Guy's seeming ignorance to his supernatural nature suggests that his powers are unintentional; it could be that the universe itself simply "bends around" Beret Guy, in order to fulfill any nonsensical or whimsical thing that he believes to be true, or an idiom/physical law that he has misunderstood.

He also appears to shop at a "mysterious shop", which seems to be cursed. This shop is mentioned in [[1772: Startup Opportunity]], [[2332: Cursed Chair]], [[2376: Curbside]], and [[2367: Masks]].

In the What if? [https://what-if.xkcd.com/6/ Glass Half Empty], he seems to be quite oblivious to pain, especially about foreign objects sticking into his head. This may explain why we never see him without his beret as it may have been stapled to his head - see title text of [[291: Dignified]]. The latter comic also suggests that he might have been born by Caesarean section. In the What if? [http://what-if.xkcd.com/147/ Niagara Straw], he appears in the final comic, going down a relativistic stream of water, oblivious to the fact that said stream of water was destroying the world, in a barrel.

Beret Guy also seems to have dogs who seem to share some of his powers, as shown in [[1614: Kites]] and [[1922: Interferometry]].

To sum up, Beret Guy is a very naive man with the superpower of having the world around him act according to his bizarre vision.

He shares several traits with Beriah from [http://www.meninhats.com/ Men in Hats], as [[Black Hat]] does with Aram from the same series, but in contrast to the latter, this doesn't appear to have been officially acknowledged.

He may also have a relative, Beret Girl, which only ever appeared in [[1190: Time]].

During [https://www.youtube.com/watch?v=dAEutGwIQ9c&t=2758s an interview in 2023], Randall revealed that Beret Guy is one of the characters he is most fond of.

{{navbox-characters}}
[[Category:Characters]]
[[Category:Characters with hats| Beret Guy]]
[[Category:Major characters]]

Category:Comics edited after their publication

2024-12-05T16:14:01Z

The-Ergster:

{{incomplete|This category was forgotten about and doesn't contain all edited comics. Help by adding more comics to this category! No clue how to find more comics, Good Luck! Only remove this notice after making sure this category is complete.}}

Randall occasionally updates comics after they are published to fix errors, appease fan complaints, or for other reasons. This is a collective list of all comics that have been edited after release.

[[Category:Distinctive comics]]

Category:Comics edited after their publication

2024-12-05T16:13:48Z

The-Ergster:

{{incomplete|This category was forgotten about and doesn't contain all edited comics. Help by adding more comics to this category! No clue how to find more comics Good Luck. Only remove this notice after making sure this category is complete.}}

Randall occasionally updates comics after they are published to fix errors, appease fan complaints, or for other reasons. This is a collective list of all comics that have been edited after release.

[[Category:Distinctive comics]]

Donald Trump

2024-12-04T00:58:40Z

The-Ergster:

{{Infobox character
| image = Donald Trump.jpeg
| imagesize = 200px
| caption = '
| first_appearance = [[980: Money]]
}}

<noinclude>:''For a list of comics, see [[:Category:Comics featuring Donald Trump|Comics featuring Donald Trump]].''</noinclude>

'''{{w}}''' is an American politician, media personality, and businessperson who served as the 45th {{w|president of the United States}} from 2017 to 2021 and will serve again from 2025 to 2029 as the 47th president. He won the 2016 election as a Republican with controversial policies. His presidency involved actions like travel bans, border wall funding, tax cuts, Supreme Court appointments, environmental deregulation, and strained international relations. After losing the 2020 election, he faced impeachments and legal issues, but continued political involvement. Amidst multiple indictments in 2023 he announced his candidacy for the 2024 election, which he won. During the 2024 presidential race Randall announced his support for Trump's opponent, [[Kamala Harris]].

{{incomplete|May need later updates due to current events.}}

{{navbox-characters}}
[[Category:Characters]]
[[Category:Real people]]
[[Category:Politicians]]

Category:Sysadmins

2024-12-02T18:55:59Z

The-Ergster:

A sysadmin, or sysop, is someone who does the maintenance, configuration, and troubleshooting of a computer system, such as a server. Randall has mentioned sysadmins multiple times in xkcd.
[[Category:Comics by topic]]

1353: Heartbleed

2024-12-02T18:55:37Z

The-Ergster:

{{comic
| number = 1353
| date = April 9, 2014
| title = Heartbleed
| image = heartbleed.png
| titletext = I looked at some of the data dumps from vulnerable sites, and it was... bad. I saw emails, passwords, password hints. SSL keys and session cookies. Important servers brimming with visitor IPs. Attack ships on fire off the shoulder of Orion, c-beams glittering in the dark near the Tannhäuser Gate. I should probably patch OpenSSL.
}}

==Explanation==
The {{w|Heartbleed bug}} refers to a critical bug in the {{w|OpenSSL}} cryptographic library. This bug was publicly revealed on Monday, 7 April 2014. Due to a programming error in OpenSSL versions 1.0.1 through 1.0.1f — meaning the bug had existed for two years — attackers could read random server memory by sending specially prepared HeartbeatRequest messages to an affected server.

OpenSSL is a very commonly used library to implement {{w|SSL/TLS}}, a cryptographic protocol not only used to secure web traffic but also for mail clients and much more. Only the user and the server can read the communication. On the web the protocol is ''https://'' (HTTP Secure), instead of the open ''http://'' standard. SSL is often used to protect sensitive web traffic, such as login requests, which contains the usernames and passwords in the requests. The server sends a certificate to the browser before the secure connection is established. If the certificate is registered the browser accepts it automatically, otherwise the user gets a popup to accept or reject this insecure certificate.

A vulnerability that lets an attacker read random clumps of memory on the server would possibly let an attacker find recent username/password requests, allowing them to gain unauthorized access to user accounts. Even worse, this vulnerability could read the server's private key, enabling anyone to impersonate the server and/or decrypt any future traffic that relies on that key, and any previously obtained prior traffic also, unless a "perfect forward secrecy" cipher is used. Furthermore, the Heartbleed exploit occurs during the handshake phase of setting up a connection, so no traces of it are logged, i.e. you can be attacked and never be the wiser.

More information is available at [https://heartbleed.com heartbleed.com] or under the reference [https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2014-0160 CVE-2014-0160 at nvd.nist.gov].

In the last panel, Megan interprets Cueball's question ("is '''everything''' compromised?") expansively. She responds that, being a computer bug, Heartbleed can only affect information which is stored on computers. Cueball concludes that information recorded in analog media, such as that written on paper or etched in clay tablets, is safe. Megan adds that imaginations are also unaffected by Heartbleed, and Cueball is reassured. The reader may wonder how our society would fare in the face of the leakage of all electronically stored private information, but having our imaginations intact is certainly reassuring.

The title text cites the {{w|Tears in rain soliloquy}}, the dying words of the replicant and main antagonist Roy Batty (played by {{w|Rutger Hauer}}) in the 1982 film ''{{w|Blade Runner}}'', implying that the 64KiB Heartbleed buffer is so complete it includes memories from replicant brains. This is ironic as in the soliloquy, Roy Batty stated "All those moments will be lost in time".

The title text also suggests patching OpenSSL oneself, which might refer to the patched version of OpenSSL by Debian, which turned out to be vulnerable in 2008, and was the topic of [[424: Security Holes]].

===Heartbleed===
In addition to the below, see [[1354|xkcd's explanation]] in the next comic.

{{w|Transport Layer Security}} (TLS), the successor to {{w|Secure Sockets Layer|SSL}}, is a protocol that provides end-to-end encryption for data transmitted over the internet and is described in [https://tools.ietf.org/html/rfc5246 RFC 5246]. The Heartbeat extension to TLS introduced in 2012 (described in [https://tools.ietf.org/html/rfc6520 RFC 6520]) provides a protocol for keeping an encrypted TLS session alive (preventing inactivity timeouts), so you do not have to do a costly TLS handshake with the server for subsequent transfer of information.

The Heartbeat protocol involves the client sending a packet with an arbitrary payload (often a random 16-to-32-byte number) that the server periodically sends back to the client to tell the client that the TLS session is still alive. When the client sends the packet to a vulnerable version of OpenSSL, the OpenSSL server reads a <code>payload_size</code> from the header sent by the client. This is a 2-byte number (0 to 0xffff=65535) that is supposed to describe the size of the payload. The OpenSSL library writes the payload to memory, but it does not check that the size of the payload written to memory matches the <code>payload_size</code> taken from the client's header. When the vulnerable server sends back the Heartbeat KeepAlive response to the client, it will readout <code>payload_size</code> number of bytes and send them back to the client. If you send a payload that is actually 16 bytes, but claims it is 0xffff bytes you will read the next 64KiB of memory of the vulnerable process starting from wherever the payload was written. An attacker can repeat this attack many times and can do this attack early in the TLS handshake, so the attack will not in any way be logged unless they are logging every incoming packet which is not typical and would result in many passwords being logged. As private keys often have an identifiable format, it is often possible for an attacker to find the private TLS key, so if they eavesdrop on network traffic they can decrypt and/or alter it. For more detailed information see: [https://blog.cryptographyengineering.com/2014/04/attack-of-week-openssl-heartbleed.html 1], [https://security.stackexchange.com/a/55117/2568 2], [https://news.ycombinator.com/item?id=7549943 3].

It is worth noting that modern operating systems use a {{w|Virtual Memory#Usage|virtual memory}} abstraction above physical memory. This means every process can only access memory assigned to it, so it would be impossible for a vulnerable web server to read memory assigned to another process (like a text editor that has erotic fan fiction stored to memory) on the same computer. For more info, see: [https://security.stackexchange.com/a/55271/2568 4].

It also should be noted that this Heartbleed bug only affects certain versions of OpenSSL, and does not affect other TLS/SSL implementations, or OpenSSH which does not even use the TLS protocol but uses the SSH-2 protocol (described in [https://tools.ietf.org/html/rfc4251 RFC 4251]). SSH is typically used for remote logins on Unix and Linux computers.

Vulnerable sysadmins need to update to a patched version of OpenSSL or one with the Heartbeats disabled. Unless their TLS keys were protected by hardware, they probably also need to revoke their old TLS keys and generate new TLS keys. To learn how to do this visit [https://leo-green.com Leo Green]. There you will find all the information you need.

Users of vulnerable systems should change their passwords after the sysadmins have revoked their old key and issued new ones (as their passwords may have been compromised). Users can check whether a given website is vulnerable via a [https://filippo.io/Heartbleed/ Heartbleed test also available as open source]. The [https://lastpass.com/heartbleed/ LastPass Heartbleed diagnostic] also indicates whether the signature on the TLS key predates the publication of the Heartbleed vulnerability.

The [https://github.com/openssl/openssl/commit/bd6941cfaa31ee8a3f8661cb98227a5cbcc0f9f3 vulnerable commit] was introduced Dec 31st, 2011, by Robin Seggelmann, the first co-author of the heartbeats RFC, and went live when OpenSSL version 1.0.1 was released on 2012-03-14 and the vulnerability was widely announced 2014-04-07.

==Transcript==
:Megan: Heartbleed must be the worst web security lapse ever.
:Cueball: Worst so far. Give us time.

:Megan: I mean, this bug isn't just broken encryption.
:Megan: It lets website visitors make a server dispense random memory contents.

:Megan: It's not just keys. It's traffic data. Emails. Passwords. Erotic fanfiction.
:Cueball: Is '''''everything''''' compromised?

:Megan: Well, the attack is limited to data stored in computer memory.
:Cueball: So paper is safe. And clay tablets.
:Megan: Our imaginations, too.
:Cueball: See, we'll be fine.

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Computer security]]
[[Category:Sysadmins]]

Category:Rockets

2024-12-02T18:51:33Z

The-Ergster:

A {{w|rocket}} is is a vehicle that uses jet propulsion to accelerate without using any surrounding air. A rocket engine produces thrust by reaction to exhaust expelled at high speed. Rocket engines work entirely from propellant carried within the vehicle; therefore a rocket can fly in the vacuum of space. Comics related to space often include rockets.
[[Category:Space]]

2981: Slingshots

2024-12-02T18:50:41Z

The-Ergster:

{{comic
| number = 2981
| date = September 4, 2024
| title = Slingshots
| image = slingshots_2x.png
| imagesize = 397x420px
| noexpand = true
| titletext = In my reboot, Dennis the Menace was just trying to send Mr. Wilson a nice comet, but accidentally wiped out his dinosaur garden.
}}

==Explanation==
The {{w|Slingshot|slingshot}} (in this comic, styled "Regular Slingshot") is primarily refering to the hand-held device used for accelerating small projectiles, such as stones or steel balls. The "forked stick and elastic" contraption (known as a catapult, in the UK) acts by a pull-back-and-release action, and has become associated with youthful recklessness (or an outright tendency towards vandalism), but is also the basis of manufactured sport/hunting devices as well as all of the more organic child-made contraptions.

The '''gravitational''' slingshot, or {{w|gravity assist}}, is not a device but a term used to describe how gravity can significantly alter the path of an object in space, such as a spacecraft or an asteroid. A gravitational slingshot generally involves a small object passing by a much more massive object, which turns the smaller object's trajectory, trading momentum and kinetic energy between the two bodies. The smaller object can undergo a large change in velocity, "paid for" (in the sense of conserving the momentum and energy of the system) with a negligible change in the velocity of the more massive body.

This comic humorously compares the two, in tabular format.

{| class="wikitable"
|-
!
! Regular slingshot
! Gravitational slingshot
|-
! Used for hunting
| ✓
| X
|-
! Used for sport shooting
| ✓
| X
|-
! Used for spacecraft propulsion
| X
| ✓
|-
! Large online enthusiast community
| ✓
| ✓
|-
! May have caused dinosaur extinction
| Probably not
| Maybe
|-
! Used by Dennis the Menace to terrorize Mr. Wilson
| ✓
| Not yet, but I'm pitching a reboot
|}

The first four categories accurately reflect reality. As a hunting tool (and as an offensive weapon), recent designs have been claimed to propel a projectile with [https://www.uslawshield.com/tactical-slingshots-mere-toy/ more force than .22 and .38 caliber pistols]. Consequently, several communities have prohibited the possession of such slingshots, which may be called "wrist rockets". The state of Massachusetts, where cartoonist Randall resides, is one of those communities. Gravitational slingshots would be inefficient and cause overkill for such purposes, as well as being difficult to achieve sufficient accuracy and specificity.

Conversely, gravitational slingshots are a useful way to change the velocity of a spacecraft without having to use large amounts of fuel, whereas building a regular slingshot capable of propelling a spacecraft is likely to be impractical - not to mention the destructive/fatal consequences, to vehicle and cargo, of near-instantaneous acceleration to useful speeds, such as the Mach 33 required for an object at sea level to escape Earth's gravity, especially when there's an atmosphere present.

Both types of slingshot excite interest among many people who may form online communities to discuss them, but for quite different reasons, and the size of overlap between these communities is uncertain.

The fifth category ventures into the absurd, at least with respect to "regular" slingshots, which did not exist (as far as we know) at the time of the {{w|Cretaceous–Paleogene_extinction_event|Cretaceous-Tertiary extinction event}}. (Humans, which invented them, did not exist at that time. Use of slingshots would therefore require some other contemporaneous intelligent species to have invented them, or some kind of {{w|A_Sound_of_Thunder|time}} {{w|A_Gun_for_Dinosaur|travel}}.) However, it is likely that the event resulted from the impact of a space-rock that was perturbed into an Earth-crossing orbit by a planet such as Jupiter, given at least a minor gravitational slingshot on its way to eventually crashing into the Earth.

The sixth category references the long-running comic and cartoon character {{w|Dennis_the_Menace_(U.S._comics)|Dennis the Menace (USA)}}, in which the titular character unintentionally harasses neighbor Mr. Wilson with (regular) slingshots and other devices and behaviors. In Randall's projected reboot of the franchise, which is elaborated on in the title text, Dennis trades his regular slingshot for a gravitational slingshot. By miscalibrating his ammunition, or the force of his slingshot, he turns a demonstration ("a nice comet") into a destructive event (the loss of Wilson's dinosaur garden). The reference is to the relative size and velocity of the space objects responsible for, respectively, comets and "meteors" versus asteroid impacts.

This comic is probably inspired by the recently released movie {{w|Slingshot_(2024_film)|Slingshot}}.

This is very similar to [[2844: Black Holes vs Regular Holes]].

==Transcript==
:[A table grid with two columns and six rows.]
:[Two column labels placed above the respective columns, six row labels to the left of the respective rows. Each table cell contains a tick for "Yes", a cross for "No", or a note.]

::[Column 1:] Regular slingshot
::[Column 2:] Gravitational slingshot

:[Row 1:] Used for hunting
::[Tick]
::[Cross]
:[Row 2:] Used for sport shooting
::[Tick]
::[Cross]
:[Row 3:] Used for spacecraft propulsion
::[Cross]
::[Tick]
:[Row 4:] Large online enthusiast community
::[Tick]
::[Tick]
:[Row 5:] May have caused dinosaur extinction
::Probably not
::Maybe
:[Row 6:] Used by Dennis the Menace to terrorize Mr. Wilson
::[Tick]
::Not yet, but I'm pitching a reboot

==Trivia==
An other form of {{w|Sling (weapon)|stone flinging hand-held weapon}} had existed since ancient times, and has been used for personal defense and for hunting game such as squirrels, birds and {{w|Goliath|Philistines}} through skillful use of its mechanical advantage and rotation. It is essentially a mimimalist hand-held form of {{w|trebuchet}} (using the the thrower's arm as a much more versatile main beam, taken back to mechanical extremes in some proposed {{w|SpinLaunch|kinetic energy space-launch}} ideas), compared to the version that is more of a cut-back {{w|crossbow}}-like 'catapult' (as well as partially duplicating the mechanics of a {{w|ballista}}), but had necessitated the easy availability of an elastic cord before it could become the common form of slingshot/catapult that then became the signature toy/tool/weapon of both Dennis Mitchell (the American version) and his British namesake (see below).

The 'gravitational slingshot' can be perhaps more likened to the ancient 'stone slinger', by dint of using a radial redirection to build up energy for the object being slung and released, and is also very dependent upon the exact timing of the 'release' (insofar as one can ever be released from any gravitational field). Although as it also makes key use of exchanging potential and kinetic energies there are also elements by which the elasticated thrower does also share some conceptual similarity to the gravitational assist. It is not recorded which particular form of slingshot became the primary inspiration for this particular spacecraft manoeuvre terminology.

The "Dennis the Menace" that the [[Randall]] refers to, familiar to those in the US, is not to be confused with the ''other'' long-running comic and cartoon character from the UK, also called {{w|Dennis the Menace and Gnasher|Dennis the Menace}}, who has a surprisingly similar premise and identical date of creation but is more willfully disruptive and capable of far more 'cartoonish' behaviour (which might well include planetary-scale fork-stick slingshots/catapults). {{w|Mark Hamill}} is a fan of the British character (possibly from his time filming the original Star Wars films in the local studios), and also has some experience with (fictional) disruption of planets by {{w|Death Star|constructed weapons}}.

{{comic discussion}}

[[Category: Charts]]
[[Category: Space]]
[[Category: Dinosaurs]]
[[Category: Fiction]]
[[Category:Rockets]]

2931: Chasing

2024-12-02T18:47:18Z

The-Ergster:

{{comic
| number = 2931
| date = May 10, 2024
| title = Chasing
| image = chasing_2x.png
| imagesize = 462x474px
| noexpand = true
| titletext = Certain hybrid events can only happen in certain locations where all the conditions are present; chasers flock to the area in and around Kansas known as tumbleweed-colliding-with-possum alley.
}}

==Explanation==

This comic is a scatter plot comparing how exciting it is to see various things with how possible it is to chase them using a convoy of coordinated vehicles.

The least chasable are stationary places like the {{w|Grand Canyon}} or {{w|International Date Line}}. It makes no sense to chase them because they don't move around, you simply go to their known locations. At the other end of the chasability spectrum are animals that move around rapidly, and fleeting astronomical and atmospherical phenomena like {{w|clouds}}, {{w|meteors}} and {{w|aurora}}. However, some of these are difficult to chase because they're small and hard to detect from a moving vehicle, e.g. {{w|gnats}}.

In the top-right position of most chasable and most exciting, tornadoes have a community of 'chasers' who attempt to predict their appearance and get as close to them as possible, which was the subject of a {{w|Twister_(1996_film)|1996 film}}, for which a sequel was due to be released shortly after this comic. A major {{w|Tornado_outbreak_of_May_6%E2%80%9310,_2024|tornado outbreak}} had also taken place immediately preceding the comic's publication.

The title text suggests that combining some of these things into a single event would multiply the excitement derived from them. This makes sense on the surface, as the rarity value of the resulting event would be high, so even two relatively mundane events could, when combined, produce an interesting outcome. However, it somewhat undermines this by suggesting that, in this particular location, the event in question (possums being hit by passing tumbleweeds) is relatively routine.

{| class="wikitable sortable"
|-
! rowspan="2" | Entity !! colspan="2" | Estimate of... !! rowspan="2" | Explanation
|-
! Chasing || Excitement
|-
| {{w|Grand Canyon|The Grand Canyon}}|| 10% || 90% || Stationary place in Arizona. It's the largest canyon in the US (but not the world), in addition to being very beautiful due to its depth and the color changes from different geological strata. Seeing a famous tourist attraction in person is exciting.
|-
| {{w|Niagara Falls}} || 15% || 75% || A generally stationary place on the border of US and Canada, between the state of New York and the province of Ontario. The waterfall is the largest in North America by width and water volume, making it very beautiful to watch.
|-
| {{w|Tourist attractions}} || 15% || 55% || Other stationary places that attract many tourists (e.g. national parks, monuments and historic places) are exciting to see.
|-
| {{w|Tourist traps}} || 10% || 40% || Stationary places that market themselves as tourist attractions, but don't really have much to offer and exist mainly to sell food and souvenirs.
|-
| {{w|Hazard (golf)#Bunker|Sand trap}} || 15% || 25% || Pits of sand in golf courses. If your golf ball lands in one, it loses all its momentum almost instantly and it is difficult to hit out to the grassy portions (fairways or greens), which is why it is a "trap". A convoy of golf-carts might "chase" a golf-ball to the sand trap it lands in, but this would not be very exciting.
|-
| The International Date Line || 15% || 10% || A jagged conceptual line running from the North to South poles around 180 degrees of longitude, used to separate the time zones that start and end each day. There's nothing to see at these locations, as the line is an abstraction and does not actually coincide with anything in real life, as well as mostly being in the Pacific Ocean, by-passing actual landfall, as well as across the Arctic Southern Oceans. The zones for {{w|time in Antarctica}} are already more pragmatically simplified or just fall back to {{w|Coordinated Universal Time}}.
|-
| Meteors || 35% || 95% || Also called "shooting stars". These are fleeting streaks of light that are visible when bits of rock or dust enter the atmosphere and burn up. These are generally rare, making them exciting to see, but there are {{w|meteor showers}} when many are visible due to the Earth passing through a large cloud of dust (usually the remnants of a comet). To astronomy buffs, these can be like natural fireworks shows. Because each meteor streak lasts for a fraction of a second, it's not generally possible to chase them, although if the rock is large enough it may survive to the ground and become a {{w|meteorite}}, which chasers [[1723: Meteorite Identification|may be able to find]] by tracking its path through the sky.
|-
| {{w|Rainbows}} || 35% || 90% || A visual effect that occurs when sunlight is refracted by water droplets in the air, spreading the light into a spectrum of different colors. Their 'location' is relative to each observer, so long as the necessary components combine correctly in the first place, so any coordinated movement is restricted to finding the right sort of standpoint from which a rainbow is visible. Moving "towards" a rainbow typically results in the rainbow "moving away" from the observer at the same speed.
|-
| {{w|Comets}} || 40% || 85% || Comets are chunks of rock and ice that orbit the Sun, usually in highly eccentric orbits that take them from the inner Solar System to the {{w|Kuiper Belt}} or {{w|Oort Cloud}} at the extreme outskirts of the Solar System. Few of them are visible to the naked eye until they are close to the Sun. They're exciting to see because they are rare, and one of the few astronomical objects that looks like more than just a tiny dot because there is a glowing "tail". While they are moving very rapidly through the Solar System, from the Earth they don't appear to move much faster than planets. So there's no need to chase them; when near the Earth, they will be visible from much of the planet for days or weeks.
|-
| {{w|Sunsets}} || 35% || 75% || Disappearance of the Sun below the horizon, should happen usually once every 24 hours (except close to the poles). Depending on weather conditions, they can sometimes be very pretty. Traveling around the Earth from east to west is needed for a continuous view of a sunset.
|-
| {{w|The Moon}} || 40% || 70% || Earth's only natural satellite with a predictable orbit. While Randall is most likely referring to chasing the Moon on the Earth, the {{w|Apollo Missions}} very much fit the description of "chase in a convoy of vehicles coordinating over radio and using instruments and data to find optimal viewing locations". That is exactly what the astronauts did, they "chased" the Moon (the Moon was moving while they flew towards it) using a convoy of vehicles (the multi-stage rockets) while they "coordinated" to Earth with their radios. Only 12 people (the {{w|Apollo astronauts}}) have actually visited it in person; the rest of us see it from about 250,000 miles (400,000 km) away. Weather permitting, it's visible for about half of every day/night cycle (though may be more obvious when this occurs significantly in the night sky, for several reasons). It doesn't move quickly in the sky, by apparent movement, so little chasing is necessary. A 'supermoon' is when the Moon looks the largest and shiniest, occurring when a full moon appears closest to the Earth in its orbit, though Randall doesn't consider this phenomenon impressive (How To, chapter 21).
|-
| Unusual clouds || 40% || 55% || Clouds with unique forms or shapes, like {{w|Lenticular clouds}}. People may want to chase after them if they’re drifting away, as they may want to view the cloud further, perhaps for scientific purposes.
|-
| Regular clouds || 35% || 40% || Clouds are an aerosol consisting of a visible mass of miniature liquid droplets. People may chase clouds for the same reasons as wanting to chase unusual clouds.
|-
| {{w|Fog}} || 30% || 25% || Atmospheric condition where water droplets are very dense near the Earth's surface, resulting in a visible haze. Fog does not move much, but dissipates over time. Fog might pull away from its least ideal conditions before it vanishes completely. This entry might be a reference to {{w|Phileas Fogg}}, who was pursued around the world.
|-
| {{w|Rain}} || 35% || 20% || Water droplets falling from clouds. In most of the world, this is a pretty common occurrence. Unless the volume is extremely high, there's rarely much excitement due to them, but extreme cases may cause flooding that can be dangerous. The only people who might chase rain are weather reporters who want to get wet.
|-
| {{w|Gnats}} || 35% || 5% || Hardly anybody wants to track down gnats, as they are annoying to chase and difficult to see, but people could theoretically use advanced instruments to do so.
|-
| Aurora || 60% || 95% || Impressive light displays that result from excitement of the Earth's {{w|magnetosphere}} by charged particles in the {{w|solar wind}}. These are generally only visible in high latitudes, so most people do not live where they're visible. Their visibility can be tracked and forecasted via monitoring of solar wind output from the Sun, and particularly intense episodes can be predicted (as well as locations for viewing) on the basis of the solar cycle and solar flare activity. The release of this comic coincided with the strongest geomagnetic storm warning forecasted by the National Oceanographic and Atmospheric Administration (NOAA) in 20 years [https://www.swpc.noaa.gov/news/g4-watch-effect-may-11] ({{w|May 2024 solar storms}}).
|-
| Your favorite band's shows || 60% || 80% || Musical acts often plan tours, where they go around the country (or world) putting on shows every few days. Extreme fans with time (and money) on their hands may "chase" them by going to a series of their shows. Since the tour dates are planned and publicized well in advance, the shows are easy to find. However, depending on the popularity of your favorite band, this might be an expensive hobby, especially for optimal viewing. Also, tickets may be sold out.
|-
| Rare birds || 60% || 60% || Many birders will "twitch" to see rare birds, and this requires a fair amount of checking location, behavior, etc. Also, rare birds tend to be exciting to see.
|-
| Regular birds || 55% || 40% || These are easier to see than rare birds.
|-
| Regular balloons || 55% || 25% || Both children and adults accidentally let go of helium balloons, and may attempt to chase after them to retrieve them.
|-
| {{w|Tumbleweed|Tumbleweeds}} || 60% || 15% || A roughly spherical portion of certain plants that breaks off from its roots and rolls along the ground, propelled by winds, to distribute the seeds of the parent plant. Most people don't find them very interesting to look at, and they're often used as a shorthand for nothing of interest happening. They don't usually travel very quickly, so it would be possible to chase them if you were so inclined. The locomotion of tumbleweeds is of interest to ecologists, as the non-native and extremely invasive plant disperses its seeds across a region.
|-
| {{w|Speed_limit_enforcement|Speed traps}} || 65% || 5% || A section of a road where police often wait for passing drivers who are exceeding the speed limit, so they can catch them and issue speeding tickets. Frequent drivers, especially truck drivers, have developed systems to warn each other of these locations ({{w|citizens band radio}} was once the most popular method, but now this can be done using mobile phone using services like {{w|Waze}}).
|-
| {{w|Tornadoes}} || 85% || 95% || Wanting to witness a tornado is the typical objective of {{w|storm chaser}}s.
|-
| {{w|Whales}} || 85% || 90% || Widely distributed and diverse group of marine mammals. They are some of the largest animals to ever live, and often travel in groups, making them exciting and easy to see (when active at the surface). They have often been chased by humans, both for the purposes of hunting and exploiting them as a resource and by tourist-oriented whale-watching trips.
|-
| {{w|Icebergs}} || 85% || 75% || Piece of freshwater ice broken off a glacier or ice shelf. These come in many sizes and shapes, making it interesting to see a new one. At the time of this comic, there had recently been substantial interest in tracking the progress of the giant {{w|Iceberg A23a}}.
|-
| {{w|Hot air balloons}} || 80% || 60% || An aircraft whose bag is filled with heated air. Hot air balloons are ridden for a variety of reasons (entertainment, sport, advertisement, etc.) and they usually involve a "chase crew" of people on the ground. To an uninvolved observer, catching an unexpected glimpse of an airborne balloon is a moderately exciting event; giving chase is not advised, however, as it may interfere with the chase crew's operation and may be perceived as a hostile act, thereby creating ''uncomfortable'' levels of excitement.
|-
| {{w|Radiosondes}} || 85% || 50% || Small instruments carried in weather balloons to gather and transmit atmospheric parameters. There's not much to see in them, but they're easy to track with a proper receiver.
|-
| Neighborhood possums || 85% || 35% || "Possum" is a common term for {{w|Virginia opossum}}s, the only species of opossum found in North America. In urban areas they will get into human garbage, and may carry diseases, so many may consider them pests and hunt them. A coordinated group of hunters can track them.
|-
| {{w|Ice cream trucks}} || 85% || 25% || Vans that sell ice cream. They're easy to chase because they often play music and/or ring a loud bell so customers will know they're coming, and make frequent stops to allow customers to make purchases. Ice cream trucks may typically be chased by children too young to drive a convoy of vehicles for their pursuit, but their excited screams might provide data that can be used to track an ice cream truck through a city.
|-
| Other chasers || 90% || 10% || May result in an awkward or friendly encounter if met in person. Chasers may bond over their enjoyment of chasing various objects, much like how [[Geohashing|geohashers]] connect with each other at specific geohashed locations. However, another group of chasers might not appreciate it if they find out that they're being the target themselves.
|}

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:[An X Y axis graph]
:[Y axis label:]
:Exciting to see in person
:[X axis label:]
:Possible to chase in a convoy of vehicles coordinating over radio and using instruments and data to find optimal viewing locations?
:[X and Y axis values (from bottom left):]
:No
:Yes

:[Top left quarter:]
:The Grand Canyon
:Meteors
:Rainbow
:Comets
:Niagara Falls
:Sunsets
:The Moon
:Tourist attractions
:Unusual clouds

:[Top right quarter:]
:Aurora
:Tornadoes
:Whales
:Your favorite band's shows
:Icebergs
:Rare birds
:Hot air balloons

:[Bottom left quarter:]
:Tourist traps
:Regular clouds
:Sand traps
:Fog
:Rain
:The International Date Line
:Gnats

:[Bottom right quarter:]
:Regular birds
:Radiosondes
:Neighborhood possums
:Regular balloons
:Ice cream trucks
:Tumbleweeds
:Speed traps
:Other chasers

{{comic discussion}}
[[Category:Scatter plots]]
[[Category:Charts]]
[[Category:Rankings]]
[[Category:Food]]
[[Category:Tornadoes]]
[[Category:Animals]]
[[Category:Weather]]
[[Category:Rockets]]

2461: 90's Kid Space Program

2024-12-02T18:45:28Z

The-Ergster:

{{comic
| number = 2461
| date = May 10, 2021
| title = 90's Kid Space Program
| image = 90s_kid_space_program.png
| titletext = NASA may not want to admit it, but at this point they ARE the 90's Kid Space Program.
}}

==Explanation==
The "launch system" is just one of the {{w|Eye popper|rubber popper toys}} popular in the 1990s. These toys are little rubber hemispheres, about 1" (25 mm) in diameter and 1/8" (3 mm) thick. When turned inside-out and placed on a hard surface, they will, after a short wait, snap back to their original shape, popping up into the air. The joke is that kids who grew up with these toys will think they're a great idea to propel a space ship to orbit, when in fact the toys launch at mere tens of kilometers per hour, far short of the thousands needed to reach {{w|orbital speed}}{{citation needed}}. But now kids playing with these are those that make rockets, hence the title 90's Kid Space Program (KSP).

Even if the popper-based propulsion system could generate enough acceleration to reach orbit, the abrupt impulse would likely cause serious harm to any astronauts.

The title text implies that many working now at {{w|NASA}} were 90s kids. Both categories would include [[Randall]], as he was born in 1984 and previously worked at NASA.

The title is a reference to the {{w|Kerbal Space Program}} (KSP) which has been a [[:Category:Kerbal Space Program|recurring theme]] on xkcd, and it has previously been hinted at that NASA's employees uses this program in [[1244: Six Words]] and [[2204: Ksp 2]]. And also that you learn more about orbital Mechanics by using KSP than from being hired by NASA in [[1356: Orbital Mechanics]].

==Transcript==
:[A command and service module representing the tip of a spacecraft, is attached by four long trusses to four equidistant points on the edge of a giant light green popper (a green "hill" with a round raised edge around it). The popper is in its inverted configuration, ready to pop. There is a caption beneath the panel:]
:The 90's Kid Space Program prepares for their first orbital launch

{{comic discussion}}

[[Category:Comics with color]]
[[Category:Space]]
[[Category:Kerbal Space Program]]
[[Category:Kids]]
[[Category:Rockets]]

2261: Worst Thing That Could Happen

2024-12-02T18:44:50Z

The-Ergster:

{{comic
| number = 2261
| date = January 29, 2020
| title = Worst Thing That Could Happen
| image = worst_thing_that_could_happen.png
| titletext = Before I install any patch, I always open the patch notes and Ctrl-F for 'supervolcano', 'seagull', and 'garbage disposal', just to be safe.
}}

==Explanation==

[[Ponytail]] and her friends are considering upgrading some part or program of their computers. They may feel the need to upgrade because the software they are currently using has some vulnerability that is only patched in newer revisions (this comic was released just two weeks after the [https://www.microsoft.com/en-US/windows/windows-7-end-of-life-support-information end of extended support] for {{w|Windows 7}}), or because they want to have access to some new feature. As part of the decision-making process, Ponytail asks her friends, "What's the worst that could happen?" If the computers they are discussing are privately owned, she may be concerned about losing personal data or having to learn new software interfaces. On the other hand, if they are discussing a corporate computer system, there may also be business-related risks. If their company relies on functionality offered by their current system that has been deprecated or modified in the updated version (such as in [[1172: Workflow]], or as with many specialized tools or machines in the real world), they may suffer downtime while they modify the rest of their workflow. Even if the upgraded system should continue to fit their needs, they may need to take some downtime to perform the update and deal with the risks of something going badly along the way, and there may be major costs associated with license subscriptions and support contracts. "What's the worst that could happen?" is also a common {{w|rhetorical question}}; Ponytail may be expressing a belief that nothing bad could happen as a result of the upgrade, and not expecting an answer.

Unfortunately, Ponytail's friends answer with their ideas for the worst things that could happen ''ever'', not ''as a result of the upgrade'', as Ponytail meant, or they are taking the question to the logical extreme and invoking {{w|chaos theory}}. The result is a list of "worst things" ridiculously unconnected to a computer upgrade. At the end, however, [[Megan]] interprets these as possible results of the upgrade, and advises against upgrading. A [[#List of worst things|list with explanations]] can be found below. Ponytail facepalms at her friends' overly-literal senses of humor.

Alternatively, Ponytail could be facepalming at the fact that the worst thing which could happen, according to her team, is that they are put on a ridiculous game show in which, if they answer a question incorrectly, they are chucked in garbage disposal. This may be bad, but it is nowhere near as bad as an erupting supervolcano or nuclear war.{{Citation needed}} However, [[Cueball]] has shown anxiety and difficulties in social situations, such as the less-than-helpful advice in [[1917: How to Make Friends]], so he (and likewise [[Hairy]] and Megan) may consider that embarrassment on the game show (which might then be immortalized online) is worse than instantaneous death in a nuclear war.

Megan and Cueball have previously experienced a severely-botched upgrade in [[349: Success]], in which Cueball somehow caused them to end up in shark-infested waters off the coast of a deserted island when he was just trying to get their computer to dual-boot BSD.

The title text talks about searching upgrade release notes for some of the things listed to be sure none are potential side effects of an upgrade. "Ctrl-F" is a common keyboard shortcut for "find text string" in many programs. Since Randall is just reading but not changing the patch notes, a web browser, PDF viewer, or word processing program such as Adobe Reader or Microsoft Word might have been used.

===List of worst things===
*The list of "worst things that could happen" discussed by the team are:

{| border =1 width=100% cellpadding=5 class="wikitable"
|'''Thing''' || '''Notes'''
|-
|"{{w|Supervolcano}}." || A supervolcano is a volcano that would (or does) eject over 1,000 cubic kilometers of material when it erupts. The United States in particular is home to a supervolcano in {{w|Yellowstone National Park}}. When it erupts, the results will be catastrophic to the entire world, possibly triggering a volcanic winter, massive crop die-offs (and subsequent cascading extinctions up the food chain), and the destruction of human civilization. This probably would not be set off by any sort of software update.{{Citation needed}}
|-
|"{{w|Robot uprising}}." || An artificial intelligence overthrows humanity and takes over the world. Hairy is probably concerned with a violent uprising in which the robots are determined to exterminate humanity, as in, for example, the {{w|Terminator (franchise)|''Terminator''}} films, rather than [[1450: AI-Box Experiment|an AI who just wants to stay in a box]]. Randall has written about robot uprisings (both violent and humorous) in [[:Category:Artificial Intelligence|several comic strips]]. If Ponytail's company is involved in artificial intelligence, a robot uprising could be a remotely plausible worst-case scenario from a botched upgrade.
|-
|"Everyone falls down a {{w|well}} at once." || There have been several well-publicized incidents in which a real person fell down a well, such as [https://www.biography.com/personality/baby-jessica Baby Jessica] and {{w|Category:Cases of people who fell into a well|these people}}. If ''everyone'' fell down a well at once, there would be nobody to get them out, which would be a pretty bad thing. It's unclear how this upgrade could cause this outcome, making this suggestion preposterous.
|-
|"Instead of hitting the tallest thing around, lightning starts hitting the nicest." || {{w|Lightning}} generally strikes the tallest object under a thunderstorm, a topic addressed in {{what if|16|''What-if #16: Lightning''}}. {{w|Lightning rods}} are built to take advantage of this effect to protect nearby important objects from the lightning. If lightning started hitting the ''nicest'' thing around, then it would presumably strike whatever it was that the lightning rods are meant to protect (nice buildings, nice people, [https://history.nasa.gov/SP-350/ch-7-3.html nice rockets]). If the computer that's being upgraded is connected to the [[1620: Christmas Settings|Universe Control Panel]], this change could be a plausible negative consequence of the update.
|-
|"{{w|Seagulls}} all get {{w|handguns}}." || Guns in the hands of humans account for the large majority of homicides and suicides in the USA. Letting handguns be wielded by seagulls, which lack the impulse control and cognitive thinking required to make the ownership of a handgun somewhat safe, would make this much worse. Seagulls are not particularly known for their intelligence, self control, or kindness toward others. At popular beaches, seagulls are known to aggressively harass humans for their food; if they wielded handguns, a great deal of violence would ensue. Even if mayhem and death were not due to intentional use (i.e., if the seagulls were capable of learning that use of a handgun would get them food or something else they might like), they would happen from accidental use.
|-
|"A really '''''slow''''' nuclear war." || No {{w|nuclear war}} involving two sides launching nuclear weapons at each other has ever been fought, but experts generally agree that an all-out nuclear war between superpowers would end very quickly and very badly for all parties involved (as well as all parties not involved). A "slow" nuclear war might play out as a series of tit-for-tat individual launches rather than a single apocalyptic exchange, but the destruction of cities and release of fallout would be the same. Perhaps the anticipation of when exactly it's "your turn" to be a target would make the slow war a worse experience.

Much of the computer networking technology used today has its roots in research into hardening nuclear command and control systems against an incoming first strike, and many works of fiction have depicted nuclear war (or the risk of nuclear war) resulting from computer and software errors in systems that are supposed to "upgrade" the decision-making process, such as ''{{w|WarGames}}'' and "{{w|Fail-Safe (novel)|Fail-Safe}}". If Ponytail's company is involved in the defense industry, a nuclear war could be a plausible worst-case scenario from a botched upgrade.
|-
|"We have to go on a game show where they show you photos of people you've met once and ask you their names, and if you get one wrong a trapdoor opens and you fall into a garbage disposal." || The premise of this game show seems to play on Munroe's frequent references to anxiety about social situations. For people who have troubles remembering names, encountering someone you've met once before can be harrowing, as you may know that you ''should'' know their name, but be unable to recall it, creating embarrassment and awkwardness (particularly if the person remembers your name with ease). The concept is that fear could be exploited in the form of a game show. Many popular game shows feature contests where contestants who fail are subjected to pain and/or humiliation, such as the ''{{w|Ninja Warrior}}'' franchise. This case is particularly exaggerated, as the inability to remember even a single name would result in being dropped into a garbage disposal, which would virtually guarantee serious maiming and/or death. The reaction of the strip characters suggests that they all share a lack of confidence in their ability to remember the names of casual acquaintances, making such a game show one of the "worst things" they could encounter. Possibly a Voltron reference.
|}

==Transcript==
:[Ponytail is standing in front of a desk with a computer. One of her hands is on the keyboard. Behind her, Cueball, Hairy, and Megan are looking at the computer screen.]
:Ponytail: We should upgrade. What's the worst that could happen?
:Cueball: Supervolcano.
:Hairy: Robot uprising.
:Megan: Everyone falls down a well at once.

:[Zoom in on Cueball, Hairy, and Megan. Cueball has turned toward the other two.]
:Cueball: Instead of hitting the tallest thing around, lightning starts hitting the nicest.
:Megan: Seagulls all get handguns.
:Hairy: A really '''''slow''''' nuclear war.

:[Large panel with the original setting. Ponytail has turned towards the other three but is now facepalming, as Cueball gesturing with his hands at chest-height are still looking at the other two facing him.]
:Cueball: We all have to go on a game show where they show you photos of people you've met once and ask you their names, and if you get one wrong a trapdoor opens and you fall into a garbage disposal.
:Hairy: '''Ooh,''' that's a good one.
:Megan: Yeah, let's put off the upgrade.

{{comic discussion}}

[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Hairy]]
[[Category:Comics featuring Megan]]
[[Category:Computers]]
[[Category:Volcanoes]]
[[Category:Robots]]
[[Category:Artificial Intelligence]]
[[Category:Weather]]
[[Category:Animals]]
[[Category:Nuclear weapons]]
[[Category:Rockets]]

1729: Migrating Geese

2024-12-02T14:54:52Z

The-Ergster:

{{comic
| number = 1729
| date = September 5, 2016
| title = Migrating Geese
| image = migrating_geese.png
| titletext = "Hey guys! I have a great idea for a migration!" "Dammit, Kevin."
}}

==Explanation==
{{w|Bird migration|Migrating}} refers to the changing of a habitat, which happens every year with birds like {{w|geese}} that travel long distances to avoid cold seasons and get back to the food in the summer time. When geese fly to their new habitat, they tend to fly in a very clear {{w|V formation}}. The V formation improves the efficiency of flying birds, particularly over long migratory routes. All the birds except the first fly in the upwash from one of the wingtip vortices of the bird ahead. The upwash assists each bird except for the "leading" one in supporting its own weight in flight, saving them up to 20% of the energy needed.

It should be noted that geese do have family structures with adult geese in "alpha" positions, but not a strict ranking order. An individual's position in formation flights is coincidental and constantly changing, so that the goose at the point of the formation can pull back and rest in the V wings while others "lead" the swarm. Popular earlier beliefs about an "alpha goose" heading a formation for the entire flight is a myth, easily disproved by watching geese formations in flight.

This comic shows such a formation with 20 geese, with several geese and areas in the V formation labeled, giving different roles to the geese and assigning these areas a new meaning. See the [[#Table of labels|table below]].

Apart from a "twin engine" goose in the bottom right arm of the V the only part of the formation that would not normally be seen is Kevin, who flies off at a 45-degree angle. In that direction there is no aerodynamic help from the other birds, and in the title text the rest of the geese also exclaim, "Dammit, Kevin" when he (again?) tells them that he has a great new idea for a migration (maybe referring to the new direction). This is either a reference to the fact that migrating birds manage to consistently arrive in the same general area every year, or to the way that vacations are sometimes suggested (by humans): "I thought of an idea for a vacation..." This was only the second time the name Kevin was used in xkcd for a fictive person, see more in [[1795:_All_You_Can_Eat#Kevin|this trivia]].

===Table of labels===
{| class="wikitable"
!Name
!Explanation
|-
|Head Goose
(4th in line to the British throne)
|Supposedly, this goose is in line to become the newest monarch of the United Kingdom after the deaths of the three (humans) who were ahead of it at the time of the comic’s publication ({{w|Charles III|Charles, Prince of Wales}}; {{w|William, Prince of Wales|William, Duke of Cambridge}}; {{w|Prince George of Wales|Prince George of Cambridge}}[https://en.wikipedia.org/wiki/Succession_to_the_British_throne]). In actuality the fourth in line to the British throne was then {{w|Princess Charlotte of Wales|Princess Charlotte of Cambridge}}. As of the death of {{w|Elizabeth II|the Queen}}, in 2022, she gained one place and the new fourth in line became {{w|Prince Louis of Wales}} (her younger brother).
In North America, the best-known goose migration is that of {{w|Canada goose|Canada geese}} to the US east coast. Canada used to be part of the {{w|British Empire}} and remains a member of the {{w|Commonwealth of Nations}}, so a "Canadian" goose would be well situated to stand within the succession (excepting, of course, for the fact that it's a goose). As the main rules of {{w|succession to the British throne}} are being Protestant and directly related to {{w|Sophia of Hanover}}, who died in 1714, the line of succession is long. [http://www.wargs.com/essays/succession/2011.html Very long.] Though there probably aren't any geese in that list (even Catholic ones), the head goose being deemed the fourth in line (or the fourth in line being deemed a head goose) may be mocking the concept of the line of succession and/or any perception of the arbitrary nature of its membership.
|-
|Quarterback
|A {{w|quarterback}} is a position in {{w|American football}}, usually placed in the second row of an American football formation, just like the associated goose. On nearly every non-kicking play, the quarterback is the player who stands behind the center and receives the ball to start the play. In modern American football, the quarterback is usually considered the leader of the team, and is often responsible for calling the play.
|-
|Comptroller
|A {{w|comptroller}} is a position in many corporations and some governments. An officer of this title is responsible for the oversight of financial operations and ensuring that accounting is conducted accurately.
|-
|Migration abort goose
|This might be a reference to launch abort capsules used in rockets to safely land astronauts in the case of a critical stage failure. Or it could be operated like an abort button aborting the entire migration for all geese.
|-
|Twin-Engine Model
|This goose has two tails offset on each side of the center of the goose, instead of one tail in the middle like the rest. The "tails" also extend beyond the wings, which makes it look like a Twin-Engine aircraft, which has two motors: one on each wing instead of one in the nose. Later Randall made no less than eight plane/birds combination like this in [[1824: Identification Chart]].
|-
|CIA Informant
|A person, usually a criminal, that surreptitiously provides information to the {{w|Central Intelligence Agency}} (CIA), a foreign intelligence agency of the United States federal government. If these geese are from Canada, the CIA might have inserted an informant to be kept up to date on their activities. However, it is unlikely that the CIA would have great interest in the migratory patterns of geese.{{Citation needed}} This is also potentially a reference to the {{w|Birds aren't Real}} satirical conspiracy theory.
|-
|Backups
|These are geese that are not used in the formation so they can replace other geese in their positions in case they have problems performing their task. This may also be a pun/joke about technology/data "migrations" where backups should be taken liberally due to risk of data loss.
|-
|Shock Front
| A shock front is the front boundary of a {{w|shock wave}} created by either a {{w|sonic boom}} or another explosion in a fluid/gas. It can also refer to the shock wave itself. A V-shaped shock-wave called a '{{w|Bow shock (aerodynamics)|bow shock}}', similar in appearance to the V-shaped goose formation, is generated by a supersonic object. Since geese fly subsonically in normal circumstances {{Citation needed}}, they do not generate a shock wave. But of course, this set of geese may be somewhat different considering the involvement of CIA and stealth technology.
|-
|Missing Valence Geese
|In Chemistry, {{w|Valence (chemistry)|valence}} electrons are the electrons in the outermost "layer" which change places when chemical reactions happen. As there is an optimal number of electrons in a layer, if there are missing valence electrons, atoms which can fill in these gaps tend to react with the atoms having the missing electrons. In case of "electron sharing" (aka covalent bond) molecules result from such an encounter. The comic suggests a second geese formation that has proper "valence geese" in the appropriate position could bond (=merge) with this one into a larger formation. A normal geese V formation like the one in the comic has one side longer than the other and this is possibly Randall's explanation for the phenomenon.
In reality, geese do form V-shaped flocks, since the rear geese can profit aerodynamically from the vortices created by the front geese, and that way the overall flock requires less energy. So there is actually some evolutionary sense for additional geese to fill the "valence holes". It is thus a little weird that there are two backup geese close to these valence vacancies, as they should then have filled them up...
|-
|Stealth cargo being escorted
|The formation is forming a protective surrounding around an empty space in the middle which in a military formation could contain protected cargo. As there is no cargo visible in the geese formation, it is titled "{{w|Stealth technology|stealth}}". This would be a nice [[:Category:Conspiracy theory|conspiracy theory]] to spread.
|-
|Kevin
|An obnoxious blowhard who insists on trying new, poorly thought-out ideas, completely ignorant no one else in the group wants to try it out with him. "Kevin" is an internet meme (especially in Europe) where it's the stereotypical name of the village idiot. Kevin is usually urged to stop talking, ironically congratulated, etc. It’s due to the fact that this name was given [https://www.quora.com/Why-does-the-name-Kevin-have-so-many-negative-connotations-in-modern-Germany-Is-it-really-because-of-Kevin-Costner mainly in low socioeconomic class] (so Kevins will probably have poor education) and possibly because it was [https://translate.google.fr/translate?sl=fr&tl=en&js=y&prev=_t&hl=en&ie=UTF-8&u=http%3A%2F%2Fprenoms.doctissimo.fr%2Ftop-prenoms-annee-1991.html&edit-text=&act=url way too common around the ’90s].

Around the time of this comic's release Kevin was a "go-to name" for [[Randall]], seen in [[1719: Superzoom]] as well as What-If #83 as a placeholder name for the comet 67P/Churyumov–Gerasimenko.

The name may also be a reference to the intelligent and playful bird [http://disney.wikia.com/wiki/Kevin Kevin], from the Disney/Pixar movie {{w|Up (movie)|Up}}, or [https://youtu.be/OyqdoxTEmdg Kevin] from {{w|South Park}}. “Dammit, Kevin” may be a reference to the meme [https://knowyourmeme.com/memes/moon-moon Moon Moon], a mentally-challenged wolf whose pack (along with other animals) responds to his strange actions with “God dammit, Moon Moon”.
|}

==Transcript==
:[Caption above the panel:]
:Understanding Migration of Geese

:[20 geese are shown flying in a typical migratory V-formation. As they are shown in silhouette it is not possible to determine if they are seen from above or from below. They are flying toward the top of the image with the first goose close to the top in the middle of the image. There is one head goose, and then there are 7 geese in the left arms and 9 geese in the right arm. Behind the left arm there are two stragglers that are not in line with the others, but closer to the middle than those above and not as close to each other as the rest but still flying in the same direction. Finally there is one goose at the bottom right corner flying at a 45 degree angle away from the other to the right. The first goose is flapping its wing, which is also the case with six other geese, no. 4 and 6 in the left and 3, 5 and 6 in the right arm as well as the middle of the two in the rear towards the middle. The rest are soaring with straight wings and all of these look the same except no. 7 in the right arm which has two tails, which both goes ahead of the wings, making it look like a plane with two engines. The head goose and 5 of the 9 geese in the right arm as well as the one bottom right are labelled with and arrow pointing to them from the label. The front goose has the label in front to the left, the other have it in front to the right, except the second last in the arm which has the label inside the V and one flying away which has the label right above it. The two behind and right of the left arm have one label behind them with two arrows from the label pointing at both geese. There is a thick curvy line in front of geese no. 3 to 5 in the left arm. In front of that line is a thinner broken line. In front of this is a label written with the same curvature. There are two areas surrounded by dotted lines. The first one is behind the last of the left arms geese, extending in the same direction for a distance of about two geese. It has a label above and left with and arrow pointing to it. The other area is in the middle of the V forming a loose triangular structure with a label inside.]
:Head goose: Head goose (4th in line to the British throne)
:Right no. 1: Quarterback
:Right no. 3: Comptroller
:Right no. 5: Migration abort goose
:Right no. 7: Twin-engine model
:Right no. 8: CIA informant
:Bottom right corner: Kevin
:Behind center: Backups
:In front of left no. 3-5: Shock front
:Empty area behind left arm: Missing valence geese
:Empty area in center: Stealth cargo being escorted

{{comic discussion}}

[[Category:Animals]]
[[Category:American football]]
[[Category:Aviation]]
[[Category:Rockets]]

1707: xkcd Phone 4

2024-12-02T14:54:16Z

The-Ergster:

{{comic
| number = 1707
| date = July 15, 2016
| title = xkcd Phone 4
| image = xkcd_phone_4.png
| titletext = The SpaceX system carefully guides falling phones down to the surface, a process which the phones increasingly often survive without exploding.
}}

==Explanation==
This is the fourth entry in the ongoing [[:Category:xkcd Phones|xkcd Phone series]], and once again, the comic plays with many standard tech buzzwords to create a phone that sounds impressive but would actually be very impractical. The previous comic in the series [[1549: xkcd Phone 3]] was released just over a year before this one and the next [[1809: xkcd Phone 5]] was released almost 8 months later.

The tagline of the phone is a reference to the tenth version of Apple's operating system for its {{w|Macintosh computer}}. It was named {{w|OS X}} and was intended to be read as "oh ess ten", but [[Steve Jobs]] was irritated that everyone else preferred "oh ess ecks". This phrase is labeled with trademark and copyright symbols, as if someone desires it to be the product's {{w|tagline}} but has poor understanding of relevant laws. In particular, "<big>{{w|™}}</big>" is a symbol for {{w|unregistered trademark}}s while "<big>{{w|®}}</big>" is a symbol for {{w|registered trademark}}s. If the phrase were an unregistered trademark, the owner would be prohibited from using "<big>{{w|®}}</big>".

From the top, going clockwise:

; 18,000 μAh (micro-Ampere hours) nickel-lithium-iron battery (non-rechargeable)

: Phone battery capacity is measured in {{w|ampere-hour}}s (which, thanks to {{w|dimensional analysis}}, is just an unusual way of denoting electric charge; one ampere-hour is 3600 Coulombs). Usually, the capacity is quoted in milliampere-hours (one-thousandth, or 10-3, of an ampere hour); however, this one is quoted in ''micro''ampere-hours (one-millionth, or 10-6, of an ampere-hour), presumably as a marketing ploy to give a more impressive-looking number. Quoted in more standard terms, this phone's battery capacity is 18 mAh. In comparison, an iPhone 6+ has a battery capacity of 2,750 mAh. This phone's battery is dreadful (under a typical current draw of 0.1A, it would power the phone for about 11 minutes). There is nothing normally called a "nickel-lithium-iron battery" — rather, this seems to be a [[739|malamanteau]] of the experimental {{w|nickel–lithium battery}} and the common {{w|lithium ion battery}} (which does not contain any iron) or the lithium-iron-phosphate battery, often called lithium-iron, but more often called the LiFePO battery. The {{w|nickel–iron battery}} may contain {{w|lithium hydroxide}}, but it's ''terrible'' for most applications. Worse, this battery is non-rechargeable, meaning that it would have to be replaced to use the phone again after it is exhausted (every 11 minutes, at that!). The [[xkcd Phone 3]] was powered by two {{w|AA battery|AA batteries}} (not included), which have an energy capacity roughly 100 times larger.

; Subwoofer

: A {{w|subwoofer}} is a large bass speaker, which this is not.{{Citation needed}} Some phones do have high-quality speakers for playing music, but these are not placed right next to the earpiece — this would be a surefire way to deafen your users. When put next to Dog Whistle, this is probably a pun, since both relate to dogs; the English onomatopoeia for the sound a dog makes is "Woof".

; "Dog whistle"

: A {{w|dog whistle}} is a high-pitched whistle that humans cannot hear, but dogs can. In speaker terminology, a bass speaker is called a {{w|woofer}} because it could reproduce the low pitch of a dog bark. A treble speaker is a {{w|tweeter}}; if this "whistle" is actually a speaker, it might be termed a ''supertweeter''. The scare quotes may be a reference to "{{w|dog-whistle politics}}", in which certain phrases have a particular meaning to a segment of the audience that passes unnoticed by the rest. This allows a candidate to surreptitiously signal agreement with that group, without alienating the rest of the audience, among whom the ideas might be unpopular if plainly stated. The [[xkcd Phone 2]] contained a "dog noticer".

; Non-porous, washable

: On the one hand, it's rare for a phone to be made of porous materials.{{Citation needed}} On the other, there are legitimately waterproof phones that seal the speakers and ports with rubber. The [[xkcd Phone 2]] was also washable (though only once).

; ''WebMD'' partnership<nowiki>:</nowiki> cough-activated feature reads aloud a random diagnosis for "coughing"

: {{w|WebMD}} is a website to help people diagnose themselves. For the vast majority of people, a cough just means an irritated throat or maybe a cold, but selecting randomly from all WebMD diagnoses gives some much more ominous — if very unlikely — ones, including {{w|ricin}} poisoning, {{w|plague}}, {{w|lung cancer}} and {{w|radiation poisoning}}.

; Wings

: These {{w|wings}} resemble the ones found on {{w|sanitary towel}}s (usually called "pads", making this a possible iPad pun) which attach the pad to the {{w|gusset}} and keep it in place between the woman's legs during her period ({{w|Menstruation}} cycle). If actually functional as {{w|aerodynamic}} wings, they would likely come into play when the "SpaceX" impact protection feature becomes engaged and would likely make holding the phone awkward if rigid. The [[xkcd Phone 3]] had a similarly positioned wristband.

; Beveled bezel

: The ''bezel'' is the ring around the edge of watches and screens. This one's {{w|bevel}}ed, which means it's cut at an angle.

; Bezeled bevel

: Punning on the above. Doesn't make much sense but could mean that it features a beveled edge which is surrounded by a bezel.

; Seedless

: Fruit such as grapes can be "seedless", which means that they're grown from a special {{w|cultivar}} that doesn't grow seeds in the normal way. Making a phone seedless probably won't do anything, but {{w|Random seed|it might hurt}} its {{w|random number generator}} (or make it better if proper alternative to PRNG is introduced). Alternatively, this might be a dig at Apple's iPhone. There are [https://farmingbase.com/why-are-some-apples-seedless/ seedless apples]. The [[xkcd Phone 3]] was boneless.

; Water resistant down to 30 meters and below 50

: {{w|Water resistance}} is often measured in terms of how deep an object can be submerged, since pressure increases with depth. In this case, the phone can be submerged to almost any depth, but there's an odd lacuna between 30 meters and 50 meters. It also plays with the confusion in describing depths greater than 50m as "below 50". Alternatively, this might indicate the phone must remain dry above 50 meters altitude, or that it is not water resistant between 30 and 50 meters but is waterproof otherwise. The [[xkcd Phone]] and [[XKCD Phone 3]] could drown. The latter was otherwise waterproof. [[xkcd Phone 2]] was only waterproof internally. A similarly absurd range was used in [[870: Advertising]]: "Up to 15% or more!".

; Turing-complete

: A computer is {{w|Turing completeness|Turing complete}} if it can perform all the operations needed to simulate a {{w|Turing machine}}. All modern computers are usually described as Turing complete, which would make this not very impressive, but no computer can ever be Turing complete in the truest sense (since they can only ever have a finite amount of memory) — if the xkcd Phone 4 is truly a universal computer, it's ''very'' impressive indeed.

; Gregorian/Julian calendar date switch

: The {{w|Julian calendar}} is the predecessor to the modern {{w|Gregorian calendar}} — the difference is that the two calendars calculate leap years differently. The current difference between the calendars is 13 days, which will remain unchanged until February 2100. The Julian calendar is still used occasionally — mainly by Eastern Orthodox Christians — but it's not something so vital that it needs a hardwired switch on the front of the phone. This may be a play on the ability to switch the time display between a 12-hour clock and a 24-hour clock. It could also be playing with the ability to switch between Daylight Savings Time and Standard or change time zones.

; ''SpaceX'' impact protection<nowiki>:</nowiki> when dropped, phone lands on barge

: The rocket company {{w|SpaceX}}, at the time that this comic was released, had recently trialed a {{w|SpaceX reusable launch system development program|reusable rocket stage}} which, after separating from the launch vehicle, lands on a {{w|Autonomous spaceport drone ship|drone barge}} to be reused. Making a phone land on the nearest barge when dropped would make it very difficult to recover, although the 11-minute battery time there might be a chance to get it even if you can't catch it.

; Parallel port

: A {{w|parallel port}} is a type of interface which transfers high-volume simultaneous data. It was often used to connect printers and other devices to computers but was generally considered obsolete by the time smartphones began to appear on the market and would be very bulky and slow compared to the USB ports generally used in phones. It was commonly found together with {{w|serial port}}s, which are used for low-volume sequential data such as [[485: Depth|mouse]] [[1110: Click and Drag|movements]]. Here it is paired with a serial interface for analog data with parallel outputs for several people.

; 12 headphone jacks

: Headphone jacks are circular ports in a phone that allow audio to be played through headphones connected to the jack. There were [http://www.businessinsider.com.au/apple-headphone-jack-iphone-side-effects-2016-7#/#smaller-headphone-makers-would-be-at-a-disadvantage-4 constant rumors] that Apple's next iPhone would not have any headphone jacks (which eventually proved true for the iPhone 7 announcement two months after this comic). Also, [http://www.google.com Google] was developing a module for the now cancelled [https://atap.google.com/ara/ Project Ara] (archive [https://web.archive.org/web/20160716080118/https://atap.google.com/ara/ here]), a modular smartphone. This module allows the device to have [http://www.overclock3d.net/news/audio/sennheiser_shows_audio_module_concepts_for_project_ara/1 Four headphone jacks], which would allow audio to be shared among 4 people, each occupying one port. The xkcd phone takes this too far when they install a whopping TWELVE of them, which is completely overkill because almost nobody needs to connect to 12 headphones at once. 12 headphones will also drain the battery, like the wireless discharging in the [[XKCD Phone 3]], because playing audio through 24 speakers, two for each pair of headphones, is very power-consuming.

; Onboard cloud

: The "cloud" is a catch-all term for the use of remote computers to store data, providing a backup if all local copies are lost and allowing the data to be accessed from a broad network. An "onboard cloud" would thus be a contradiction in terms and appears to be a marketing ploy to use the "cloud" buzzword to describe the device's onboard storage capacity.

; New BrightGloTM display incorporates genetically spliced jellyfish protein (should have used the glowing genes, not the stinging ones)

: {{w|Aequorea victoria}} is a species of jellyfish that contains {{w|green fluorescent protein}}, a gene that is bioluminescent and gives off light. This protein was supposed to be used to light the phone's screen. Unfortunately, the developers messed up, and accidentally took the [http://bmcgenomics.biomedcentral.com/articles/10.1186/s12864-015-1568-3 stinging kind], which means that touching the phone screen will be as painful as a jellyfish sting i.e. very painful.

; ✓ Certified

: The phone is just certified in general and doesn't specify what part of the phone has been certified. It might be a reference to [[1096: Clinically Studied Ingredient]], in which buzzwords such as "studied" and are intended to make a given product sound more legitimate.

; Software-defined

: {{w|Software-defined radio}}s are quite popular in some areas, meaning the radio hardware is quite universal and can be adapted to different radio protocols just by changing software. SDR would actually be quite a nice feature for a cellphone. Of course, it doesn't specify if it's the radio that is software defined.

; Exposed ductwork

: A phone shouldn't even have ductwork, unless it has a very sophisticated cooling system, but this could supply air to the dog whistle. Exposed ductwork is a trademark of {{w|Bowellism|Bowellist}} architecture such as the {{w|Lloyd's Building}} in London and the {{w|Pompidou Centre}} in Paris. Exposed ductwork is also considered a crucial flaw in a death star. May also refer to a transparent window in the side of the phone allowing the user to see the circuitry inside, similar to computer cases with transparent side panels popular among DIY computing enthusiasts.

; Voice interaction<nowiki>:</nowiki> {{w|Siri (software)|Siri}}, {{w|Cortana (software)|Cortana}}, {{w|Google Now}} and {{w|Amazon Echo|Alexa}} respond simultaneously

: These are all {{w|intelligent personal assistant software}} (from Apple, Microsoft, Google, and Amazon respectively) and all do the same thing: control your phone and answer questions using speech recognition. Having all four talks at once would mean you'd have a total cacophony while gaining nothing. The [[xkcd Phone 3]] could have Siri included.

The title text pokes fun at the number of SpaceX rockets that [https://www.youtube.com/watch?v=V3wZRdg-Tmo crashed and exploded] before they got the landing gear right.

==Transcript==
:[An image of a smartphone featuring wings is shown. Clockwise from the top left the labels read:]
:18,000 μAh nickel-lithium-iron battery (non-rechargeable)
:Subwoofer
:"Dog whistle"
:Non-porous, washable
:''WebMD'' partnership: Cough-activated feature reads aloud a random diagnosis for "coughing"
:Wings
:Beveled bezel
:Bezeled bevel
:Seedless
:Water resistant down to 30 meters and below 50
:Turing-complete
:Gregorian/Julian calendar switch
:''SpaceX'' impact protection: When dropped, phone lands on barge
:Parallel port
:12 headphone jacks
:Onboard cloud
:New BrightGloTM display incorporates genetically spliced jellyfish protein (should have used the glowing genes, not the stinging ones)
:✓ Certified
:Software-defined
:Exposed ductwork
:Voice interaction: Siri, Cortana, Google Now and Alexa respond simultaneously

:[Below the phone:]
:Introducing
:<big><big>The xkcd Phone 4</big></big>
:Did you know "4" is "IV" in Roman numerals?®©™

{{comic discussion}}
[[Category:xkcd Phones]]
[[Category:Comics sharing name|xkcd Phones]]
[[Category:Animals]] 
[[Category:Virtual Assistants]]
[[Category: Calendar]]
[[Category:Rockets]]

2017: Stargazing 2

2024-12-02T14:52:22Z

The-Ergster:

<noinclude>:''"2017", this comic's number, redirects here. For the comic named "2017", see [[1779: 2017]].''</noinclude>
{{comic
| number = 2017
| date = July 9, 2018
| title = Stargazing 2
| image = stargazing_2.png
| titletext = I mean, it wasn't exactly MY thesis. When the FAA came to shut down our observatory for using the telescope mirror to shine light at airplanes, I took a thesis and a bunch of doctorates from the supply cabinet on my way out.
}}

==Explanation==
This is the second comic in the [[:Category:Stargazing|Stargazing]] series: The first was [[1644: Stargazing]], two and a half years earlier. It was followed by [[2274: Stargazing 3]] one and a half years later.

This comic continues with [[Megan]] as a TV host mixing accurate astronomical information with trivialities, as well as utterly bizarre statements. (See this [[1644: Stargazing#Relevant TV-shows|section]] from the original Stargazing comic about the host and also the [[1644: Stargazing#Trivia|trivia]], from the original comic, regarding the gender of the host).

In the first panel, the host voices surprise that the stars are visible again after disappearing during daylight.

The host mentions three stars in a constellation which she says is called The Triangle, likely referring to the constellation {{w|Triangulum}}, which is in fact just three main stars in a narrow triangle. However, this may also simply be intended to show the host's lack of knowledge of constellations, since she then goes on to point out three other stars forming a triangle and concludes that one can form lots of triangles by connecting groups of three stars. In Euclidean and non-Euclidean geometry, any set of three non-collinear points will form a triangle, so to say that there are a "lotta triangles" is both trivial and an understatement.{{Citation needed}} (There are about 125 billion triangles visible in the night sky with around 9096 visible stars.)

Then she points to planets, calling them dots known as "fool's stars" (like fool's gold). Planets such as Venus and Jupiter are often mistaken as stars, and the word itself is derived from the Greek, ''planētēs'' or "wanderer." She also notes that lacking interstellar transportation, humanity will likely only reach the planets within our solar system. However, she then makes the seemingly ludicrous assertion that humans will turn these planets into interplanetary landfills, which might be a comment on how humans have used the Earth. See [[2633: Astronomer Hotline]] where an astronomer calls fireflies "ground stars" and other names.

The host also notices a dot of "space trash": An artificial satellite. Since the nascent Space Age, the Earth's orbit has gradually accumulated artificial materials that include satellites, spent rockets, and space stations. There are concerns such debris accumulation will increasingly imperil current and future space projects. However, the host claims there is an app that can tell you "whose fault it is," presumably a satellite-tracking smartphone app such as [http://itunes.apple.com/us/app/skyview-satellite-guide-find/id694309958?mt=8 SkyView] which can inform you who launched a given satellite and thus whose "fault" that particular bit of space-junk might be.

The host eventually goes off on a tangent when someone from the audience points out something blinking in the sky. The host says it is a plane, and tells them what is inside it. The host continues, "don't bother trying to catch that one." This could be understood as she means it's too hard to point the telescope at it properly because it is moving too fast. In the title text, however, she means this literally, revealing that at one point during her studies she apparently used the reflective mirror of a telescope to shine light directly at airplanes, which caused the {{w|Federal Aviation Administration}} (FAA) to close down the observatory. She claims it was worth getting shut down by the FAA because she completed her thesis for her graduate degree. "Got a thesis out of it" is a phrase typically used by a scholar after discussing a research project, as a way of indicating that it was actually the main research they had conducted as a student in graduate school. Conducting research and writing it up in a thesis is one of the major hurdles toward earning a graduate degree (masters or doctorate).

In the title text, she clarifies that as she was exiting the observatory, she literally "got", as in "stole", someone else's thesis paper and multiple doctorates (presumably framed degrees), either to fraudulently claim them as her own accomplishments, or perhaps just because she wanted to steal stuff. Usually "got a thesis" is shorthand for the process of "writing a lengthy thesis paper and having it be accepted as a requirement for graduation", however in this case she simply swiped someone else's document. The revelations that she's extremely unqualified (and unethical) would explain her many bizarre statements.

==Transcript==
:[In a dark panel, Megan is a TV host standing in front of a group of 5 people: two Cueballs, Ponytail, Hairbun and a Megan-like woman.]
:Host: Welcome back to stargazing.
:Host: When the stars disappeared this morning, I figured I had to find a new job, but they're ''back!'' This ''rules!''

:[A frame-less white panel in which the host points to the upper right with the Megan-like woman, Ponytail and Cueball looking in that direction.]
:Host: Those three stars form a constellation called the triangle.
:Host: Those three are another triangle.
:Host: Lotta triangles. Very important shape.

:[Back to a dark panel with the host now pointing to the upper left in a close-up.]
:Host: Those dots are planets, or "fool's stars." Without interstellar travel, they're the only ones we can realistically hope to dump trash on.
:Host: Speaking of space trash, that dot is a satellite. There are apps that will tell you whose fault it is.

:[The host is now turned right not pointing, still in a close-up.]
:Off-panel voice: What's that blinking one?
:Host: Airplane. They're full of snacks and money and stuff, but don't bother trying to catch them- they're ''way'' too high up.
:Host: Learned that the hard way in grad school.
:Host: Got a thesis out of it, at least.

{{comic discussion}}

[[Category:Stargazing]]
[[Category:Comics sharing name|Stargazing]]
[[Category:Comics with inverted brightness]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Hairbun]]
[[Category:Comics featuring Ponytail]]
[[Category:Multiple Cueballs]]
[[Category:Astronomy]]
[[Category:Scientific research]]
[[Category:Rockets]]

1382: Rocket Packs

2024-12-02T14:50:33Z

The-Ergster:

{{comic
| number = 1382
| date = June 16, 2014
| title = Rocket Packs
| image = rocket_packs.png
| titletext = Every year: 'It's <year>--I want my jetpack [and also my free medical care covering all my jetpack-related injuries]!'
}}

==Explanation==
In the early 20th century, visions of the future often stipulated that everyone would travel around with rockets strapped to their backs. However, this has not yet come to pass,{{Citation needed}} at least for the majority of consumers.

In this comic, [[Randall]] is pointing out that the problem with personal rocket packs - more commonly called {{w|jet packs}} - is not how to attach a rocket to someone's back, but other practical considerations. One might be how to keep the hot exhaust from burning the user's {{w|Calf_(anatomy)|calves}}. Many {{w|jet pack}} designs actually do have ways to deal with this, such as moving the rockets farther from the user, but there are many other practical issues which have made this an impractical form of travel given current technology.

The title text starts with the trope "{{tvtropes|IWantMyJetPack|I want my jet pack}}", a theme also explored in [[864: Flying Cars]]. It continues with pointing out that if people did start using rocket packs, there would also be more injuries, raising health care costs. That's something that people usually don't consider when imagining a future where these devices are commonplace.

So the year when the comic was published the demand was:
:'' 'It's 2014--I want my jetpack [and also my free medical care covering all my jetpack-related injuries]!' ''

==Transcript==
:[Text above the frame.]
:Rocket packs are easy.
:[In the frame: Cueball is lying face down on the ground with his Rocket Packs on his back and his calves severely burned.]
:Cueball: Ow.
:[Text below the frame.]
:The hard part is inventing the calf shields.

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Rockets]]

681: Gravity Wells

2024-12-02T14:45:52Z

The-Ergster:

{{comic
| number = 681
| date = December 28, 2009
| title = Gravity Wells
| image = gravity_wells.png
| titletext = This doesn't take into account the energy imparted by orbital motion (or gravity assists or the Oberth effect), all of which can make it easier to reach outer planets.
}}
{{TOC}}
* The xkcd page links to [http://xkcd.com/681_large/ a much larger version].

==Explanation==
The comic shows the gravitational potential (energy transferred per unit mass due to gravity) for the positions of each planet in the solar system — including some moons and Saturn's rings. An object traveling along an upward slope loses energy, while an object traveling along a downward slope gains energy. Escaping a planet or moon's orbit requires enough energy (e.g. by walking, jumping, or rocket) to reach the top of either peak that defines the edge of the well. The peak to the left indicates the minimum energy required to exit orbit. The peak to the right indicates the maximum energy required to exit orbit. In order to exit orbit with the minimum amount of energy, you would have to travel towards the center of the solar system; to exit orbit with the maximum amount of energy, you would have to travel away from the center of the solar system (the Sun). In reality, the strength of gravity decreases with distance from the planet. However, a comparison of energy expended to escape the gravitational pull allows for a simpler comparison between the objects.

The height of the graph is scaled to kilometers via the gravitational potential an object has at the given height assuming at a constant acceleration due to Earth's surface gravity. The {{w|Sun|Sun's}} gravity well is not shown in its entirety, but is just indicated on the far left as ''"Very very far down"''. Had it been shown in its full extent it would have made the rest of the drawing so small in comparison that it would have been unreadable. As the gravitational potential increases with distance from the sun, the graph has a general upward slope. To rise out of each well on the diagram, and therefore escape the planet's gravity, it would require the same energy required to rise out of a physical well of that depth at Earth's surface gravity.

The length of each gravity well is scaled to the diameter of the planet and the spacing between the planets is not to scale with distance from the sun. This is necessary to make the graph readable. Because the distances between the planets are condensed, the gravitational potential - from the gravity pulling toward the sun - accumulates quicker. This is the reason for the large peaks between the planets. The moons shown in the chart are at the appropriate distance from their respective planets' gravity wells for their orbits. Each planet is shown cut in half at the bottom of its well, with the depth of the well measured down to the planet's flat surface.

==== Inner Planets ====
* {{w|Mercury (planet)|Mercury}} — no facts listed
* {{w|Venus (planet)|Venus}} — no facts listed
* {{w|Earth}} and {{w|Moon}}: The listed depth of the gravity well at Earth was originally listed at 5478 km rather than the correct value of 6379 km seen in the cutout. Randall has since corrected it. The Moon's is 288 km.
* {{w|Mars}}: The listed depth of the gravity well of Mars is 1286 km.

==== Outer Planets ====
* {{w|Jupiter}}: Jupiter is so massive and dense that it is one thirteenth the mass of a small {{w|Brown dwarf}} which is the smallest kind of star. Saturn, while similar in size, is composed of much lighter gas material. Hence Saturn's mass and therefore its gravitational pull are much smaller. If a few dozen times the mass of gasses contained in Jupiter had condensed in that location, the gravitational pull would cause the pressure and temperature to increase to a level that is sufficient to ignite {{w|Nuclear fusion|nuclear fusion}}. Had that happened during the creation of our solar system, we would have two {{w|Sun|Suns}} and our solar system would be a {{w|Binary system (astronomy)|Binary system}}. Jupiter has {{w|Moons of Jupiter|67 moons}} of which 3 are shown;
** {{w|Ganymede (moon)|Ganymede}} — moon of Jupiter, no facts given
** {{w|Io (moon)|Io}} — moon of Jupiter, no facts given
** {{w|Europa (moon)|Europa}} — moon of Jupiter, no facts given

* {{w|Saturn}}: The diagram shows the position of the {{w|rings of Saturn}} in Saturn's gravity well. Saturn's rings start fairly near the planet and extend out quite far, therefore multiple stripes are shown in the figure. The rings are also shown in multiple colors and roughly match the observed colors from photos take by the {{w|Cassini–Huygens|Cassini spacecraft}} expedition as it passed Saturn. All of the colors of the planets and moons represent the predominant color of that object as observed from earth. Saturn has {{w|Moons of Saturn|62 moons}} of which one is shown;
** {{w|Titan (moon)|Titan}}, a moon of Saturn. The figures on Titan are sirens, a reference to Kurt Vonnegut's ''{{w|The Sirens of Titan}}''.

* {{w|Uranus}}: Notably absent is any "your-anus" jokes.
* {{w|Neptune}}: Megan's quote is a paraphrase of {{w|Carl Sagan|Carl Sagan's}} quote, "...but from a planet orbiting a star in a distant globular cluster, a still more glorious dawn awaits, not a sun-rise, but a galaxy rise." [http://www.youtube.com/watch?v=zSgiXGELjbc Video here]

==== Cut outs and sketches====
The following items are listed from top to bottom and left to right.

* Mars moons: The Mars cutout shows the Mars moon system, including the moons Deimos and Phobos. The depth of the Mars gravity well is listed at 1286 km.
** {{w|Deimos (moon)|Deimos}}: The gravity on Deimos, a moon of Mars, is so weak that a bike jump would be sufficient to escape its gravity.
** {{w|Phobos (moon)|Phobos}}: The gravity on Phobos, a moon of Mars, is so weak that you could launch a baseball into space simply by throwing it.

* Your mom and a local football team: The sketch next to Jupiter is playing on the classic "Yo Mama" joke. It combines "Yo Mama is so fat" and "Yo Mama is so horny". The sketch implies that she has a huge gravitational pull because she is very fat, and has sex with an entire football team by demonstrating a football team falling into her very deep gravity well. A "Yo Mama" joke also appears in comic [[89: Gravitational Mass]].

* Earth's Moon: The cut out shows the significant difference in strength between the {{w|gravity well}} of the Earth and the Moon. Cueball comments that the {{w|Apollo Lunar Module|Apollo Lunar Module}} was very small and the {{w|Saturn V}} rocket was very large because escaping the Earth's gravity well takes much more energy than escaping the Moon's. The cut out also shows objects like the {{w|International_Space_Station|International Space Station}}, the {{w|Space shuttle|space shuttle}}, {{w|GPS satellite|GPS satellites}} and {{w|Geostationary orbit|geo-stationary satellites}} at their respective positions within Earth's gravity well. The depth of Earth's gravity well is listed correctly at 6 379 km (note the difference from the non-cutout number). The depth of the Moon's gravity well is listed at 288 km.

=== How to calculate gravity wells ===
The text near the bottom of Jupiter's gravity well explains that the depth of the well is mass-of-planet over radius-of-planet with Newton's constant and 9.81 m/s² as constants, where 9.81 m/s² is the acceleration of a free falling body at Earth's gravity.

The calculation for a gravity well is:
:depth = (G * Planet-mass ) / (9.81 m/s2 * Planet-radius)
::where G is {{w|Isaac Newton|Newton}}'s {{w|gravitational constant}}, and
::9.81 m/s2 is the {{w|acceleration}} rate of a {{w|Gravity of Earth|free falling body on earth}} at sea level (g).

====Title text====
The title text indicates that the planets motion can affect the amount of energy for escape velocity. It is possible to change speed by using the planets orbital speed and gravity. This is known as a performing a slingshot or a {{w|gravity assist}}, and is done to gain speed or to brake when needed. The use of rocket engines are more effective when used at a high speed slingshot maneuver, which is known as the {{w|Oberth effect}}, where most energy is going into moving the rocket as opposed to moving the exhaust — conserving the maximum useful energy. On earth the same principle is used when launching rockets. Rockets are always launched in an eastward direction to make maximum use of the rotational energy of the earth. Launching rockets in a westward direction would require significant additional energy. Because of this most artificial satellites are flying east around the globe.

The size of the gravity-well as described in this comic is not accounting for these factors. Therefore, leaving the solar system (or any of the gravity wells of the planets) could require less energy than described by the graph, assuming that the launch and slingshots are properly designed and executed.

==== Escape Velocities ====
The following table was adapted from the table in {{w|Escape velocity#List of escape velocities|Escape velocity}}, using ''h'' = ''V_e''^2 / 2''g'':
{| class="wikitable" border="1"
| Location || with respect to || Ve (km/s) || Well depth (km) ||
| Location || with respect to || Ve (km/s) || Solar well (Mm) || Total depth (Mm)
|-
| on the Sun, || the Sun's gravity: || 617.5 || 19,435,000 || || || || || || 19,435
|-
| on Mercury, || Mercury's gravity: || 4.3 || 942 ||
| at Mercury, || the Sun's gravity: || 67.7 || 233.6 || 235
|-
| on Venus, || Venus' gravity: || 10.3 || 5,407 ||
| at Venus, || the Sun's gravity: || 49.5 || 124.9 || 130
|-
| on Earth, || the Earth's gravity: || 11.2 || 6,393 ||
| at the Earth/Moon, || the Sun's gravity: || 42.1 || 90.3 || 97
|-
| on the Moon, || the Moon's gravity: || 2.4 || 294 ||
| at the Moon, || the Earth's gravity: || 1.4 || || 91
|-
| on Mars, || Mars' gravity: || 5 || 1,274 ||
| at Mars, || the Sun's gravity: || 34.1 || 59.3 || 61
|-
| on Jupiter, || Jupiter's gravity: || 59.5 || 180,400 ||
| at Jupiter, || the Sun's gravity: || 18.5 || 17.4 || 198
|-
| on Ganymede, || Ganymede's gravity: || 2.7 || 372 || || || || ||
|-
| on Saturn, || Saturn's gravity: || 35.6 || 64,600 ||
| at Saturn, || the Sun's gravity: || 13.6 || 9.43 || 74
|-
| on Uranus, || Uranus' gravity: || 21.2 || 22,907 ||
| at Uranus, || the Sun's gravity: || 9.6 || 4.7 || 28
|-
| on Neptune, || Neptune's gravity: || 23.6 || 28,400 ||
| at Neptune, || the Sun's gravity: || 7.7 || 3.02 || 31
|-
| on Pluto, || Pluto's gravity: || 1.2 || 73 || || || || ||
|-
|at Solar System galactic radius, || the Milky Way's gravity: || 525 || 14,000
|}

==Transcript==
:'''Main Text'''
:Gravity Wells scaled to Earth surface gravity
:This chart shows the "depth" of various solar system gravity wells.
:Each well is scaled such that rising out of a physical well of that depth — in constant Earth surface gravity — would take the same energy as escaping from that planet's gravity in reality.
:Each planet is shown cut in half at the bottom of its well, with the depth of the well measured down to the planet's ''flat'' surface.
:The planet sizes are to the same scale as the wells. Interplanetary distances are not to scale.
:Depth = (G × PlanetMass) / (g × PlanetRadius)
:G = Newton's constant
:g = 9.81 m/s2

:'''Planetary Descriptions'''
:To Sun, very very far down
:Mercury
:Venus
:Earth - 6379 km [originally 5,478 km]
:Moon - 288 km
:Mars - 1,286 km
:Ganymede
:Io
:Jupiter
::[A drawing of a "very deep" gravity well, "Your mom" at the bottom, several member of "local football team" falling down towards her.]
::Jupiter is not much larger than Saturn, but much more massive. At its size, adding more mass just makes it denser due to the extra squeezing of gravity.
::If you dropped a few dozen more Jupiters into it, the pressure would ignite fusion and make it a star.
:Europa
:Titan
::Two alarms: Weeoooeeoooeeooo
:Saturn
::Rings
:Uranus
:Neptune
::Megan: An even more glorious dawn awaits!

:'''Mars Inset'''
:[Mars gravity well, with one of the Mars rovers on its surface, with its moons Deimos and Phobos as smaller gravity wells.]

:[Figure of a man (to scale) in Deimos's gravity well.]
:You could escape Deimos with a bike and a ramp.

:[Figure of a man (to scale) in Phobos's gravity well.]
:A thrown baseball could escape Phobos.

:'''Earth Inset'''
:[Zoomed-in view of Earth/moon gravity well, featuring the relative locations of the atmosphere, Low Earth Orbit, the International Space Station, the Space Shuttle, GPS satellites, and satellites in geosynchronous orbit.]
:Cueball: This is why it took a huge rocket to get to the moon but only a small one to get back.

:It takes the same amount of energy to launch something on an escape trajectory away from Earth as it would to launch it 6,000 km upward under constant 9.81 m/s2 Earth gravity.

:Hence, Earth's well is 6,000 km deep.

==Trivia==
This comic used to be [https://web.archive.org/web/20211215032220/https://store.xkcd.com/products/gravity-wells-poster available as a poster] in the xkcd store before it was [[Store|shut down]].

{{comic discussion}}

[[Category:Comics with color]]
[[Category:Large drawings]]
[[Category:Charts]]
[[Category:Illustrations of scale]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:American football]]
[[Category:Baseball]]
[[Category:Your Mom]]
[[Category:Space]]
[[Category:Mars rovers]]
[[Category:Comics with xkcd store products]]
[[Category:Rockets]]

505: A Bunch of Rocks

2024-12-02T14:45:12Z

The-Ergster:

{{comic
| number = 505
| date = November 17, 2008
| title = A Bunch of Rocks
| image = a_bunch_of_rocks.png
| titletext = I call Rule 34 on Wolfram's Rule 34.
}}

==Explanation==
[[Cueball]] awakens to find himself trapped for eternity in an endless expanse of sand and rocks. At first, he uses this time to derive all of mathematics and physics, plus more, including {{w|quantum mechanics}} and {{w|general relativity}}. Next Cueball creates a computer that can process any possible function, out of rocks and rules for the interaction between rocks. He then simulates a particle followed by the interactions between particles, followed by the entire universe. The amount of time it takes to simulate the change in the universe merely from one instant to the next takes is extremely long, as the time it takes to update just one row of rocks would be eons, assuming a realistic time to place each rock.

Cueball is using the rocks to build a {{w|cellular automaton}}, a computational model based on simple rules to advance from one state to the next. Certain cellular automata are {{w|Turing-complete}}, which means that they can be used to represent any conceivable algorithm if expanded infinitely, including simulating the physics of the universe. He specifically seems to be running Wolfram's {{w|Rule 110}}, which is capable of universal computation. When using Rule 110 for universal computation, one builds a background pattern, which can be seen in the comic as the pattern of smaller triangles, and then performs computation by sending out "rockets" to collide and interact with each other. Cueball can simulate the functioning of an entire universe because he has unlimited time and space (and rocks).

Cueball then apologizes for any flaws we see in the simulation. This implies that the audience is living in Cueball's simulation, making Cueball essentially God, and that he might make mistakes along the way. The final frame cuts to a classroom where a bored student stares at his hands waiting for class to end. Cueball admonishes the student for thinking that class is lasting forever, the joke being that the boredom felt in a classroom is nothing compared to the boredom that inspires Cueball to spend his endless time toiling to keep the universe moving. Indeed, the minutes of lecture actually took many "billions and billions of millennia" for Cueball to simulate. Another possible explanation is that the entirety of this comic is a fantasy in Cueball’s mind as he zones out during a math lecture.

The Swiss patent office line refers to {{w|Albert Einstein}}, who was employed as a Swiss patent clerk while coming up with his theory of special relativity. This joke is also referenced in [[1067|1067: Pressures]]. Also, there is a standing joke that very few important inventions have come from Switzerland, since the country hadn't been involved in the world wars, and thus has not been part of the weapons race, nor was it a driving force in the preceding Industrial Revolution. In the center of the comic, the binary numbers pointing to the particle are both 42. This is a reference to the comedic answer to the ''Ultimate Question of Life, the Universe, and Everything'' from the ''The Hitchhiker's Guide to the Galaxy'' series.

Cueball mentions that if we see an artifact flutter in and out of reality, he must have made a mistake in the last "billions and billions of millennia." This implies that the small period of time the artifact is present in his time is much longer than our universe has existed. That is a ''very'' long time. However, because it was a really long time, the difference could be [https://en.wikipedia.org/wiki/Butterfly_effect more than just a small mote of dust disappearing]. It is also possible, however, that it took billions of years to simulate an instant in our universe.
The line "I've rederived modern math in the sand and then some," is possibly referring to "Surreal Numbers: How two ex-students turned on to pure mathematics and found total happiness" by Donald Knuth, in which a young couple finds themselves stranded on a deserted island (similar to Cueball), and spend much of their time deriving the properties of surreal numbers from a few base axioms.

The title text suggests that {{w|Rule 34 (Internet meme)|Rule 34}} should be called on {{w|Elementary cellular automaton#Random initial state|Wolfram's Rule 34}}. Rule 34 (see [[305: Rule 34]]) is a humorous rule of the Internet that states, "If you can imagine it, there is porn of it. No exceptions." Wolfram's Rule 34 is a cellular automaton. Therefore, the title text says that either someone has made pornography featuring the cellular automaton in question, or someone has used the cellular automaton to produce pornography. Which, of course, Cueball in the comic has, since his universe presumably contains naked people. And literal pornography.

From ''[[xkcd: volume 0]]'':
{{quote|Things simulated in stones in the desert are ''exactly'' as real as things simulated in silicon on your computer.}}

===Graphs===
The three diagrams in the "Physics, too. I worked out the kinks..." panel are, from left to right:
# The {{w|Normal distribution}} of the {{w|Gaussian curve}} marking the points that represent a standard deviation of σ and 2σ. This is one of the fundamental building blocks of statistics. In quantum mechanics, particles are viewed as inherently random, therefore the time at which a particle will decay, the position of a particle, and its velocity are all calculated using similar curves. A deviation of at least σ occurs 32% of the time, while a deviation of 2σ or more occurs about 5% of the time.
# The {{w|Inclined plane#History|Epitaph of Stevinus}}, an explanation of the mechanical advantage of using an {{w|inclined plane}}. The inclined plane is one of the six classical {{w|simple machine}}s, one of the fundamental building blocks of mechanical and civil engineering.
# The last graph is unknown. It may represent coupled pendulums, {{w|length contraction}}, or a hypothetical solution to something we haven't derived yet.

The graph that represents particle interaction is a {{w|Feynman Diagram}}. This shows the interaction of subatomic particles that collide and exchange some momentum via a photon. The slope of the middle line represents the distance moved and the time lost/gained during the interaction.

==Transcript==
:[Cueball is standing in a desert with lots of rocks lying around. He is narrating his own situation. The first panel spans the entire width of the comic. The first line of text is written to the left of him, the second line to the right.]
:So I'm stuck in this desert for eternity.
:I don't know why. I just woke up here one day.

:[The next four panels take up the second line of the comic.]
:[Cueball stand in the desert.]
:I never feel hungry or thirsty.

:[Cueball walks in the desert.]
:I just walk.

:[Zooming out while Cueball continues to walk in the desert.]
:Sand and rocks

:[Zooming far out as Cueball again just stands in the desert. First line of text, above him, is a continuation of the text in the previous panel. The second line is below him.]
:stretch to infinity.
:As best as I can tell.

:[The next three panels take up the third line of the comic. The last takes up half the width.]
:[Cueball is sitting in the desert, in a contemplative position. First line of text above him, the second below.]
:There's plenty of time for thinking out here.
:An eternity, really.

:[Cueball is sketching stuff in the sand. First line of text above him, the second below.]
:I've rederived modern math in the sand
:and then some.

:[Three different graph types are depicted. First line of text above them, the second below.]
:Physics too. I worked out the kinks in quantum mechanics and relativity.
:Took a lot of thinking, but this place has fewer distractions than a Swiss patent office.

:[The next eight panels take up the fourth and fifth lines of the comic. All pictures are the same size.]
:[Cueball is walking along the desert, laying out rocks on a line. Four have been deployed. He is laying down the fifth and has a sixth in his other hand.]
:One day I started laying down rows of rocks.

:[Cueball, with a rock in his hand, continues to deploy rock 16, in a more intricate pattern. There are grid-lines in the sand (5 rows, 6 columns), with each intersection either empty of filled with a rock. No rocks lay anywhere but at an intersection on the grid.]
:Each new row followed from the last in a simple pattern.

:[Zooming out showing even more laid out rocks. Cueball is seen directly from above, and we see his shadow falling on the grid of rocks (7 rows, 14 columns).]
:With the right set of rules and enough space,

:[Continues to zoom further out showing clear triangular patterns (with no rocks) in the laid out grid of rocks. Cueball is not seen. (8 rows, 42 columns). First line of text above the grid, the second line below.]
:I was able to build a computer.
:Each new row of stones is the next iteration of the computation.

:[Zooming far out (no Cueball) with rows intersected by five clear V lines on top of them. The V's are drawn inside each other, with the smallest V at the top right, and the other V's starting just to the right of the previous one, and then continuing the same distance past the previous V, as the total length of the first V. The "*" in the first line of text above this grid references to the footnote below written in a smaller font.]
:Sure it's rocks instead of electricity, but it's the same* thing. Just slower.
:<nowiki>*Turing-complete</nowiki>

:[Cueball stands in a contemplative pose (on a clean white background - i.e. no dessert).]
:After a while, I programmed it to be a physics simulator.

:[A black panel with white drawings and text. A small white dot (a particle) is labeled by two arrows coming of two binary strings.]
:Every piece of information about a particle was encoded as a string of bits written in the stones.
:00101010
:00101010

:[A Feynman diagram showing two particles interacting. Two arrows going in and out with a snaking line between them.]
:With enough time and space, I could fully simulate two particles interacting.

:[The next two panels take up the sixth line of the comic. The second panel takes up three-quarters of the width.]
:[Cueball standing before the vastness of the desert, with his programmed lines of rock stretching to infinity.]
:But I have infinite time and space.

:[A black panel with white drawings and text. Depiction of two large galaxies, one with four jets coming out of its center, the other a flat disc. Several smaller galaxies and/or stars are shown around them.]
:So I decided to simulate a universe.

:[The next four panels take up the seventh line of the comic. They are of similar widths.]
:[Cueball is walking by his grid of rocks, lines indicate he has just thrown another rock down in its place. It falls so hard it sinks into the sand that splashes out around it. The 14 rocks above him lie on the grid, four others below this grid have not been used yet.]
:The eons blur past as I walk down a single row.

:[Zoom far far out to show multiple rows of rocks. It is not very clear that there are several triangular patterns (with no rocks) in different sizes in the laid out grid of rocks. There are about 50 rows and 90 columns. There are six large triangles on top of each other at the left edge. To the right, there are three even larger triangles from top to bottom, the one in the middle further to the left than the one above, but further right than the bottom one.]
:The rows blur past to compute a single step.

:[Shows the placement of two particles in the simulation.]
:And in the simulation...

:[The two particles have moved just long enough as to not overlap with their previous positions, shown as an after-image with faint gray lines. The text continues directly the one from the previous panel.]
:another instant ticks by.

:[The next two panels take up the eighth line of the comic. They each take up half the width.]
:[A Cueball-like person (you) observes a mote of dust vanish.]
:So if you see a mote of dust vanish from your vision in a little flash or something

:[Cueball is standing between two rocks on the ground, while holding two rocks, one lifted up to his head. The first line of text is above him. It is a direct continuation of the text in the previous panel. The second line stands below to the right of him.]
:I'm sorry. I must have misplaced a rock
:sometime in the last few billions and billions of millennia.

:[Cueball stands in the "clean" part of his infinite desert, in front of the vastness of his infinity of infinite lines or rocks.]
:Oh, and...

:[A Cueball-like student sits in a classroom with his head in his hands, Megan sits behind him, and a teacher points to the blackboard. A clock shows the time at five minutes to ten.]
:If you think the minutes in your morning lecture are taking a long time to pass for ''you''...

==Trivia==
This comic used to be [https://web.archive.org/web/20220125023401/https://store.xkcd.com/products/signed-prints available as a signed print] in the xkcd store before it was [[Store|shut down]].

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Multiple Cueballs]]
[[Category:Comics with xkcd store products]]

[[Category:Binary]]
[[Category:Math]]
[[Category:Physics]]
[[Category:Programming]]
[[Category:Footnotes]] 
[[Category:Rockets]]

839: Explorers

2024-12-02T14:44:12Z

The-Ergster:

{{comic
| number = 839
| date = December 27, 2010
| title = Explorers
| image = explorers.png
| titletext = We're going to have to work together to get over our hangups if we're going to learn to move on Catan's hexagonal grid. It's bad enough that we lost our crew of pawns when we passed within firing range of Battleship.
}}

==Explanation==
This comic blends {{w|board game}}s such as {{w|chess}}, {{w|The Settlers of Catan}}, and {{w|Battleship (game)|Battleship}}, with {{w|exploration}}, making possible references to {{w|space exploration}} and the {{w|Age of Discovery}}.

The typical representation of explorers has them travel from their homeland aboard a ship to unknown distant places. The travel can get very long, implying the need for food supplies on the ship; and the fact that the crew members have to live together with little room (the ship) for such a long time, with possibilities of failure, getting lost or dying for various reasons, can often lead to tensions between some of them. In the Age of Exploration the explorers were mainly sailors from Europe traveling on the sea to other continents, whereas in space exploration they are astronauts or robots from Earth traveling in space to other planets (or whatever celestial bodies), but the general concepts of exploration remain the same.

Here the explorers are two chess pieces, a knight and a bishop; they have left their "home board", presumably a full 8x8 chess board, aboard a smaller "capsule" made of a small 3x3 chess board in motion. It appears to be flying through space with some kind of miniature rocket-thruster located beneath each corner of the board, trailing exhaust gas/smoke, but the drawing is somewhat ambiguous and it could be floating in water with corner nascelles providing thrust, if it weren't for the conspicuous lack of ripples, or rolling along a flat surface with wheels leaving a residue. They are apparently headed for a Settlers of Catan board, and already passed near a Battleship board, so these game boards are like islands or regions which the chess pieces explore, coming from a chess board.

Ba3, Nc3 and Ke5 are the identification of chess pieces and their respective position: Ba3 is a bishop on the A3 square, Nc3 a knight on the C3 square, and Ke5 a king on the E5 square. Chess is pretty much a representation of the structure of medieval European society (with the king and queen being the most crucial pieces, the bishops representing the somewhat powerful clergy, the knights corresponding to the armies, the rook alluding the castles, and the pawns being, as the medieval working classes, the most numerous and disposable assets); so chess pieces exploring other places, approaching the "coast of Catan", and reporting to the king ("calling Ke5"), is reminiscent of explorers from Europe who under their king's jurisdiction set sail to other continents during the Age of Exploration.

The explorers are communicating with a "{{w|Mission control center|mission control}}", which is common in space exploration. Also, an "ETA" is an {{w|estimated time of arrival}}.

In chess, the knight and the bishop have different move constraints. The knight can only move two squares horizontally and one square vertically, or two vertically and one horizontally, so on the capsule the knight explorer can only go from one corner square to a black square, or vice-versa. The bishop can only move diagonally, so this bishop is bound to move only on the white squares. The knight is also the only piece that can "jump" over other pieces, which seems to annoy the bishop, hence the "hopping around"; apparently the bishop put all the food onto the middle square, which the knight can't reach, because the knight was taunting him about his not being able to get onto a black square.

The two pieces are from the opposite chess camps (one black and the other white). This can be a reference to multinational space mission crews, where formerly opponent nations joined their efforts on space missions. But in chess it also means they can capture each other, by getting on the square where the other stands. Here, with the chess turn-by-turn gameplay, the knight won't be able to capture the bishop (except of course in case of error or dumb move), since the bishop will always be able to escape, whereas the bishop is actually one or two moves away from capturing the knight. So saying that he's "this close" to capturing him is a play on words, he is "this close" as in a few moves away, as well as "this close" as in severely annoyed and about to act on it.

Assuming it’s the bishop’s turn this capture could be accomplished by the Bishop moving to C1, there after the knight would be forced to move to either A2 or B1. The Bishop then moves to B2. The knight then must move to C1 or C3 if it moved to A2, or A3 or C3 if it moved to B1 – all valid positions from which the Bishop could capture. If it’s the knights turn, the situation is the same except the Bishop would simply move to B2 regardless of the knight move. Although if there are other pieces, they may simply just not move on a black square.

Finally, the title text adds two jokes. The Settlers of Catan board has a hexagonal grid, which means the chess pieces will have difficulty to move on it, since they are used to moving on a square grid (though luckily, there do exist {{w|Hexagonal chess|hexagonal variations of chess}}). This can draw a parallel with explorers facing, in distant lands, weather conditions, wild animals, atmosphere or whatever condition, to which they are not used at all in their homeland. Battleship is a game where players send shots on the opponent's board, which is why the chess capsule received shots when it passed within firing range of a Battleship board; in pure chess style, it's the {{w|Pawn (chess)|pawns}} of the crew, the least valuable and most disposable chess pieces, who took the shots. It could also be a reference to the ''{{w|en passant}}'' chess move, where, under certain conditions, a pawn can be captured after having "passed within firing range" (so to speak) of an enemy pawn; this could explain why only the pawns were lost in passing Battleship.

==Transcript==
:[A black bishop, Ba3, and a white knight, Nc3, are on a three by three chessboard. Both are on white squares. There is a heap of supplies at b2, also a white square. The chessboard is mounted on rockets and appears to be flying through the air.]
:Ba3: Mission Control, come in. This is Ba3 on the capsule calling Ke5 on the home board. We're on track and approaching the Coast of Catan. Our ETA is—
:Nc3: Control, this is Nc3. Bishop put all our food in the center so I can't get it. I demand—
:Ba3: Control, knight will get his food back when he stops hopping around bragging about how comfy the black squares are. I swear to God, I'm ''this'' close to capturing him and completing the misson alone.

==Trivia==
*There is a misspelling of ''mission'' in the last sentence:
**''...and completing the '''misson''' alone.''

*The fact that the black King is located on e5 suggests that the chess game back on the home board is in the endgame phase, where there are few pieces left on the board and the King becomes a valuable attacking piece. Since there are so few pieces and resources back at home, this comic may therefore be a nod to common movie plots such as that of ''Interstellar'', where settlers are forced to flee to another world because of the depletion of the old.

{{comic discussion}}

[[Category:Chess]]
[[Category:Food]]
[[Category:Board games]]
[[Category:Rockets]]

786: Exoplanets

2024-12-02T02:45:50Z

The-Ergster:

{{comic
| number = 786
| date = August 30, 2010
| title = Exoplanets
| image = exoplanets_2010.png
| titletext = I'm just worried that we'll all leave and you won't get to come along!
}}

==Explanation==
[[Beret Guy]] runs to wake up [[Cueball]], who is probably under the covers in bed, with his potentially middle of the night revelation that Humankind is discovering "{{w|exoplanet}}s" or planets that exist outside of our solar system. The indication is that these planets are habitable enough for humans, even if just for a visit.

Then Beret Guy takes it a bit further thinking that one of the countries on Earth could restart {{w|Project Orion (nuclear propulsion)|Project Orion}} (which is later mentioned in [[2423: Project Orion]]. As Beret suggests, Project Orion was an early project to produce a spacecraft that would ride the shockwave from a series of nuclear bombs it dropped in order to travel very, very fast. However, the one major downside of Project Orion was the fallout that the launching of any such craft would present on Earth. One could try to boost the Orion spacecraft into orbit with conventional rockets, but Orion spacecraft are heavy — being composed of giant pusher plates and rows upon rows of nuclear bombs, they are hard to lift. On top of this, the {{w|Nuclear Test Ban Treaty}} means that the craft would be flatly illegal to build and launch on Earth, no matter what you did. However, if an asteroid mining project were to be started, the Orion drive spacecraft, the nuclear bombs, and all the infrastructure needed to man, build, and crew it could all be built safely in space, well away from the Earth's fragile biosphere, where little harm could be done. Some commercial spaceflight programs are interested in starting asteroid mining in the future, or even now: For example, see: https://www.planetaryresources.com.

In summary, Beret is very excited that we can see (with the Hubble telescope and other earth-bound telescopes) and find exoplanets. Then with some advances in space technology we can create nuclear propulsion in space to reach these planets, and it will all be happening quite possibly within a few decades. He is thus worried that Cueball will miss all of this ongoing excitement.

Cueball would just rather snooze, as he is not impressed. Beret Guy gives him only one snooze because as is apparent in the title text he is afraid that Cueball will be left behind if he snoozes too long! Giving the fact that he just stated that it may take hundreds of years this is of course silly but fits well with Beret Guy's behavior.

Exoplanets have been discovered starting in 1996, but there are still only a few confirmed {{w|List of habitable planet candidates|planet candidates}} in the habitable zone at a distant star. This did change fast after that time since new ways of finding planets are created — see [[1071: Exoplanets]], which was posted with the same title. At that point, there were exactly 786 Exoplanets confirmed — the number of this comic - probably not a coincidence when it comes to [[Randall]].

Part of the humor of this particular strip is that Beret Guy seems to have a sense of urgency and immediacy about something that is actually occurring at a snail's pace over decades, where Cueball finishing sleeping, or hitting snooze twice, couldn't possibly make one crystalline erg of difference.

[[1624: 2016]] is similar to this comic in that in each case, one character wakes up another character in order to inform that character about an event that is neither immediately relevant to that character nor short/urgent enough that that character could miss it if he slept until the morning.

==Transcript==
:[Beret Guy runs into a bedroom arms up calling to someone who is in the bed under the covers. Only part of the bed is visible. The person under the covers speaks. Later part of his face can be seen, and it could be Cueball.]
:Beret guy: Wake up! Wake up!
:Cueball (under the cover): What is it?

:[Beret Guy stands with his arms out talking to Cueball hiding under the covers of the bed now completely inside the panel.]
:Beret guy: We're alive during the time when they're first discovering other planetary systems! They're finding them as fast as they can build new instruments to look for them!

:[In this frame-less panel only Beret Guy is shown standing with one arm out and one arm up looking left away from the off-panel bed.]
:Beret Guy: And if one of Earth's cultures advances its space program enough to start enriching uranium on asteroids, we'll lose the main barrier to restarting Project Orion and building nuke-riding city-ships!

:[Beret Guy bends down, hands on his knees, to eye level with Cueball in the bed, who is finally peeking out from the covers, only showing part of his face (so it could be any character, as any hair could be hidden, and the hat could be on the bed stand).]
:Beret Guy: The only known technology capable of fast interstellar travel could be operational within just a few generations, and we're discovering all these destinations to pick from!
:Beret Guy: Come ''on!''
:Cueball: Can I hit "snooze"?
:Beret Guy: Okay, but ''just once!''

==Trivia==
*This was the first time Randall released a comic with the exact same name as a previous comic, in this case [[1071: Exoplanets]], released on June 20, 2012. Since then, he has done so [[:Category:Comics sharing name|a few times]]. When the new comic was released, it caused problems on xkcd as the title of the image file (<code>explanets.png</code>) was the same for the two comics. This was resolved by renaming this comic's image, adding the year of its release to the title: <code>explanets_2010.png</code>.

* The number of this comic ([[786: Exoplanets]]) is the same number of planets featured in the comic [[1071: Exoplanets]] (786 planets) with the same title. It isn't clear whether this is a coincidence or Randall purposefully waited for the number of discovered planets to be the same as this comic's number.

*Cueball is not completely visible in this comic, and the last image only shows a face. Given that almost all characters without a beard have the same face, this could be any character, including one with a hat (which could be hidden or outside of the frames) or hair (several of the usual styles). The comic's official transcript refers to this person as "bed man", meaning it isn't intended to be a female character. As it is easier to explain the comic using Cueball's name, and given that he is the usual guy to draw when no particular features are added, it still makes sense to call him Cueball in this comic.

{{comic discussion}}

[[Category:Comics featuring Beret Guy]]
[[Category:Comics featuring Cueball]]
[[Category:Astronomy]]
[[Category:Exoplanets]]
[[Category:Comics sharing name|Exoplanets01]]
[[Category:Nuclear weapons]]
[[Category:Rockets]]

3013: Kedging Cannon

2024-12-02T02:44:44Z

The-Ergster:

{{comic
| number = 3013
| date = November 18, 2024
| title = Kedging Cannon
| image = kedging_cannon_2x.png
| imagesize = 740x259px
| noexpand = true
| titletext = The real key was inventing the windmill-powered winch.
}}

==Explanation==

Prior to the invention of powered ships, oceangoing vessels moved primarily by means of wind power, which meant that they were restricted by the direction and power of the winds. If a sailing vessel needs to travel upwind (against the wind), they typically make use of a technique called {{w|Tacking_(sailing)|tacking}} (or "tacking against the wind") which involves zigzagging across the wind's direction, using the airfoil of the sail to exert force perpendicular to it. This method is significantly slower and more difficult than traveling downwind, but it makes upwind navigation possible.

This comic portrays a fictional scenario where a ship's captain, apparently unfamiliar with tacking, has developed an alternative method based on {{w|kedging}} (also known as warping).

The basics of kedging are not dissimilar to the comic: a boat affixes a rope or chain to an anchor point (such as a literal anchor) and winches itself closer. Traditionally, kedging involves deploying an anchor from the vessel, either manually or via a smaller boat, and then {{w|winch|winching}} the ship toward the anchor point using ropes or chains. This is a real method, but is clearly very slow and labor intensive. Generally kedging is only effective in shallow waters and employed when tacking is not an option, as for example in harbors or narrow channels where space is tightly constricted. The captain in this strip appears to be using it for long-distance travel, which would be highly impractical. What's more, he deploys his anchor with a cannon, wasting large amounts of gunpowder (although with the setup as depicted, wasting gunpowder would be the least of a ship's concerns, as firing something the weight of an anchor any meaningful distance would require so much force it would outright rupture just about any age of sail artillery piece{{acn}}). Meanwhile, a confused Cueball looks on, wondering why the Captain isn't trying to use tacking instead.

This approach to transportation has been used in war when the wind halts[https://www.history.navy.mil/our-collections/art/exhibits/conflicts-and-operations/the-war-of-1812/uss-constitution-escaping-a-british-squadron.html], with ongoing gunfire. An editor mentioned this because it happened to be a top result in a casual websearch for “kedging” but did not look further. Still, this may be where the concept of using a cannon to deploy the anchor came from, as such a situation may involve an excess supply of gunpowder.

Where the water is too deep for the anchor to reach the bottom, a so-called {{w|sea anchor}} could theoretically be used, but would be even less practical. Kedging with a sea anchor would effectively be a very slow and inefficient version of rowing, which is an alternative (albeit labor-intensive) method to travel against the wind.

Another issue with kedging is that it would take substantial energy to draw in the rope, as they'd be moving the entire ship forward. In pre-steam power ships, the obvious answer would be to draw it in by hand, but this would require a large number of people exerting a great deal of effort, and that kind of effort (once again) could be better used in rowing. The title text indicates that the captain's system has solved this by incorporating a windmill mechanism that harnesses wind power to draw in the kedging rope. This implies that there is indeed sufficient wind that could be used for tacking, as otherwise the windmill would be ineffective. An analysis of the efficiency is below.

==In real life==
On some rivers, {{w|chain boat}}s were used for about a century. A chain would be laid the length of the river, and the boat used a winch to pull itself along the chain. Rudders and booms could replace the chain in the center of the river even around bends. It turned out to be very difficult to drive the chain with enough force - several techniques were attempted. Many ferries still exist that {{w|Cable ferry|use a chain}} (or cable) laid ''across'' a river, tethered at each bank.

{{cot|Speed and economic analysis of dual wind-winched kedging cannons compared to tacking}}
A dual-anchor kedging cannon system for sailing upwind, consisting of:
* Two kedging cannons firing 16 kg anchors
* 6-meter diameter windmill powering winch system
* Dual-winch setup for continuous operation
* Operating in 15 knot headwind conditions

Vessel specifications:
* Length: 30 feet (9.1 meters)
* Displacement: 10,000 lbs (4536 kg)
* Sail area: 600 sq ft (55.7 m²)
* Wetted surface: 40 m²
* Frontal area: 8 m²

;Wind power generation
Available wind power is given by:
''P'' = ½''ρAv''³''η''
where:
* ''ρ'' = 1.225 kg/m³ (air density)
* ''A'' = ''π''(''D''/2)² = 28.3 m² (windmill area)
* ''v'' = 7.72 m/s (wind speed)
* ''η'' = 0.245 (combined efficiency)

This yields 1.95 kW of usable power.

;Drag forces
Total drag combines water and air resistance:
''F''drag = ''F''water + ''F''wind
where:
* ''F''water = ½''ρ''w''C''d''A''w''v''²
* ''F''wind = ½''ρ''a''C''a''A''f''v''²

Using:
* Water density (''ρ''w) = 1025 kg/m³
* Hull drag coefficient (''C''d) = 0.04
* Wetted area (''A''w) = 40 m²
* Air density (''ρ''a) = 1.225 kg/m³
* Air drag coefficient (''C''a) = 0.8
* Frontal area (''A''f) = 8 m²

Total drag force = 1053.4 N

;Anchor ballistics
For 300 m range with 45° launch angle:
* Required velocity = 54.7 m/s
* Launch energy = 23.7 kJ
* Black powder energy per shot = 680.4 kJ
* Launch efficiency = 3.5%

;System performance
* Winch speed = 3.60 knots
* Cycle time = 194.7 seconds
* Effective speed = 3.04 knots
* Compared to tacking speed = 4.95 knots
* Speed ratio (kedging/tacking) = 0.61

;Economic analysis
* Shots needed per nautical mile: 6.1
* Black powder cost per shot: $10 (0.5 lbs @ $20/lb)
* Cost per nautical mile: $60.76
* Powder consumption: 9.2 lbs/hour
* Operating cost: $184.90/hour

Example 100 nmi journey:
* Total powder cost: $6,076.12
* Journey time: 32.9 hours

;Conclusion
The dual-anchor kedging cannon system is both slower and significantly more expensive than traditional tacking:

Speed disadvantage:
* Achieves only 61% of tacking speed
* 100 nmi journey takes 32.9 hours vs 20.2 hours tacking

Economic disadvantage:
* High powder costs ($60.76 per nautical mile)
* Requires significant powder storage (303 lbs for 100 nmi journey)
* Additional wear and tear on mechanical systems

Key limiting factors:
* Limited wind power available (1.95 kW from 6 m windmill)
* High drag forces (1053.4 N total)
* Poor ballistic efficiency (3.5% of powder energy converts to useful launch)
* Long cycle times due to realistic winching speeds

The system could potentially be improved by:
* Larger windmill (though practical size limits on boats)
* More aerodynamic anchor design
* More efficient powder-to-launch energy conversion
* Reduced transfer time between anchors

Therefore, given both the energy constraints and economic factors, traditional tacking remains far more practical for upwind progress. The key insight is that while the kedging cannon seems to "cheat" the wind by going straight upwind, it actually requires converting wind energy to mechanical work less efficiently than a well-designed sail plan, while also consuming expensive gunpowder. The indirect path of tacking makes better use of the available wind force with no consumable costs.
{{cob}}

==Transcript==
:[A two-masted sailing ship with its sails up is floating on a calm sea with tiny waves. Two tiny figures can be seen at the ship's bow. One of them is speaking. In the next panel it becomes clear this is the captain.]
:Captain: I hope someday someone invents a way to sail upwind.
:Captain: Using the kedging cannon just wastes so much gunpowder.

:[Close-up on the deck of the ship, showing two persons behind the taffrail. Cueball is standing behind the ship's captain and talking to him. The captain is wearing a black bicorne navy hat and aiming a cannon containing an anchor forward. Chains are draped from the cannon.]
:Cueball: The '''''what?'''''
:Cueball: Wait, do you not know how to sail upwind? Is that why your ship takes forever to--
:Captain: Stand by...'''''Fire!'''''

:[Distant shot showing the anchor and its chain being launched out in front of the ship, towards the right of the panel. Cueball and the Captain can still be seen behind the cannon. The cannon has exhaust fumes coming out in front and the sound it makes is indicated:]
:Cannon: ''Boom''

:[Same setting but the anchor is now under water and the chain has become taut as the ship is dragged forward to the right. Movement lines behind the ship indicated its progress and it is also further into the frame than the previous panel. The movement is caused by pulling the chain back in on the ship. This produces a series of sounds:]
:Dragging chain: ''Click click click''

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Characters with hats]]

3012: The Future of Orion

2024-12-02T02:44:18Z

The-Ergster:

{{comic
| number = 3012
| date = November 15, 2024
| title = The Future of Orion
| image = the_future_of_orion_2x.png
| imagesize = 740x300px
| noexpand = true
| titletext = Dinosaur Cosmics
}}

==Explanation==

Stars in the night sky sometimes change, occasionally varying in brightness, very rarely exploding, and imperceptibly moving. For example, {{w|Betelgeuse}}, a star in the constellation {{w|Orion (constellation)|Orion}}, is expected to explode as a {{w|supernova}} between [https://astrobites.org/2023/07/01/betelgeuse-betelgeuse-betelgeuse-is-it-supernovatime/ tens of] and [https://earthsky.org/brightest-stars/betelgeuse-will-explode-someday/ a thousand] years, and then disappear from the night sky. And all stars move relative to us and each other, which results in apparent movement in the sky called {{w|proper motion}}, a function of a star's relative movement in three dimensions and its distance from us.

This comic shows changes in Orion from Betelgeuse disappearing and three of its fastest moving stars, and recommends revising the {{w|constellation}} (or creating a new {{w|Asterism (astronomy)|asterism}}) from one which depicts a hunter to another matching a different hunter, the {{w|Tyrannosaurus}} from Ryan North's [https://www.qwantz.com Dinosaur Comics].

Depending upon the artistic imagination of the observer, western (and northern-hemisphere) traditions may evoke the right 'string' of stars as either Orion's bow-arm holding a bow (perhaps having loosed an arrow towards {{w|Taurus (constellation)|Taurus, the Bull}}, with his off-arm raised aloft and behind having just released the bowstring) or else holding some creature he has caught/is fighting (with his off-arm, the other arm holding a raised club/sword that will strike the beast), with other astronomical traditions maybe 'recognising' various similar or different imageries according to their own cultural ideas (and perspective upon the constellation, e.g. from a southern orientation). In the form adjusted to match the "dinosaur comics" image, the rightmost group becomes the creature's tail and the upper-left maps to the open-jawed head and neck. The torso and legs (the latter sometimes depicted as leading only down to the kneeling Orion's knees, depending upon the imagined pose, hence the enclosed trapezoid of either his lower knee-length robe or from one lower leg crossing the ground, excusing the apparently anomolous leg-to-torso ratio that doesn't fit a hunting human quite as much as the depicted dinosaur) are essentially the same in both versions, but mirrored in sidelong profile, with the minor difference of both shoulders' positions within the asterism, and the traditionally short and stubby T-Rex arms not being granted 'star arms' in their own right.

It should be noted that the main stars (but not the nebula) of {{w|Orion's Sword}} are drawn, but do not fit the dinosaur image in any way. In the original Orion constellation, they are rarely connected with the 'lines' of the constellation, but are matched against a sword (or its scabbard) when rendered as a more pictorial Orion. In the full dinosaur they match nothing from the image, but may be considered to be dripped saliva, discarded blood/torn flesh from whatever it might currently be eating or, perhaps (from its subpelvic position), other expelled material...

The proper motion of {{w|Chi1 Orionis|χ¹ Orionis}} shown near the top at the end of Orion's arm (and the back of the dinosaur's head) is 0.20 arcseconds per year, so it will traverse the depicted angular distance of 0.84 degrees in about 15,000 years. {{w|Pi1 Orionis|π¹ Orionis}} at the top of Orion's bow (and the end of the dinosaur's tail) has a proper motion of 0.14 arcseconds per year, so it will traverse its distance of 0.87° in about 23,000 years. However, with a proper motion of 0.46 as/yr, {{w|Pi3 Orionis|π³ Orionis}}, in the middle of the bow, will take only about 9,600 years to traverse its longer depicted distance of 1.24°. (The angular distances traversed by the stars were measured relative to the distance between Orion's two outermost belt stars, {{w|Alnitak}} and {{w|Mintaka}}, the dinosaur's hips.) Thus, the new constellation won't form until its current name has lasted more than three times as long as it already has. There are various other stars that notably move around within or near the vicinity of Orion, given {{w|File:OrionProper.gif|suffiently long}} viewing time, perhaps allowing Randall some small leeway in what way to re-represent the original hunter's pose, though the 'resemblance' of the reworked constellation to its dinosaur image remains a remarkable coincidence.

[[File:School of Athens Raphael detail 03.jpg|thumb|Hipparchus and Ptolemy compare globes in {{w|Raphael}}'s famous fresco ''{{w|The School of Athens}}''. Ptolemy is shown with a crown because of his erroneous association with the royal house of Ptolemaic Egypt.]]
There are no official constellations depicting dinosaurs. However, {{w|Draco (constellation)|Draco}} represents a mythological reptilian dragon, and the lizard {{w|Lacerta}} was described in 1687. The first fossil to be later identified as a dinosaur was found in 1676, but the term "dinosaur" was not introduced until 1842. The earliest constellations in the northern hemisphere were recognized around 3000 BC. By the 2nd century AD, the Greek mathematician and astronomer {{w|Ptolemy}} listed 48 constellations visible from the northern hemisphere in his ''{{w|Almagest}},'' following the star catalogs and globes made by {{w|Hipparchus}} which have since been lost to history. The remaining modern southern constellations were mostly finalized by {{w|Nicolas Louis de Lacaille}} in 1756. Dozens of {{w|former constellations}} have been recognized, sometimes for hundreds of years, before being disregarded, replaced by others, or because they were only recognized by cultures apart from dominant Western traditions. ({{w|Micronesian navigation#Navigation by the stars|Polynesian navigators}} settled {{w|Polynesian Triangle|a vast expanse of the south Pacific Ocean}} from 26,000 to 950 years ago apparently without naming constellations, but instead [https://openresearch-repository.anu.edu.au/items/f617b33c-531b-41b4-b550-5aec81face2c recording the positions of stars] on {{w|Compass rose#Sidereal|sidereal compass dials}}.) The {{w|International Astronomical Union}} established the current official list of 88 constellations in 1922.

The title text is another joke regarding Dinosaur Comics, replacing "comics" with "cosmics" because we're talking about a dinosaur in the sky.

Orion is also mentioned in [[1020: Orion Nebula]]. T-Rex is also featured in [[1452: Jurassic World]]. In 2006, [[Randall]] emulated the style of Dinosaur Comics with [[145: Parody Week: Dinosaur Comics]] and he lists the comic as one of those comics [[Design_of_xkcd.com#Comics_I_enjoy|he enjoys]]. Randall and Ryan North are known to be friends. And on the day Randall posted this comic, Ryan wrote the following in his "[https://web.archive.org/web/20241117023759/https://qwantz.com/ What are the haps my friends]" section beneath his own comic: November 15th, 2024: [https://xkcd.com/3012/ HEY DID YOU SEE XKCD TODAY??]

==Transcript==
:[Star map of the Orion constellation at present, everything black on white background. The majority of the twenty-three points are connected with the traditional constellation lines. As is usual, the three stars of "Orion's Sword" are left unconnected, and neither is Sigma Orionis, in its position very close to Alnitak on Orion's Belt. In a frame above the stars there is a label:]
:Orion Today:

:[In the next panel the same stars are drawn (except Sigma Orionis, which features in no further panels) but without the constellation lines. Three of the dots that mark the stars are drawn in grey, and from them a short red line is going to an additional red dot that marks a new star position. A fourth star has a red cross over it. There are two labels in red. From the upper label goes two long red arrows in opposite directions towards the red and grey stars and lines (two of those are close together beneath the label, one is above). A small red arrow goes from the other label to the crossed out star. The rest of the stars remain unchanged. In a frame above the stars there is a label:]
:Predicted Changes:
:Upper label: Star movement
:Lower label: Star Death (Betelgeuse)

:[Star map of the future Orion constellation, all map features black on white, with Betelgeuse now missing and the three moved stars where their red 'new' positions were in the prior panel. A set of mostly different constellation lines are drawn joining the majority of the twenty-one points (excepting the traditional Sword stars). A red label is written with a red arrow pointing to a constellation line at the top right. In a frame above the stars there is a label:]
:Orion in the future:
:Label: Suggested lines

:[In the last panel the same stars with constellation lines are drawn. It overlays an image of Dinosaur Comics T-rex, the full color habitual 'final pane' pose, but flipped left/right to match and generally encompasses the new constellation lines in a way typical of more classical artistic constellation depictions. In particular, bow and right arm of Orion (in some versions, left arm holding captured prey) now matches the dinosaur tail, whilst the raised left arm (sometimes considered the right arm, holding a club aloft) now matches the neck and dropped jaw of its head. The stars of "Orion's Sword" remain as three dots between the legs constellation/dinosaur legs, without any connection to either, or indeed any 'sword'-equivalent.]

{{comic discussion}}

[[Category:Comics with color]]
[[Category:Comics with red annotations]]
[[Category:Astronomy]]
[[Category:Space]]
[[Category:Dinosaurs]]

3011: Europa Clipper

2024-12-02T02:43:41Z

The-Ergster:

{{comic
| number = 3011
| date = November 13, 2024
| title = Europa Clipper
| image = europa_clipper_2x.png
| imagesize = 333x356px
| noexpand = true
| titletext = They had BETTER make this a sample return mission.
}}

==Explanation==

[[File:Animation of Europa Clipper trajectory around Jupiter.gif|thumb|right|The ''Europa Clipper's'' projected course around {{w|Jupiter}}, represented as the stationary green dot. In gold is Jupiter's moon {{w|Callisto (moon)|Callisto}}, in cyan is the moon {{w|Europa (moon)|Europa}} — the primary target of the spacecraft's study — and in orange-red is the innermost of Jupiter's four {{w|Galilean moons|"Galilean"}} moons, {{w|Io (moon)|Io}}. The spacecraft's track is shown in magenta. Jupiter's largest moon {{w|Ganymede (moon)|Ganymede}} is not shown, but its gravitational pull affects the ''Clipper's'' trajectory. A mission goal is to achieve a 6:1 {{w|orbital resonance}} with Europa [https://www.researchgate.net/profile/Martin-Ozimek/publication/383115312_AAS_24-433_Europa_Clipper_Mission_Analysis_Pump_Down_Trajectory_Design/links/66bcd845311cbb094938dbd6/AAS-24-433-Europa-Clipper-Mission-Analysis-Pump-Down-Trajectory-Design.pdf by September 2034]. ]]

The ''{{w|Europa Clipper}}'' space probe was launched from the {{w|Kennedy Space Center}} in Florida on [https://europa.nasa.gov/mission/about/ October 14, 2024]. It is expected to arrive at Jupiter and begin exploration of Jupiter's moons, particularly {{w|Europa (moon)|Europa}}, in April of 2030.

Europa is an icy moon. Water ice covers its surface. Around 15 to 25 kilometers (10 to 15 miles) beneath the ice, there is expected to be liquid water which may contain some [https://europa.nasa.gov/why-europa/ingredients-for-life/ basic forms of life]. To sample this liquid, its icy crust would need to be breached. The thickness of the ice dwarfs the ''Europa Clipper's'' 31 meter span.

Europa's surface of ice over liquid water could be loosely compared to the caramelized crust on the popular dessert {{w|crème brûlée}}—a comparison that may have been prompted because the {{w|Cassini-Huygens}} probe, after landing on Saturn's moon Titan in January of 2005, found that its surface had what was described as [https://www.sciencenews.org/article/world-unveiled-cr%C3%A8me-br%C3%BBl%C3%A9e-titan a "crème brûlée" consistency]. The hard surface of the caramel cream dessert is traditionally cracked open with a {{w|Tableware#Spoon|spoon}}, so [[Randall]] jokes that such equipment will be deployed by the ''Europa Clipper''.

In truth, no such spoon is present on the probe, and Europa's icy crust is too thick to be penetrated by a spoon of such size. Advanced measures are needed to prevent contamination of liquid water by Earth's organisms such as {{w|tardigrade}}s, {{w|deinococcus radiodurans}}, or {{w|bacillus subtilis}}. The ''Europa Clipper's'' course has been charted to avoid any contact with the surface of Europa (although it will fly through some sparse material it ejects into space) so as to prevent {{w|Planetary protection|contamination by microorganisms from Earth}}.

The successful deployment of any spacecraft's instrument is considered a cause for celebration because deployable spacecraft instruments often fail to correctly extend, unfurl or undock. The ''Clipper'' has a magnetometer that will be used at the end of a 8.5 meter boom (not apparent in the comic which, spoon extension aside, is an otherwise fairly accurate depiction) as part of its study of the moons' environment.

<div style="display: flex; justify-content: center; align-items: center; margin: 1em 0;">
<div style="text-align: center; margin: 0 1em;">
[[File:Europa_-_Perijove_45_(cropped).png|200px|alt=Europa]]
<div>Europa</div>
</div>
<div style="text-align: center; margin: 0 1em;">
[[File:2014_0531_Crème_brûlée_Doi_Mae_Salong_(cropped).jpg|200px|alt=Crème brûlée]]
<div>Crème brûlée</div>
</div>
<div style="text-align: center; margin: 0 1em;">
[[File:Europa_Clipper_spacecraft_model.png|200px|alt=The Europa Clipper spacecraft]]
<div>The ''Europa Clipper'' spacecraft</div>
</div>
</div>

The title text expands on the joke by stating that the spacecraft "had BETTER" return samples of Europa to Earth. However, the ''Europa Clipper'' is not a {{w|sample-return mission}}, and if it were, such samples are unlikely to be good to eat.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

:[A space probe with two rectangular solar panels, a circular dish of the front, and a very large spoon extending beneath, longer than the span of both solar panels]

:[Below the panel:]
:Good news: NASA's '''''Europa Clipper''''' is en route to Europa and has successfully deployed its crème brûlée spoon.

==Trivia==
Initially, the ''Europa Clipper'' mission was planned to include a lander component, but it was removed from the project early on. The Europa Lander proposal lags significantly behind the Clipper in development and has not secured funding. An actual sample return mission is currently far into the future of {{w|Ocean Worlds Exploration Program|the pertinent plans for exploration}}.

In {{w|Arthur C. Clarke}}'s novel ''{{w|2010: Odyssey Two}}'', the monolith aliens tell humanity ''"All these worlds are yours — except Europa. Attempt no landing there."'' Contrary to the suggestion of the comic, no landing or any other physical interaction beyond observation of the surface and analysis of the ejecta of Europa is planned.

In {{w|Greek mythology}}, {{w|Europa (consort of Zeus)|Europa}} was a {{w|Phoenician}} princess whom {{w|Zeus}}, the king of the gods, abducted after transforming himself into a bull. The name of the continent Europe may derive from this legend, though alternative theories suggest it originates from ancient Greek words meaning "wide-gazing" or "broad face." Additionally, there is an {{w|Oceanid}} named {{w|Europa (Greek myth)|Europa}} (with a sister named {{w|Asia (Oceanid)|Asia}}), one of the many daughters of the {{w|Titans}}, {{w|Oceanus}} and {{w|Tethys (mythology)|Tethys}}. The name Europa is also used in {{w|Europa (Greek myth)|other mythological}} and {{w|Europa (Roman province)|geographical}} contexts. Jupiter's moon Europa was named after the Phoenician princess, following the tradition of naming Jovian moons after Zeus's lovers.

Diacritics are previously featured in comic [[Diacritics]] and [[2619]].

{{comic discussion}}
[[Category:Space]]
[[Category:Space probes]]
[[Category:Food]]

3010: Geometriphylogenetics

2024-12-02T02:43:04Z

The-Ergster:

{{comic
| number = 3010
| date = November 11, 2024
| title = Geometriphylogenetics
| image = geometriphylogenetics_2x.png
| imagesize = 316x391px
| noexpand = true
| titletext = There's a maximum likelihood that I'm doing phylogenetics wrong.
}}

==Explanation==

{{w|Phylogenetics}} refers to the practice of examining relationships among things that follow the principle of "descent with modification of progeny". In the course of descent with modification, one thing may give rise to two (the progeny), different modifications happen to each, and those modifications become established. Iterated "splits" over time yield a tree of objects; it is the purpose of phylogenetics to recover ("reconstruct") these trees, and use the information gained to inform study of the things contained. Phylogenetics has been most commonly applied to the classification/taxonomy of biological species and investigations of their evolutionary history, but it has also been used to examine the evolution of genes and biosynthetic pathways. Similar conceptual approaches have been used in the study of human languages and their evolution.

Data for phylogenetic analyses may come from any attributes ("characters") of the things being examined. {{w|Computational_phylogenetics|Rigorous techniques}} for these analyses became available starting in the {{w|Willi_Hennig|1950s}}, and these replaced earlier methods based largely on the individual judgement of experts. In phylogenetic studies of organisms, their DNA is far and away the most data-dense source of information, and consequently, most present-day investigations are based on analyses of selected genes and, increasingly, whole genomes. Thanks to the advent of more robust datasets, and more robust methods of data analysis, it is now commonplace for studies, especially on relatively understudied creatures, to reconstruct an evolutionary history (a phylogeny) that is radically different from what had previously been assumed. This is the "phylogenetic revolution" referred to in the caption. One example is the genus {{w|Hippopotamus|Hippopotamus}}, which had been considered a relative of pigs, which the animals somewhat resemble, until modern data and methods revealed it to be more closely related to whales, despite the animals being very different physically (hippos spend time in water, but [https://www.youtube.com/watch?v=X-YRJCSZRJU can't swim]).

This comic presents a tree, which resembles and purports to be a phylogenetic tree, in which the endpoints ("terminal taxa") are geometric shapes. This has been given the name "geometriphylogenetics" — a portmanteau of "{{w|geometry}}" and "phylogenetics". The claim is that triangles have been moved from the lower part of the tree (where they would be closely related to squares, rectangles, pentangles, and the like) to the upper part (placing them closer to circles and ellipses). This is a riff on the findings, and even the wording, of authentic phylogenetic research papers that report "revolutionary" results. The absurdity, and the joke, is that geometries do not change over time. Human understanding might change, but triangles and circles and rectangles themselves did not evolve or descend from ancestors, they are not progeny of some other geometries of ages past, and therefore phylogenetic principles and techniques don't apply to their study. Moreover, geometries do not contain DNA,{{cn}} so genetic analysis, even if it was ever relevant, is impossible.

The title text alludes to {{w|Computational_phylogenetics#Maximum_likelihood|maximum likelihood}}, one of the most robust, and most frequently used, methodologies for phylogenetic analysis. The method builds a number of trees from the data, assigns to each a probability that it conforms to a pre-selected model of evolution, and then selects the tree that has the highest (maximum) likelihood of conformity to the model. In this case, though, the statement "There's a [high probability] that I'm doing phylogenetics wrong" doesn't just have the maximum probability of the available options; it has the maximum ''possible'' probability of 1, because it is definitely the case.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

:[A tree diagram, or a dendrogram is shown, consisting of lines that branch off from left to right, starting with one horizontal line on the left. Eight results are shown on the right: ellipse on Path 1, circle on Path 2, triangle on Path 3, parallelogram on Path 4, trapezoid on Path 5, square on Path 6, rectangle on Path 7, and a pentagon on Path 8. The paths are listed in order top to bottom.]
:[Path 3 and the triangle are bold black, while the other branches are dimmer. The paths are connected as follows: Path 2 and 3 are connected, then both connect together to Path 1; Path 4 and 5 are connected, as are Path 6 and 7, and these two paths are connected altogether; Path 8 is then connected to the branch containing Paths 4 to 7. All of Paths 1 to 3 are then connected to Paths 4 to 8, the branches all culminating in a single line on the left.]

:[Caption below the panel:]
:The phylogenetic revolution continues:
:Triangles were long believed to be related to squares, but genetic analysis proves that they are actually very pointy circles.

{{comic discussion}}

[[Category:Geometry]]
[[Category:Biology]]
[[Category:Charts]]
[[Category:Statistics]]

3009: Number Shortage

2024-12-02T02:42:40Z

The-Ergster:

{{comic
| number = 3009
| date = November 8, 2024
| title = Number Shortage
| image = number_shortage_2x.png
| imagesize = 284x269px
| noexpand = true
| titletext = "10 minutes ago we were down to only 2 0s!" "How many do we have now?" "I ... don't know!!"
}}

==Explanation==

This comic presents a situation where the ability to use numbers is a limited resource. Even quantifying how many numbers are left uses up some of those numbers when stating the results.

In real life, being able to write or say digits is not a limited resource.{{cn}} However, the comic does parallel many {{w|Math Blaster Episode I: In Search of Spot|educational video games}} for young children where numbers and mathematical concepts are treated as living people or factory goods, in order to give some sort of story or context to the math-related activities. In addition, the plight faced by the shortage resembles the {{w|look-and-say sequence}} where trying to quantify the list changes it, requiring it to be quantified again (which changes it again, and so on).

The comic conflates numbers with decimal digits. So when [[Blondie]] says "15 2s and 12 3s", that uses up two 2s (one in "2s" and one in "12") and one 3 (in "3s"). She adjusts the counts as she's speaking, so when she says "13 2s", that uses up another 3, leaving only 10 3s as she's completing the sentence.

In the title text, she uses the last two 0s when saying that they had two 0s left, so now they have no more 0s. But she can't use the number 0 to describe this situation because they're now out of them.

Blondie could have taken a different approach by saying "14 2s and 11 3s", which would be accurate once it has been said.

Jokes with a similar theme been made about letters, such as shortages of vowels (and later consonants) in {{w|The Onion}}'s [https://web.archive.org/web/20020124120633/www.theonion.com/onion2816/vowels2816.html "Clinton Deploys Vowels to Bosnia"].

===Continuation===

A continuation of the pattern would go:

* "We have only 15 2s and 12 3s left."
* "No, wait, 13 2s and 10 3s."
* "No, wait, 12 2s and 9 3s."
* "No, wait, 10 2s and 8 3s."
* "No, wait, 9 2s and 7 3s."
* "No, wait, 8 2s and 6 3s."
* "No, wait, 7 2s and 5 3s."
* "No, wait, 6 2s and 4 3s."
* "No, wait, 5 2s and 3 3s."
* "No, wait, 4 2s and 1 3."
* "No, wait..."
* "How many more do we have?"
* "I...don't know..."

At that point, having used up the last 3 at the end of the previous line, Blondie would lack the necessary 3s to articulate that there are "3 2s and 0 3s."

==Transcript==
:[Blondie is standing on the left, facing Cueball and Megan on the right.]
:Blondie: The Math Department number shortage is getting worse. We have only 15 2s and 12 3s left.
:Blondie: No, wait, 13 2s and 10 3s.
:Blondie: No, wait...

{{comic discussion}}

[[Category:Comics featuring Blondie]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Math]]
[[Category:Comics with lowercase text]]

3005: Disposal

2024-12-02T02:42:18Z

The-Ergster:

{{comic
| number = 3005
| date = October 30, 2024
| title = Disposal
| image = disposal_2x.png
| imagesize = 740x331px
| noexpand = true
| titletext = We were disappointed that the rocket didn't make a THOOOONK noise when it went into the tube, but we're setting up big loudspeakers for future launches to add the sound effect.
}}

==Explanation==

This comic came out a couple of weeks after the successful first attempt to 'catch' a rocket during {{w|Starship flight test 5}}, based upon {{w|SpaceX}} having {{w|Falcon 9 first-stage landing tests|an extensive history}} of bringing rocket stages back to Earth in a controlled manner. Whereas the traditional approach was for such rocketry to allow most of the initial launch-vehicle to be a single-use stage that was effectively destroyed once it had fulfiled its purpose, it has become a developmental aim across much of the commercial side of the industry to introduce as much reusability as possible in the mission hardware to potentially save costs and construction time.

In order to accomplish a successful recovery, expended stages have been given unprecedented ability to control their fall back to the ground, often in a manner that allows them to propulsively halt their descent directly over a prepared landing pad (on land or sea) and settle down softly enough on landing gear to be refurbished and reused (sometimes for {{w|List of Falcon 9 first-stage boosters#Booster 1061|more than twenty subsequent missions}}). For the recent Starship test, the one (and, as of this comic, only) attempt to recover its {{w|SpaceX Super Heavy#B9%E2%80%93B12|Super Heavy Booster}} involved being precisely guided to be ''caught'' by the {{w|SpaceX Starbase#Orbital Launch Pad A|original launch tower}}; though it is never expected to refly, as a test prototype, it survived the whole process. This is in contrast with [https://www.youtube.com/watch?v=bvim4rsNHkQ plenty of examples], where the landings (or their aftermath) were not quite so successful.

Though SpaceX is the current leader in such an accomplishments, there are other companies who are various degrees along a similar developmental route. [[Randall]] claims that he has an organisation that is amongst them, and has achieved the non-trivial feat of being able to direct the discarded rocket stage ''very precisely'', yet without that extra bit of ability to ensure that it doesn’t then subsequently explode. The team has therefore decided to exploit their achievement (to precisely control the rocket) to send it 'safely' into a hole that (barely larger than the rocket's cross-section, and with a sturdy lid directly manhandled by a [[Cueball]] employee) allows it to {{wiktionary|rapid unplanned disassembly|rapidly disassemble}} in a planned and 'safe' manner. Of course, as a [[:Category:Compromise|'compromise']], it does not achieve the original aims of recoverability and reusability, yet it also is intrinsically far more complicated than the default option of just letting the hardware generally fall to destruction somewhere in a handy 'empty' down-range area that {{w|Spacecraft cemetery|shouldn't inconvenience anybody}}.

With the comic depicting the 'disposed' stage as powering downwards, this might explain their lack of success in perfecting any form of intact recovery, as practical examples of this technology tend to spin the craft around to make use of the main thruster(s) for a {{w|retrorocket}}-assisted {{w|VTOL|landing}}, or at least don't try to counteract the passive deceleration provided by parachutes or other purposeful aerodynamic drag, in order to touch the ground at a survivable velocity.

An explosion in a sealed container is potentially much more dangerous than an explosion in the open, depending on the strength of the container. If the container is strong enough to hold the pressure from the explosion, that pressure could be released in a controlled fashion, safely. But if the container is too weak, it could suffer a catastrophic failure, sending shards of its walls and anything around it flying outwards at high speed. Even if the container is initially strong enough, it could be weakened by repeated explosions, and fail at a random time in the future. As the 'container' is mostly a hole dug into the ground, of indeterminate depth, it might be considered fairly robust in itself, especially if given a reinforced lining. However, this then risks forcing the majority of the resulting explosion up into the lid, which looks strong and heavy yet is closed at least partly by the effort of just one person. It also risks that worker being right next to the track of the descending rocket stage, where they would be at risk of experiencing all kinds of secondary damage, if not being directly in the explosion if they get the timing of the lid-closure wrong. An actual {{w|Operation_Plumbbob#Missing_steel_bore_cap|attempt to put a lid on an underground explosion}} succeeded only in blowing the lid off at such velocity that it was never found.

The title seems to refer to the sound effects of dragging an element into the trash on computers. Or, alternatively, the sound of a canister being sucked into a vacuum tube. This is perhaps a reference to Tesla vehicles being quiet and having "vroom" noises pumped into the cabin to satisfy customers.

==Transcript==

:[A two-stage rocket is ascending with a plume of exhaust behind it]
:[The first stage falls off and the second stage ignites]
:[The first stage begins to fall, turned off]
:[The first stage reignites to control trajectory and attitude]
:[The first stage falls toward a large, but barely wider hole with a lid. A Cueball is holding the lid open, which has a hinge attaching it to the ground]
:[Cueball pushes the lid closed]
:Click
:[The first stage, now out of sight, explodes, with Cueball shielding his ear with one hand and flinching away from the loud noise]
:BOOOOM

:[Caption below the panels:]
:Our rockets were good at steering, but we couldn't get them to land without exploding, so we just dug a rocket disposal hole.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Space]]
[[Category:Rockets]]

3003: Sandwich Helix

2024-12-02T02:41:55Z

The-Ergster:

{{comic
| number = 3003
| date = October 25, 2024
| title = Sandwich Helix
| image = sandwich_helix_2x.png
| imagesize = 257x376px
| noexpand = true
| titletext = The number one rule of string manipulation is that youâ€™ve got to specify your encodings.
}}

==Explanation==

This comic details an important issue in communication: even if the content of your message goes through, there might be important context that is necessary to correctly interpret it.

Communication is a way to convey ideas, and Cueball is explaining a concept of communication he calls a "Sandwich Helix". However, when pressed on what that is, he says nobody knows — indicating that, over the years, communication has failed to retain the meaning of this supposedly very important concept. The humor is that if this truly was the #1 rule of communication, communication should have been able to retain its meaning. On the basis that the number #1 rule about communication would probably be the ''most'' important rule, it might even be construed to be the rule about properly communicating all context (by some apparent analogy), which would be irony — but only if anyone still understood it.

The comic also displays the difference between meaning and message. Cueball is parroting a message (possibly a cliche repeated by self-help authors and influencers), even though the meaning is lost.

The fictitious "Sandwich Helix" plays on another concept in communication, the "{{w|Compliment sandwich|Compliment Sandwich}}" (a.k.a. "Shit Sandwich"), wherein a statement of criticism is sandwiched between two complimentary statements in order to make the negative statement easier to accept. The difference is that the Compliment Sandwich is a communication technique which is well known and whose meaning has not been lost (though it is currently disputed whether the technique is effective or whether it even might accomplish the inverse of its goals). A possible inspiration for the "helix" part is the {{w|Models of communication#Dance|Helical Model of Communication}}. The creator of the model, Frank Dance, emphasised the role of communication problems. He shows communication as a dynamic and non-linear process.

The title text contains several odd-looking characters that seem random (but are actually meaningful, to those familiar with them) where an apostrophe should be, as an example of a string that did NOT have its encoding handled properly. It is an example of {{w|Mojibake}}. Some special characters and symbols require a special {{w|Character encoding|encoding}} (such as UTF-8, Windows-1252, Shift-JIS, etc) in order to be stored and displayed properly, and are encoded using the equivalent of multiple characters. If the code to display the text doesn't understand what encoding was used and assumes a different/lesser level of encoding, you can get "garbage" similar to what is in the title text. In this case, the original character was probably <code>’</code>, which when encoded in UTF-8 and decoded in Windows-1252 becomes <code>â€™</code>. Similar garbage is seen in the title text of [[1683: Digital Data]].

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

:[Cueball, with his palm out, is standing in front of a class and facing Ponytail and Hairy, who are sitting at their classroom desks.]
:Cueball: Always remember the #1 rule of communication:
:Cueball: ''Sandwich Helix.''
:Ponytail: What does that mean?
:Cueball: Unfortunately, the context has been lost.
:Cueball: But we know the message, and that's the important part.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring Hairy]]
[[Category:Unicode]]
[[Category:Language]]

225: Open Source

2024-11-21T22:13:08Z

The-Ergster:

{{comic
| number = 225
| date = February 19, 2007
| title = Open Source
| image = open source.png
| titletext = Later we'll dress up like Big Oil thugs and jump Ralph Nader.
}}

==Explanation==
[[Richard Stallman]], or ''rms'' after his handle, is an old-school hacker known for establishing the {{w|Free Software Foundation}} (FSF) and initiating the {{w|GNU Project}} in the early 1980s, which produced major portions of what would later be the {{w|Linux|GNU/Linux}}<ref>https://itsfoss.com/gnu-linux-copypasta/</ref> operating system. In this capacity, he's also known for being one of the most ardent and outspoken proponents of {{w|open source software}}, often referred to by Stallman as {{w|free software}}. In fact, his advocacy is so emphatic and polemical that he has garnered active dislike from traditionalists who believe that software {{w|source code}} should be retained as a trade secret by its developer(s). Stallman has expressed that he did not even wish to be in a comic using the phrase '''Open Source''' (see the [[#Trivia|trivia section]]).

While this dislike may not rise to the level of hiring {{w|ninja}} assassins to remove him from the world though that is historically inaccurate, it is strong. The joke of the comic, as it also turns out, is that the two [[Cueball]]s dressed up as ninjas were just out to have a fun time teasing Stallman, and they seemed to know that Stallman's paranoia about {{w|Microsoft}} makes him sleep with no fewer than two {{w|katana}} swords near his bed. This type of sword was one of the traditionally made Japanese swords that were used by the {{w|samurai}} of feudal Japan mainly as a sidearm. A ninja or more accurately a Shinobi no mono was basically special forces in feudal Japan. They specialized in espionage, sabatoge, etc. they were a rough combination of MI6, CIA, and Navy SEAL in feudal japan. Although they did not specialize in assassinations, that is something that they could do. Although samurai could also be shinobi/ninjas if they chose to do that job, samurai is a social class while shinobi no mono/ninjas were a job, not a social class. So this makes sense in this comic with Stallman, the samurai, and the ninjas, the lackeys of the oppressing Microsoft (at least in his mind). It also turns out that they specifically choose targets for their raids who have reason to be paranoid of larger companies that might send someone after them, and thus sleep with weapons near their beds. Stallman has received a Katana due to this comic (see the [[#Trivia|trivia]] section).

{{w|GPL}} refers to the 'GNU General Public License', which is a copyright license written by the FSF that covers much GNU software and plenty of other free software besides. It stipulates that software so copyrighted must always be provided along with full source code, and that everyone in possession of such software is free to use, study, modify, and redistribute it for any purpose whatsoever (including sale or resale), provided they give due credit to any other contributing developers and provide access to the complete source code and retain all copyright notices.

Legally, this gives all users of such software exactly the same rights under copyright as the developer(s) and prevents any developers from ever taking away those rights from users, which is the defining feature of '{{w|Free software#Definition|free-as-in-libre}}' software. It also has the effect of making all software ''derived'' from GPL software thereby also GPL, even if 'derived' merely means 'borrowed a few lines of code from'. Some (e.g. Microsoft's {{w|Steve Ballmer}}) have therefore argued that this makes GPL software behave as a kind of {{w|viral license|'license virus'}}, which spreads GPL-guaranteed freedoms to any software used in close conjunction with GPL'd software during development, such that businesses should actively avoid adopting {{w|FOSS|free and open source software}}, so as not to jeopardize software developers' legal standing with regard to {{w|proprietary software|proprietary IP copyright}}s.

During the attack, Richard Stallman begins to speak like he quotes an old play. For instance, the wording "For a GNU dawn!" is pronounced "For a g'new dawn!", following the pronunciation of {{w|GNU}}, so it is a version of ''New Dawn'', a sentence used often in fiction. He even gets annoyed when it turns out that the ninjas just run away. He had clearly waited a long time to, even looking forward to, defending himself with his katanas.

Because the two "ninjas" had so much fun pranking Stallman, they plan to do more of these raids, even mentioning two other possible future targets on their way out of the window:

{{w|Eric S. Raymond}} is a famous {{w|Hacker (programmer subculture)|hacker}} who wrote ''{{w|The Cathedral and the Bazaar}}'' and has been something of an unofficial spokesperson for open source as a {{w|Open-source software development|software development methodology}}. The plan to prank Eric Raymond could be a bad one, since he is an experienced martial artist, swordsman, and firearm enthusiast. However, this seems to be the attraction of these two "ninjas," as can be seen by what they seem to know about their other possible target:

{{w|Linus Torvalds}} is the creator of {{w|Linux kernel|Linux}}, a free/open source operating system kernel inspired by the {{w|Unix}} kernel, which proved to be the final component that, combined with then pre-existing GNU system functions and {{w|userland}} components, produced the first fully free operating system, {{w|Linux|GNU/Linux}}. The plan to prank Torvalds would at first sound more boring as the mild-mannered {{w|Finland|Finn}}, while known to be strongly, abrasively opinionated, is otherwise mostly harmless. However, one of the ninjas seems to know otherwise, since it is rumored that Linus sleeps with {{w|nunchaku|nunchucks}} in the same way that Stallman sleeps with two katana swords. The ''nunchaku'' is a traditional Okinawan martial arts weapon consisting of two sticks connected at one end by a short chain or rope.

A third possible target of this prank is mentioned in the title text. {{w|Ralph Nader}} is a famous consumer rights advocate, most famous for {{w|Ralph Nader presidential campaign, 2000|his controversial 2000 presidential run}}, and the 1965 book ''{{w|Unsafe at Any Speed}}''. Nader is an environmentalist and a member of the Green Party, and he supports clean energy, thus naturally being opposed to "Big Oil" companies.

==Transcript==
:[The first panel has the second panel inside it. It also has a slightly light gray background color. Just above the inlaid second panel is Richard Stallman lying in his bed sleeping, the bottom part at the foot of the bed hidden behind the second panel below. Below his bed under his head lies a katana sword in its sheath, and another one hangs in its sheath behind the end of the bed. Two ninjas with swords and black cloths around their heads jump through the skylight, smashing it so glass scatters around them. Each of them is hanging one-handed from the same rope coming down from the skylight. The rope ends just above the inlaid frame below. The two ninjas shout at Richard Stallman, from four speech bubbles that have pointy ends to indicate how the two alternately speak. (These bubbles are white, not gray.)]
:Richard Stallman: ''Zzzz''
:Top Ninja: Richard Stallman! Your viral open source licenses have grown too powerful.
:Bottom Ninja: The GPL must be stopped.
:Top Ninja: At the source.
:Bottom Ninja: You.

:[In the second inlaid panel (with normal white background), Richard Stallman wakes up immediately, and while sitting up in bed, he pulls out both his katana swords from their sheaths, leaving the sheaths under and behind the bed. One hand is up in the air with the sword from behind the bed, and the other is still pointing down with the swords from below the bed. Lines indicate the fast movement of the swords. His three speech bubbles are like those of the ninjas, the last two even breaking the panel entering into the large first panel.]
:Katana swords: Shing! Shing!
:Richard Stallman: Hah! Microsoft lackeys! So it has come to this!
:Richard Stallman: A night of blood I've long awaited. But be this my death or yours, free software will carry on! For a GNU dawn! For freedom!
:Richard Stallman: ...Hey, where are you going?

:[An outside scene at night with black sky. Richard Stallman's gray house can be seen with the broken white skylight on the roof. The ninjas are jumping out of a window at ground height while taking off their ninja cloth around their heads, holding them in their hand, thus revealing that they both look like Cueball. The first one is already on the grassy ground beneath the window, his sword pointing down and to the left; the other just jumps from the window pane, his sword pointing up and to the right. Again, they have speech bubbles like before. It is not possible to tell which of the two ninjas from before is first out the window.]
:Ninja in window: Man, you're right, that never gets old.
:Ninja on the grass: Let's do Eric S. Raymond next.
:Ninja in window: Or Linus Torvalds. I hear he sleeps with nunchucks.

==Trivia==
*The phrase "So it has come to this" is the title of [[1022: So It Has Come To This]].
*In [[1624: 2016]], [[Cueball]] smashes through the ceiling, also hanging on a rope, to wake a person in a bed. Not as a threat though, but still a very similar situation.
*In the title text of [[163: Donald Knuth]], [[Black Hat]] reveals that he broke into [[Donald Knuth]]'s house through the skylight as well.
*Because of this comic, Stallman has [http://blog.xkcd.com/2007/04/19/life-imitates-xkcd-part-ii-richard-stallman/ been given a katana] by fans of xkcd.
*At his [https://www.youtube.com/watch?v=AHp_Vh9TESU&t=1645 talk at JCCC3] (as well as in a note in ''[[xkcd: volume 0]]''), [[Randall]] mentioned that the comic he originally published had the assassins say "free software," and Richard Stallman says "open source software." He swapped the two terms after complaints that Richard Stallman was [https://www.gnu.org/philosophy/open-source-misses-the-point.html opposed to the phrase "open source."] Even after this change, he got an e-mail from Stallman himself saying that he didn't even want to be portrayed in the same comic as the words "open source." The full note in volume 0 is:
{{quote|Originally, I had the phrases "open source" and "free software" reversed here, but a flood of 1:00 AM letters told me Stallman notoriously hates the term "open source" and would never use it. The comic title was "Open Source" and I couldn't change that, so I just switched who said what and went back to sleep. Only one person wrote in post-change to complain about "Open Source" still being used in the title - Stallman himself}}
:*Stallman's well-known opposition to the term "open source" stems from the fact that "open source" refers specifically to a methodology for software development involving allowing customers to actively participate in development and testing of software products by giving them access to in-development source code and soliciting feedback; as such, the term was first adopted as a means to promote free software ideas to business interests. In contrast, Stallman and the FSF view free software as a political issue concerning the basic freedoms that should belong to all computer users, and thus 'open source' as an appeal to software businesses misses the point of getting individuals to think about their rights as users.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Richard Stallman]]
[[Category:Comics featuring real people]]
[[Category:Multiple Cueballs]]
[[Category:Computers]]
[[Category:Comics edited after their publication]]

3014: Arizona Chess

2024-11-21T22:10:50Z

The-Ergster:

{{comic
| number = 3014
| date = November 20, 2024
| title = Arizona Chess
| image = arizona_chess_2x.png
| imagesize = 740x315px
| noexpand = true
| titletext = Sometimes, you have to sacrifice pieces to gain the advantage. Sometimes, to advance ... you have to fall back.
}}

==Explanation==

[[White Hat]] and [[Cueball]] are playing a timed game of tournament-style chess. At the start of the comic White Hat has the advantage because, as well as having one more pawn than Cueball, he has more time left to play his remaining moves — 6 minutes and 35 seconds, versus Cueball's 28 seconds, as shown on the {{w|chess clock}} display above them.

However, Cueball has an unexpected advantage. The building is sited across the border of Arizona with another state, with White Hat on the Arizona side, and the game is being played at a very particular time of year, when (most of) the United States exits {{w|Daylight Saving Time}}, which happens at 2:00 AM on the morning of the first Sunday in November. As Arizona doesn't observe Daylight Saving Time (DST), unlike neighboring US states, only one clock gains an hour. White Hat's time remains normal, but Cueball's time "falls back" one hour, as his departure from daylight saving time occurs, giving him 60 additional minutes of play time. White Hat immediately protests, likely trying to communicate that such is not how chess clocks work. Chess clocks are simple timers, tracking how much time each player has used since the beginning of the match. They're not based on local time, and changing the time remaining during play would certainly be a violation of the rules. Even clocks that do track local time are generally not so carefully calibrated that they would reliably switch times so close to a state line.

Cueball ignores these protests, and now seems confident of victory, since he has far more play time remaining. Daylight Slaying Time is a pun on Daylight Saving Time, but note that the comic takes place as the non-Arizona clock stops observing DST and joins the Arizona clock in Standard Time.

The title text makes use of a pun. To "fall back" in a strategic sense means to withdraw from an attack, or even to retreat. This can be part of a valid strategy, as withdrawing from an engagement can allow you to press the attack elsewhere, at a more advantageous time and place, or can draw enemy forces into an attack under circumstances that you control. [https://www.timeanddate.com/time/dst/spring-forward-fall-back.html "Spring forward, fall back"] is a mnemonic used for daylight saving time; we advance the clock forward when entering DST in the spring, and move it backward when leaving it in the fall (autumn).

There are buildings in the US that are built across state lines (and county and city boundaries), and even some buildings that extend across international boundaries (these are known as {{w|line house}}s). The existence of these buildings can result in eccentric situations when laws and ordinances vary substantially between the locations. For example, a casino might be built on a state border where gambling is legal in one state but illegal in the other. In such a case, the gaming can only happen on one side of the building (the other side being reserved for other services and functions). It's not uncommon for businesses and tourist attractions to lean into the novelty of this by demarking the boundary inside the building and specifically encouraging things that are legal only on one side of the line. Such situations are likely the inspiration for this strip, but using such a line to manipulate a competition based on time zone is highly unlikely.

Ongoing state-level efforts to end time changes could also increase the number of places where this situation could happen, as more DST/non-DST boundaries arise.

The comic was published five days before the start of the {{w|World Chess Championship 2024}} in Singapore.

==Transcript==

:[White Hat and Cueball are sitting across from each other playing chess. The time, shown above them in white on a black screen, reads 6:35 for White Hat, and 0:28 for Cueball.]
:White Hat: It’s late, I’m up a pawn, and you’re out of time. It’s over.
:Cueball: Ah, you’re forgetting something.

:[Cueball gestures with one hand above the chessboard. His time now reads 0:19.]
:Cueball: Did you know this building straddles the Arizona border?
:Cueball: It actually runs right through the table. You're on the Arizona side.

:[Cueball raises his hand further to gesture at his time. It beeps and is now blank and white.]
:Cueball: This tournament started Saturday, November 2nd. Now it's almost 2AM on the 3rd.
:Cueball: And there's something you should know about Arizona.
:Chess clock: BEEP

:[White Hat raises his head slightly to look at the timer. Cueball's time now reads 60:07. Cueball lowers his hand to make a move.]
:White Hat: '''''What?!''''' No! That's not how... '''''No!!'''''
:Cueball: Looks like it's daylight '''''slaying''''' time.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring White Hat]]
[[Category:Chess]]
[[Category:Daylight saving time]]

3001: Temperature Scales

2024-11-19T20:34:31Z

The-Ergster:

{{comic
| number = 3001
| date = October 21, 2024
| title = Temperature Scales
| image = temperature_scales_2x.png
| imagesize = 740x535px
| noexpand = true
| titletext = In my new scale, °X, 0 is Earths' record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.
}}

==Explanation==

Since the invention of the {{w|thermometer}}, a number of different {{w|temperature}} scales have been proposed. In modern times, most of the world uses the 1745 {{w|Celsius}} scale for everyday temperature measurements. A small number of countries (the USA and {{w|Territories of the United States|its territories}}, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau) retain the {{w|Imperial units|imperial system}} (or the related {{w|United States customary units|US customary system}}), which uses the 1724 {{w|Fahrenheit}} scale. The other widely used temperature scale is the 1848 {{w|Kelvin}} scale, which uses the same degrees as Celsius, but is rooted at {{w|absolute zero}}, making it both useful in scientific calculations and easy to convert to and from Celsius (which, along with degrees Fahrenheit, is now defined relative to kelvins.) The Kelvin scale has been part of the widely adopted official {{w|metric system}} since 1954. Even in countries that use Fahrenheit, scientific measurements are usually made in degrees Celsius or kelvins.

The comic compares these scales, and a number of others, on [[Randall]]'s scale of "cursedness." The joke is highlighting how different the temperature scales are, and how impractical most of them are. All of the listed scales (except Randall's new °X scale defined in the title text) are real, but most are obsolete. Please see also [[1923: Felsius]], a combination of degrees Fahrenheit and Celsius.

{| class=wikitable
! scope="col" | Unit
! scope="col" | Water freezes
! scope="col" | Water boils
! scope="col" | Notes
! scope="col" | Cursedness
! scope="col" | Explanation
|-
| {{w|Celsius}} || 0 || 100 || Used in most of the world || 2/10 || The Celsius (°C) scale, also known as "centigrade", was devised by Swedish astronomer {{w|Anders Celsius}} in 1742 and revised in 1745, a year after his death. 0°C represents the freezing point of water and 100°C represents the boiling point, both under {{w|standard atmospheric pressure}}. The Celsius scale is now defined in terms of kelvin. By the given "cursedness," it is regarded as one of the least problematic temperature scales.
|-
| {{w|Kelvin}} || 273.15 || 373.15 || 0K is absolute zero || 2/10 || Kelvins (plural with a lowercase 'k' as a temperature unit, like meters, ohms, watts, and amps; or as the symbol 'K', without the degrees symbol '°', unlike most other such units) are a unit of temperature devised by {{w|Lord Kelvin}} in 1848. They use the same degrees as Celsius do, but shifted by 273.15 to set absolute zero at 0K (based on the {{w|Boltzmann constant}}.)
<center>Celsius = kelvin – 273.15.</center>
<center>kelvin = Celsius + 273.15.</center>
While kelvins are very useful for calculations in {{w|thermodynamics}} and material physics, they can be unintuitive to laypersons.
|-
| {{w|Fahrenheit}} || 32 || 212 || Outdoors in most places is between 0–100 || 3/10 || Fahrenheit (°F) is officially used in a few countries and informally in several others. It originated in a time when factors of 360 were favored in science over powers of ten, which is why the freezing and boiling points of water are set 180° apart. Devised around 1724, {{w|Daniel Fahrenheit}} chose not to base 0° on the freezing point of water, instead originally setting it at the coldest temperature he could achieve: the freezing point of an {{w|ammonium chloride}} {{w|brine}} solution.
<center>Celsius = (Fahrenheit – 32) × 5/9.</center>
<center>Fahrenheit = Celsius × 9/5 + 32.</center>
Although those reference points are now considered arbitrary and outdated by modern scholars the scale gained popularity in Anglophone countries, and - as Randall notes - some retroactive justification coined that claims 0°F to 100°F as covering the entire range of temperatures humans would encounter in daily life. 100°F is {{w|Human body temperature#Historical understanding|close to normal human body temperature}} (the original intent was to set 90°F as exactly this, 90 being a quarter of 360). The Fahrenheit scale remains officially used only in the U.S., its territories, the Bahamas, Belize, the Cayman Islands, Liberia and Palau.
|-
| {{w|Réaumur scale|Réaumur}} || 0 || 80 || Like Celsius, but with 80 instead of 100 || 3/8 || Abbreviated as °Ré, this system devised by {{w|René Antoine Ferchault de Réaumur}} in 1730 was used in some places until the early 20th century, mostly for cheese-making.
<center>Celsius = Réaumur / 0.8.</center>
<center>Réaumur = Celsius × 0.8.</center>
The rating (3/8) is a joke on the boiling point of water in this system being 80 instead of 100 as it is in the Celsius scale; converting this to an out-of-ten scale would give 3.75/10, labeling it as more cursed than Fahrenheit but less so than Rømer.
|-
| {{w|Rømer scale|Rømer}} || 7.5 || 60 || Fahrenheit precursor with similarly random design || 4/10 || Abbreviated as °Rø, this scale was created by the Danish astronomer {{w|Ole Rømer}} around 1702. Much like Fahrenheit, it originally used the freezing point of ammonium chloride brine as the benchmark for 0°, and the scale is built with factors of 360 in mind with the boiling point of pure water at 60°. Like the Fahrenheit scale, the freezing point of pure water was not originally considered significant by Rømer, but the scale was later updated to give the value of 7.5 at this point.
<center>Celsius = (Rømer – 7.5) × 40/21.</center>
<center>Rømer = Celsius × 21/40 + 7.5.</center>
The Rømer scale is considered the predecessor of both the Celsius and Fahrenheit scales, because Réaumur was inspired by Rømer's scale, Celsius based his work on Réaumur and Fahrenheit specifically designed his scale with more divisions than Rømer's to reduce the necessity for fractions.
|-
| {{w|Rankine scale|Rankine}} || 491.7 || 671.7 || Fahrenheit, but with 0°F [''sic;'' should be 0°Ra] set to absolute zero || 6/10 || The Rankine scale (°R or °Ra), created by {{w|William Rankine}} in 1859, is to Fahrenheit what the Kelvin scale is to Celsius: an absolute temperature scale. The scale is mostly obsolete, but is still occasionally used in legacy industrial operations where absolute temperature scales are required. It is described as more cursed than the otherwise identical Fahrenheit scale, despite being rooted at a more universal zero point.
<center>Celsius = (Rankine – 491.67) × 5/9.</center>
<center>Rankine = (Celsius + 273.15) × 9/5.</center>
Another comic, [[2292: Thermometer]], expresses disdain for this scale.
|-
| {{w|Newton scale|Newton}} || 0 || 33-ish || Poorly defined, with reference points like "the hottest water you can hold your hand in"{{acn}} || 7-ish/10 || The famous scientist and mathematician {{w|Isaac Newton}} published this scale in 1701, which was referred to by the the °N symbol. Sadly, the degrees of temperature specified do not correlate exactly with amounts of {{w|heat}} because his scale is nonlinear. His scale used three fixed-points: 0ºN, the temperature of air when water begins to freeze, 12ºN, the heat of blood in the human body, 34ºN, rapidly boiling water.[https://www.whipplemuseum.cam.ac.uk/explore-whipple-collections/meteorology/early-thermometers-and-temperature-scales] Therefore:
<center>Celsius = 37 × Newton / 12 if Newton ≤ 12; or 63 × (Newton – 12) / 22 + 37 if Newton > 12.</center>
<center>Newton = 12 × Celsius / 37 if Celsius ≤ 37; or 22 × (Celsius – 37) / 63 + 12 if Celsius > 37.</center>
Very few scientists other than Newton ever used this scale,{{citation needed}} but it did appear on commercial thermometers around 1758.[https://www.scienceandsociety.co.uk/results.asp?image=10413117&wwwflag=&imagepos=43] The cursedness rating (7-ish/10) is a joke about the vagueness of the scale's definition.
|-
| {{w|Wedgwood scale|Wedgwood}} || –8 || –6.7 || Intended for comparing the melting points of metals, all of which it was very wrong about || 9/10 || Created by the potter {{w|Josiah Wedgwood}} in 1782, the '°W' scale was based on the shrinking of clay when heated above red heat, but was found to be very inconsistent.
<center>Celsius = (Wedgwood + 8) × 100/1.3.</center>
<center>Wedgwood = (Celsius × 1.3/100) – 8.</center>
The comic has a typo, as the scale is called Wedgwood, without the second 'e'.
|-
| Galen || –4? || 4?? || Runs from –4 (cold) to 4 (hot). 0 is "normal"(?) || 4/–4 || The Greek physician {{w|Galen}} suggested a "neutral" temperature around 180 A.D.,[https://www.loebclassics.com/view/galen-temperaments/2020/pb_LCL546.3.xml] when he was a prominent physician in the {{w|Roman Empire}}. Created by mixing equal parts of boiling water and ice, on either side of this neutral point he described four degrees of heat and four degrees of cold. Assuming his extremes were those points, Galen's scale is also nonlinear:
<center>Celsius = 22 × (Galen + 4) / 4 if Galen ≤ 0; or 78 × Galen / 4 + 22 if Galen > 0.</center>
<center>Galen = 4 × Celsius / 22 – 4 if Celsius ≤ 22; or 4 × (Celsius – 22) / 78 if Celsius > 22.</center>
This range from +4 to –4 is humorously used as its rating, implying –100% cursedness. Technically this makes it the least cursed of all the listed scales, but the idea of negative cursedness, and cursedness itself, is not clear. There is no standard modern abbreviation for Galen's scale.
|-
| {{w|Celsius#History|''Real'' Celsius}} || 100 || 0 || In Anders Celsius's original 1742 specification, bigger numbers are ''colder''; others later flipped it || 10/0 || Most scales' temperatures can be indefinitely large, but have an absolute minimum temperature. By starting at a maximum value and counting down, this scale is indeed cursed, as nearly all possible temperatures through 1.42×1032K, the maximum attainable physical temperature,[https://doi.org/10.4236/jamp.2024.1210198] will be negative on this scale. The cursedness rating (10/0) is a joke on the scale "flipping" the fixed points of modern Celsius. Division by zero is strictly undefined (see [[2295: Garbage Math]]) and may be interpreted in a number of counter-intuitive ways.
<center>Celsius = 100 – real_Celsius.</center>
<center>real_Celsius = 100 – Celsius.</center>
The original logic was that zero could be easily calibrated to the height of a {{w|Millimetre of mercury|column of mercury}} at the temperature of boiling water, and further measurements then made of the amount it ''reduced'' in height under cooler conditions. This orientation survives in the historic {{w|Delisle scale}} devised in 1732 by French astronomer {{w|Joseph-Nicolas Delisle}}, which arguably inspired the Celsius scale. The scale originally used by Professor Celsius was changed, to more or less the form already described above, after his death in 1745. Delisle's scale was never reversed.
|-
| [https://physics.stackexchange.com/questions/459851/john-daltons-temperature-scale#459863 Dalton] || 0 || 100 || A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton || 53.9/50 || {{w|John Dalton}} proposed a logarithmic temperature scale in 1802 during his work on what became {{w|Charles's Law}}. The scale is defined so that absolute zero is at negative infinity, with the exponent chosen to match the Celsius scale at 0 and 100:
<center>Celsius = 273.15 × ''e''(Dalton / 320.55) – 273.15.</center>
<center>Dalton = 320.55 × {{w|Natural logarithm|''ln''(}} (Celsius + 273.15) / 273.15 ).</center>
There is no standard abbreviation for Dalton's scale. While Dalton temperature is defined for all positive and negative numbers, the nonlinear scale is difficult to work with since the amount of heat represented by a change of one degree Dalton is not constant. Degrees Dalton differ from Celsius ones by as much as 3.9 degrees between 0 and 100, but diverge much more for more extreme temperatures. The rating (53.9/50) is a joke about the unit, as 53.9 Dalton equates to 50 degrees Celsius — i.e., it could be said to be 107.8% (even more than entirely) cursed.
|-
| °X || 42.9 || 151.4 || '''Title text:''' "In my new scale, °X, 0 is Earths' [''sic''] record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed." || Randall has not stated the cursedness of his new scale. || The {{w|Lowest temperature recorded on Earth|record lowest surface temperature on Earth}} as of 2024 is –89.2°C (–128.6°F), recorded at the {{w|Vostok Station|Vostok Research Station}} in Antarctica on July 21, 1983.[https://wmo.asu.edu/content/world-lowest-temperature] The average surface temperature as of 2023, the most recent available, is 14.8°C (58.6°F.)[https://climate.copernicus.eu/climate-indicators/temperature] The {{w|Highest temperature recorded on Earth|record highest temperature}} is 56.7°C (134.1°F), recorded on July 10, 1913 at {{w|Furnace Creek, California|Furnace Creek Ranch}} in Death Valley, California.[https://wmo.asu.edu/content/world-highest-temperature]

{{cot|Derivation and graph}}
To break the scale into two linear parts (below and above 14.8°C), we define two separate equations for each range:

1. Below 14.8°C (from –89.2°C to 14.8°C):
* 0 °X corresponds to –89.2°C
* 50 °X corresponds to 14.8°C

We calculate the slope m₁:

<center>m₁ = (50 – 0) / (14.8 – (–89.2)) = 50 / (14.8 + 89.2) = 50 / 104 ≈ 0.48</center>

Now, using the point (14.8°C, 50 °X), we calculate the intercept b₁:

<center>50 = 0.48 × 14.8 + b₁</center>

<center>50 = 7.1 + b₁</center>

<center>b₁ = 50 – 7.1 = 42.9</center>

Thus, the equation for temperatures '''below 14.8°C''' is:

<center>'''X = 0.48 × C + 42.9'''</center>

2. Above 14.8°C (from 14.8°C to 56.7°C):
* 50 °X corresponds to 14.8°C
* 100 °X corresponds to 56.7°C

We calculate the slope m₂:

<center>m₂ = (100 – 50) / (56.7 – 14.8) = 50 / 41.9 ≈ 1.19</center>

Now, using the point (14.8°C, 50 °X), we calculate the intercept b₂:

<center>50 = 1.19 × 14.8 + b₂</center>

<center>50 = 17.6 + b₂</center>

<center>b₂ = 50 – 17.6 = 32.4</center>

Thus, the equation for temperatures '''above 14.8°C''' is:

<center>'''X = 1.19 × C + 32.4'''</center>

;Freezing and boiling points of water

Freezing point of water (0°C): Since 0°C is below 14.8°C, we use the equation X = 0.48 × C + 42.9:

<center>X = 0.48 × 0 + 42.9 = 42.9</center>

So, '''the freezing point is 42.9 °X.'''

Boiling point of water (100°C): Since 100°C is above 14.8°C, we use the equation X = 1.19 × C + 32.4:

<center>X = 1.19 × 100 + 32.4 = 119 + 32.4 = 151.4</center>

So, '''the boiling point is 151.4 °X.'''

[[File:XvsC.png|400px|center]]

See also [[2701: Change in Slope]] for a general discussion of separate linear scales between three points.
{{cob}}
<center>Celsius = (°X – 42.9) / 0.48 if °X < 50; or (°X – 32.4) / 1.19 if °X ≥ 50.</center>
<center>°X = 0.48 × Celsius + 42.9 if Celsius < 14.8; or 1.19 × Celsius + 32.4 if Celsius ≥ 14.8.</center>

Due to average temperature records increasing almost every year as a result of {{w|climate change}},[https://www.space.com/last-12-months-broke-temperature-records] Randall's new °X scale must be re-calibrated each year. While such °X values for everyday temperatures will vary over time, more extreme values like absolute zero or the {{w|Tungsten#Physical properties|melting point of tungsten}} will shift vastly more.

("Surface" temperatures are measured 1.5 meters above ground inside a shaded shelter, to accurately represent air temperature, because measurements closer to the ground are usually quite different due to sunlight, {{w|albedo}}, and the thermal capacity of soil.)
|}

[[File:Temperature Scales.png|center|600px]]

===Examples===

Here are some various temperatures in the above scales:

{| class=wikitable style="text-align: center;"
! Unit scale
! Typical {{w|room temperature}}
! {{w|Properties of water#Melting point|Freezing point of water}}
! {{w|Boiling point#Boiling point of water with elevation|Boiling point of water}}
! Midrange {{w|human body temperature|human body core temperature}}
! Recommended {{w|Refrigerator#Temperature zones and ratings|refrigerator temperature}}[https://www.realsimple.com/food-recipes/shopping-storing/food/refrigerator-temperature]
! Recommended {{w|Refrigerator#Freezer|freezer temperature}}[https://www.fsis.usda.gov/food-safety/safe-food-handling-and-preparation/food-safety-basics/freezing-and-food-safety]
! Typical warm bath temperature[https://www.kohlerwalkinbath.com/blog/everything-you-need-to-know-about-the-ideal-bath-temperature/]
! Typical {{w|Coffee#Brewing|hot coffee}} temperature
|-
| Celsius || 22 °C || 0 °C || 100 °C || 37 °C || 2.5 °C || –18 °C || 39 °C || 77 °C
|-
| Kelvin || 295 K || 273 K || 373 K || 310 K || 276 K || 255 K || 312 K || 350 K
|-
| Fahrenheit || 72 °F || 32 °F || 212 °F || 98.6 °F || 36.5 °F || 0 °F || 102 °F || 171 °F
|-
| Réaumur || 17.6 °Ré || 0 °Ré || 80 °Ré || 29.6 °Ré || 2 °Ré || –14.4 °Ré || 31.2 °Ré || 61.6 °Ré
|-
| Rømer || 19.1 °Rø || 7.5 °Rø || 60 °Rø || 26.9 °Rø || 8.8 °Rø || –2 °Rø || 28 °Rø || 47.9 °Rø
|-
| Rankine || 531 °Ra || 492 °Ra || 672 °Ra || 558 °Ra || 496 °Ra || 459 °Ra || 562 °Ra || 630 °Ra
|-
| Newton || 7.1 °N || 0 °N || 34 °N || 12 °N || 0.8 °N || –5.8 °N || 12.7 °N || 26 °N
|-
| Wedgwood || –7.71 °W || –8 °W || –6.7 °W || –7.52 °W || –7.97 °W || –8.23 °W || –7.49 °W || –7 °W
|-
| Galen || 0 || –4 || 4 || 0.8 || –3.5 || –7.3 || 0.9 || 2.8
|-
| ''Real'' Celsius || 78 || 100 || 0 || 63 || 98 || 118 || 61 || 23
|-
| Dalton || 24.8 || 0 || 100 || 40.7 || 2.9 || –21.9 || 42.8 || 79.6
|-
| °X || 59 °X || 43 °X || 151 °X || 76.4 °X || 44.1 °X || 34.3 °X || 78.8 °X || 124 °X
|-
| Felsius || 47 || 16 || 156 || 67.8 || 19.5 || –9.2 || 70.6 || 123.8
|}

Here are the conversion formulas for the [[1923: Felsius|Felsius scale from comic 1923]]:
<center>Celsius = (Felsius − 16) / 1.4.</center>
<center>Felsius = Celsius * 7/5 + 16.</center>

==Transcript==

:Temperature Scales

:[A table with five columns, labelled: Unit, Water freezing point, Water boiling point, Notes, and Cursedness. There are eleven rows below the labels.]

:[Row 1:] Celsius, 0, 100, Used in most of the world, 2/10
:[Row 2:] Kelvin, 273.15, 373.15, 0K is absolute zero, 2/10
:[Row 3:] Fahrenheit, 32, 212, Outdoors in most places is between 0–100, 3/10
:[Row 4:] Réaumur, 0, 80, Like Celsius, but with 80 instead of 100, 3/8
:[Row 5:] Rømer, 7.5, 60, Fahrenheit precursor with similarly random design, 4/10,
:[Row 6:] Rankine, 491.7, 671.7, Fahrenheit, but with 0°F set to absolute zero, 6/10
:[Row 7:] Newton, 0, 33-ish, Poorly defined, with reference points like "the hottest water you can hold your hand in", 7-ish/10
:[Row 8:] Wedgewood, –8, –6.7, Intended for comparing the melting points of metals, all of which it was very wrong about, 9/10
:[Row 9:] Galen, –4?, 4??, Runs from –4 (cold) to 4 (hot). 0 is "normal"(?), 4/–4
:[Row 10:] ''Real'' Celsius, 100, 0, In Anders Celsius's original specification, bigger numbers are ''colder''; others later flipped it, 10/0
:[Row 11:] Dalton, 0, 100, A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton, 53.9/50

{{comic discussion}}

[[Category:Charts]]
[[Category:Math]]
[[Category:Physics]]
[[Category:Science]]

Donald Trump

2024-11-19T20:34:05Z

The-Ergster:

{{Infobox character
| image = Donald Trump.jpeg
| imagesize = 200px
| caption = '
| first_appearance = [[980: Money]]
}}

<noinclude>:''For a list of comics, see [[:Category:Comics featuring Donald Trump|Comics featuring Donald Trump]].''</noinclude>

'''{{w}}''' is an American politician, media personality, and businessperson who served as the 45th {{w|president of the United States}} from 2017 to 2021 and will serve again from 2025 to 2029 as the 47th president. He won the 2016 election as a Republican with controversial policies. His presidency involved actions like travel bans, border wall funding, tax cuts, Supreme Court appointments, environmental deregulation, and strained international relations. After losing the 2020 election, he faced impeachments and legal issues, but continued political involvement. Amidst multiple indictments in 2023 he announced his candidacy for the 2024 election, which he won. During the 2024 presidential race Randall announced his support for trump's opponent, Kamala Harris.

{{incomplete|update due to current events}}

{{navbox-characters}}
[[Category:Characters]]
[[Category:Real people]]
[[Category:Politicians]]

Donald Trump

2024-11-19T20:33:48Z

The-Ergster:

{{Infobox character
| image = Donald Trump.jpeg
| imagesize = 200px
| caption = '
| first_appearance = [[980: Money]]
}}

<noinclude>:''For a list of comics, see [[:Category:Comics featuring Donald Trump|Comics featuring Donald Trump]].''</noinclude>

'''{{w}}''' is an American politician, media personality, and businessperson who served as the 45th {{w|president of the United States}} from 2017 to 2021 and will serve again from 2025 to 2029 as the 47th president. He won the 2016 election as a Republican with controversial policies. His presidency involved actions like travel bans, border wall funding, tax cuts, Supreme Court appointments, environmental deregulation, and strained international relations. After losing the 2020 election, he faced impeachments and legal issues, but continued political involvement. Amidst multiple indictments in 2023 he announced his candidacy for the 2024 election, which he won. During the 2024 presidential race Randall announced his support for trump's opponent, Kamala Harris.

{{incomplete|update}}

{{navbox-characters}}
[[Category:Characters]]
[[Category:Real people]]
[[Category:Politicians]]

Donald Trump

2024-11-19T20:33:30Z

The-Ergster:

{{Infobox character
| image = Donald Trump.jpeg
| imagesize = 200px
| caption = '
| first_appearance = [[980: Money]]
}}

<noinclude>:''For a list of comics, see [[:Category:Comics featuring Donald Trump|Comics featuring Donald Trump]].''</noinclude>

'''{{w}}''' is an American politician, media personality, and businessperson who served as the 45th {{w|president of the United States}} from 2017 to 2021 and will serve again from 2025 to 2029 as the 47th president. He won the 2016 election as a Republican with controversial policies. His presidency involved actions like travel bans, border wall funding, tax cuts, Supreme Court appointments, environmental deregulation, and strained international relations. After losing the 2020 election, he faced impeachments and legal issues, but continued political involvement. Amidst multiple indictments in 2023 he announced his candidacy for the 2024 election, which he won. During the 2024 presidential race Randall announced his support for trumps opponent, Kamala Harris.

{{incomplete|update}}

{{navbox-characters}}
[[Category:Characters]]
[[Category:Real people]]
[[Category:Politicians]]

3008: Proterozoic Rocks

2024-11-19T20:32:10Z

The-Ergster:

{{comic
| number = 3008
| date = November 6, 2024
| title = Proterozoic Rocks
| image = proterozoic_rocks_2x.png
| imagesize = 740x272px
| noexpand = true
| titletext = These rocks are from a time before eyes, brains, and bones, pieces of a land warmed by an unseen sun.
}}

==Explanation==

{{w|Proterozoic eon}} rocks such as the 1.1 billion-year-old rocks in the comic were formed 2500 to 538.8 million years ago, some of them surviving {{w|plate tectonics|tectonic movements}} until today. Proterozoic rocks which were formed from sediment at the bottom of an inland sea such as the former {{w|Western Interior Seaway}} would be in North America today.

The first animal eyes are believed to have [https://www.pnas.org/doi/10.1073/pnas.1716824114 developed on trilobites] half a billion years ago, around the transition between the proterozoic and {{w|phanerozoic eon}}s at the start of the {{w|Cambrian}} period. This transition began a great proliferation of biological diversity known as the {{w|Cambrian explosion}}.

Cueball talks about feeling a connection to the rock, which spans "a vast abyss of time that stretches back as far as the eye can see." This could be interpreted as expressing the need to connect to something that exists vastly beyond the current turbulent era, to put it into perspective and to find strength in knowing that nature transcends human troubles. The title text extends this theme.

The distant past, before the emergence of complex eye-bearing life, is illustrated by the final panel in black. This indicates that Randall is showing what is perceived rather than what was physically present, as light existed and would have made the Earth's surface visible, had there been eyes to see it. The dark far past may also be an analogy for the darkened far future, as there may be [https://www.euronews.com/green/2023/09/26/triple-whammy-of-extreme-heat-scientists-pinpoint-when-earth-could-become-uninhabitable no human life on Earth in around 250 million years]. This timeline is far beyond the immediate cares of the current world, applying further perspective to present worldviews.

[[2013: Rock]] also compares the age of rocks to milestones in the development of life.

==Transcript==

:[Cueball is seen at a distance, walking amid a rocky landscape.]
:I love being near Proterozoic rocks.
:These ones are 1.1 billion years old.
:That's so, '''''so''''' old.

:[Cueball standing next to a rock.]
:Eyes evolved half a billion years ago. The first time a rock was ever looked at, these rocks were already 500 million years old.

:[Cueball sitting atop a large rock.]
:People say geologic time makes them feel small. But when I touch this rock, it's like I'm a part of it, spanning a vast abyss of time that stretches back as far as the eye can see.

:[A completely black panel except for text in white lettering.]
:And then 500 million years farther.

== Trivia ==

*This comic was published on the day when {{w|Donald Trump}}'s re-election as president of the USA was announced. Randall was vocal in his support for the opposing candidate {{w|Kamala Harris}}; the xkcd homepage featured [https://web.archive.org/web/20241106175959im_/https://imgs.xkcd.com/news/harris_news@2x.png a drawing with a "Vote for Harris" sign] [https://web.archive.org/web/20241106215812/https://xkcd.com/ during the run-up to the election]. The drawing remained in place through the remainder of the week, accompanying comic 3009.

*The use of "farther" in the final panel could be erroneous; {{wiktionary|further#Usage notes|for some}}, "further" is the preferred word for metaphorical usage (e.g. for stretches of time).

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Geology]]
[[Category:Biology]]
[[Category:Comics with inverted brightness]]

3008: Proterozoic Rocks

2024-11-19T20:31:53Z

The-Ergster:

{{comic
| number = 3008
| date = November 6, 2024
| title = Proterozoic Rocks
| image = proterozoic_rocks_2x.png
| imagesize = 740x272px
| noexpand = true
| titletext = These rocks are from a time before eyes, brains, and bones, pieces of a land warmed by an unseen sun.
}}

==Explanation==

{{w|Proterozoic eon}} rocks such as the 1.1 billion-year-old rocks in the comic were formed 2500 to 538.8 million years ago, some of them surviving {{w|plate tectonics|tectonic movements}} until today. Proterozoic rocks which were formed from sediment at the bottom of an inland sea such as the former {{w|Western Interior Seaway}} would be in North America today.

The first animal eyes are believed to have [https://www.pnas.org/doi/10.1073/pnas.1716824114 developed on trilobites] half a billion years ago, around the transition between the proterozoic and {{w|phanerozoic eon}}s at the start of the {{w|Cambrian}} period. This transition began a great proliferation of biological diversity known as the {{w|Cambrian explosion}}.

Cueball talks about feeling a connection to the rock, which spans "a vast abyss of time that stretches back as far as the eye can see." This could be interpreted as expressing the need to connect to something that exists vastly beyond the current turbulent era, to put it into perspective and to find strength in knowing that nature transcends human troubles. The title text extends this theme.

The distant past, before the emergence of complex eye-bearing life, is illustrated by the final panel in black. This indicates that Randall is showing what is perceived rather than what was physically present, as light existed and would have made the Earth's surface visible, had there been eyes to see it. The dark far past may also be an analogy for the darkened far future, as there may be [https://www.euronews.com/green/2023/09/26/triple-whammy-of-extreme-heat-scientists-pinpoint-when-earth-could-become-uninhabitable no human life on Earth in around 250 million years]. This timeline is far beyond the immediate cares of the current world, applying further perspective to present worldviews.

[[2013: Rock]] also compares the age of rocks to milestones in the development of life.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

:[Cueball is seen at a distance, walking amid a rocky landscape.]
:I love being near Proterozoic rocks.
:These ones are 1.1 billion years old.
:That's so, '''''so''''' old.

:[Cueball standing next to a rock.]
:Eyes evolved half a billion years ago. The first time a rock was ever looked at, these rocks were already 500 million years old.

:[Cueball sitting atop a large rock.]
:People say geologic time makes them feel small. But when I touch this rock, it's like I'm a part of it, spanning a vast abyss of time that stretches back as far as the eye can see.

:[A completely black panel except for text in white lettering.]
:And then 500 million years farther.

== Trivia ==

*This comic was published on the day when {{w|Donald Trump}}'s re-election as president of the USA was announced. Randall was vocal in his support for the opposing candidate {{w|Kamala Harris}}; the xkcd homepage featured [https://web.archive.org/web/20241106175959im_/https://imgs.xkcd.com/news/harris_news@2x.png a drawing with a "Vote for Harris" sign] [https://web.archive.org/web/20241106215812/https://xkcd.com/ during the run-up to the election]. The drawing remained in place through the remainder of the week, accompanying comic 3009.

*The use of "farther" in the final panel could be erroneous; {{wiktionary|further#Usage notes|for some}}, "further" is the preferred word for metaphorical usage (e.g. for stretches of time).

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Geology]]
[[Category:Biology]]
[[Category:Comics with inverted brightness]]

3012: The Future of Orion

2024-11-19T20:31:17Z

The-Ergster:

3012: The Future of Orion

2024-11-15T17:58:15Z

The-Ergster:

{{comic
| number = 3012
| date = November 15, 2024
| title = The Future of Orion
| image = the_future_of_orion_2x.png
| imagesize = 740x300px
| noexpand = true
| titletext = Dinosaur Cosmics
}}

==Explanation==
{{incomplete|Created by a GIANT SPACE DINOSAUR - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:Orion Today
:[Star map of Orion's belt 2024]
:
:Predicted Changes
:Scribbled on: Star movement
:Scribbled on: Star Death(Beatlejuice)
:[Star Map's predicted changes over next couple centuries]
:
:Orion in the future
:Scribbled on: Suggested lines
:[New lines are drawn overlaying the future changes]
:
:[[https://www.qwantz.com/ Dinosaur Comics] dinosaur overlayed]

{{comic discussion}}

3012: The Future of Orion

2024-11-15T17:57:05Z

The-Ergster: Transcript

{{comic
| number = 3012
| date = November 15, 2024
| title = The Future of Orion
| image = the_future_of_orion_2x.png
| imagesize = 740x300px
| noexpand = true
| titletext = Dinosaur Cosmics
}}

==Explanation==
{{incomplete|Created by a GIANT SPACE DINOSAUR - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:Orion Today
:[Star map of Orion's belt 2024]
:
:Predicted Changes
:(Star movement)
:(Star Death(Beatlejuice))
:[Star Map's predicted changes over next couple centuries]
:
:Orion in the future
:(Suggested Lines)
:[New lines are drawn overlaying the future changes
:
:[[https://www.qwantz.com/ Dinosaur Comics] dinosaur overlayed]

{{comic discussion}}

Donald Trump

2024-11-13T19:47:33Z

The-Ergster:

{{Infobox character
| image = Donald Trump.jpeg
| imagesize = 200px
| caption = '
| first_appearance = [[980: Money]]
}}

<noinclude>:''For a list of comics, see [[:Category:Comics featuring Donald Trump|Comics featuring Donald Trump]].''</noinclude>

'''{{w}}''' is an American politician, media personality, and businessperson who served as the 45th {{w|president of the United States}} from 2017 to 2021. He won the 2016 election as a Republican with controversial policies. His presidency involved actions like travel bans, border wall funding, tax cuts, Supreme Court appointments, environmental deregulation, and strained international relations. After losing the 2020 election, he faced impeachments and legal issues, but continued political involvement, including announcing his candidacy for the 2024 election amidst multiple indictments in 2023. Trump then won the 2024 election in one of the biggest landslides ever seen. Randall has mentioned his support for Kamala Harris and he is against trump.

{{navbox-characters}}
[[Category:Characters]]
[[Category:Real people]]
[[Category:Politicians]]

1176: Those Not Present

2024-11-12T12:52:03Z

The-Ergster:

{{comic
| number = 1176
| date = February 20, 2013
| title = Those Not Present
| image = those not present.png
| titletext = 'Yeah, that squid's a total asshole.' [scoot scoot]
}}

==Explanation==
[[Cueball]] (likely representing [[Randall]]), is sitting listening to a conversation with three other people. As the talk progresses, each member contributes gossip about a different group absent from the table, and talking mostly negatively about their qualities and goals. As Cueball notices this, he has decided to leave conversations deemed toxic, by scooting his chair a little bit more farther from the table any time somebody badmouths someone not present. In each panel, he scoots progressively further away, with the previous conversation diminishing as he moves, until he reaches another conversation with [[Megan]], [[Hairy]], and [[Beret Guy]], discussing a blurry video about {{w|giant squids}}. He asks to join them, as this conversation seems far more interesting to him than one criticizing people behind their backs.

The title text jokes that the second group, is, unfortunately, also criticising the giant squid. As the squid is not present, Cueball starts to scoot his chair even more, to hopefully find a non-toxic conversation somewhere else. It is unclear if he is moving to back to where he came from (as possibly the first group seem to be less toxic than the second), or even further onwards (to seek out a new and more palatable conversation).

==Transcript==
:Every time someone says something negative about a person who's not in the room, I scoot my chair back a few inches.
:[Cueball, Ponytail and two other people are sitting at a table drinking.]
:Person: ''He's'' not so bad, but his ''friends''...
:[Cueball scoots away from table.]
:''Scoot scoot''

:Ponytail: His band is never gonna take off if...
:[Cueball scoots further away.]
:''Scoot scoot''

:[Megan, Beret Guy, and Hairy come into view.]
:Off-screen: Yeah, his sister is even ''weirder''.
:Off-screen: Did you see she had...
:''Scoot scoot''
:Beret Guy: ...and there's a video, but it's blurry...

:[Cueball turns around and leans his arm on his chair.]
:Cueball: What're you talking about?
:Hairy: Giant squid!
:Cueball: Mind if I join you?

==Trivia==
*In the first panel, the word "friends" was originally misspelled as "frends".

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring Hairy]]
[[Category:Comics featuring Beret Guy]]
[[Category:Multiple Cueballs]]

3007: Probabilistic Uncertainty

2024-11-08T18:08:31Z

The-Ergster:

{{comic
| number = 3007
| date = November 4, 2024
| title = Probabilistic Uncertainty
| image = probabilistic_uncertainty_2x.png
| imagesize = 474x385px
| noexpand = true
| titletext = "One popular strategy is to enter an emotional spiral. Could that be the right approach? We contacted several researchers who are experts in emotional spirals to ask them, but none of them were in a state to speak with us."
}}

==Explanation==
This comic is about the difficulty of dealing psychologically with 50/50 odds, and is likely inspired by the {{W|2024 United States presidential election}}, as this comic was released the day prior. The odds of the election as reported by many media sources were close to 50/50 <ref>https://www.270towin.com/2024-presidential-election-polls/</ref> <ref>https://www.nytimes.com/interactive/2024/us/elections/polls-president.html</ref> <ref>https://projects.fivethirtyeight.com/polls/president-general/2024/national/</ref>, where the pre-election polls show roughly a 50/50 chance of either {{w|Kamala Harris}} or {{w|Donald Trump}} being elected. It seems more and more people suffer from pre-election anxiety <ref>https://www.cnet.com/health/mental/stressed-about-election-day-9-expert-approved-protect-your-mental-health/</ref> <ref>https://www.cbsnews.com/news/election-2024-stress-anxiety-tips-experts/</ref> <ref>https://jedfoundation.org/resource/election-stress-tips-to-manage-anxious-feelings-about-politics/</ref> <ref>https://fortune.com/well/article/election-anxiety/</ref> <ref>https://www.nytimes.com/2024/11/04/us/politics/election-anxiety.html</ref> and the uncertainty of the results doesn't help.
This 50/50 scenario is the third scenario shown in the comic.

Further, with regards to N/A - the odds of "precisely" 50/50 are probabilistically zero, unless the event under consideration is something relatively trivial such as a coinflip or die roll (and even with those it is extremely unlikely the coins or dice are perfectly "fair"). Any scenario that involves social sciences, such as an election (or even a single relationship) will never be precisely 50/50 (or, indeed, *any* discrete value).

{| class="wikitable"
!Odds
!How to think about it in an emotionally healthy way
!Explanation
|-
| Good outcome more likely || Recognize that the bad outcome is possible, but be reassured that the odds are in your favor || An optimistic attitude with a dose of realism.
|-
| Bad outcome more likely || Prepare for the bad outcome while remembering that the future isn't certain and hope is justified || A realistic attitude with a dose of optimism.
|-
| Precisely 50/50 || ????? N/A ???? || {{w|N/A}} stands for "not available", "no answer", "not applicable" or "not assessed". The actual worst case scenario, with no single obvious stance to take. (Thus also leaving ambiguous which fall-back position one should prepare to hold in reserve.)
|}

When facing a situation with equal odds of a positive or negative outcome, it is possible to prepare emotionally for either result. Here are some strategies to consider:

;Acknowledge and accept uncertainty
:Recognize that uncertainty is a natural part of life. By accepting that you cannot control the outcome, you can reduce anxiety and focus on what you can manage—your response.

;Practice {{w|defensive pessimism}}
:This strategy involves setting low expectations and contemplating potential negative outcomes. By doing so, you can prepare yourself to handle setbacks and reduce anxiety. Research indicates that defensive pessimism can be an effective way to manage stress and improve performance.

;Develop {{w|coping}} mechanisms
:Equip yourself with strategies to manage emotions regardless of the outcome. Techniques such as mindfulness, deep breathing, and positive self-talk can help maintain emotional balance.

;Focus on what you can control
:Concentrate on aspects within your control, such as your effort, preparation, and attitude. This focus can empower you and reduce feelings of helplessness.

;Set realistic expectations
:Understand that both success and failure are possibilities. By setting realistic expectations, you can mitigate disappointment and appreciate positive outcomes more fully.

;Seek support
:Discuss your feelings and concerns with trusted friends, family, or a mental health professional. Sharing your thoughts can provide relief and offer new perspectives.

By practicing those strategies, you may prepare yourself emotionally to handle either outcome with resilience and composure.

The title text is a joke making use of ambiguous wording: "researchers who are experts in emotional spirals" could either refer to researchers who study emotional spirals, or researchers who are undergoing emotional spirals themselves. Evidently, all the researchers "we" contacted were the latter, and thus unable to advise the comic.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
[A table titled "Coping With Probabilistic Uncertainty", with two columns labeled "Scenario" and "How to think about it in an emotionally healthy way". The boxes in the Scenario column contains text followed by a rectangle split into two parts; the left part is a smiley face, the right part is a frowny face with slanted, angry eyes.]

Row 1, column 1: "Good outcome more likely". The smiley face portion of the rectangle is about 75%.
Row 1, column 2: "Recognize that the bad outcome is possible, but be reassured that the odds are in your favor".

Row 2, column 1: "Bad outcome more likely". The smiley face portion of the rectangle is about 25%.
Row 2, column 2: "Prepare for the bad outcome while remembering that the future isn't certain and hope is justified".

Row 3, column 1: "Precisely 50/50". The rectangle is split in half.
Row 3, column 2: "????? N/A ????"

==Trivia==
* This comic was posted a day before Election Day in the US, where the media has been reporting (based off of voter polls) that the 2 presidential candidates ([[Kamala Harris]] and [[Donald Trump]]) are closely contesting for the White House. This may be a possible reason behind the creation of this comic.

* Randall has dealt with the possibility of a tied electoral count 12 years before in ''what-if? [https://what-if.xkcd.com/19 #19]''

==References==
{{reflist}}

{{comic discussion}}

[[Category:Psychology]] [[Category:Statistics]]

3006: Demons

2024-11-08T18:07:46Z

The-Ergster:

{{comic
| number = 3006
| date = November 1, 2024
| title = Demons
| image = demons_2x.png
| imagesize = 285x458px
| noexpand = true
| titletext = Though they do appreciate how much he improved the heating system for the flame pit.
}}

==Explanation==
{{w|Maxwell's demon}} is a thought experiment devised by {{w|James Clerk Maxwell}} that appears to refute the {{w|second law of thermodynamics}}, which roughly says that heat always flows from hotter regions to colder. In the thought experiment, two chambers, both containing a gas at the same temperature, have a door between them. A being (later called a demon by {{w|Lord Kelvin}}) lets only fast-moving gas molecules move from the first chamber to the second, and only slow-moving ones move from the second chamber to the first. The second chamber's gas gradually warms as the average speed of its molecules increases, and the first chamber's gas likewise cools, apparently contradicting the second law. However, the actions of such a demon would use up at least the amount of energy that could later be extracted from having a gas separated into hot and cold parts, so such a demon could not gain energy and Maxwell's demon does not break the second law of thermodynamics. The second law of thermodynamics is a fairly common theme in xkcd, last being mentioned in [[2848: Breaker Box]].

This demon behaves very differently from mythological {{w|demons}}, which exist in the afterlife (usually some form of {{w|hell}}) and punish evil humans after death by causing them great suffering (for example, by boiling them in oil or casting them into flame pits). [[Randall]] jokes that if Maxwell's demon were to encounter more stereotypical mythological ones, he would probably not fit in very well because of his very different approach, proposing treating humans like the particles of the thought experiment. While a few physics-savvy humans might feel offended by such treatment, real suffering could be caused by the anxiety of knowing that, once you choose to cross the door, you are not allowed to return ''for all eternity''.

The scientist Maxwell challenged traditional notions about physical phenomena by providing modern statistical explanations of "large-scale effects" such as temperature changes and modern infinitesimal explanations of "distant effects" such as electromagnetic forces. In a similar vein, Maxwell's demon in the comic challenges the mythological demons' traditional notion of torture by proposing modern psychological torture.

The title text continues the joke by suggesting that while Maxwell's demon's idea for torturing the souls of the damned might seem whimsical to the other demons, it could still be used to heat the flame pits better. The other demons' appreciation of this technical improvement mirrors real-life situations where kids that "have trouble fitting in with the others" due to their unusual ideas for games and atypical interests (e.g., in thermodynamics) occasionally earn some appreciation when their cleverness is found to be useful.

This comic was published on 1 November, 2024, the day after Halloween, around the time when many contemporary comic strips have demonic, supernatural or other spooky themes, as well as 4 days before the anniversary of Maxwell's passing (5th of November).

==Transcript==
:[Three demons, Cueball-like in general appearance but with horns and pointed tails, are standing together while surrounded by flames. The leftmost demon is holding a pitchfork and the next one has his hands down. They are looking at the third to the right standing a bit apart from them. This last demon, Maxwell's demon as given in the caption, holds his palms up while looking at the other two.]
:Demon with pitchfork: What's our plan for the souls today? Boil them in oil?
:Middle demon: We could cast them into the flame pit.
:Maxwell's demon: What if we set up two rooms with a door in between, but– get this– '''''we only let them go through it one way!'''''

:[Caption below the panel:]
:Maxwell's Demon had trouble fitting in with the others.

{{comic discussion}}

[[Category:Physics]]
[[Category:Religion]]
[[Category:Demons]]

Category:Comics edited after their publication

2024-11-08T18:03:43Z

The-Ergster:

Randall occasionally updates comics after they are published to fix errors, appease fan complaints, or for other reasons. This is a collective list of all comics that have been edited after release.

[[Category:Distinctive comics]]

Category:Ghosts

2024-11-08T18:02:24Z

The-Ergster:

{{incomplete|Needs More Detail}}
Ghosts, the ethereal representation of those who have passed away, often seen in movies such as [https://www.explainxkcd.com/wiki/index.php/Category:Ghostbusters Ghostbusters], are a recurring topic on xkcd.

Category:Ghosts

2024-11-08T18:01:45Z

The-Ergster:

{{incomplete|needs more detail}}
Ghosts, the ethereal representation of those who have passed away, often seen in movies such as [https://www.explainxkcd.com/wiki/index.php/Category:Ghostbusters Ghostbusters], are a recurring topic on xkcd.

Category:Ghosts

2024-11-08T18:00:51Z

The-Ergster:

{{incomplete|needs more detail}}
Ghosts, the ethereal representation of those who have passed away, often seen in movies such as [{{:Category:Ghostbusters}}], are a recurring topic on xkcd.

Category:Ghosts

2024-11-07T21:49:56Z

The-Ergster: Added title text

Category:Ghosts

2024-11-07T21:49:13Z

The-Ergster:

{{incomplete}}
Ghosts, the ethereal representation of those who have passed away are often seen in movies such as [https://www.explainxkcd.com/wiki/index.php/Category:Ghostbusters Ghostbusters], and are a recurring topic on xkcd.

Category:Ghosts

2024-11-07T21:44:34Z

The-Ergster:

{{incomplete|Could have a more in-depth explanation}}
Ghosts, the ethereal representation of those who have passed away, are a recurring topic on xkcd.

3005: Disposal

2024-11-07T21:41:59Z

The-Ergster:

{{comic
| number = 3005
| date = October 30, 2024
| title = Disposal
| image = disposal_2x.png
| imagesize = 740x331px
| noexpand = true
| titletext = We were disappointed that the rocket didn't make a THOOOONK noise when it went into the tube, but we're setting up big loudspeakers for future launches to add the sound effect.
}}

==Explanation==
{{incomplete|Created by a MINESHAFT-TARGETING ROCKET - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

This comic came out a couple of weeks after the successful first attempt to 'catch' a rocket during {{w|Starship flight test 5}}, based upon {{w|SpaceX}} having {{w|Falcon 9 first-stage landing tests|an extensive history}} of bringing rocket stages back to Earth in a controlled manner. Whereas the traditional approach was for such rocketry to allow most of the initial launch-vehicle to be a single-use stage that was effectively destroyed once it had fulfiled its purpose, it has become a developmental aim across much of the commercial side of the industry to introduce as much reusability as possible in the mission hardware to potentially save costs and construction time.

In order to accomplish a successful recovery, expended stages have been given unprecedented ability to control their fall back to the ground, often in a manner that allows them to propulsively halt their descent directly over a prepared landing pad (on land or sea) and settle down softly enough on landing gear to be refurbished and reused (sometimes for {{w|List of Falcon 9 first-stage boosters#Booster 1061|more than twenty subsequent missions}}). For the recent Starship test, the one (and, as of this comic, only) attempt to recover its {{w|SpaceX Super Heavy#B9%E2%80%93B12|Super Heavy Booster}} involved being precisely guided to be ''caught'' by the {{w|SpaceX Starbase#Orbital Launch Pad A|original launch tower}}; though it is never expected to refly, as a test prototype, it survived the whole process. This is in contrast with [https://www.youtube.com/watch?v=bvim4rsNHkQ plenty of examples], where the landings (or their aftermath) were not quite so successful.

Though SpaceX is the current leader in such an accomplishments, there are other companies who are various degrees along a similar developmental route. [[Randall]] claims that he has an organisation that is amongst them, and has achieved the non-trivial feat of being able to direct the discarded rocket stage ''very precisely'', yet without that extra bit of ability to ensure that it doesn’t then subsequently explode. The team has therefore decided to exploit their achievement (to precisely control the rocket) to send it 'safely' into a hole that (barely larger than the rocket's cross-section, and with a sturdy lid directly manhandled by a [[Cueball]] employee) allows it to {{wiktionary|rapid unplanned disassembly|rapidly disassemble}} in a planned and 'safe' manner. Of course, as a [[:Category:Compromise|'compromise']], it does not achieve the original aims of recoverability and reusability, yet it also is intrinsically far more complicated than the default option of just letting the hardware generally fall to destruction somewhere in a handy 'empty' down-range area that {{w|Spacecraft cemetery|shouldn't inconvenience anybody}}.

With the comic depicting the 'disposed' stage as powering downwards, this might explain their lack of success in perfecting any form of intact recovery, as practical examples of this technology tend to spin the craft around to make use of the main thruster(s) for a {{w|retrorocket}}-assisted {{w|VTOL|landing}}, or at least don't try to counteract the passive deceleration provided by parachutes or other purposeful aerodynamic drag, in order to touch the ground at a survivable velocity.

An explosion in a sealed container is potentially much more dangerous than an explosion in the open, depending on the strength of the container. If the container is strong enough to hold the pressure from the explosion, that pressure could be released in a controlled fashion, safely. But if the container is too weak, it could suffer a catastrophic failure, sending shards of its walls and anything around it flying outwards at high speed. Even if the container is initially strong enough, it could be weakened by repeated explosions, and fail at a random time in the future. As the 'container' is mostly a hole dug into the ground, of indeterminate depth, it might be considered fairly robust in itself, especially if given a reinforced lining. However, this then risks forcing the majority of the resulting explosion up into the lid, which looks strong and heavy yet is closed at least partly by the effort of just one person. It also risks that worker being right next to the track of the descending rocket stage, where they would be at risk of experiencing all kinds of secondary damage, if not being directly in the explosion if they get the timing of the lid-closure wrong. An actual {{w|Operation_Plumbbob#Missing_steel_bore_cap|attempt to put a lid on an underground explosion}} succeeded only in blowing the lid off at such velocity that it was never found.

The title seems to refer to the sound effects of dragging an element into the trash on computers. Or, alternatively, the sound of a canister being sucked into a vacuum tube. This is perhaps a reference to Tesla vehicles being quiet and having "vroom" noises pumped into the cabin to satisfy customers.

==Transcript==

:[A two-stage rocket is ascending with a plume of exhaust behind it]
:[The first stage falls off and the second stage ignites]
:[The first stage begins to fall, turned off]
:[The first stage reignites to control trajectory and attitude]
:[The first stage falls toward a large, but barely wider hole with a lid. A Cueball is holding the lid open, which has a hinge attaching it to the ground]
:[Cueball pushes the lid closed]
:Click
:[The first stage, now out of sight, explodes, with Cueball shielding his ear with one hand and flinching away from the loud noise]
:BOOOOM

:[Caption below the panels:]
:Our rockets were good at steering, but we couldn't get them to land without exploding, so we just dug a rocket disposal hole.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Space]]
[[Category:Rockets]]

2712: Gravity

2024-11-07T21:36:11Z

The-Ergster: /* Celestial Bodies */

{{comic
| number = 2712
| date = December 16, 2022
| title = Gravity
| image = gravity_2x.png
| titletext = It's a long way down.
}}
{{TOC}}
*To experience the interactivity of the game, visit the {{xkcd|2712|original comic}}.

==Explanation==
This interactive comic promotes Randall's new book [[What If? 2]], which was released in September and is available for purchase. You pilot a small spaceship throughout a vast area in space exploring various bodies and planets within the play area, many containing easter eggs alluding to the book What If? 2 and previous xkcd comics. The flight mechanics are Newtonian so the spaceship can use the gravity of planets to alter its trajectory or enter orbit. The spaceship has indicator circles around it which appear when a gravitational body comes into range, showing the direction towards their center of gravity and the size of the body. A circle also appears around the spaceship whenever it collides with a gravitational body, acting as a shield. The shield remains until the player orients the spaceship upright so its landing gear can deploy.

This comic was the ground work for the next [[:Category:April fools' comics|April fools' Day comic]] of 2023: [[2765: Escape Speed]].

You can easily fly between planets if you pay attention to orbital mechanics: don't just floor the accelerator. The background stars show your velocity and orientation relative to the nearest gravity well. If you are having difficulties navigating space, point towards a gravity orb and accelerate for only a few seconds. Wait until the background stars spin wildly, and then reduce your velocity to 0 before gently accelerating towards the object.

With a keyboard the arrow keys rotate the spaceship and accelerate it forward and backward. You can also use the standard first-person shooter keys 'w', 'a', 's' and 'd', and the standard vi text editor navigation keys 'h', 'j', 'k', and 'l' to control the spaceship. Despite some spaceships having no unique backward texture, they can all reverse. On mobile the comic will full screen, pressing either side of the center rotates the spaceship, and pressing in the center accelerates it forward. Various additional glitches may occur if you're playing on mobile. Having a starting position slightly below the take-off pad means you're already 'glitched' inside the planet from the off. Escaping the planet may need inverted 'accelerating' (turning perpendicular to the local vertical and thrusting backwards until you can glitch back out into more open space. You may also be trapped within the cannonball 'orbit', with seemingly inconsistent collision-detection, such that you can be sat ''with landing gear extended'' upon features (projectile tracks, etc) that seem not to count as solid for most other purposes.

There is no "universal" point of view — the bottom of the window, "down", is oriented towards the object exerting the most gravity upon the player. Multiple things found in this comic draw attention to this, such as how on Earth Ponytail says to White Hat, "I checked downforeveryoneorjustme.com and it says just me", and he replies "Yeah, I guess down isn't down for everyone." Throughout the play area are coins that change the spaceship into different rockets and non-space-based vehicles.

===Celestial Bodies and Transcript===

This is a table of all celestial bodies:

{|class="wikitable sortable"
!
!
!
! colspan="4"|References
!
|-
! Name
! Transcript
! Tiles (X, Y)
! What If?
! xkcd
! Movies
! Other
! Explanation
|-
|'''Starting Planet'''

<code>origin</code>
|
Cueball: "To celebrate the world of ''What If? 2'', here is your very own tiny planet to explore!

Megan: "Welcome!"

*Ground caption: "Give someone the science question-and-answer book ''What If? 2'' for the Holidays: xkcd.com/whatif2"

*Cueball feeding T-Rex: "Burger?"

Isaac Newton: "Robert Hooke must be down there ''somewhere!''"

Megan to Cueball: "If you ever get lost in space, just fly down. That's where the ground is."

Beret Guy to squirrel: "Hi!"
|(0, 0)
|Y
|
|
|Y
|The player begins on the launch pad in a landed position. Collecting the orbiting cannonball will transform you into a different rocket, although it does not improve your abilities.

Cueball feeding the T-Rex is possibly a reference to What If #78: {{what if|78|T-rex Calories}}.

{{w|Isaac Newton}} is referencing the {{w|Newton's cannonball}} thought experiment, where a cannon is fired at greater and greater speeds until the cannonball goes into orbit. Newton's comment suggests that instead of demonstrating orbits, he is firing repeatedly to hit his rival, {{w|Robert Hooke}}.
|-
|'''Earth'''

<code>earth</code>
|
"How am I supposed to cause the extinction of the dinosaurs if they keep moving out from under my comet?"

"Unusually high-speed squirrels."

"Jump in! The water's fine!"

"Ugh, the frame rate is really bad out today."

"I don't know why people complain about going down rabbit holes. These lil guys are adorable!"

"Ahh, the mysterious natural wonders of sailing stones"

"I'm Bananas Georg.
Every year our company publishes global per capita banana consumption numbers, so to make the printing easier, I eat enough bananas on December 31st to make sure it's a round number."

"Weird, I feel ''heavier''."

"Hey"

"I checked downforeveryoneorjustme.com and it says just me"
"Yeah, I guess down isn't down for everyone"
|(27867, -35648)
|Y
|Y
|
|Y
|A planet with among other things:
* A {{what if|162|crane dropping a comet}} onto a dinosaur
* Unusually high-speed squirrels (creating a sonic boom). Reference to ''What If? 2'' Chapter 56: Walking Backward in Time, where these squirrels are surprisingly present in the past
* Megan inviting Cueball into a pool
* A region where the frame rate is intentionally limited. Reference to Chapter 56 again, where the weather and sun cycle fast enough to cause similar strange visual effects
* A flagpole
* A literal {{w|burrow|rabbithole}} referencing the figuratively speaking [[wikt:rabbit hole|rabbit hole]]
* Someone playing [[1920|consequence archery]]
* A lake with an eel
* The {{what if|157|earth-moon firepole}}
* A "doot cone," a reference to [[Volcano Types]]
* Two figures being attacked by a third with a sword
* Two kids playing soccer (Catching the ball will turn the spaceship into a soccer ball)
* A farmer on a tractor being stuck in gooey candy. Reference to ''What If? 2'' Chapter 64: Lemon Drops and Gumdrops, where it rains candy
** A nearby hummingbird excited by all the sugar
** Cueball attempting to eat the falling candy, but having it hit his teeth painfully
* A banana pile being consumed by "Bananas Georg" to make the per capita annual banana count round, referencing the "[https://reallyreallyreallytrying.tumblr.com/post/40033025233/average-person-eats-3-spiders-a-year-factoid Spiders Georg]" meme as well as ''What If? 2'' Chapter 11: Banana Church, where he also makes an appearance
* Megan and Cueball digging a hole (in the center of this planet is the "Earth's core", referenced below)
* The {{what if|147|Niagara Falls water being redirected into the LHC}} (Large Hadron Collider)
* Japan leaving earth. Reference to ''What If? 2'' Chapter 50: Japan Runs an Errand
* A tube to the bottom of the ocean. Reference to ''What If? 2'' Chapter 30: Mariana Trench Tube
* Ponytail and White Hat making a reference to [https://downforeveryoneorjustme.com downforeveryoneorjustme.com]
* Two mini asteroid moons: A tiny version of B612 with Little Prince and the rose, plus one with just Cueball standing on it. They can be found by flying straight up from the Super Mario flagpole.
|-
|Earth's Core
|
|(28850, -28570)
|
|
|
|
|[[Cueball]] and [[Megan]] floating in a small space in the center of the planet in inverted rotations. Can be legally accessed using a high velocity collision onto the surface of the planet, although requires tapping the up arrow afterwards many, many times.
|-
|'''Europa'''

<code>europa</code>
|
|(13180, -2540)
|Y
|
|
|Y
|Europa, one of Jupiter's many moons (in real life). A broken, icy crust has a single path into its core.
|-
|Europa's Crust
|
"It's so unfair we don't get to compete in EuroVision."

"The region of the solar system where liquid water can exist on the surface is the habitable zone, and the region where it can exist beneath the surface of moons is the Eurozone."

"WHIRRRR"
|
|Y
|
|
|
|Europa's crust, with a single entrance into the core demarcated by an octopus leaving a hole.
EuroVision is a European song competition that includes many European countries, and it's not too much of a leap to claim that "Euro" includes Europa

Cueball states that Europa, with liquid underneath its surface, is in the Eurozone, a pun on the ''other'' Eurozone.

A Roomba whirs across the icy crust.

Cueball has a hairdryer and is melting the surface of the crust. A direct reference to {{what if|35|What If's Hairdryer}}.
|-
|Europa's Core
|"We've always used neutrinos for astronomy, but if we place my 'optical telescope' in orbit above the kryosphere, we could potentially observe the universe using electromagnetic waves. Who knows what else there is out there besides stars! There could be other worlds!"

"Hi, I'm Annie. Welcome to the depths of Europa. There's some weird stuff down here."

"We were caught in a powerful November gale on the Great Lakes outside Whitefish Bay. Our ship foundered and sank here." "This is Jupiter's moon Europa." "It was a REALLY powerful gale."

"Does our book club really need this much secrecy?" "That sounds like a question a SPY would ask."
|
|
|
|Y
|
|A watery ocean with octopi looking out into the great unknown using telescopes. This is a reference to octopus's intelligence here on earth! It may also be a reference to (Spoilers!) a certain 2013 science-fiction film featuring Europa, if not a 1987 book. There's also a secret path leading to a book club, through the wreck of the Edmund Fitzgerald.

The woman presenting herself as Annie is a reference to Annie Rauwerda, the creator of the popular social media accounts {{w|Depths of Wikipedia}}.

The November gale discussion is a reference to the Gordon Lightfoot song "The Wreck of the Edmund Fitzgerald" and the actual events described in the song.
|-
|'''B-612'''

<code>b612</code>
|
Probe: "Asteroid deflection mission to earth. The package is delivered. Commencing planetary threat neutralization."

Sign: "Welcome to B-612"
|(2610, 3700)
|Y
|Y
|
|Y
|A reference to [[618: Asteroid|Asteroid]]. In a tragic turn of events, the Earth-bound asteroid being blown up is the home of {{w|The Little Prince|the little prince}}.
|-
|'''Dog Park Planet'''

<code>dogplanet</code>
|
[Dog Park]

"I want more dogs!"

"Ball! Again!"

"I hope it lands soon."

"English adjective order means that you're "Clifford the Big Red Dog" but not "Clifford the Red Big Dog""

"You can't have too many dogs!"

|(1240, 11230)
|Y
|Y
|
|
|A planet covered in dogs, along with dog walkers, some fences, and a sign that reads "Dog Park". Two dogs watch a ball which is traveling in what appears to be a circular orbit around the planet. One dog is much larger than anything else on the planet. A hole is being dug by two dogs. Visible at the bottom, there is an empty space in the center of the planet in the shape of a dog bone.

Planets named "Giant Dog Planet" and "Tiny Dog Planet" appear in [[1253: Exoplanet Names]].

Ponytail's explanation of adjective order was originally miswritten, saying "Clifford the Red Big Dog" twice.

The two Cueballs excited by all the dogs reference ''What If? 2'' Chapter 60: Dog Overload.
|-
|'''What If? 2 Planet'''

<code>goodhart</code>
|
Cueball to White Hat: "The tower over there is the Vehicle Assembly Building, and then behind it is the Vehicle Disassembly Building."

Ponytail to Cueball: "You know how tires pollute the environment with rubber particles? Well, I've developed a solution."

"MMM SPIDERS HOMF HOMF"

Shooting star caption: "THE MORE YOU KNOW"
Sauropod: "Oh no!"

Person on uncontrolled helicopter: "AAAAAA"

Geyser: "Fwoosh!"
Cueball and Megan: "Oooh!"

Giant phone crushing city: "ALERT" "Giant phone crushing city" "Dismiss" "More"

Cueball with jetpack: "Wheeeee!"

Cueball to Megan: "Do you ever look up at the night sky and think, "Wow, I bet those little white dots taste ''delicious!''"

Neighbor: "Why is my house on fire ''again?!''"
Cueball: "Dunno"
Laser captioned: "Laser"

Person with Washington Monument: "Okay, let it drop!"
|(-13300, -3260)
|Y
|Y
|
| Y
| In aerospace, a Vehicle Assembly Building is where spacecraft are constructed. Randall Munroe whimsically refers to the launchpad as the Vehicle Disassembly Building.

Contains a figure in a cave saying "MMM SPIDERS HOMF NOMF", which refers to [[1268: Alternate Universe|Alternate Universe]] and may also be a reference to the [https://reallyreallyreallytrying.tumblr.com/post/40033025233/average-person-eats-3-spiders-a-year-factoid Spiders Georg] meme.

Collecting the small dot above the mountain peak will turn the spaceship into a flying person figure.

''What If? 2'' references include:
* A car preventing rubber pollution by being in a rubber ball, referencing Chapter 25: Tire Rubber
* People catching helicopters, one by the skid and another by the blade, referencing Chapter 2: Helicopter Ride (by the blade is reportedly more effective for downing the helicopter)
* Old Faithful, which appears in Chapter 8: Geyser
* A giant phone, presumably running on archaic {{w|vacuum tube}}s, from Chapter 36: Vacuum Tube Smartphone
* A jetpack takeoff appearing in Short Answer Section #1
* A T-Rex being weighed against an elephant, referencing Chapter 7: T. Rex Calories
* Igniting a house with a laser, referencing Chapter 37: Laser Umbrella
* Dropping the Washington Monument to propel a plane, referencing Chapter 18: Airliner Catapult
|-
|'''The Sun'''

<code>sun</code>
| "The sun is governed by magnetohydrodynamics, or 'Magic' for short"

"My countertop!"

"This will make a good soup base"

"Can I touch it yet?" "No, be patient. It's still too hot. Give it another 20 or 30 billion years."

"It's okay. I'm wearing five layers of sunscreen."

TV Anchor: "The forecast for today is lots of sun"

"This should be enough sunscreen"
|(-14950, 12080)
|Y
|Y
|
|
|Difficult to escape from if you hit the core. The description of magnetohydrodynamics is a reference to [[1851: Magnetohydrodynamics]]. Throwing a countertop into the Sun is a reference to {{what if|89|What If? Tungsten Countertop}}. Both the five layers of sunscreen (effective against ultraviolet) and the ten-meter blob (still ineffective against heat) are references to ''What If? 2'' Chapter 62: Sunscreen. Waiting for it to cool down before touching it may reference Chapter 64: Walking on the Sun.
|-
|Sun's Core
|Cueball: "The core of the sun may seem hot, but it only produces about as much energy per volume as a lizard" Megan: "Wow. So how many lizards are there?" Cueball: "No-one knows."
|
|Y
|
|
|
|Difficult to escape from. Can be escaped by rotating around the Sun until reaching an escape-like velocity. Comparing the Sun's heat per volume to lizards is a reference to {{what if|148|What If? Eat the Sun}}.
|-
|'''Soupiter'''

<code>soupiter</code>
|"I think it's chicken noodle? Hard to tell."
|(-800, -9040)
|Y
|
|
|
|A model of the solar system filled with soup out to the orbit of Jupiter. As commented by Cueball, noodle soup. Soupiter was the title of ''What If? 2'' Chapter 1, but it filled the Solar System ''out to'' Jupiter and became a black hole, rather than another fun planet.
|-
|'''Earth without Japan'''

<code>nojapan</code>
|"Something is missing."
|(-7680, -5850)
|Y
|
|
|
|Earth, except it's missing Japan. Reference to ''What If? 2'' Chapter 50: Japan Runs an Errand.
|-
|'''Just Japan'''

<code>japanmoon</code>
|
|(-5930, -5800)
|Y
|
|
|
|A moon with water surrounding... just Japan. In ''What If? 2'', this is a possibility for where Japan might go without intending to return.
|-
|'''A blob labeled "Pigeons"'''

<code>pigeons</code>
|
|(-9020, -2490)
|Y
|
|
|
|A reference to Chapter 6 of ''What If? 2'', where it would take 1.6 x 10^25 pigeons to lift you and a chair up to the halfway point of Australia's Q1 skyscraper.
|-
|'''Starship Enterprise'''

<code>enterprise</code>
|
|(2389, -60879)
|Y
|
|
|
|Star Trek reference: The Enterprise-C, 2344, commanded by Captain Garrett's. While defending a Klingon outpost, the weapons discharges resulted in the creation of a temporal rift, through which the badly damaged Enterprise drifted. In the comic, there is a large, invisible gravity distortion near the Enterprise-C.
|-
|'''Dinosaur Planet'''

<code>qwantz</code>
|"Welcome... to Jurassic Park."
|(20403, -49559)
|
|
|Y
|
|An homage to [https://www.qwantz.com/ Dinosaur Comics], a webcomic Randall has mentioned several times before. All the dinosaurs on the planet are black-and-white versions of the clip art dinosaurs in that comic. Also references the Jurassic Park movies, with CEO John Hammond welcoming paleontologists Dr. Sattler and Dr. Grant to the planet. The long grass depicted is a plot point in later films.
|-
|'''Cat blocking traffic flowing through portals'''

<code>roads</code>
|
|
|Y
|
|
|
|Roads in space may reference ''What If? 2'' Chapter 5: Cosmic Road Trip.
|-
|'''Edge of the Universe'''

<code>outside</code>
|"Welcome, traveler!" (found inside the edge of the bubble universe)
|(6081, 26138)
|
|Y
|
|
|It looks like a planet labeled "edge of the universe". Outside the universe, so inside the "edge of the universe" planet, is another universe, the bubble universe, whose outside is labeled "edge of the bubble universe". Hidden entrance is between 10 and 11 'o clock. It is a reference to [[Bubble Universes]].
|-
|'''A tree larger than the planet it's growing on'''

<code>roads</code>
|
|
|
|Y
|
|
|May be a reference to [[2: Petit Trees (sketch)|Petit Trees]]. More probably, a reference to ''The Little Prince'', a French children's novel about a traveler from a distant asteroid. In the novel, baobab trees are a serious threat to the Prince's home asteroid, as they are so large that their roots would engulf the asteroid entirely. Randall has alluded to The Little Prince numerous times before, especially in what-if articles.
|-
|'''Milliways'''

<code>outside</code>
|
|''in code:'' (0, -14500)'', in game:''(0, 29000)
|
|
|Y
|Y
|A reference to Milliways, the Restaurant at the End of the Universe from ''The Hitchhiker's Guide to the Galaxy''. On one side of the planet, Ponytail, Cueball, Megan, and other characters gather on the patio of the Milliways restaurant; on the other side, the Sojourner rover examines a rock.
|-
|'''The Great Attractor'''

<code>greatattractor</code>
|
|(-596048, 247952)
|
|Y
|
|
|Beret Guy stands on the surface of a large ball labeled "The Great Attractor". The gravity is extremely strong (over 200 times that of the black holes), leading to various bugs and collision issues. It's a reference to [[Great Attractor]], in which Beret Guy is gravitationally attracted to the Great Attractor more strongly than usual.
|-
|'''Present'''

<code>present</code>
|
"I didn't do any of my Christmas shopping yet because I was too busy drawing tiny planets."

"I'm done with my shopping! I got everyone What if? 2"

"...You got me my own book?"

"Yeah! I figured that since you wrote it, it must be right up your alley."

"It does make a good gift, though. You can get it at xkcd.com/whatif2"

"I got you this present!"

"Is it an angry bobcat?"

"It might not be."
|in code: <code>[22820,-18920]</code> in game: <code>[45640,37840]</code>
|
|Y
|
|
|The xkcd cast react to giving each other What if 2? as a present. Black Hat gives Cueball a "gift" which he claims, "might not be a bobcat", a reference to [[A-Minus-Minus]] A quarter of the planet was missing on the release day, but it's fixed now.
|-
|'''Black hole cluster'''

''from'' <code>maw1</code> ''to'' <code>maw14</code>
|
|
|
|
|Y
|
|A cluster of black holes with extremely high gravitational strength, set to the maximum of 2048. Not particularly easy to land on with multiple conflicting gravitational fields, but once landed on, rather difficult to escape. Likely a reference to the [[wikia:w:c:starwars:Maw Cluster|Maw Cluster]] in Star Wars.
|-
|'''Remnant'''

<code>remnant</code>
|"All right, that's close enough"
"Oh no"

{{w|Walkin' on the Sun|"So don't delay, act now, supplies are running out"}}

"In 5 billion years, the Sun will run out of fuel and suffer gigennial burnout."

"The immense gravity of the sun's remnant means that this is the tallest possible skyscraper."
|(19620, 3800)
|Y
|
|
|Y
|A white dwarf stellar remnant, with high gravity (making it difficult to escape, although it's possible to achieve escape velocity by flying sideways). Has various small landmarks, including a "skyscraper" and suspension bridge, using a penny for scale. There is a set of images of a rocket descending towards the planet, falling, and then trying to escape by sledding. The band is performing Smash Mouth's "Walkin' on the Sun". Most of these are references to ''What If? 2'' Chapter 63: Walking on the Sun.
|-
|'''Steerswoman Planet'''

<code>steerswoman</code>
|"As a Steerswoman, I have to answer any question anyone asks me, or I'm expelled from the order."
"What's one question that you would be unwilling to answer?"
"Oh no."

"Handle this artifact with great care. It contains a magical wizard's potion which the ancients called 'trinitrotoluene'"
|(-35070, -2500)
|
|
|
|Y
|A reference to the Steerswoman series of books by Rosemary Kirstein. Includes a number of references to the series, including a group of people observing a small object orbiting the planet.

Trinitrotoluene is better known as {{w|TNT}}, a powerful explosive.
|-
|'''Peeler'''

<code>peeler</code>
|
|(-9270, 620)
|Y
|
|
|
|A reference to the question posed by ''What If? 2'' Chapter 13: Lose Weight the Slow and Incredibly Difficult Way. A large potato peeler is seen removing the earth's crust.

|-
|'''Unknown Planet'''

<code>unknown</code>
|
|(-63587, 9395)
|
|
|
|
|This location was not in the list. There is a non-escapable gravity object here.
<pre>Comic.voyager.pos
Object { x: -63587, y: 9395, a: 3.625954916940618, vx: 0, vy: 0, ax: 0, ay: 0, va: 0, aa: 0, isColliding: true, … }
</pre>
|-
|}

===Spaceships===

This is a table of all spaceships:

{|class="wikitable sortable"
|-
! Filename
! Name
! Description
! Location
|-
| <code>ship2</code>
| '''Default'''
| The starting spaceship.
| It is possible to change back to this spaceship by collecting a dot located within the Black Hole cluster
|-
| <code>ship-tintin</code>
| '''Tintin'''
| Spaceship in the shape of the {{w|Destination Moon (comics)|moon rocket from Tintin}}
| On the starting planet; can be obtained by collecting the cannonball in orbit
|-
| <code>ship-figure</code>
| '''Figure'''
| Stick figure
| On Goodhart, atop the mountain up which Sisyphus is pushing his boulder.
|-
| <code>ship-soccer</code>
| '''Soccer Ball'''
| Soccer-ball-shaped spaceship
| On Earth, between two figures playing ball
|-
| <code>ship1</code>
| '''Alternative Spaceship'''
| Default spaceship with landing gear on both sides of the spaceship. The landing gear deploys by unfolding on landing.
| Only available by using console to change Comic.ship = ship1
|}

==Data and Maps==

View the data embedded in the comic on [[2712: Gravity/Data|this page]].

Maps created by the community:
*https://bacontime.github.io/xkcd2712 | A zoomable map of the universe with markers for all planets, coins and with the option to highlight secret passages
*https://www.reddit.com/r/xkcd/comments/zpe7bz/i_rendered_the_entire_what_if_2_universe_as_a/ | The whole universe rendered as one big image

==Hacks==
Various modes and hacks have been found or developed by the community and can be activated by opening the browser console (F12, Ctr+Shift+I or Cmd+Option+I to open your browser's developer tools, then choose the Console tab) and typing a command. <div class="mw-collapsible mw-collapsed leftAlign" style="width:100%">
 
*'''Speedhack:''' <code>ship.engines = "warp"</code> - Speed hacking, sets speed to 1.4x. set to "standard" to reset to normal speed
*'''Teleport to planet:''' <code>[Comic.voyager.pos.x, Comic.voyager.pos.y] = Comic.planetRects.'''''origin'''''.slice(0,2)</code> - teleport near a planet, in this example near earth. You'll still have to fly a bit towards the nearest planet to reach it. Replace '''''origin''''' with the ID of the planet you want to go to, from the table above.
*'''Teleport to coordinate:''' <code>[Comic.voyager.pos.x, Comic.voyager.pos.y] = '''''[0, -2000]'''''</code> - teleport to an exact coordinate. <code>[0, -2000]</code> happens to take you to the starting area.
*'''Improved radar:''' <code>Comic.wayfinderFarDistance = Infinity</code> - make the direction of all objects visible. This can be hard to understand though. reset with <code>Comic.wayfinderFarDistance = 10000</code>.
*'''Chaos Mode:''' <code>ship.engines="infinite improbability drive"</code> - Seems to randomly teleports the ship. A reference to its namesake in Hitchhiker's Guide to the Galaxy.
*'''Insta Death:''' <code>ship.shields = false</code> - Kill the player if they land on a planet, the code never sets it to false, so it seems to be always true.
*'''No Clip:''' <code>noclip = true</code> - Enables noclip.
*'''Select ship:''' <code>Comic.ship = "ship-tintin"</code> - Select ship (use filename from list of ships)
*'''Autorotate:''' <code>Comic.cameraRotation = false</code> - View does not rotate with ship
*'''Goggles:''' <code>ze.goggles()</code> - returns a warning: "they do nothing!". This is a reference to Hoverboard, where ''ze.goggles()'' would give you the ability to see false walls. Both of which are a reference to the Simpsons episode "Radioactive Man" (season 7, episode 2), where Rainier Wolfcastle, playing Radioactive Man, complains that his safety goggles do nothing against a deluge of acid, sounding like "Ze goggles, zey do nothing!" with his accent.
*'''Python:''' <code>python("import antigravity")</code> - reverses gravity, so the ship falls away from planets. A reference to [[353: Python]]. Reset with <code>Comic.gravityConstant = 100</code>.
*'''Light Mode''' <code>Comic.lightMode = true</code> - inverts the color of the comic. reset with <code>Comic.lightMode = false</code>
</div>
 

==Trivia==
* The objects in the mini universe of this browser game are all at fixed positions and do not interact through gravity, however, the ship controlled by the player is affected by gravity. While this makes it technically a relatively easy integration problem (of the position of the player ship forward in time), the integrator used seems to be a relatively simple one, but certainly not a simplistic one, because it does not conserve angular momentum. This can be seen when one manages to get into orbit around some object, e.g., the core of the sun. The orbit slowly decays over time.

* The logic for extending the landing legs and landing is rather simple. A ship can (normally) land if it is facing away from the surface it collides with, and if its momentum is more-or-less directed towards the surface. Once landing is triggered, the ship will rotate to face directly away from the object exerting the most gravity on the player, regardless of how sloped the surface is. The only way to get into space again is to accelerate forwards, as neither turning nor accelerating backwards cancels the landed state. All of this can be abused to land on almost everything. To land on the underside of an object, simply point your ship away from the object and slowly accelerate backwards to counteract the force of gravity. Landing on the side of an object is more difficult, as ships cannot accelerate sideways. The first method is to accelerate backwards to launch yourself upwards and towards the object so that at the top of your arc you will collide with the object. Then, rotate your ship accordingly to land. Method two is to just repeatedly slam your back of your ship into the object until you land. Note that with any of these weird landing methods, your ship will turn to face away from the source of gravity and can clip into objects.

* Executing <code>window.python("import antigravity")</code> or <code>python("import antigravity")</code> as Javascript on the page will reverse gravity, multiplying the gravity constant by -1.

* Executing <code>window.ze.goggles()</code> or <code>ze.goggles()</code> as Javascript on the page will show a warning in the console: "<code>they do nothing!</code>"

* Ponytail's comment on earth that she "checked downforeveryoneorjustme.com and it said just me" may be referencing the actual website at that domain, which checks if other websites are down.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
===Origin:===
Megan: Welcome!

Cueball: To celebrate the world of what if? 2, here is your very own planet to explore!

Ground text: Give someone the science question-and-answer book what if? 2 for Christmas:
xkcd.com/whatif2

Beret Guy: Hi!

Megan to cueball: If you ever get lost in space, just fly down. That's where the ground is.

Sir Isaac Newton: Robert hooke must be own there somewhere!

Cueball to dinosaur: Burger?

===B612:===

Robot: Asteroid Deflection mission to earth. The package is delivered. Commencing planetary threat neutralisation.

===Europa:===

====Surface:====

Roomba: Whirrr

Cueball to Megan: The region of the solar system where liquid water can exist on the surface is the habitable zone, and the region where it can exist beneath the surface of moons is the Eurozone.

Cueball's hairdryer: Whirrr

Megan to Cueball: It's so unfair that we don't get to compete in Eurovision

====Underwater:====

Blondie: Hi, I'm Annie! Welcome to depths of Europa! There's some weird stuff down here!

Unnamed sailor guy to Cueball: We were caught in a powerful November gale on the great lakes outside Whitefish bay. Our ship foundered and sank here.

Cueball to Unnamed sailor guy: This is Jupiter's moon Europa.

Unnamed sailor guy to Cueball: It was a really strong gale.

Octopus: We've always used neutrinos for astronomy, but if we place my new "optical telescope" in orbit above the kryosphere, we could potentially observe the universe using electromagnetic waves.

Octopus: Who knows what else there is besides stars! There could be other worlds!

=====Secret book club=====

Cueball: Does our book club really need this much secrecy?

Danish: Sounds exactly like the sort of question a spy would ask!

===nojapan & japanmoon:===

Megan: something is missing

===Goodhart:===

Guiser: Fwoosh!

Cueball & Megan: Oooh!

Alert on the giant phone: Alert! Giant phone crushing city! Dismiss. More.

Cueball in jetpack: Wheeeee!

Cueball to Megan: Do you ever look up at the night sky and think "Wow, I bet those little white dots taste Delicious!"

Cueball 1: Why is my house on fire again?!

Cueball 2: Dunno

Cueball: Okay, let it drop!

Cueball to White hat: Over there is the vehicle assembly building, and then behind it is the vehicle disassembly building.

Ponytail to Cueball: You know how tires pollute the environment with rubber particles? Well, I've developed a solution.

Cueball: Mmm spiders Homf Nomf

Brontosaurus: Oh no!

Text above star falling on Spinosaurus: The more you know

Cueball & pilot of Helecopter 1: Aaaaaa

===Soupiter:===

Cueball or Ponytail (impossible to tell): I think it's Chicken Noodle? Hard to tell.

===Earth:===

Beret Guy: I don't know why people complain about going down rabbit holes. These lil guys are adorable!

Ponytail to Megan: Ah, the mysterious natural wonder of sailing stones

(as cueball is climbing the firepole down to earth): Climb Climb Fling Fling Boom

Volcano: Doot!

Hummingbird: Yesssssss!

Candies as they fall on cueball's teeth: Plink

Cueball: Ow!

Candies as they fall on cueball's teeth: Plink

Cueball: Ow!

Bananas Georg: I'm bananas Georg. Every year, our company publishes global per capita banana consumption numbers, so to make the printing easier, I eat enough bananas on December 31st to make sure it's a round number.

Cueball to Megan, both in deep pit: Weird, I feel heavier.

Ponytail: I checked downforeveryoneorjustme.com and it said just me.

White hat: Yeah, I guess down isn't down for everyone.

Person in crane: How am I supposed to cause the extinction of the dinosaurs if they keep moving out from under my comet?

Knit cap while looking at supersonic squirrel: Unusually high speed squirrels

Megan to cueball: Jump in! The water's fine!

Knit cap: Ugh, the frame rate's really bad out today. (if you go in the rectangle containing the words, the whole game begins to stutter.)

===Sun:===

====Outside:====

Jill: This would make a good soup base.

Hairy to Cueball: Can I touch it yet?

Cueball to Hairy: No, Be Patient. It's still to hot. Give it another 20 or 30 billion years.

Unnamed guy with baseball cap: My countertop!

Megan to Cueball: The sun is governed by Magnetohydodynamics, or "Magic" for short.

====Inside:====

Hairy: This should be enough sunscreen.

Ponytail on the news: The forecast for today is lots of sun

Cueball 1 to Cueball 2: It's okay, I'm wearing five layers of sunscreen

=====Core:=====

Ponytail but with black hair to Cueball: The core of the sun may seem hot, but it only produces about as much energy per volume as a lizard.

Cueball to Ponytail but with black hair: Wow. so how many lizards are in there?

Ponytail but with black hair to Cueball: Nobody knows.

===Remnant:===

Band consisting of 2 Hairies & a Beret guy: So don't delay, act now, supplies are running out

Spaceship captain: All right, that's close enough.

Spaceship captain: Oh no.

Ponytail 1 to Cueball 1: The immense gravity of the sun's remnant means that this is the tallest possible skyscraper.

Ponytail 2 to Cueball 2: In 5 billion years, the sun will run out of fuel & suffer gigential burnout.

===Dogplanet:===

Cueball: I want more dogs!

dog 1: Ball! Again!

dog 2: I hope it lands soon.

Ponytail: English adjective order means that you're "Clifford the big red dog" but not "Clifford the red big dog"

Cueball to Ponytail: You can't have too many dogs!

===Quantz:===

Gardener: Welcome ... to Jurassic park.

===Enterprise:===

Ground text: U.S.S. Enterprise

Ground text: NCC-1701-C

===Greatattractor:===

Ground text: The Great Attractor

Ground text: The Great Attractor

Ground text: The Great Attractor

Ground text: The Great Attractor

Ground text: The Great Attractor

Ground text: The Great Attractor

Ground text: The Great Attractor

= Page Discussion =
Due to the length of this article, the [[Talk:2712: Gravity|Comic Discussion]] is not fully transcluded here.

[[Category:Space]]
[[Category:Book promotion]]
[[Category:Interactive comics]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Black Hat]]
[[Category:Comics featuring Ponytail]]
[[Category:The Little Prince]]
[[Category:Bobcats]]
[[Category:Dynamic comics]]
[[Category:Comics with animation]]
[[Category:Comics with lowercase text]]
[[Category:What If?]]
[[Category:Rockets]]