explain xkcd - User contributions [en]

Talk:2925: Earth Formation Site

2024-04-29T16:31:07Z

172.70.90.92:

The title text is only true for geocentric latitude and longitude, not geodetic (which is what is commonly used). [[Special:Contributions/172.69.58.125|172.69.58.125]] 18:32, 26 April 2024 (UTC)

I'm impressed that whatever distant body that sign is placed upon, has actually developed plant life. Especially since it would need to be parked in place relative to the rest of the observable cosmos, & thus seems unlikely to have a suitably close star making regular appearance overhead...
[[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 19:11, 26 April 2024 (UTC)
:👍[[User:Tier666|Tier666]] ([[User talk:Tier666|talk]]) 09:52, 28 April 2024 (UTC)
::Magrathea? [[User:L-Space Traveler|L-Space Traveler]] ([[User talk:L-Space Traveler|talk]]) 14:46, 27 April 2024 (UTC)
: Hi Proph! I just wanted to say that I enjoy reading your comments here and in the SMBC comment page, if you are in fact ProphetZarquon in both places. [[Special:Contributions/172.70.175.28|172.70.175.28]] 21:46, 26 April 2024 (UTC)
::If there's another Prophet Zarquon out there - wait, nope, looks like that's me, too...
::[[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 03:25, 27 April 2024 (UTC)

:The spatial location of a famous person's birth is technically not where the Solar System now is, also. If you're going to be picky about that. If you do allow the Earth's worldline to be accounted for, then it's broadly true that Earth formed (looks out of window at home) here. I think the principle concern there is whether Earth formed in the collision of planets named Ear and Theia, or whether Earth was Earth before Theia came along, which either way seems to be why there is such a large Moon beside it - made of material from both of the previous planets. And it probably counts as a change of course from the previous situation, although the apparent likelihood that Theia formed in Earth's orbit in originally a Trojan relationship may bear on that - if one planet just caught up with the other in orbit, like tailgating in traffic. Robert.Carnegie@gmail.com [[Special:Contributions/141.101.98.184|141.101.98.184]] 17:35, 27 April 2024 (UTC)

The ridiculously specific date may be a reference to how real historical markers frequently get dates incorrect [[Special:Contributions/172.70.127.135|172.70.127.135]] 23:29, 26 April 2024 (UTC)

The other side of the sign says, "At this exact point in space, 13.7878693 billion years ago, the Big Bang took place." That's true of every point in space, according to the current model. The Big Bang implies that all of space was a single point, and space itself expanded outward from that point. [[User:Nitpicking|Nitpicking]] ([[User talk:Nitpicking|talk]]) 03:07, 27 April 2024 (UTC)

The explanation needs to be rewritten. It is missing the point and far to detailed for just saying: The marker could be standing at any point of earth's surface, as reinforced by the title text. The whole discussion about galaxies and solar systems moving is just a matter of the reference system and does not contribute to the understanding of the comic.--[[Special:Contributions/172.70.243.32|172.70.243.32]] 07:28, 27 April 2024 (UTC)
: I disagree. The section is saying that it could not have reasonably happened on Earth itself due to the fact the Earth and the Solar System itself move around through space. [[User:SomeoneIGuess|someone, i guess]]([[User talk:SomeoneIGuess|talk i guess]]|[[Special:Contributions/SomeoneIGuess|le edit list]]) 13:25, 27 April 2024 (UTC)
::Randall was once a physicist. He's aware of the fact that there is no absolute system of measurements, and that locations on Earth are always relative to Earth coordinates, not some sort of galactic map. [[User:Nitpicking|Nitpicking]] ([[User talk:Nitpicking|talk]]) 14:10, 27 April 2024 (UTC)
:::Can you be 'once a physicist'? Once you've been a physicist, aren't you always a recovering physicist?[[Special:Contributions/172.70.90.92|172.70.90.92]] 16:31, 29 April 2024 (UTC)
::More immediately, it could not have reasonably happened on Earth, since Earth didn't exist until it happened.[[Special:Contributions/172.69.195.3|172.69.195.3]] 10:53, 29 April 2024 (UTC)
: I wholeheartedly agree. The whole joke, as reinforced by the title text, is that the marker could be anywhere on Earth. Simplify, simplify.[[User:DKMell|DKMell]] ([[User talk:DKMell|talk]]) 16:21, 29 April 2024 (UTC)

Can the Earth's core even have a latitude and a longitude? Aren't those all referring to the surface? --[[Special:Contributions/162.158.90.198|162.158.90.198]] 11:47, 27 April 2024 (UTC)
:You're right. That is the joke, in fact. [[User:Nitpicking|Nitpicking]] ([[User talk:Nitpicking|talk]]) 14:10, 27 April 2024 (UTC)
:Well, 162.158... is 'right' except that you ''can indeed'' have a latitute, longitude and also ''altitude/depth'' on top, not just restricting yourself to the surface (or Mean Sea Level or whatever other geometric surface you consider as your default).
:As to whether the (centre of the) core can have latitude and longitude, it's a very similar argument as that of whether the (coordinate) poles can have longitudes as well as ±90° latitude.
:If you are asking what either pole's longitude is, it would depend upon the what the algorthm was specified (or fails to have been) for the situation, as you could be told 'undefined', 'NaN', given a placeholder constant (e.g. zero), an effectively random value, a value determinate upon what led to this (you were at <location>, 10 miles south of the north pole, and modified that by 10 miles direct northwards travel, so maintain the same longitude as <location> had), a value that would normally be out of range (e.g. for silently passing on, to do the error-catching/checking later on) or several other options.
:If you're ''specifiying'' the longitude of a pole (for use in an onward algorithm) then it may well (or may not!) be possible to provide any/all of these, but perhaps ultimately ignored/chucked away as meaningless. (Unless you have it doing something like "go ten miles south from north pole, what's the <location> now?", intentionally or otherwise disambiguating via the 'arbitrary but definite' polar longitude.)
:So, similarly, if you're asking "What lat/long is the location of the core", the chances are that you're going to get to go through a different manner of deriving a result from that of requesting information such as "This is my lat/long. Is this (above) where the core is?".
:...though, yes, this still ''is'' very much the joke. Including all the ambiguity as to the rationale involved in however it apparently became disambiguated. [[Special:Contributions/172.69.195.122|172.69.195.122]] 21:59, 27 April 2024 (UTC)

It's a [https://www.explainxkcd.com/wiki/index.php?title=2925:_Earth_Formation_Site&curid=27482&diff=340784&oldid=340779 valid edit], as it goes, but the ''reason'' seems a little over-omniscient. Speaking from another country that does 'signs' quite a bit (for visibility, as well as strategically placed 'table'-style info for closer perusal), I'm not sure we can say it's anywhere near uniquely US-practice. [[Special:Contributions/141.101.99.120|141.101.99.120]] 10:28, 29 April 2024 (UTC)

Talk:2906: Earth

2024-03-14T16:13:16Z

172.70.90.92:

I originally read the caption as "how badly ''we'd'' messed up", which... changes Sagan's tone somewhat. [[Special:Contributions/172.71.155.54|172.71.155.54]] 08:02, 14 March 2024 (UTC)

At first I thought the joke was that the rocket firing had somehow gone so catastrophically badly that the entire Earth had literally been reduced to dust. [[User:Fabian42|Fabian42]] ([[User talk:Fabian42|talk]]) 08:37, 14 March 2024 (UTC)
:I also had this notion at first. That after the failed burn Earth had been destroyed... But I think not so anymore. So thx explain xkcd. ;-) --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 12:43, 14 March 2024 (UTC)

So, according to explainxkcd, that’s a ''square'' “spacecraft window”?? Why have we never seen a square spacecraft window in any other context, ever? Did Randall screw up that badly in the original comic, or was it a previous explainxkcd editor who screwed up here? [[Special:Contributions/172.70.214.60|172.70.214.60]] 08:58, 14 March 2024 (UTC)
:I'm not sure what you're on about and why anyone has to have screwed up. Why can't it be a rectangular (we don't know it's square) spacecraft window? [[User:Bischoff|Bischoff]] ([[User talk:Bischoff|talk]]) 09:53, 14 March 2024 (UTC)
::This is very clearly a triangle shaped window in a very elongated spaceship [[User:Whimsical|Whimsical]] ([[User talk:Whimsical|talk]]) 11:24, 14 March 2024 (UTC)
::: Maybe it is part of a huge spider-shaped window? (I home people here will remember that meta-reference to What If) [[Special:Contributions/172.71.94.208|172.71.94.208]] 12:28, 14 March 2024 (UTC)
::::This picture from the [https://en.wikipedia.org/wiki/Cupola_(ISS_module)#/media/File:Tracy_Caldwell_Dyson_in_Cupola_ISS.jpg Cupola] module of the ISS has trapeze like windows. But the one behind the astronaut could easily have been a rectangle from what can be seen in the picture. So to argue that this window could not have been shot the same is just silly. Of course it was important to the joke that you did not realize it was a window until reading the caption. Also if this space craft has held up to go so far form Earth with living inhabitants it is obviously not a space ship in use today! --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 12:43, 14 March 2024 (UTC)
:::::There is precedent with the [https://www.sciencephoto.com/media/990677/view/crew-at-window-of-space-shuttle-discovery-2006 Space Shuttle] (aft flight-deck window, others were round, the 'forward flight-deck' ones were of course the main flight/piloting ones with awkward quadrilateral shapes and pesky instrument panels where none are in the comic). The windows in the Shuttle were actually a weight issue (certainly, at first, they were plain (chunky!) glass, and added a ''lot'' of weight to the design.
:::::Also look at {{w|File:Blue Origin M7.jpg|Blue Origin's capsule}} for more current design that could end up eventually on an orbital/extra-orbital vessel. Although Crew Dragon is more conservative, and {{w|File:MACES in Orion mock-up.jpg|Orion's interior}} looks like it isn't so big (while Starship's eventual window configuration might eventually be vastly more conservative than the Dan Dare/Flash Gordon aesthetic of the concept imagery).
:::::So... Possible, but depends upon the design needs for the craft (fully space-capable whilst ''designed' for re-entry, is all we really know). [[Special:Contributions/172.70.90.92|172.70.90.92]] 16:13, 14 March 2024 (UTC)

In my mind is the scene in C.S. Lewis's religious novel Out of the Silent Planet, where an English philologist, Ransom, is abducted by criminals into outer space and meets aliens. In chapter fifteen, a wise sorn tries to figure out which planet Ransom is from. Probably Thulcandra, the garbage planet of the Solar System. Ransom doesn't like the sound of that, but the sorn gets out something that isn't a telescope and he shows Thulcandra to Ransom, and yup, that's us. Lewis writes it better. I don't know if Carl Sagan had read this. --Robert Carnegie rja.carnegie@gmail.com [[Special:Contributions/141.101.99.75|141.101.99.75]] 13:12, 14 March 2024 (UTC)
:Hoo boy, yep that book (and its sequel) are beyond even Narnia in their religious symbolism (though the later environmentalist movements could definitely find an allegory in them, too, not sure how intended that was, in CSL's time, some time before a practical Gaia Hypothesis/etc). I can imagine Randall knows of the book (though clearly more influenced by Sagan in a direct lineage). Not entirely sure Sagan will have taken interest in that genre, nor taken the above to heart. Probably no more than his genuine scientific and rhetoric interests, which may be sufficient genesis for his own coined meme. But that's just my gut feeling. i.e. Worthy of note, but not directly (or singly-indirectly) connected. [[Special:Contributions/172.70.85.153|172.70.85.153]] 14:20, 14 March 2024 (UTC)

The color for the blue dot seems to be around #B6C8EB. --[[User:1234231587678|1234231587678]] ([[User talk:1234231587678|talk]]) 15:18, 14 March 2024 (UTC)

2520: Symbols

2024-03-14T02:44:12Z

172.70.90.92: /* Symbols */ Nonredirecting versions of each wikilink (and the second shouldn't even be the plural, in context).

{{comic
| number = 2520
| date = September 24, 2021
| title = Symbols
| image = symbols.png
| titletext = "röntgen" and "rem" are 20th-century physics terms that mean "no trespassing."
}}

==Explanation==
This comic refers to elements of (mostly mathematical or engineering) notation commonly used in various fields of math and science. Each piece of notation is presented as "symbolizing" not what it specifically means, but a typical ''context'' in which it might be encountered, see [[#Symbols|below]].

Many of the individual descriptions look like verbiage that might be found on informational or warnings signs or placards, although typically with a silly edge.

The title text refers to two non-SI units of radiation measurement, {{w|Roentgen (unit)|röntgen}} and {{w|Roentgen equivalent man|rem}}. In the mid-20th century when they were in use, the dangers of radiation weren't as well understood as today, so an area with radiation that was noteworthy back then is [https://archive.md/v3dME probably dangerous], hence the no trespassing part.

Later [[Randall]] made a similar comic, [[2586: Greek Letters]], regarding the use of Greek letters in math.

===Symbols===
'''d⁄dx: An undergrad is working very hard''' d/dx is the symbol for a single-variable {{w|Derivative|derivative}}. This is one of the basic operations in {{w|calculus}} and consequently is ubiquitous in the work of undergraduates in the sciences. A hard-working undergraduate in the relevant fields would churn through exercises using this symbol.

'''∂⁄∂x: A grad student is working very hard''' The replacement of the standard "d" letters with the curly letters "∂" denotes the partial derivative, which generalizes the ordinary derivative to multi-variable calculus. Problems with partial derivatives, especially partial differential equations, can be extremely challenging. Although PDEs would typically be first taught at an undergraduate level, difficult partial derivatives would be encountered in graduate-level work.

'''ħ: Oh wow, this is apparently a quantum thing''' ħ (pronounced "h-bar") is a symbol used for (the reduced) {{w|Planck's constant}}, a universal, fundamental constant in quantum physics. h, the normal version of Planck's constant, is equal to the energy of a photon divided by its frequency. ħ is equal to h/2π, and angular momentum in quantum mechanical systems is measured in quantized integer or half-integer units of ħ.
Classical physics appears as a limit of quantum physics if all "actions" (quantities of dimension energy * time, momentum * length, or angular momentum) are much larger than ħ. Conversely, you can also formally set ħ=0 to get classical results from quantum formulae. This means that effects that are proportional to some power of ħ cannot be explained classically, and instead are "a quantum thing".

'''Rₑ: Someone needs to do a lot of tedious numerical work; hopefully it's not you''' The {{w|Reynolds number}} (which is usually denoted by "Re," not "Re" as it appears in the comic) is the most important dimensionless group in fluid mechanics. Named for Osborne Reynolds, Re characterizes the relative sizes of inertial and viscous effects in a moving fluid. Large values of Re are indicative of turbulent flow, which cannot usually be retrieved analytically, and so numerical modeling is necessary. Accurate numerical studies of high-Reynolds-number flows are notoriously difficult to create and program.

Alternatively, Rₑ could stand for electronic {{w|transition dipole moment}} in a molecule. This appears in quantum-mechanical calculations of transition probabilities and also includes a lot of unpleasant numerical work. Rₑ is also a term used for the radius of the Earth at mean sea level, though this is not necessarily a complex term in and of itself.

Another alternative is that Rₑ could refer to Relative Error, a measurement of precision or accuracy. Used often in the analysis of scientific data and numerical analysis.

'''(Ta⁴ - Tb⁴): You are at risk of skin burns''' The {{w|Stefan-Boltzmann law}} says that a perfectly absorbing ("black body") source emits electromagnetic radiation with a power per unit area of σT4, where σ is a known constant and T is the absolute temperature. The quantity (Ta4 – Tb4) thus appears in any calculation of purely radiative energy transfer between two bodies, one at temperature Ta and the other at Tb. When the radiative transfer is large enough to be the most important form of heat interchange, it is normally also large enough to sear the skin with thermal or ultraviolet burns.

'''NA: You are probably about to make an incredibly dangerous arithmetic error''' NA, or {{w|Avogadro's number}}, is the number of molecules in a mole of a substance, approximately the number of carbon atoms in exactly 12 grams of carbon-12. This is an enormous number, exactly 6.022 140 76 × 10²³, or 602 214 076 000 000 000 000 000. Working with NA, it is easy to accidentally divide by it instead of multiplying or vice versa, leading to erroneous and nonsensical answers such as ~10-23 molecules (even though you can't have less than 1 whole molecule) or ~1046 moles (>1043 to 1045 kilograms, depending on the chemical) of a substance.

'''µm: Careful, that equipment is expensive''' {{w|Micrometre|Micrometer}}s are a very small unit of distance. Micrometers are commonly used to measure wavelengths in the infrared, and infrared detectors are very expensive, compared with visible wavelength counterparts. Of course, micrometers are used as a measurement of distance in other contexts, but any distance-measuring device capable of accurately measuring micrometer distances would also be expensive. Similarly, tools used to create or calibrate items within micrometer tolerances can also be expensive.

'''mK: Careful, that equipment is very expensive''' {{w|Kelvin}} is a temperature scale roughly speaking similar to Celsius, but taking absolute zero as its zero point instead of the freezing point of water (rigorously speaking, its definition is now {{w|2019_redefinition_of_the_SI_base_units#Kelvin|based on the Boltzmann constant}}). {{w|Millikelvin}}s (1/1000 of a Kelvin) are used for high precision temperature work. Frequently this is used in processes of cooling temperatures to nearly absolute zero - such as superconductors or other quantum effects that occur when atoms are almost still. This is suggesting that the symbol appears on a sensitive experimental system probing quantum mechanical behavior that would likely only exist in an advanced laboratory. Any equipment that works down at mK temperatures, or at least to mK precision and accuracy, is likely to be very expensive.

'''nm: Don't shine that in your eye''' {{w|Nanometre}}s are frequently seen in the listed wavelengths for lasers. Pointing a visible or infrared laser at someone's eye is notoriously dangerous; the tightly-focused coherent light can cause permanent damage very quickly.

'''eV: Definitely don't shine that in your eye''' {{w|Electronvolt}} energies are typical of moderate-energy particle beams, produced by accelerating electrons (or protons) over macroscopic voltages. These particle beams can be {{w|Anatoli Bugorski|even more damaging (and are probably a direct reference to Anatoli Bugorski)}} to soft tissues than optical-wavelength lasers.

'''mSv: You're about to get into an Internet argument''' The {{w|millisievert}} is a unit of radiation dose absorbed. It is a very small dosage, but the joke refers to Internet trolls debating the effects of low-dose radiation sources, such as 5G wireless networks. [[Randall|Randall's]] comment may also be referring to [[Radiation]].

'''mg/kg: Go wash your hands''' This unit measures the dose of a drug or other chemical in milligrams per kilogram of body mass. If the appropriate dose - or worse, the lethal dose - is measured in mg/kg (parts per million), then the substance may be quite toxic.

'''µg/kg: Go get in the chemical shower''' A unit 1/1000 times the size of mg/kg. If a dosage is measured in micrograms per kilogram (parts per billion), any accident probably requires whole-body decontamination procedures.

'''π or τ: Whatever answer you get will be wrong by a factor of exactly two''' π is defined as the ratio of a circle's circumference to its diameter, while τ is defined as the ratio of a circle's circumference to its radius (and is therefore equal to 2π). {{w|pi|π}} has been used as the primary constant for describing the circumference and area of circles millennia ago, but proponents of {{w|Turn (angle)|τ}} claim that τ is more natural in most contexts since it makes working in radians more straightforward. Actually, the "Pi" symbol used to be occasionally used for the constant now called Tau. The joke here is that whichever constant you use, it will probably be the wrong one (off by a factor of two, one way or the other) for the formula you are trying to use. The debate over Pi vs. Tau was solved by Randall in this compromise: [[1292: Pi vs. Tau]].

==Transcript==
:[A list with 14 different scientific constants/symbols are shown. Next to each symbol is a description. Above the list is a heading and beneath that a subheading.]
:::::<big>Symbols</big>
::::And what they mean

:::d⁄dx    An undergrad is working very hard
:::∂⁄∂x    A grad student is working very hard
:::ħ       Oh wow, this is apparently a quantum thing
:::Rₑ     Someone needs to do a lot of tedious numerical work; hopefully it's not you
:(Ta⁴ - Tb⁴)    You are at risk of skin burns
:::NA    You are probably about to make an incredibly dangerous arithmetic error
:::µm    Careful, that equipment is expensive
:::mK    Careful, that equipment is very expensive
:::nm    Don't shine that in your eye
:::eV     '''''Definitely''''' don't shine that in your eye
:::mSv  You're about to get into an internet argument
::mg/kg      Go wash your hands
::µg/kg      Go get in the chemical shower
::π or τ      Whatever answer you get will be wrong by a factor of exactly two

{{comic discussion}}

[[Category:Math]]
[[Category:Physics]]
[[Category:Chemistry]]
[[Category:Biology]]
[[Category:5G]]

Talk:2350: Deer Turrets

2024-03-12T15:20:42Z

172.70.90.92:

There's no "next" button on [[2349]]? --[[Special:Contributions/108.162.219.250|108.162.219.250]] 18:44, 24 August 2020 (UTC)
:The reason there's no Next button is that it's the newest comic. --[[Special:Contributions/162.158.158.43|162.158.158.43]] 21:04, 24 August 2020 (UTC)

Is this about something? I mean, it could be a commentary on the way politics handled Covid, some politicians taking terrible decisions, then saying it was a mistake and that science is still learning, but then still taking terrible decisions afterwards. [[Special:Contributions/141.101.69.83|141.101.69.83]] 21:02, 24 August 2020 (UTC)

:That's definitely my take on this comic. The similarity with certain political meetings in the covid situation is quite abvious, in my opinion. [[Special:Contributions/90.127.120.72|90.127.120.72]] 16:02, 25 August 2020 (UTC)

:I saw it as a send up of the agile development practices of Silicon Valley and many other businesses today. The principle is that if an idea is going to fail, you want it to fail fast, so you can learn and pivot quickly to a better idea. This can ideally result in a culture that values constructive failure. If taken too far, it can lead to sloppy practices, waste, and outright harm to customers and to the public. [[User:JSekula71|JSekula71]] ([[User talk:JSekula71|talk]]) 20:12, 27 August 2020 (UTC)

The thing about icebergs, is that 9/10ths of them would be ''on fire'', if they weren't kept underwater. Truth! [[Special:Contributions/162.158.155.192|162.158.155.192]] 22:17, 24 August 2020 (UTC)

(to the tune of “Do-Re-Mi”) ''Does are near, now flee in fear; The ray will boil everyone; The antlered gun is taking aim; Now it’s vaporised my lung...'' [[User:Lightcaller|Lightcaller]] ([[User talk:Lightcaller|talk]]) 22:43, 24 August 2020 (UTC)

Deer don't gallop. Are you sure that's about the deer? [[Special:Contributions/172.69.33.187|172.69.33.187]] 22:54, 24 August 2020 (UTC) Dear IP_address, deer most certainly do gallop. Since I'm a nice guy (rarely), I LMGTFYed that to confirm. [[User:Cellocgw|Cellocgw]] ([[User talk:Cellocgw|talk]]) 12:35, 25 August 2020 (UTC)
:No deer run. [[Special:Contributions/172.69.34.210|172.69.34.210]] 02:25, 26 August 2020 (UTC)
:Some deer run. [[Special:Contributions/162.158.159.116|162.158.159.116]] 16:04, 24 September 2020 (UTC)

I don't think you can build an iceberk-proof airship. Or at least, you won't get it into air because it would be too heavy. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 00:21, 25 August 2020 (UTC)

You make a ship iceberg proof by making it fly. You can't be sunk if you fly over. [[User:Hax|Hax]] ([[User talk:Hax|talk]]) 07:16, 25 August 2020 (UTC)

I think the "Is it really??" means "Is it really okay?", not "Is it really a mistake?". [[Special:Contributions/162.158.183.137|162.158.183.137]] 11:03, 25 August 2020 (UTC)

Gotta keep on trying 'til you run out of cake. [[Special:Contributions/108.162.210.188|108.162.210.188]] 13:18, 25 August 2020 (UTC)

Some airplanes crash into mountains. Some mountains look like icebergs. Therefore, some airplanes crash into some icebergs. [[User:These Are Not The Comments You Are Looking For|These Are Not The Comments You Are Looking For]] ([[User talk:These Are Not The Comments You Are Looking For|talk]]) 03:51, 1 September 2020 (UTC)

The current explanation says, “Deer are well-defined by their tendency to move around” - though I’m not too familiar with deer (they’re not common animals in my place), I’m not sure if this explanation is okay. Maybe “well-known” instead of “well-defined”? Intuitively, the set {A | A has tendency to move around} is not well-defined... [[User:Yosei|Yosei]] ([[User talk:Yosei|talk]]) 14:01, 20 March 2021 (UTC)

“in their general direction” – Sounds like a ''Monty Python and the Holy Grail'' reference to me (“I fart in your general direction!”) --[[Special:Contributions/172.70.242.44|172.70.242.44]] 23:18, 21 September 2023 (UTC)

== When Mao went to clear the sparrow but for the locust, it was 42% as deadly as fauna-mounted autocannons ==

Just saying. [[Special:Contributions/172.69.34.150|172.69.34.150]] 07:17, 25 August 2020 (UTC)

Didn't the designer of the Titanic go down with ship? SanFranSam [[Special:Contributions/172.69.35.53|172.69.35.53]] 04:25, 26 August 2020 (UTC)

== Laughed ==

The part that made me laugh the hardest was the Citation Needed on the claim that there are no flying icebergs! Well played.
[[User:BlakeFelix|BlakeFelix]] ([[User talk:BlakeFelix|talk]]) 11:03, 26 August 2020 (UTC)

Ok, this iceberg (https://www.explainxkcd.com/wiki/index.php/2829:_Iceberg_Efficiency) could definitely pose a threat to an airship. Perhaps it's Black Hat's way of justifying his grandfather? IDK {{unsigned ip|172.70.231.77|12:32, 12 March 2024}}

1964: Spatial Orientation

2024-02-03T03:13:18Z

172.70.90.92: /* Explanation */ Proper name for Earth, Moon, Sun. Leaving/clarifying "ful ..." and "new moon"s, plus sunrise (as events). Converting URL-link to wikipedia into 'nicer' template-link for same (the edit that I came here for, before noticing the rest...)

{{comic
| number = 1964
| date = March 7, 2018
| title = Spatial Orientation
| image = spatial_orientation.png
| titletext = Here, if you know the number of days until the vernal equinox, I can point you to the theater using my pocket Stonehenge.
}}

==Explanation==
Location in space is always relative, as we cannot observe empty space itself and find an absolute location. Planets are subject to different types of motion, including rotation, precession, and others.

;The Earth (rotation)
[[Cueball]] starts by stating that as he is facing west, the Earth's spin will be carrying him backwards. Except at the poles, everything on Earth's surface is being rotated to the east, "toward" the rising Sun in the east or "away" from the setting Sun in the west.

On the equator, Earth's spin is about 464 meters per second (with 464 m being 1/60 of 1/60 of 1/24 of Earth's equatorial circumference of 40070 km, based on the number of seconds in a day, ignoring the difference between sidereal and ephemeris days). So, on the equator at sunrise, on the day of a March or September equinox, this spin, by itself, would take someone toward the Sun at about 464 meters per second.

This spin would be slower than 464 m/s at 39 degrees North. The average radius of the Earth is 6371 km. This means that the distance from a line between the poles through the center of the Earth to a point on Earth's surface at 39°N is approximately 6371 km times the cosine of 39° (0.68 radians), which is 4951 km. So, the distance around the Earth along the 39° latitude "line" is 2π times 4951 km, which is about 31,109 km. (This estimate ignores the oblateness of the Earth.) The rotation of the Earth on its axis would transport points on Earth at 39° latitude to the east at 360 meters per second (1/60 of 1/60 of 1/24 of 31,109). Determining how the direction that is currently east for Cueball is oriented relative to the Sun and the solar system depends on some of the issues Cueball identifies later.

;The Earth (orbit)
Cueball then seemingly corrects himself in his head, having accounted for the fact that the Earth is also revolving around the Sun.

The Earth's orbit around the Sun is counter-clockwise, when viewed from above the North Pole looking down. Earth's counterclockwise orbit around the Sun means that, for most latitudes, the direction the Earth is moving around the Sun corresponds roughly to west at noon, and east in the middle of the night. The Earth is spinning, so "east" from any given location on the surface is not always the same direction relative to the Sun.

The speed of the Earth's orbit around the Sun depends on the time of year. The Earth moves faster around the Sun when it is closest to the Sun in early January, and slower when it is far away in early July (which may be counterintuitive to those in the northern hemisphere). However, Earth's average orbital speed is reportedly about 29.78 kilometers per second, with Earth's average distance from the Sun being a bit less than 150 million kilometers. Earth's orbit around the Sun is nearly circular, with an {{w|Orbital eccentricity|eccentricity}} of just 0.0167.

;Earth's tilted axis
Cueball knows that the Earth's axis is tilted (by 23°) relative to its orbit around the Sun and knows that he is 39° north of the equator, but is unsure how to combine this information to figure out his orientation relative to the plane of the solar system.

The Earth’s orbit around the Sun, under Keplerian assumptions, is an ellipse, which lies within a plane. Furthermore, the entire solar system, to some extent, lies within a plane, since the orbital inclinations of Mars and the gas and ice giants are within 2½° of Earth’s and the orbital inclinations of a major body in the solar system (such as a planet) rarely, if ever, varies from that of another by more than 8°. With the exception of Eris, all planets and dwarf planets have an orbital inclination within about 30° of Earth’s.

Cueball is attempting to determine where the plane of the solar system lies with regard to him. Ignoring any possible difference between Earth’s orbit and this plane, and assuming that Cueball is standing on flat ground, the angle between the line from the center of the Earth through Cueball (which runs through his body parallel to his legs and spine if he is standing straight up) and the plane of the solar system can be expressed in terms of two angles: the angle between the plane of Earth’s equator and the solar plane, and the angle between the Earth’s equatorial plane and the vertical line through Cueball. Cueball is at 39°N, so if Cueball is standing straight up, the angle between the plane of the Earth’s equator and the long axis of his body is also 39°. As stated in the comic, Earth’s axis is currently tilted by about 23.4° (an amount which is very slowly decreasing as part of a 41,000 year cycle).

Cueball is trying to determine whether to add together 39° and 23° to get the angle between himself and the solar system’s plane or subtract them. The answer depends on the time of day and the time of year. On the day of the summer solstice in the northern hemisphere (around June 21), the north pole is tilted toward the Sun, so at the longitude that is currently experiencing solar noon, the solar plane passes through a point that is 23° north of the equator. So, if it is solar noon on the summer solstice, Cueball should subtract the angles to find that the direction his body is pointing is roughly 16° away from the solar plane. If he were to somehow lean so that he could tilt his body 16° to the south, the solar plane would pass through the vertical axis of his body and his scalp would be pointed directly toward the Sun. On the other hand, on the day when the northern hemisphere is experiencing the winter solstice (around December 21), the northern hemisphere is pointing away from the Sun, so at solar noon on that day, he would add the angles together to find that his vertical stance is 62° away from the plane of the solar system. (The Sun is never truly directly overhead at latitudes further from the equator than 23.4°. At arctic latitudes that are less than 23.4° from the north pole – more than 67° north of the equator - the Sun is not visible on the day of the winter solstice even when it is noon.)

If it is not a solstice day, or if it is not noon, the calculations could become more complicated. The comic was uploaded roughly two weeks before the northern hemisphere’s spring equinox. Cueball notices that the Sun is “passing over his left shoulder” as he faces west. At temperate latitudes in the northern hemisphere, the Sun would be to the left of a person facing west around midday almost any time of year, although how many degrees to the left depends on the calculations discussed above.

An easier way to identify a line that is aligned with the solar plane would be to simply point directly at the Sun (without hurting his eyes). Since the distance between Cueball and the center of the Earth is minuscule compared to the distance between the Earth and the Sun, if he simply points directly at the Sun (preferably without looking directly at it), his arm and finger will be pointing in a direction that is basically parallel to the line connecting the Earth and Sun, which obviously lies on the plane of the Earth's orbit. The Earth's position will have changed minimally in the eight minutes it took the Sun's light to reach Earth, so the apparent direction to the Sun matches the actual direction. However, this will only provide one line that lies on the plane of the solar system and a line is insufficient to uniquely identify a plane.

;The Moon
Cueball knows about the Moon's path across the sky and knows that its orbit around the Earth appears counter-clockwise when viewed from above the North Pole, but is confused about whether the Moon is moving toward the Sun or away from it.

Like the Earth, the Moon, when viewed from above Earth’s North Pole, both orbits counterclockwise and rotates on its axis counterclockwise (with equal rotational periods such that the same side of the Moon always faces us). (In fact, almost every body in the Solar System both orbits the body it is orbiting counterclockwise and spins on its axis counterclockwise, with the rotational axes of Venus and Uranus being major exceptions.)

A {{w|new moon}} happens when the Moon is closer to the Sun than the Earth is, thus casting the near side of the Moon in darkness because it is the far side of the Moon that is facing the Sun. Conversely, a {{w|full moon}} happens when the Moon is on the other side of the Earth from the Sun; this is why a lunar eclipse can only occur during a full moon. In that sense, it could be said that the Moon is moving perpendicular to the line between it and the Sun at the time of the full moon and the new moon, moving toward the Sun after the full moon until the next new moon, and moving away from the Sun after the new moon until the next full moon.

In another sense, since the Moon is orbiting the Earth and the Earth’s orbit around the sun is elliptical, it could be said that the Moon is getting closer to the Sun whenever Earth is moving toward its perihelion, the point in its orbit that is closest to the Sun, around January 2 to January 5, and moving away as the Earth moves toward its aphelion, the point in its orbit that is furthest from the Sun, around July 3 to July 6. (Yes, the Earth is closest to the Sun in January, despite what those in the northern hemisphere who are tilted away from the Sun at that time may think.) In yet another sense, since the Moon follows the path of the Earth, and the Earth’s orbit around the Sun is roughly circular, and the instantaneous motion of an object in a circular orbit is always perpendicular to the radius connecting it to the orbited body, it could be said that the Moon is always moving perpendicular to the line connecting the Earth and Sun, which is at most a fraction of a degree away from the line connecting the Moon and the Sun.

The semi-major axis of the Moon’s orbit around the Earth (the furthest distance between the Moon and the center of its orbit) is 384,400 km. Compared to the semi-major axis of Earth’s orbit around the Sun, which is 149,600,000 km, the axis of the Moon’s orbit is only 0.26% as large. The Moon’s orbital period is 27.3 days, but its synodic period (the time between full moons; the time it takes the Moon to reappear at the same point in the sky) is 29.5 days.

Cueball internally attempts to orient himself amidst the galactic chaos but is confused and has to restart. It is then revealed to the reader, that some passersby were only trying to ask Cueball for directions to the theater, and he was just grossly overthinking it. (A recurring theme in xkcd. See: [[222: Small Talk]], [[439: Thinking Ahead]], [[1643: Degrees]]). One can imagine Cueball having his mind in astrophysics so much that he needs to calculate the angle of the road relative to the plane of the galaxy to determine which way a destination is in conversational terms.

In the title text, Cueball mentions he has a pocket Stonehenge. During the equinoxes the sun lines up with the actual Stonehenge's pillars. Assuming you were at the actual monument, armed with the date you could calculate the cardinal directions based on the Sun's location relative to the pillars.

==Transcript==
:[Cueball appears to be tilted on a descending slope, with his arms held out. There is a thought bubble above his head, with the top, left and right of the bubble cut off due to its size. His thoughts are arranged into four paragraphs in the bubble.]
:Cueball (thinking): I'm facing West so the Earth's spin is carrying me backward. But our orbit is carrying me forward around the Sun.
:The Sun is passing over my left shoulder. I'm at 39°N, so I'm tilted. But wait, Earth's axis is tilted by 23°. Do I add or subtract that to get the tilt of the Solar System?
:Ok, I see the Moon. It follows the Sun's path, but is it moving toward it or away? I know it orbits counterclockwise from the North...
:My head hurts. Let me start over.

:[Two off-screen voices coming from the bottom right of the panel.]
:Off-screen voice #1: He's just standing there. Hey, do you know which way the theater is or not?
:Off-screen voice #2: Let's ask someone else.

:[Caption below the panel:]
:I spend way too much time trying to work out my orientation relative to other stuff in the universe.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Astronomy]]

Talk:887: Future Timeline

2024-02-01T21:12:09Z

172.70.90.92:

The explanation is really messed up. You can hardly tell where one year ends and the next begins. Can someone who's better at editing than me fix this, perhaps by putting a line across the page after each year? [[User:GizmoDude|GizmoDude]] ([[User talk:GizmoDude|talk]]) 19:11, 7 April 2016 (UTC)

This one slipped under the transcripting radar. I may do it. --[[User:Quicksilver|Quicksilver]] ([[User talk:Quicksilver|talk]]) 20:52, 17 August 2013 (UTC)
:Do not talk about radars, just do it. The transcript is done right now, but the explain section still does need a big radar!--[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 20:20, 18 August 2013 (UTC)

Find the song! I have no idea so far but the repeating phrase "Social security trust fund exhausted" should match a refrain.--[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 20:20, 18 August 2013 (UTC)

They now have the dogs driving cars... http://www.youtube.com/watch?v=BWAK0J8Uhzk Let's not wait for 2053.[[Special:Contributions/173.245.54.90|173.245.54.90]] 21:01, 20 March 2014 (UTC)

Out of curiosity (I'm new to the standards of explainxkcd), are out of date pages considered incomplete? Or is it up to editors to chose when to update a pages explination. I would assume the former, except that would make maintaining the pages significantly more difficult. Also, referencing the Linux takes over. Since Android is now a part of the libux kernel,should thia be changed? It would definently put linux over the 50% mark. [[User:Mrmakeit|Mrmakeit]] ([[User talk:Mrmakeit|talk]]) 05:03, 4 April 2014 (UTC)
:Pages can not become out of date, as they refrence the meening of the comic at the time of creation. [[Special:Contributions/108.162.216.209|108.162.216.209]] 15:24, 10 December 2014 (UTC)

I would change the 2nd paragraph to say that the entirety of the search results are a super long set-up and "All your base..." is the punch-line. [[User:Smperron|Smperron]] ([[User talk:Smperron|talk]]) 08:46, 10 November 2014 (UTC)

I would correct the entry in 2014 that says that the Taliban are the organisation responsible for the September 11th attacks. The more accurate explanation would be that The US believed Al Qaeda (the real organisation responsible) were hiding out in Afghanistan and that defeating the Taliban, and bringing stability to the country was an important stepping stone towards finding Osama Bin Laden. Of course we now know he was in Pakistan all along, but still that was the original rationale for invading Afghanistan.--[[Special:Contributions/141.101.98.192|141.101.98.192]] 15:27, 15 December 2014 (UTC)

This further details stuff is wrong about the comic. The lines are just random answers to Google searches. There is no explanation. I move to remove this table, or convert it into links or summaries of the articles in the links. This sucks. It is good enough as it is now without the table (as the table is random and the explanations on the table are incorrect. [[Special:Contributions/108.162.216.209|108.162.216.209]] 22:12, 15 December 2014 (UTC)
:Let's get to work on the table then. I'm adding suitable references to incomplete sections to aid as jumping off points, from where further expansion can be done on a case-by-case basis. Can you provide some inspiration as to which explanations are most egregiously in need of correction? [[User:Pmw57|Pmw57]] ([[User talk:Pmw57|talk]]) 01:44, 8 January 2015 (UTC)

As of 2014 I have noticed that a lot of US sites are moving from html to closed sources such as Adobe so the quote: "The prediction about GNU/Linux Operating Systems is ambiguous" is now fighting through government agencies. Users of Linux trying to access the volcano archive (once supplied by listserv using linux) now have to get access via Windows machines. This has to be the saddest computing news in a long time. [[User:Weatherlawyer|Weatherlawyer]] ([[User talk:Weatherlawyer|talk]]) 08:19, 4 January 2015 (UTC)

“The prediction about GNU/Linux Operating Systems is ambiguous, as Android (based on Linux) constitutes nearly 50% of the mobile OS market” — GNU/Linux refers to an operating system consisting of the GNU userland toolchain over the Linux kernel. Android is based on Linux but not GNU, therefore, it is irrelevant in GNU/Linux context. [[Special:Contributions/108.162.230.107|108.162.230.107]] 11:18, 23 January 2015 (UTC)

Can we change this to Incomplete explanation of the month? [[User:Foldark|Foldark]] ([[User talk:Foldark|talk]]) 22:03, 28 March 2015 (UTC)

2145:War... War never changes
(the Great War happens) {{unsigned ip|173.245.54.252}}

Is it just my reading, or does it say "ACHEIVE" instead of "ACHIEVE" where it says something about 192 UN member nations achieving millennium development goals in the comic? (It's under 2015.) --[[Special:Contributions/172.68.55.70|172.68.55.70]] 21:45, 10 November 2016 (UTC)
:No, it reads like this for me too. (Even on the original comic page, where I'd expect it to have been long fixed already.) --[[Special:Contributions/172.68.11.87|172.68.11.87]] 19:35, 11 November 2016 (UTC)

Some of these predictions seem very realistic. [[Special:Contributions/162.158.59.172|162.158.59.172]] 00:22, 25 December 2016 (UTC) Jawa457

I am not sure if this needs to be added or not since it was not happening when the comic was produced and it is not the government doing it but a private tech company microchipping its employees in 2017 [https://www.google.com/search?q=microchipping+workers&rlz=1C1OPRB_enUS709US709&oq=microchipping+workers&aqs=chrome..69i57j0.3111j0j7&sourceid=chrome&ie=UTF-8 Google results] since I do not know which news articles will disappear over time. [[Special:Contributions/162.158.62.231|162.158.62.231]] 12:03, 17 August 2017 (UTC)

I think we can delete incomplete tag. --{{unsigned|1337-PI|04:21, 26 February 2021 (UTC)}}

I feel it would have been funny, if a bit confusing, if the first few years numbers after 2037/2038 started referring to, e.g. 1970, 1971, before suddenly "Year 2038 bug finally exterminated". You know it's gonna happen... at least to some poor schmucks somewhere in the world.--[[User:Twisted Code|Twisted Code]] ([[User talk:Twisted Code|talk]]) 12:52, 22 November 2022 (UTC)

; The link is bad

[//origo.hu/gazdasag/20180822-az-usa-allamadosaga-rekordot-dontott.html Here]'s a working one. [[Special:Contributions/162.158.93.27|162.158.93.27]] 14:57, 22 December 2018 (UTC)

How do I add an Incomplete tag to the top? It's now 2024 so more stuff needs to be added. {{unsigned|Danger Kitty|20:18, 1 February 2024}}
:You just need the {{template|incomplete}} template.
:e.g. <code><nowiki>{{incomplete|This page will need updating to account for facts known up until the start of 2024}}</nowiki></code>, but you might instead prefer a version that follows a comment format more of <code>Created by THE 2024 EQUIVALENT OF A BOT - Needs to be updated to the current year. Please change this comment when editing this page. Do NOT delete this tag too soon.</code> to blend in with the 'starter' version currently used and then tweaked... [[Special:Contributions/172.70.90.92|172.70.90.92]] 21:12, 1 February 2024 (UTC)

Talk:1026: Compare and Contrast

2024-01-12T04:47:01Z

172.70.90.92:

Commenter J. Curwen posted a link to a modern paraphrasing of Sonnet 18. I think it would be appropriate to repost it here.
http://www.shakespeare-online.com/sonnets/18detail.html [[User:Lcarsos|lcarsos]] ([[User talk:Lcarsos|talk]]) 17:58, 16 August 2012 (UTC)

Shakespeare woos Randall with charts? Holy ambiguous dependent, Batman! - [[User:Frankie|Frankie]] ([[User talk:Frankie|talk]]) 12:47, 26 January 2013 (UTC)

I prefer to believe that thou art in fact harbinger of hurricane season, and a major cause of heatstroke in the elderly ;) [[User:PotatoGod|PotatoGod]] ([[User talk:PotatoGod|talk]]) 05:26, 22 December 2017 (UTC)

Are we sure that Sonnet 18 is *the* most famous sonnet? Is opening the explanation in this way a subtle reference to xkcd 1368 ("one of the most recognisable arches in St. Louis")? [[Special:Contributions/172.70.90.92|172.70.90.92]] 04:47, 12 January 2024 (UTC)

Talk:2867: DateTime

2023-12-17T15:49:55Z

172.70.90.92:

Comics like this are why this wiki exists. [[Special:Contributions/172.70.100.172|172.70.100.172]] 23:30, 13 December 2023 (UTC)
:The time falsehoods gist linked above is a really good explanation about why a programmer might panic about calculating time. Especially the ones about calling "getCurrentTime()" twice in a row doesn't always mean the results are in the order you think they were called, or even different values. t2 might very well be the same or less than t1. It can be maddening. [[Special:Contributions/162.158.197.149|162.158.197.149]] 23:40, 13 December 2023 (UTC)
::The last item is the most important to me: ''Users prefer to use the local timezone.'' This causes so much frustration while browsing the web! [[File:PissedOff.gif]] --[[Special:Contributions/162.158.110.68|162.158.110.68]] 00:26, 14 December 2023 (UTC)
::Worth noting that events can take place over long periods. A sunspot or an illness or a relationship doesn't happen at a single point in time, it takes place over days or weeks or longer. When did it "start"? Who knows? Also I miss calling TI4-1212 here in DC. [[Special:Contributions/172.70.175.27|172.70.175.27]] 01:39, 14 December 2023 (UTC)
::Out of curiosity, could someone explain the item in that time falsehoods list that says "Months have either 28, 29, 30, or 31 days"? My guess is that it's a reference to their being more calendars in the world than Gregorian? But I'm not sure if there's more than that going on, there.[[User:ModelD|ModelD]] ([[User talk:ModelD|talk]]) 18:18, 14 December 2023 (UTC)
:::Isn't that true of Gregorian calendars? February has 28 or 29 depending on the year, AJSN have 30 and JMMJAOD have 31.[[User:Gavin|Gavin]] ([[User talk:Gavin|talk]]) 18:33, 14 December 2023 (UTC)
::::It's saying that "months have either 28, 29, 30, or 31 days" is a falsehood. The first one that comes to mind is the [https://www.timeanddate.com/calendar/julian-gregorian-switch.html switch from the Julian calendar to the Gregorian calendar]: "In North America, for example, the month of September 1752 had only 19 days, as the day count went straight from September 2 to September 14". [[Special:Contributions/172.70.43.108|172.70.43.108]] 21:03, 14 December 2023 (UTC)
:::: (Ninjaed, with an actual example! But retrying reply anyway as it had other details.) But how many days had <insert your choice of month(s) during which a given system changed from Julian to Gregorian>? I think possibly, without looking up when each and every transition occured, below 20 days is possible. (As in the ''n''th of one month to the ''n''th of the next is less than 20 days, for the right month and a number of ''n''s. For other ''n''s, you can only actually count from the month before to the month ''after'' (two full calendar months), the daycount for that being below the typical bimonthly stretch of 59, 60, 61 or 62 days (under more standard conditions)... [[Special:Contributions/172.70.90.48|172.70.90.48]] 21:07, 14 December 2023 (UTC)

Related insanity on Computerphile with Tom Scott: https://m.youtube.com/watch?v=-5wpm-gesOY [[User:Fabian42|Fabian42]] ([[User talk:Fabian42|talk]]) 03:54, 14 December 2023 (UTC)

Even with just Special Relativity, the question doesn't really make sense, because the answer will depend on the inertial reference frame. "Impossible to know and a sin to ask" is not a bad way to describe questions about non-invariants. [[Special:Contributions/162.158.154.189|162.158.154.189]] 08:09, 14 December 2023 (UTC)
:Is it even ''possible'' for two observers to agree on the answer and be sure that it's correct for both of them? [[User:BunsenH|BunsenH]] ([[User talk:BunsenH|talk]]) 16:53, 14 December 2023 (UTC)

I can see Randall's point, so for your average everyday programming I'd say "please use a library function instead of trying to do it yourself, or you'll end up like the guy in the lower frame..." --[[User:IByte|IByte]] ([[User talk:IByte|talk]]) 11:02, 14 December 2023 (UTC)

When I googled "DateTime" all I came up with was Python libraries, nothing about relativity or other effects. Is that what Randall's talking about? [[Special:Contributions/172.69.22.125|172.69.22.125]] 22:03, 14 December 2023 (UTC)
:Ideally, the standard library functions for a language would cover many of the "quirks" without the programmer having to worry about remembering the details. The required inputs for the functions would be sufficient to determine the necessary offsets. But programmers still have to be careful about some of the issues, and not all languages (and their libraries) are sufficient for all situations. When things like relativistic effects have to be taken into account, the usual languages (and their libraries) don't have the needed flexibility/complexity and precision. [[User:BunsenH|BunsenH]] ([[User talk:BunsenH|talk]]) 00:18, 15 December 2023 (UTC)
::I should clarify, I'm not saying the Python library doesn't have functions for those quirks. I'm just asking: what does Randall mean when he says "DateTime" (two capital letters, no space, as per the comic title)? Is he talking about the Python library? Or something else I didn't find yet?[[Special:Contributions/172.69.134.163|172.69.134.163]] 02:51, 15 December 2023 (UTC)
:::Doesn't matter. For one the usage of CamelCase in such cases is pretty much standard regardless of language and besides of that the problems he's talking about/implying are pretty much true for every language. [[User:Elektrizikekswerk|Elektrizikekswerk]] ([[User talk:Elektrizikekswerk|talk]]) 10:58, 15 December 2023 (UTC)
::::OP, I suspect your Google cookies/whatever are just too used to serving you answers to Python questions, as being the answers you most like to visit. I just added to the "it's definitely Python" explanation another three more (of an easy dozen or so, before I gave up) links that I found from searches for "DateTime library <language>", or equivalent. And even those that didn't give that exact wording in their actual modules tended to have "What's the standard DateTime library for <foo>..?" as an FAQ (including LISP, Forth, COBOL, even a few for one or other Assembler variant, which I tried just for laughs) because the concept of "DateTime" record is just too ubiquitous (whether stored as "seconds since epoch" a distillation of an ISO format or just "[yy]yymmddHHMMSS[.###]" pseudo-value/string) and goes way back before Python (1991+) as you can find mentions of one kind or other in my old Ada (c1980) and Pascal (c1970) manuals/references. [[Special:Contributions/172.70.162.206|172.70.162.206]] 15:47, 17 December 2023 (UTC)

:::The majority of libraries that provide time-calculation services call it something along the lines of DateTime. The reason you're getting Python results is because Python is currently the most popular programming language, especially for people learning to program. --[[Special:Contributions/172.71.150.154|172.71.150.154]] 19:51, 15 December 2023 (UTC)

The recently-added link for "hyperbolic" goes to a W'pedia page for "Hyperbolic motion (relativity)". This is obviously intended as a joke, but I'm not convinced that an unmarked joke like this is appropriate. [[User:BunsenH|BunsenH]] ([[User talk:BunsenH|talk]]) 16:04, 15 December 2023 (UTC)
:I highly doubt this was meant as a joke, I'm quite convinced this was genuinely added to be helpful and fail to see how this COULD be a joke. ??? If it's not the correct concept it's too subtle to be a joke. [[User:NiceGuy1|NiceGuy1]] ([[User talk:NiceGuy1|talk]]) 05:46, 17 December 2023 (UTC)

My first impression of the comic was that Randal was talking about romantic dates, and that participants may be too distracted to accurately recall when specific events occurred during them. [[User:These Are Not The Comments You Are Looking For|These Are Not The Comments You Are Looking For]] ([[User talk:These Are Not The Comments You Are Looking For|talk]]) 02:22, 17 December 2023 (UTC)

2288: Collector's Edition

2023-12-15T11:33:14Z

172.70.90.92:

{{comic
| number = 2288
| date = April 3, 2020
| title = Collector's Edition
| image = collectors_edition.png
| titletext = I'm sure you can find some suitable worldbuilding material if you scavenge through the archives.
}}
{{TOC}}
*To experience the interactivity of the game, visit the {{xkcd|2288|original comic}}.

==Explanation==
This was the tenth [[:Category:April fools' comics|April fools' comic]] released by [[Randall]]. The previous one was [[2131: Emojidome]] from Monday April 1, 2019. The next became [[2445: Checkbox]] released on Thursday April 1, 2021.

It is a large draggable image that acts as a shared virtual sandbox for users to interact. Chests are "Items" (small and often humorous images) which could be collected from other comics, and then placed in this image by viewers, but today they are no longer dropped. The collection then updated for all viewers in real-time. Multiples of the same item are often seen.

There is a "backpack" at the bottom, similar to backpacks in video games containing items collected by the player. As hinted by the title text, items could be found by visiting different xkcd comics/pages. Randomly, some pages would have a treasure chest which contained the sticker related to the page. The hint would refer to the page which currently had a chest.

The sticker images can be seen at <nowiki>h</nowiki>ttps://xkcd.com/2288/collectors/static/loot/loot_'''XXX'''.png, where XXX is a number from 001 to 253. Additionally, some images can be found at custom URLs, for example the periodic elements can be found at <nowiki>h</nowiki>ttps://xkcd.com/2288/collectors/static/loot/element-'''XX'''.png, where XX is the element, and text loot at <nowiki>h</nowiki>ttps://xkcd.com/2288/collectors/static/loot/loot-words-'''X'''.png, where X is the sentence.

===Hints===
{| class="wikitable"
!Hint
!Comic
!Unlocked item
!Item image
!Notes
|-
|Doctors in a row||Maybe [[1529: Bracket]] or [[497: Secretary: Part 4]]? Need confirmation.||Cory Doctorow || [[File:2288_loot_019.png|50px]] || These comics all have the same hint, but only one will have the chest
|-
|Get out the (US) vote||[[2224: Software Updates]]|| Statue of liberty ||[[File:2288_loot_246.png|75px]]||
|-
|Find a box of nice stuff on a picture with words like these|| [[1133: Up Goer Five]] [[ 1375: Astronaut Vandalism ]](maybe incomplete) || Signpost || [[File:2288_loot_126.png|75px]] ||
|-
|Plug in or find another power source||[[1373: Screenshot]]|| ||[[File:2288_loot_228.png|50px]] or [[File:miniloot-words-dispenser.png|75px]] (maybe incomplete)||
|-
|Sweet dreams, kitty||[[729: Laser Pointer]] (maybe incomplete)|| Cat licking laser point || [[File:2288_loot_090.png|75px]] ||
|-
|What is this hint pointing to? Hell if I know.||[[1052: Every Major's Terrible]]||2 + lightbulb = boat||[[File:2288_loot_185.png|75px]]||
|-
|Somebody set up us the bomb||[[286: All Your Base]]||Exploding rock||[[File:loot_197.png|75px]]||
|-
|Cowabunga||[[1412: Teenage Mutant Ninja Turtles]] (maybe incomplete)||Women Science Fiction Authors || [[File:loot_175.png|75px]] || [[197: Ninja Turtles]] also works
|-
|I want to believe||[[2156: Ufo]]||Ufo||[[File:loot_210.png|75px]]||
|-
|Bleeped||[[290]], [[398]], [[430]], [[447]], [[533]], [[549]], [[677]], [[724]] or [[1671]]|| *$@#! ||[[File:loot_044.png|75px]]||Comics that involve swearing
|-
|why waste time say few word when lot word do trick||[[7]], [[111]], [[139]], [[143]], [[179]], [[217]], [[445]], [[470]], [[822]], [[823]], [[1022]], [[1247]], [[1491]], [[1921]], [[1991]], [[2182]] or [[2231]]|| First Annual Award for Excellence in Being Very Smart ||[[File:loot_159.png|75px]]||
|-
|Cooler than electric scooters||[[139]], [[409]], [[577]], [[578]], [[579]], [[580]] or [[581]]||An electric skateboard||[[File:loot_006.png|75px]]||
|-
|Take it from the top||[[1: Barrel - Part 1]] (maybe incomplete)||I am a turtle from [[889: Turtles]] || [[File:loot_095.png|75px]] ||
|-
|I accept the yucca gnocchi, this meal is a success!||[[1713: 50 ccs]] (maybe incomplete)||Man carrying parentheses from [[297: Lisp Cycles]] || [[File:loot_031.png|75px]] ||
|-
|Catch up on the news||[[1699: Local News]] (maybe incomplete)|| || ||
|-
|Participation trophy||[[2288: Collector's Edition]] (maybe incomplete)|| Server rack || [[File:loot_096.png|75px]] ||
|-
|Find an opportunity for a sojourn||[[665]], [[681]], [[695]], [[1091]], [[1504]], [[1613]], [[1663]] or [[2111]]||Opportunity Mars rover from [[2111: Opportunity Rover]]||[[File:loot_161.png|75px]]||
|-
|Tastier than tau day||[[179: e to the pi times i]] (maybe incomplete)||First annual award for excellence in being very smart || [[File:loot_159.png|75px]] || Need to find out the difference between this, and the entry below!
|-
|Tastier than tau day||[[235]], [[396]], [[872]], [[1029]], [[1342]], [[1655]] or [[1967]]|| Pie sign ||[[File:loot_056.png|75px]]|| Published on Pi day
|-
|418 I'm a teapot||[[1866: Russell's Teapot]] (maybe incomplete)||S.S. NASA: Space is Hard || [[File:loot_216.png|75px]] ||
|-
|26th September, 1983||[[2052: Stanislav Petrov Day]]||White dove||[[File:loot_205.png|75px]]||Might also be written "September 26th, 1983". Locale dependent?
|-
|There are 4241 as of Apr 1, 2020||[[1071: Exoplanets]] (maybe incomplete)|| Little girl from [[2264: Satellite]] || [[File:loot_151.png|75px]] ||
|-
|asableiK||[[645: RPS]]|| A reverse Polish hotdog ||loot_079.png|| "Kielbasa" backwards, which is "sausage" in Polish
|-
|Critical mass elements||[[235: Kite]] or [[239: Blagofaire]]|| ||loot_203.png||
|-
|Some Februarys are more equal than others||[[390: Nightmares]]? (maybe incomplete)|| Cueball wheelie from [[272: Linux User at Best Buy]] || loot_036.png || Comic-hint connection largely conjectural; 390 was the first comic published on a leap day.
|-
|Five spice||[[1511: Spice Girl]] or [[1554: Spice Girls]]|| Rock guitarist ||loot_022.png||
|-
|Call the plumber||[[290: Fucking Blue Shells]] (maybe incomplete)|| || loot_058.png ||
|-
|Was it a rat I saw?||[[1632: Palindrome]] (maybe incomplete)|| Cueball with a large sack, pulling a wagon || loot_103.png || or [[1503: Squirrel Plan]] for Cueball holding a balloon caught in a ceiling fan.
|-
|Churchill's gonna have to seriously rehydrate||[[1148: Nothing to Offer]]|| Bottle of soda ||loot_045.png||
|-
|Keep coming back|| || || ||
|-
|A new model released each year||Triggered by visiting all xkcd phone comics in order|| Phone screaming "Noooo" || loot_235.png ||
|-
|Tea Time||Maybe [[581: The Race: Part 5]]? Need confirmation.||All our tea ||loot_232.png||
|-
|Try pattern-matching! Look for comic 'bout alphabet?||[[1045: Constraints]]||Two Tetris blocks||loot_092.png||
|-
|Where's Hilbert?||[[195: Map of the Internet]] (maybe incomplete)|| Hilbert Curve || loot_021.png ||
|-
|Science fiction fetish||[[1585: Similarities]]|| ||loot_202.png||
|-
|The first one was funnier||[[11: Barrel - Part 2]] (maybe incomplete)||Falling feather / Sign "The uncomfortable truths well" || loot_250.png / loot_067.png ||
|-
|It's up to over 260 million cycles!||[[1941: Dying Gift]]|| Megan on a tire swing ||loot_127.png||
|-
|Sleeping Beauty is the same everywhere though||[[2233: Aurora Meaning]] (maybe incomplete)|| Sleeping Cat || loot_163.png ||
|-
|On the internet, nobody knows you're an arachnid||[[1530: Keyboard Mash]] (maybe incomplete)|| Cobwebbed frame from [[1135: Arachnoneurology]]|| loot_191.png ||
|-
|Did James Cameron pay for the rice cooker too?||[[1598: Salvage]] (maybe incomplete)||Rice bowl || loot_152.png ||
|-
|Never going to give you up||[[351]], [[389]], [[396]], [[524]], [[573]], [[609]], [[802]], [[1212]], [[1757]] or [[1981]]|| Cueball in car listening to music ||loot_010.png||
|-
|If red touches yellow, that's 24 ohms||[[1604: Snakes]], [[227: Color Codes]]? (maybe incomplete)|| Yoda with an mp3 player from What If || loot_247.png ||
|-
|An enthusiastic but questionable business opportunity||[[1021]], [[1032]], [[1117]], [[1293]], [[1493]], [[1533]], [[1772]], [[1812]], [[1871]], [[1903]], [[1997]], [[2140]], [[2209]] or [[2277]]|| Beret guy with a goat on leash ||loot_115.png||
|-
|Read the fine manual||[[293]], [[434]], [[456]], [[912]], [[1343]] or [[1692]]|| ||Multiple: loot_106.png, miniloot-words-hair.png, miniloot-words-ominous.png, miniloot-words-eruption.png, miniloot-words-flying.png or miniloot-words-ghost.png (maybe incomplete)||
|-
|That thing's undecimodal!||[[1347: t Distribution]] (maybe incomplete)|| Floating tentacled alien || loot_209.png ||
|-
|Actually, it's Myanmar-Shave now||[[491: Twitter]] (maybe incomplete)||Expensive bottle || loot_253.png ||
|-
|You don't have to find all 99||[[121: Balloon]] (maybe incomplete)||Balloon copter || loot_002.png || Or [[51: Malaria]] ?
|-
|Going in circles||[[378: Real Programmers]] (maybe incomplete)|| Cueball spinning in desk chair || loot_098.png ||
|-
|Couldn't you try knitting, or maybe stamp collecting?||[[37]], [[53]], [[60]], [[75]], [[79]], [[148]], [[168]], [[174]], [[236]], [[259]], [[287]], [[296]], [[326]], [[331]], [[389]], [[437]], [[451]], [[559]], [[590]], [[605]], [[687]], [[719]], [[733]], [[790]], [[845]], [[966]], [[1004]], [[1119]], [[1145]], [[1169]], [[1208]], [[1278]], [[1304]], [[1329]], [[1340]], [[1355]], [[1405]], [[1480]], [[1546]], [[1598]], [[1677]], [[1697]], [[1705]], [[1788]], [[1795]], [[1960]], [[1995]], [[2032]], [[2123]], [[2208]] or [[2252]]||Phishing License sign||loot_158.png||Mostly comics that include "My hobby:"
|-
|It's the ciiiiircle of HONK||[[537: Ducklings]] or [[1729: Migrating Geese]]||DUCKLOOP'D?||loot_069.png||
|-
|Fool me twice||Maybe [[880: Headache]]? Need confirmation.|| Raptor Attack || loot_033.png ||The second April fools' comic
|-
|oOOOoooo||Maybe [[316: Loud Sex]]? Need confirmation.|| Sleeping cat || ||
|-
|Maybe we can ask for new wishes||[[879: Lamp]]||Genie and his bottle||loot_004.png||If you place the genie last, you get another genie (indefinitely) - Needs verification, this may also just be a bug!
|-
|HACK THE PLANET||[[1337: Hack]] (maybe incomplete)|| Crash and Burn in the pool from the end of ''Hackers'' || loot_130.png ||
|-
|Monetization haute couteur||[[20]], [[23]], [[55]], [[123]], [[149]], [[150]], [[162]], [[208]], [[231]], [[242]], [[256]], [[273]], [[285]], [[303]], [[327]], [[377]], [[386]], [[420]], [[435]], [[442]], [[482]], [[505]], [[552]], [[556]], [[585]], [[614]], [[627]], [[657]], [[681]], [[688]], [[705]], [[710]], [[802]], [[821]], [[980]], [[1033]], [[1040]], [[1079]], [[1127]], [[1133]], [[1196]], [[1298]] or [[1428]] (maybe false positives)||Two bags of money ||loot_162.png||
|-
|Maybe writing a script would help||[[1319: Automation]]|| ||miniloot-words-eater.png (maybe incomplete)||
|-
|Go big to go small||[[1365: Inflation]]|| ||loot_245.png||
|-
|Are you projecting||[[850]], [[977]], [[1500]], [[1784]], [[1799]], [[2242]] or [[2256]]||Squirrel on a gun||loot_237.png||
|-
|Do spiders really have six legs||[[8]], [[43]], [[126]], [[427]], [[442]] or [[1110]]|| ||loot_007.png||
|-
|Istanbul or Constantinople or St. Trimble's Island?||[[1688: Map Age Guide]]||Cephalopod||loot_071.png||
|-
|Another rulebook?||[[393: Ultimate Game]]|| Merlin in a chair from [[270: Merlin]] ||loot_037.png||
|-
|Moooooon||[[482]], [[681]], [[1276]], [[1291]], [[1300]], [[1389]], [[1458]], [[1515]], [[1633]], [[1738]], [[1878]] or [[2258]]|| MOOOOOON ||loot_192.png||
|-
|Take a flight from LOL to FFS||[[1937: IATA Airport Abbreviations]]|| ||loot_049.png||
|-
|Everyone deserves a second chnace||All comics searched, no matches|| || ||The misspelling is intentional. [[745: Dyslexics]] would have been a good fit
|-
|Community contribution||[[822]], [[823]], [[824]], [[825]], [[826]]|| [Citation Needed] protester from [[285: Wikipedian Protester]] || loot_035.png ||
|-
|On the other side of the wardrobe||[[665: Prudence]], [[969: Delta-P]] or [[2218: Wardrobe]] (maybe incomplete)||Authentic Reindeer pulling sled from [[1776: Reindeer]] || loot_154.png ||
|-
|Today's your lucky day||[[1053: Ten Thousand]] (maybe incomplete)|| Ms. Frizzle || loot_105.png ||
|-
|[This hint has been redacted due to a copyright claim]||[[1005: SOPA]]|| ||loot_038.png||
|-
|Try a different approach||[[55: Useless]] (maybe incomplete)|| Equals sign ||loot_times.png or loot_div.png (maybe incomplete)||
|-
|The cake is a lie!||[[606: Cutting Edge]]|| Cake ||loot_144.png||
|-
|Joanna, fire.||[[322: Pix Plz]]|| Joanna with EMP cannon ||loot_026.png||
|-
|Everything changes from time to time when the fire nation attacks|| [[965: Elements]] || Symposium || ||
|-
|90KG x 300M||[[382: Trebuchet]]|| Trebuchet ||loot_041.png||
|-
|Copyright Enforcement Brigade||[[344: 1337: Part 4]]|| ||loot_046.png||
|-
|Where Cape Town meets Chukotka||[[1500: Upside-Down Map]]|| Crater ||loot_128.png||
|-
|Take a ride in a barrel||View all five barrel comics in reverse order ([[31]], [[25]], [[22]], [[11]], [[1]])|| Cueball at the door to the playpen-ball-filled apartment from [[150: Grownups]] || loot_005.png ||
|-
|Compiling...||[[303: Compiling]]|| ||loot_030.png||
|-
| || [[2288: Collector's Edition]] || Sheeple eye || loot_109.png ||
|-
| || [[2288: Collector's Edition]] || Time machine from [[1747: Spider Paleontology]] || loot_167.png ||
|}

Click “Expand” to see the full image.
<div class="mw-collapsible mw-collapsed">
[[File:2288_full.png]]
</div>

==Trivia==
* This comic is the 2020 April Fools comic and was supposed to be released Wednesday, April 1st, but did not go live until Friday, April 3. (Friday's comic, [[2289: Scenario 4]], was published a day later for a [[2289: Scenario 4#Trivia|very rare Saturday release]].) However, the message below was displayed on the top of the page from Wednesday until the comic finally went live:
<blockquote>
Note: For technical reasons Wednesday's comic will be posted Thursday instead. Apologies for the delay!
</blockquote>
* This is one of the few comics released four days after the previous one. The last time this occurred was [[2224: Software Updates]].
* Placement is limited to 10,000 horizontal units and 5,000 vertical units from the origin. Users received no messages if they try placing something outside the boundary, with a silent fail with the object not being placed.
* Coordinates are relative to the bottom left corner of the canvas. As the default coordinates are (-370,-277) and the origin is in the center, the displayed portion of the canvas can be found to be twice this in magnitude, 740 x 544 units.
* The comic contains 32993 separate images.
* The most common image is loot-30.png, which appears 2576 times.

==Transcript==

:[Cueball stands to the left of a vibrating box.]
:[The words "Collector's Edition" are written above him and boxed.]

{{comic discussion}}

[[Category:April fools' comics]]
[[Category:Comics featuring Cueball]]
[[Category:Interactive comics]]
[[Category:Dynamic comics]]