explain xkcd - User contributions [en]

Talk:3063: Planet Definitions

2025-03-14T20:13:31Z

172.71.182.225: natural satellite

The one currently posted has Pluto highlighted in the second box and not highlighted in the first box. Too hard to tell if it's trolling or a genuine mistake. :-D

:Apparently a mistake since it's fixed now. [[User:HughNo|HughNo]] ([[User talk:HughNo|talk]]) 19:59, 14 March 2025 (UTC)

And the first one also has a moon hilighted instead I think?? [[Special:Contributions/162.158.126.5|162.158.126.5]] 15:59, 14 March 2025 (UTC)

:Was about to write the same. The coloring in the first two lines arund Pluto seem wrong (or mistankingly switched). --[[Special:Contributions/172.71.222.246|172.71.222.246]] 16:17, 14 March 2025 (UTC)

the coloring of Pluto does look inverted in the two first lines, they probably got switched by mistake--[[Special:Contributions/172.71.90.43|172.71.90.43]] 17:28, 14 March 2025 (UTC)

This, this is the hill I will die on. I was radicalised by this paper: [https://arxiv.org/abs/2110.15285 Moons Are Planets: "Scientific Usefulness Versus Cultural Teleology in the Taxonomy of Planetary Science"]
In short; planets are what planetary scientists study. Round things with the *good stuff*: atmospheres, oceans, volcanoes (of lava or water ice) (see diagram page 53).
Pluto, Titan, Ceres, Io and Europa are all in the sweet spot where you're not so small you're just a lump of rocks who happen to be stuck together into a lump, and not so large you're just a mostly undifferentiated mass of fusing hydrogen/helium plasma.
And it's consistent with our pre-20th Century understanding of what a planet is, whereas the IAU definition is trying to preserve 19th Century astrology. An amazing read and a strong recommend for anyone who cares about this subject. [[Special:Contributions/172.69.79.138|172.69.79.138]] 16:45, 14 March 2025 (UTC)

Does this sort of count as pi-related for pi day? [[User:TomtheBuilder|TomtheBuilder]] ([[User talk:TomtheBuilder|talk]]) 17:04, 14 March 2025 (UTC)
:he doesn't do themed comics anymore 😔 [[User:CalibansCreations|'''Caliban''']] ([[User talk:CalibansCreations|talk]]) 17:12, 14 March 2025 (UTC)

I was somewhat disappointed to get to the end of the table without seeing either an astrology or Sailor Moon joke. -- [[User:Angel|Angel]] ([[User talk:Angel|talk]]) 18:12, 14 March 2025 (UTC)

Is it possible that Uranus is marked under "Empiricist" because of the "Randall has seen Uranus" joke? [[Special:Contributions/172.70.42.178|172.70.42.178]] 18:38, 14 March 2025 (UTC)

The "{{w|Classical planet|Classical Planets}}" should be 7, including the Sun and the Moon.
:The average distance of the orbit of the Moon around the Earth must be slightly farther away than the orbit of the Sun around the Earth, since the Moon lags behind the Sun a little more each day, but the orbits must cross or we would never have a solar eclipse :P [[User:SammyChips|SammyChips]] ([[User talk:SammyChips|talk]]) 19:41, 14 March 2025 (UTC)

Wouldn't the Regolithic one depend on the exact definitions of "dirt", "ice", and "covered"? It seems that an argument could be made that the giant planets also count there but have a much thicker atmosphere on the outside, and disqualifying because of the atmosphere could exclude others like Earth depending on the exact threshold used. [[User:SammyChips|SammyChips]] ([[User talk:SammyChips|talk]]) 19:08, 14 March 2025 (UTC)

Has Randall not seen the sun before?
:I'm impressed that he has seen Uranus (unless that actually is a joke), especially if he saw it unaided (apparently it actually can be barely seen with the naked eye if the conditions are incredibly good). [[User:SammyChips|SammyChips]] ([[User talk:SammyChips|talk]]) 19:36, 14 March 2025 (UTC)
:Could the sun be classified as a "world"? --[[User:MothWaves|MothWaves]] ([[User talk:MothWaves|talk]]) 19:43, 14 March 2025 (UTC)

Technically, spacecraft have landed on Mercury, Jupiter, and Saturn. Just not in a survivable manner. [[User:Redacted II|Redacted II]] ([[User talk:Redacted II|talk]]) 19:37, 14 March 2025 (UTC)

It looks like the Pluto error in Traditionalist and Modernist images were fixed. I now see Pluto highlighted in traditionalist and Pluto unhighlighted in Modern. [[Special:Contributions/172.68.7.91|172.68.7.91]] 19:44, 14 March 2025 (UTC)

//Jean-Luc Margot wrote a serious planet definition proposal// in 2024 as a starting point for community conversations and welcomes feedback. In 2019 I wrote a small article myself on planet and moon classes simply by size. //Mondklassen "wwwahnsinn"// (in German).
[[Special:Contributions/162.158.159.108|162.158.159.108]] 19:49, 14 March 2025 (UTC)

I'm disputing that there has never been a formal definition of "planet" prior to 2006 - the ancient Greek definition of "wandering [relative to seemingly-fixed stars] points of light in the night sky" seems formal enough to me. I marked it {{tl|actual citation needed}}.

Does anyone else strongly dislike the term '''natural satellite''' replacing ''moon''? Under the new nomenclature, only Earth's moon is 'the Moon'. All other moons are now merely natural satellites. Phobos, Deimos, Ganymede, are no longer considered moons. My biggest problem with the new definition is that planets themselves are natural satellites of stars. [[Special:Contributions/172.71.182.225|172.71.182.225]] 20:13, 14 March 2025 (UTC)

2951: Bad Map Projection: Exterior Kansas

2024-06-28T20:42:06Z

172.71.182.225: /* Explanation */ Aligned images

{{comic
| number = 2951
| date = June 26, 2024
| title = Bad Map Projection: Exterior Kansas
| image = bad_map_projection_exterior_kansas_2x.png
| imagesize = 740x706px
| noexpand = true
| titletext = Although Kansas is widely thought to contain the geographic center of the contiguous 48 states, topologists now believe that it's actually their outer edge.
}}

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

[[File:Azimuthal_equidistant_projection_SW.jpg|300px|thumb|Polar {{w|azimuthal equidistant projection}}, as on the {{w|flag of the United Nations}}, but with an "exterior Antarctica"]]

[[File:Exterior_Kansas_Azimuthal_Projection.png|thumb|Projection of the world from the same perspective as the comic. This uses an azimuthal equidistant projection, so distances from the center point (39°50′S 98°35′E) are correct but areas are distorted. ]]

[[File:now.gif|325px|thumb|The map in [[1335: Now]] shows an exterior {{w|Arctic Ocean}} and Antarctica in the center]]

This is the seventh comic in the series of [[:Category:Bad Map Projections|Bad Map Projections]] displaying Bad Map Projection #45: Exterior Kansas.

This comic portrays an unusual projection of a map of the contiguous United States based loosely on an {{w|azimuthal projection}}. Maps of individual countries are common, especially in academic settings. It is typical for such maps, which only display a limited area of the globe, to use a projection that does not severely distort the shape of the country or its internal borders, but a country that is large enough (as with the United States) will always noticeably suffer from certain distortions of at least one element chosen from distances, areas or angles. This usually occurs at its extremities (though some projections can be made more faithful to its extremities at the expense of distorting its interior).

Here, however, Randall has opted for a much different projection. Rather than placing the geographical center of the country in the middle and the borders on the outside, this map has gone the opposite direction, with the border of the US toward the center, and the geographical center of the contiguous US (Kansas) and surrounding states distorted to surround the entire map. This, understandably, results in the shape of both the national and state borders being largely unrecognizable as it effectively puts ''every'' bit of the chosen map features out towards the distorted extremities. Much of the internal area of Kansas itself (should one wish to display further internal features) may be located far beyond the comic's edges, perhaps even to infinitely far away on the projected plane.

If Alaska and Hawaii were present in this map and represented in geographically accurate locations (as opposed to inset, as is common in many maps of the United States), Alaska would in the upper right of the empty space, between Minnesota and Washington, while Hawaii would be in the center to the right, off the coast of California. Both would be rather small, with Hawaii particularly compressed (to an extent dictated by the exact projection method used). Additionally, if all 50 states were included, the geographical center would be further to the northwest, resulting in an "Exterior South Dakota" projection.

==Transcript==
{{incomplete transcript|Map description could be improved? Do NOT delete this tag too soon.}}

:[A distorted map of the contiguous United States with the states labeled, where the Atlantic and Pacific coasts and the Canadian and Mexican borders are located closest to the center, with there being a gray void in the middle of the map, while the central U.S. states are distributed in the edges of the panel, with Kansas being in all of the four corners of the map.]

:[Caption below the panel:]
:Bad Map Projection #45:
:Exterior Kansas

{{comic discussion}}

[[Category:Bad Map Projections]]
[[Category:US maps]]

2922: Pub Trivia

2024-04-20T07:10:47Z

172.71.182.225: /* Explanation */ Put the addition in the wrong spot.

{{comic
| number = 2922
| date = April 19, 2024
| title = Pub Trivia
| image = pub_trivia_2x.png
| imagesize = 422x666px
| noexpand = true
| titletext = Bonus question: Where is London located? (a) The British Isles (b) Great Britain and Northern Ireland (c) The UK (d) Europe (or 'the EU') (e) Greater London
}}

==Explanation==
{{incomplete|Created by A BOT ASKING BAD TRIVIA QUESTIONS - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

Many pubs have {{w|pub trivia|trivia nights}}, where patrons form teams and compete to answer questions about a range of topics. The typical goal for trivia games is that they be challenging, yet possible, and so the questions whose answers are too difficult or too easy generally make for a poor game. In addition, it's usually preferable that questions are clearly worded with a single, objective answer, so as to avoid disputes about which answers are correct.

Cueball has apparently been hired by one bar to infiltrate ''other'' bars' quiz nights and ask particularly bad questions. The implication is that this will make the games unpleasant, in the hopes that people will leave, and possibly go to the bar that hired Cueball.

Cueball uses a variety of strategies to write bad questions, including questions that are trivial (where the answer is painfully obvious), unanswerable (either because there is no answer, or because the answer is unknown), ambiguously worded or arguable.

Many of his questions could be altered slightly to make them more reasonable for such a game, but that would defeat Cueball's purpose.

{| class="wikitable"
|-
! Question !! Problem with the Question !! Explanation !! More Reasonable Alternative(s)
|-
|1. Which member of {{w|BTS}} has a birthday this year?||Multiple correct answers||All people have birthdays every year{{Citation needed}} (other than pedantic exceptions due to calendar issues or timezone alterations, or someone dying before their birthday, none of which apply in this case). Therefore, all seven members of BTS have birthdays this year.||Which member of BTS has a birthday today/this week/this month? Which member of BTS turns [a specific age] this year?
|-
|2. How many sides does a {{w|platonic solid}} have?||Multiple answers, ambiguous language||There are five {{w|Platonic solids}}, with 4, 6, 8, 12 or 20 faces (colloquially called sides) in {{w|Euclid|Euclidean}} {{w|Euclidean geometry|3-space}}. The solids have, respectively, 6, 12, 8, 30 and 30 edges (also occasionally called sides colloquially). A more devious quizmaster might actually include this as a trick question with the correct answer being 'zero', since strictly speaking solids do not have 'sides'.||How many Platonic solids are there? What is the highest number of faces on a Platonic solid? How many faces does a [specific platonic solid] have? How many faces (or edges, or vertices) do ''all'' the platonic solids have (i.e., added together)?
|-
|3. What is the smallest lake in the world?||Arguable||While the largest lakes are relatively straightforward to categorize, smaller bodies of water range in size down to individual puddles. There is no clear, definitional line at which a body goes from being a lake to a pond, for example. In addition, the size of small lakes will fluctuate due to variability in precipitation, and other weather effects, and some lakes only exist for brief periods (intermittent lakes). Hence, which small bodies of water are "lakes" and which is the smallest can't be clearly answered, without specifying a whole list of parameters and standards.||What lake has the largest surface area in the world? What is the world's deepest lake? What lake is recognized by the Guinness World Records as the world's smallest? (Benxi Lake in China).
|-
|4. Which Steven Spielberg movie features more shark attacks, {{w|Jaws (movie)|Jaws (1975)}} or {{w|Lincoln (movie)|Lincoln (2012)}}?||Trivial||''Jaws'' is a famous movie about a killer shark, and features at least five fatal shark attacks. Lincoln is a movie about the passage of the Thirteenth Amendment to the U.S. Constitution, containing zero shark attacks.{{Citation needed}} Anyone with even a passing familiarity with American popular culture should be able to get this one right, and someone with no knowledge could likely guess the answer from the titles alone. How many times is the shark seen on screen? Which film won more {{w|Academy Awards}}? This might be mistaken for a silly trick question, as ''Lincoln'' is a much less famous movie.||How many fatal shark attacks occur in "Jaws"?
|-
|5. How many planets were there originally?||Ambiguous||The question doesn't specify a time frame or culture, and also doesn't specify that it's referring to our solar system (in the observable universe, there are almost certainly trillions of planets, as there are trillions of stars and almost every one of them has a planet orbiting it). Additionally, it asks how many "were there", as opposed to how many planets were known (the number which are known and defined as such is far smaller than the number of planets in the universe). The word "originally" could imply the origin of the solar system, or the origin of the universe, in which case the answer would be 'zero' as no planets had yet accreted.||How many planets were known to Ancient Greece? How many planets were known to science prior to the invention of the telescope? How many planets were in our Solar System at the end of the 20th century?
|-
|6. What {{w|NFL}} player has scored the most points outside of a game?||Ambiguous, Unknowable||The term "scored the most points" generally only applies within the context of a game, making it very unclear what kind of "points" the question is referring to. Does it mean points in non-NFL games? Points in games other than football? Points outside the context of any game at all (such as 'making a point' in conversation)? Even if this were clarified, points scored in official games in professional sports leagues are meticulously recorded and published, points scored in any other context are not, so the question is likely impossible to answer. Arguably, Brian Jordan would be an answer, with 121 Minor League and 755 MLB runs scored (points).||Which NFL player scored the most points in a game/season/career?
|-
|7. The {{w|Wright brothers}} built the first airplane. Who built the last one?||Unknowable||Orville and Wilbur Wright are widely credited with designing and building the first airplane (in the sense of a heavier-than-air flying machine that could take off, steer and land under its own power). In modern times, design and construction of airplanes has become a huge, international industry, with many airplanes of widely varying sizings being built each year. Since airplanes are built continuously, which one was made most recently depends on when the question is asked (and would be very difficult for the average person to know -- and not trivial for even a member of the aerospace industry to know). If it's asking about the last airplane ''ever'', that's impossible to know, since that plane hasn't been built yet (and hopefully won't for a very long time).||Who built the first airplane '''after''' the Wright brothers? When was the final Wright Model B aircraft built?
|-
|8. Is every even number greater than 2 the sum of two primes?||Unknown, Possibly unknowable||This is a famous, centuries-old {{w|open question}} in math known as {{w|Goldbach's conjecture}}. Mathematicians widely believe that it is true, and it has held true for every number checked up to 4 ⋅ 1018, but since it's impossible to check every number, we can't assume it's universally true. No mathematical proof of its veracity exists at this point. Since it is {{w|Gödel's incompleteness theorems|known}} that something can be true but impossible to prove (and, being true, impossible to disprove), this may be the situation forever.||According to which mathematical conjecture is every even number greater than 2 the sum of two primes?
|-
|9. Not counting {{w|Canberra}}, what city is the capital of {{w|Australia}}?||No answer exists||Australia has only one capital (unlike some countries, which divide the legislative and administrative capitals, for example), and that capital is Canberra. Hence, by definition, there is no national capital "not counting Canberra". Though each constituent state also has its state capital (inclusive of Canberra, which is the entirety of its {{w|Australian Capital Territory|own state territory}}), this would still leave us with an ambiguous choice. Before 1927, the answer could be Melbourne, as that was where the Parliament sat at that time. ||What city is the capital of Australia? What is currently the largest city in Australia? What is the smallest state capital in Australia? Not counting Canberra, what city was the most recently founded state capital of Australia? What city was the capital city before Canberra?
|-
|10. Who played the drums?||Trivial, yet unknowable without context||As worded, the question could be answered with anyone who's ever played the drums, in any context, whether professional or not, in all of history. This would include a huge number of people, most of whom would not be well-known. Most people would be able to offer a technically correct answer, and almost none of them would be interesting. Or maybe the host is wondering who it was that played drums that night, as part of the bar's live music.||Who played the drums for some specific band/album/track/concert?
|-
|(Title text) Where is {{w|London}} located? (a) the {{w|British Isles}} (b) {{w|Great Britain and Northern Ireland}} (c) the {{w|United Kingdom|UK}} (d) {{w|Europe}} (or 'the {{w|European Union|EU}}') (e) {{w|Greater London}}||Multiple answers||All choices are technically correct as they are various geographical areas that include the city of London, England. Also note that the City of London is different from the city ''named'' London as it is technically surrounded by it, hence (e) as an answer. Answer (d) is both correct and incorrect, as it conflates a geographic region, Europe, and a political body, the European Union. The United Kingdom (and therefore London) {{w|Brexit|left the EU}} in 2020, but is still geographically included in Europe. In addition, 'the UK' is short for the United Kingdom of Great Britain and Northern Ireland, so answers (b) and (c) refer to the same thing. This also does not get into cities named London outside of the UK, so for example "Ontario" or "Canada" could also be possible answers if the test designer were truly evil, thus making none of the answers correct. ||What is the capital of the United Kingdom? (answer: London) Where is London, England '''not''' located? (a) the British Isles (b) Great Britain and Northern Ireland (c) the UK (d) Europe (e) the EU (answer: (e))
|}

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

:[Cueball, holding a wireless microphone in one hand and a pencil and notebook in the other, reading from the notebook]:
:Welcome to pub trivia! Round one is 10 questions:

# Which member of BTS has a birthday this year?
# How many sides does a platonic solid have?
# What is the smallest lake in the world?
# Which Steven Spielberg movie features more shark attacks - ''Jaws'' (1975) or ''Lincoln'' (2012)?
# How many planets were there originally?
# What NFL player has scored the most points outside of a game?
# The Wright brothers built the first airplane. Who built the last one?
# Is every even number greater than 2 the sum of two primes?
# Not counting Canberra, what city is the capital of Australia?
# Who played the drums?

:[Caption below the panel]:
:A local pub trivia place hired me to run bad quizzes at competing bars.

{{comic discussion}}
[[Category: Comics featuring Cueball]]
[[Category: Comics featuring real people]]
[[Category: American football]]
[[Category: Astronomy]]
[[Category: Geography]]
[[Category: Math]]
[[Category: Music]]

2447: Hammer Incident

2023-06-02T23:57:34Z

172.71.182.225: /* Explanation */

{{comic
| number = 2447
| date = April 7, 2021
| title = Hammer Incident
| image = hammer incident small.png
| titletext = I still think the Cold Stone Creamery partnership was a good idea, but I should have asked before doing the first market trials during the cryogenic mirror tests.
}}

==Explanation==
The {{w|James Webb Space Telescope}} (JWST) is a {{w|space telescope}} created to be the successor of the {{w|Hubble Space Telescope}} under construction at time of publishing and launched December 25, 2021, though in [[2014: JWST Delays]], xkcd predicted its launch would actually occur during late 2026.

It's implied that Cueball dropped a hammer on the mirror of the JWST and broke it. In superstition, breaking a mirror causes seven years of bad luck. The cost estimate for the JWST is currently US$10 billion, and Cueball is at a NASA official hearing for breaking this very expensive piece of equipment, no doubt costing NASA (and thus the nation) hundreds of millions of dollars more for repair work. However, Cueball is more concerned about personally experiencing seven years of bad luck.

In actuality the mirror panel is not made of glass, so it's likely that a dropped hammer would dent and distort the panel rather than shattering it. Presumably Cueball's hammer drop would damage or destroy only one mirror panel out of the JWST's eighteen panels. (If he had destroyed the entire telescope, he may have been facing 7×18=126 years of bad luck, and the damage costs would be much, much higher. [[2153:_Effects_of_High_Altitude|Then again, this depends on the altitude that the destruction happened.]]) Even breaking a single panel would likely be very expensive because it would require extremely accurate machinery and extensive calibration tests to make and install a replacement panel, especially because the back of JWST's mirrors are made of beryllium. Beryllium is expensive to purchase, since it is relatively scarce, and is very hard and abrasive, so making things out of it is difficult (and expensive due to the specialized machinery required and the precautions necessary to prevent inhalation). Breaking a beryllium mirror would lead to dust formation; single exposures to beryllium dust [http://who.int/ipcs/publications/cicad/en/cicad32.pdf can cause] acute beryllium poisoning and massively increase the risk of lung cancer, which is very bad luck on behalf of Cueball. In addition to the property damage, Cueball is probably liable for injuring his coworkers, which is probably the main reason why the NASA workers are so angry at him because human lives are more valuable than mere money.{{Citation needed}}

The title text refers to the {{w|Cold Stone Creamery}}, a chain that mixes ice cream with various other ingredients, such as fruit or candy, in front of the customer before serving it. The usual surface for mixing is a piece of granite which is kept cold (about -10°C). It's implied that Cueball had tried mixing his ice cream and flavorings in the style of Cold Stone Creamery on the JWST mirror, which is also kept cold -- in fact much colder, as it's cooled to as low as 7 K (-266°C, or -447°F). If Cueball had mixed ice cream this way on the JWST, he would likely have scratched and/or stained the surfaces on the telescope and perhaps have gotten gunk into the instrumentation, and possibly, due to the localized temperature differential from ice cream hundreds of degrees ''warmer'' than the material, promoted damaging distortions or fractures -- hardly the 'good idea' mentioned in the title text. (It also would not have worked: at sufficiently low temperatures, ice cream hardens and cannot be mixed.)

The bad luck from breaking a mirror is also referenced in [[1136: Broken Mirror]].

A similar space-related hearing is shown in [[2148: Cubesat Launch]].

==Transcript==
:[Cueball, holding a palm up in front of him, stands before a long desk, behind which is a seated panel of four people, consisting of Ponytail, Hairy, a Cueball-like guy and Hairbun. Hairy is the only one to have one arm on the desk, all other arms are held down with hands below the desk.]
:Cueball: Yes, I know you're mad that I dropped that hammer.
:Cueball: But think about me—
:Cueball: '''''Seven years of bad luck!'''''

:[Caption below the panel]:
:Man, NASA is really on my case about the James Webb Space Telescope.

==Trivia==
*The JWST has previously been mentioned in [[2014: JWST Delays]], [[1730: Starshade]], and [[1461: Payloads]].
*For some reason, the original version of this comic was very large (4332×4838px), [https://archive.is/yJXTS well overflowing the boundaries of the page]. This was probably a mistake, as the [https://imgs.xkcd.com/comics/hammer_incident.png current version] is significantly smaller at 289 × 323px.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring Hairy]]
[[Category:Comics featuring Hairbun]]
[[Category:Multiple Cueballs]]
[[Category:Telescopes]]
[[Category:Space probes]]