explain xkcd - User contributions [en]

2976: Time Traveler Causes of Death

2024-08-25T14:39:48Z

172.68.34.60:

{{comic
| number = 2976
| date = August 23, 2024
| title = Time Traveler Causes of Death
| image = time_traveler_causes_of_death_2x.png
| imagesize = 332x677px
| noexpand = true
| titletext = Many a hungry time traveler has Googled 'trilobites shellfish allergy' only to find their carrier had no coverage in the Ordovician.
}}

==Explanation==
{{incomplete|Created by a TIME TRAVELLING BOT WITH NO CELL SERVICE IN THE PROTOZOIC ERA- Please change this comment when editing this page. Do NOT delete this tag too soon.}}

Time travel is a common sci-fi/fantasy plot, in which someone from one era is sent forward or backward in time to another era. Normally, the travel itself goes off without a hitch, with the usual threats to the time traveler being what happens at some point ''after'' they arrive at their destination. More rarely, a time traveler might immediately encounter some hazard because of where their time travel method has deposited them.

This comic takes the latter situation to the extreme, observing different causes of death for potential time travelers through the ages based on the geologic evolution of Earth from its formation over 4 billion years ago to the present; see detailed explanation in the [[#Table of death causes|table]]. The chart shows only the most likely cause for a given period of time, although the title text reveals that there may always be others possible.

The title text suggests that an alternative fate within the "eaten by fish" era is the exact opposite - eating something hazardous. A time traveler, having fortuitously avoided the primary "Starving" fate of the prior era, may try eating a {{w|trilobite}}, a kind of shellfish. They may find that either some existing allergy is triggered by this prehistoric shellfish, or that the creatures of that age spark a new allergic condition that (as a modern human) they were not previously aware of. A person with a known allergy might check for the possible presence of a problematic ingredient in a potential snack by referencing online resources - a facility that is not available here, with the smartphone stuck in the past, long before any network is available to connect to (notwithstanding that Google Search has not existed historically for more than three decades). Alternatively, suspecting the food they've eaten has not agreed with them, they could find they are denied easy access to the best online information on how to properly treat their symptoms.

===Table of death causes===
{| class=wikitable
! scope="col" | Cause of death
! Scope=“col” | Time frame
! scope="col" | Explanation
|-
| Lava || Earth Forms || During the formation of the Earth, the surface was a hellish landscape of lava.{{fact}}
|-
| Asphyxiation || 4 billion years ago || Before {{w|cyanobacteria}} started photosynthesizing and producing oxygen, the atmosphere of the Earth was mainly composed of hydrogen sulfide, methane, and carbon dioxide. Humans need oxygen to breathe.{{citation needed}}
|-
| Meteors || 3.9 billion years ago || During the hypothesized {{w|Late Heavy Bombardment}}, the Earth's surface was subjected to a large number of asteroid and comet impacts, destroying much of Earth's early crust. According to the table, the heavy bombardment was so severe that this was the most likely cause of death during a period when there where still no oxygen. Even when these meteors came at an alarming rate, however, the chance of being hit by one of these before asphyxiation in an atmosphere without any oxygen seems remote. Of course if the time machine had some oxygen along with it and the reason people died from lack of oxygen was that they stayed there for a long time, the chance of death-by-meteor would increase.
|-
| Asphyxiation || 3 billion years ago || See above.
|-
| Slightly slower asphyxiation || 2 billion years ago|| Cyanobacteria had started photosynthesizing, leading to the {{w|Great Oxygenation Event|Oxygen Catastrophe}}, but oxygen levels still weren’t high enough to support human life.
|-
| Freezing || Less than 1 billion years ago || During the {{w|Cryogenian|Cryogenian Ice Age}}, the Earth’s temperature fell to -12°C, much too cold to support human life if not properly prepared.
|-
| Starving || 600 to 485 million years ago || During this time, the temperature was mild and comfortable; however, the only life during this time was single-cell organisms and – especially later – tiny multicellular organisms, which are very difficult to survive off of. (Imagine surviving only on bacteria today).
|-
| Eaten by fish || 485 to 250 million years ago || During the {{w|Great Ordovician Biodiversification Event}} and subsequent times, fish {{w|Evolution of fish|evolved jaws}} and some species grew quite large.
|-
| Trampled || 252 to 66 million years ago || The {{w|Mesozoic Era}} is often called the “Age of Dinosaurs." The majority of these dinosaurs were herbivorous and many were quite large, so being eaten would be less likely than being trampled on.
Note that this is an almost exact inversion of what happens in the classic story ''{{w|A Sound of Thunder}}'', in which the traveler survives personally unscathed but tramples an 'age of dinosaur' creature (to unfortunate effect).
|-
| Eaten by mammals || 66 million years ago to sometime before now || The {{w|Cenozoic Era}}, which began 66 million years ago, is often referred to as the "Age of Mammals". Though some eras have more likely causes of death (such as wars, but that would basically be during the "Now" period in the table), overall being eaten by large mammals is probably the biggest risk.
|-
| Time machine door gets stuck || Roughly present day || As the timeline approaches the present day, the conditions on Earth become more than suitable enough for a human time traveler to survive extended periods of time — as evidenced by the fact hominids and early humans begin to emerge. As such there's nothing else more likely to kill them than getting stuck in the time machine and starving (or, if the time machine is air-tight, asphyxiating). This assumes the Time Machine is also a {{w|Faraday Cage}} (that can block the signal of an emergency call) or the traveler doesn't take their phone with them, although the title text indicates they will. Or that the "Now" period extends back before cell phones and compatible cellular networks, maybe covering the entire period of human civilization. It could also be that time travel is deadly if the machine door does not close all the way. But mostly it is a punchline comparing severely dangerous situations to severely harmless ones.
|-
|}

==Transcript==
:[A chart with a time line going from top to bottom is shown. Starting when the Earth forms and ending at present day. The chart is a rectangle divided into 11 segments. Each segment has a label written inside it, except the bottom which is too thin, thus the label is to the right of the chart with an arrow pointing to the segment. The left side of the chart is a timeline with ticks and labels for the time period. At the top an arrow points to the top left corner of the chart with a label indicating the starting time. And then there are 5 ticks, the first four equidistant and then only half the distance for the last tick. A final label is at the bottom of the chart. Above the chart there is a heading:]
:Top causes of death for time travelers by geologic era:

:[Text in the table from the top, with the time to the left differentiated from the labels which are indented:]
:Earth forms
::Lava
::Asphyxiation
:4 billion years ago
::Meteors
::Asphyxiation
:3 billion years ago
:2 billion years ago
::Slightly slower asphyxiation
:1 billion years ago
::Freezing
::Starving
:500 million years ago
::Eaten by fish
::Trampled
::Eaten by mammals
:Now
::Time machine door gets stuck

== Trivia ==

Modern adults can actually have great difficulty surviving without modern conveniences, and may die of freezing if released into an earlier era than they are familiar with. Children of certain ages may thrive well, neither freezing or being eaten by mammals, after a period of adaptation.

{{comic discussion}}

[[Category:Timelines]]
[[Category:Time travel]]
[[Category:Geology]]
[[Category:Animals]]

Talk:515: No One Must Know

2024-03-19T14:57:06Z

172.68.34.60:

The "Trivia" about her name is silly. By that logic black hat should be called ''pie''. [[Special:Contributions/184.66.160.91|184.66.160.91]] 19:40, 7 July 2013 (UTC)

:How can you say the truth is silly?? It just *is*. [[Special:Contributions/108.162.219.223|108.162.219.223]] 08:11, 22 December 2013 (UTC)

::And in this case the truth is trivial! :¬D [[User:ExternalMonolog|ExternalMonolog]] ([[User talk:ExternalMonolog|talk]]) 15:28, 22 January 2014 (UTC)ExternalMonolog

:That, and the internet already HAS a psychopath with "pie" in their name. Has anyone here even read Cupcakes? ...I just realized that this alludes to the pastry terms in the comic. [[Special:Contributions/108.162.218.101|108.162.218.101]] 21:05, 12 February 2014 (UTC)
::Cupcakes? The best known 'Pie'-named character is fiction is the assassin (sic! Though not a psycho) in ''Imajica''. [[Special:Contributions/141.101.104.4|141.101.104.4]] 19:14, 1 August 2014 (UTC)

He calls her a cake (Danish pastry) and she calls him a pie. It is part of the joke. It is thus obviously not her name. But as she looks too much like Megan to not have another name than ''evil girl with long hair'' - it is as good a name as any on these wiki pages. This is not Randall's thruth - just explain XKCD's name. [[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 16:04, 14 May 2014 (UTC)

It's probably not meant to be cueball, IMO. [[User:Mr FJ|Mr FJ]] ([[User talk:Mr FJ|talk]]) 06:47, 25 June 2014 (UTC)
:For the same reason as explained in my comment above Cueball is just a name used in this wiki. So any bald character is per definition Cueball. Randall uses this charachter in many different settings and there are often more than one of "him" in a given cartoon.--[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 16:03, 2 December 2014 (UTC)

Is it possible that the victim is actually Cueball, and the girl is Megan, so they (Megan and Black Hat) would want to kill Cueball because he found out about them? [[Special:Contributions/10.25.42.185]] 11:06, 9 April 2018
:I think the title text pretty firmly rules this possibility out. Megan wouldn't want to torment Cueball first if the only reason she wanted to kill Cueball was because he found about her affair. [[User:Jrfarah|Jrfarah]] ([[User talk:Jrfarah|talk]]) 03:30, 27 February 2022 (UTC)

Oh, my god, did they ACTUALLY kill him? [[Special:Contributions/172.68.34.60|172.68.34.60]] 14:57, 19 March 2024 (UTC)

2897: Light Leap Years

2024-02-21T18:00:10Z

172.68.34.60:

{{comic
| number = 2897
| date = February 21, 2024
| title = Light Leap Years
| image = light_leap_years_2x.png
| imagesize = 288x389px
| noexpand = true
| titletext = When Pope Gregory XIII briefly shortened the light-year in 1582, it led to navigational chaos and the loss of several Papal starships.
}}

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

A {{w|light year}} is a unit of distance, commonly used in astronomy, equal to the distance light travels in a vacuum in one year; the year used is the {{w|Julian year (astronomy)|Julian year}}, or 365.25 days. The joke of this strip is based on the fact that "one year" isn't a precise unit of measurement: there have been different definitions, evolving over time, of what what constitutes a year. The Gregorian calendar (the one most commonly used in modern times) includes a system of leap years in which an additional day is added every fourth year (with some exceptions) to make up for incompatibilities between day and year cycles. This temporarily changes the length of a year from 365 to 366 days, which could be taken to change the length of a light year. In this comic, [[Randall]] assumes that a light year is based on the length of the ''current'' year, which means that during leap years, it's based on 366 days, and during non-leap years, 365 days. That means that at the start and end of leap years, databases with astronomical distances have to be adjusted.

2024 is a leap year in the {{w|Gregorian calendar}} used in most parts of the world, and leap day (Feb. 29) was just over one week away when this comic was released. The comic portrays [[Cueball]] and [[Ponytail]] updating astronomical distances in some sort of database, noting how long and unpleasant the process is; the caption reveals that the reason is that leap years "make light-years 0.27% longer" (366/365 = 1.0027397...). This makes the distance to Alpha Centauri "0.27% shorter".

Standardized systems of measurement naturally don't change continually. As the comic points out, the difficulty in having to regularly update every reference to these units would be enormous and pointless. In real life, a light year is defined by the {{w|Julian year (astronomy)|Julian year}}, defined as 365.25 days, with each day being 86,400 SI seconds in length. This results in a light year which is standardized at 9,460,730,472,580.8 km, no matter how long the calendar year may be.

The title text jokes that {{w|Pope Gregory XIII}}, the originator of the Gregorian calendar, "briefly shortened the light-year in 1582." In reality he shortened the year, as he decided to advance the Julian calendar by 10 days to make up for excess past leap days, leading to "navigational chaos and the loss of several Papal starships". This is of course ludicrous, as there were no starships in the 16th century, there's never been a "Papal starship", and the light-year wasn't developed as a unit of measurement until 1838. The joke is that the evolving and somewhat loose and changing definitions of early calendars had significant impacts on the units of measurement we still use today. Such changes were of only minor significance at the time, but as technology has advanced and become increasingly reliant on precise and consistent measurements, such changes could be disastrous.

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

:[Cueball is sitting at his laptop and leaning to the back of his office chair, while having his other hand on the laptop. He is looking at Ponytail standing behind him. The text from the laptop screen is shown above it, indicated with a zigzag line.]
:Cueball: It took until February, but I finally got all the distances updated!
:Ponytail: I really wish we didn't have to do this.
:[Laptop screen:]
:Proxima Centauri
:Distance: [in red, crossed out] <s>4.2493 ly</s>
:[in green] 4.2377 ly

:[Caption below the panel:]
:Astronomers hate leap years because they make light-years 0.27% longer.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Ponytail]]
[[Category:Comics with color]]
[[Category:Astronomy]]
[[Category:Time]]
[[Category:Calendar]]
[[Category:Comics featuring real people]]

Talk:1489: Fundamental Forces

2024-02-07T17:26:17Z

172.68.34.60:

«The off-panel audience, probably a student or class, is interested, but quickly begins to realize Cueball's lack of understanding. Instead of acknowledging the problem directly, Cueball simply blusters onwards.»

My interpretation is rather different. It looks like Cueball is a physicist who knows that the distinction of "four fundamental forces" is basically wrong/obsolete (the term "force" is not even used anymore in theoretical physics), but since his audience are high school students, he can't go into the many complex details underlying the fundamental interactions, and therefore is forced to gloss over it. This is confirmed by the title text (if Cueball didn't understand the theory of fundamental interactions, he wouldn't give that answer). --[[Special:Contributions/188.114.101.78|188.114.101.78]] 10:31, 20 February 2015 (UTC)

To me it appeared as a typical exam situation for Cueball with '''him''' being the pupil. And ironically that situation looks similar to the real scientific understanding of the topic. [[User:Renormalist|Renormalist]] ([[User talk:Renormalist|talk]]) 11:12, 20 February 2015 (UTC)
: I could see that, to an extent - it doesn't jive with the title text IMO, and it's less funny that a student would be glossing over this stuff than a someone in an instructive role, but I could see it -- [[User:Brettpeirce|Brettpeirce]] ([[User talk:Brettpeirce|talk]]) 11:46, 20 February 2015 (UTC)

Irony like this is not uncommon in physics. What was the first encounter with electric phenomena? Triboelectricity. What don't we understand at all? Right. Or take Zenos paradoxon. Or the divisibility paradoxon. The oldest nuts tend to be the toughest. [[Special:Contributions/108.162.230.221|108.162.230.221]] 12:26, 20 February 2015 (UTC)

:Those paradoxes are perfectly explained through calculus. Zeno's requires only algebra. [[Special:Contributions/108.162.219.100|108.162.219.100]] 06:13, 24 February 2015 (UTC)

:I'm not sure about ''the'' first one, but one of first electromagnetic phenomenons we encountered was light. We first observed it about 200000 years ago. :P [[Special:Contributions/141.101.104.77|141.101.104.77]] 13:45, 21 February 2015 (UTC)
::The first electromagnetic phenomenon we encountered was the the propagation of electric signals along the neuron's axon toward synaptic boutons situated at the ends of an axon. It was literally the first thing we experienced, as there can be no experience without it. However, the triboelectricity was the effect the electricity was named AFTER. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 06:48, 14 October 2021 (UTC)

I knew from the title, "Fundamental Forces", that this was going to be a great one. {{unsigned ip|199.27.128.200}}

I prefer Chromatic Force and Flavor Force. Why use weak names when we have new strong ones? [[Special:Contributions/108.162.254.98|108.162.254.98]] 11:58, 20 February 2015 (UTC)

In high school Physics, my class was taught that physicists had recently combined the Electromagnetic and Weak Nuclear forces into the Electro-Weak Force, so there were only three and if we were to find the Higgs Boson, there might be just two or one. [[Special:Contributions/108.162.241.11|108.162.241.11]] 21:55, 20 February 2015 (UTC)
:Actually, it is the Higgs Boson, that combines the electromagnetic and the weak nuclear interaction into the electroweak interaction, so it's still 3. But actually, even if electromagnetism and the weak interaction can be described in one theory, they are still viewed as two different phenomena, so it actually will always be 4. (Unless we discover other interactions). --[[Special:Contributions/141.101.105.192|141.101.105.192]] 22:23, 20 February 2015 (UTC)
:: Old timer physicists say the same thing about magnetism and electricity. [[Special:Contributions/141.101.64.35|141.101.64.35]] 16:53, 21 February 2015 (UTC)

Is it just possible that Randall posted this forum to see how we here actually try to explain strong and weak Forces? [[Special:Contributions/188.114.111.224|188.114.111.224]] 22:34, 21 February 2015 (UTC)

In the first panel, Cueball forgot to mention Einstein's field equations. [[Special:Contributions/108.162.254.77|108.162.254.77]] 11:35, 22 February 2015 (UTC)

This comic and the ensuing discussion is more intriguing when the Chrome xkcd substitutions extension is turned on. Weak Horse, Strong Horse, Flavor Horse, Chromatic Horse... [[Special:Contributions/199.27.128.194|199.27.128.194]] 01:57, 24 February 2015 (UTC)

couldnt the title text joke just be joking about how the professor doesnt know anything? like if hes just saying that from a quantum point of view that gravity is the hardest, then its not really a joke. the joke is its the only one he can describe easily, but then he says its the most difficult one. i think thats irony, but maybe not. but yeah thats just my tide whats yours.[[User:TheJonyMyster|TheJonyMyster]] ([[User talk:TheJonyMyster|talk]]) 03:57, 26 February 2015 (UTC)

When I read this comic, I see a metaphor for the scientific community's difficulties explaining these interactions to laymen. Cueball is a stand-in for scientists, and while he likely understands these concepts very well, has no earthly idea how to encapsulate them for someone who hasn't studied them in-depth. As the concepts become more abstract and unintuitive, Cueball's explanations become more incomprehensible to the increasingly vexed lay audience. Gravity is a phenomenon that is readily observable to anyone, and so the audience accepts it without question--note that Cueball's explanation doesn't really do the topic any better justice than his explanations of the other forces; he just doesn't need to. Electromagnetism is less intuitive to a layman, but its effects are still observable, so the audience, accepting it, seems more concerned that Cueball glosses over a hint that it's a bit more complex than his initial explanation would suggest. The explanations of strong and weak forces are no more coherent, but the complete lack of observable effects to laymen makes this lapse unforgivable to the audience. The alt text highlights the irony of this situation, where the lack of any comprehensible explanation of the strong and weak forces leads the audience to believe that they are not well-understood, but in fact it is gravity, the force they simply accepted without question, that is a mystery. {{unsigned ip|173.245.56.209}}

As a philosopher, my interpretation was not that Cueball "can't encapsulate" the ideas, but that no one really understands them, even specialists. Like Socrates was the expert ethicist simply by virtue of not knowing what the good is, Cueball (Monroe?) is the expert physicist because he refuses to bullsh** about which and how many are the most "fundamental" horses. The fact is that knowing the mathematical formula that describes the phenomenon doesn't constitute understanding. Same goes for gravity. Hence the scrollover punchline. [[User:CircularReason|CircularReason]] ([[User talk:CircularReason|talk]]) 14:55, 13 June 2015 (UTC)

I find a different humor in this than it seems the rest of you do. As an out of practice physicist now teaching high school physics this is word for word what I would have said should I have to explain the fundamental forces without researching any of the things that have slipped my mind. There is something about the way Randall captures the exact way I think (have been trained to think?) that had me guffawing at this comic and feeling a bit sheepish at 793: Physicists {{unsigned ip|173.245.56.164}}

What is a "fundamental horse"? [[User:Malamanteau314|Malamanteau314]] ([[User talk:Malamanteau314|talk]]) 04:59, 6 November 2015 (UTC)
:There are four fundamental horses which we have a decent understanding of, but the one we understand the least is "Death". [[Special:Contributions/108.162.238.76|108.162.238.76]] 01:36, 20 January 2016 (UTC)
::Death is the rider, not the horse itself. [[User:Mikemk|Mikemk]] ([[User talk:Mikemk|talk]]) 07:50, 16 February 2016 (UTC)
:::The horses name is Binky. [[User:Andyd273|Andyd273]] ([[User talk:Andyd273|talk]]) 14:00, 4 October 2016 (UTC)
::::His name is Susan, and he wants you to respect his life choices. 03:47, 29 January 2017 (UTC)
:::::No. [https://wiki.lspace.org/Binky His name is Binky.] [[User:L-Space Traveler|L-Space Traveler]] ([[User talk:L-Space Traveler|talk]]) 21:21, 26 April 2023 (UTC)
Should the explanation be updated to note the discovery of gravitational waves? [[User:Mikemk|Mikemk]] ([[User talk:Mikemk|talk]]) 07:50, 16 February 2016 (UTC)

For the record, this is, with only a very little exaggeration, exactly how the four fundamental fources were presented to me in high school. Spot on. -CDJ

This makes me think of FunTime from the Origami Yoda books. That stunk. [[Special:Contributions/172.68.34.60|172.68.34.60]] 17:26, 7 February 2024 (UTC)

Talk:409: Electric Skateboard (Double Comic)

2024-02-07T17:24:14Z

172.68.34.60:

I think the "double comic" reference is just that. There are just two - unrelated - comics strung together here, with no relation to the original Sunday format, which Watterson abandoned halfway through, in favor of the "latter" comic's style. Anonymous 22:39, 3 December 2013 (UTC) {{unsigned ip|173.245.54.91}}

I think the reference in the first comic is to Mario Kart Double Dash, where there were two characters on the kart. In the game, both characters were able to hold and utilize "weapons", sometimes different weapons, like the one red turtle shell used by Megan and the three green turtle shells used by Cueball. [[Special:Contributions/108.162.240.18|108.162.240.18]] 14:56, 29 January 2014 (UTC)

bill if youre reading this please do a pairing comic [[Special:Contributions/173.245.54.5|173.245.54.5]] 00:06, 24 December 2015 (UTC)

Big fan of both Calvin and Hobbes ''and'' xkcd. Randall pulled this one beautifully.

2712: Gravity

2024-01-26T17:19:14Z

172.68.34.60: /* Celestial Bodies */

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

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

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

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

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

===Celestial Bodies===

This is a table of all celestial bodies:

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

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

Megan: "Welcome!"

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

*Cueball feeding T-Rex: "Burger?"

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

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

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

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

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

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

"Unusually high-speed squirrels."

"Jump in! The water's fine!"

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

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

"Ahh, the mysterious natural wonders of sailing stones"

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

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

"Hey"

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

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

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

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

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

A Roomba whirs across the icy crust.

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

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

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

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

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

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

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

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

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

"I want more dogs!"

"Ball! Again!"

"I hope it lands soon."

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

"You can't have too many dogs!"

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

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

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

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

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

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

"MMM SPIDERS HOMF HOMF"

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

Person on uncontrolled helicopter: "AAAAAA"

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

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

Cueball with jetpack: "Wheeeee!"

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

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

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

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

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

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

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

"My countertop!"

"This will make a good soup base"

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

"I got you this present!"

"Is it an angry bobcat?"

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

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

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

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

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

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

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

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

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

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

===Spaceships===

This is a table of all spaceships:

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

==Data and Maps==

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

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

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

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

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

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

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

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

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

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

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

Beret Guy: Hi!

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

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

Cueball to dinosaur: Burger?

===B612:===

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

===Europa:===

====Surface:====

Roomba: Whirrr

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

Cueball's hairdryer: Whirrr

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

====Underwater:====

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

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

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

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

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

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

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

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

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

===nojapan & japanmoon:===

Megan: something is missing

===Goodhart:===

Guiser: Fwoosh!

Cueball & Megan: Oooh!

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

Cueball in jetpack: Wheeeee!

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

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

Cueball 2: Dunno

Cueball: Okay, let it drop!

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

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

Cueball: Mmm spiders Homf Nomf

Brontosaurus: Oh no!

Text above star falling on Spinosaurus: The more you know

Cueball & pilot of Helecopter 1: Aaaaaa

===Soupiter:===

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

===Earth:===

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

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

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

Volcano: Doot!

Hummingbird: Yesssssss!

Candies as they fall on cueball's teeth: Plink

Cueball: Ow!

Candies as they fall on cueball's teeth: Plink

Cueball: Ow!

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

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

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

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

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

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

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

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

===Sun:===

====Outside:====

Jill: This would make a good soup base.

Hairy to Cueball: Can I touch it yet?

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

Unnamed guy with baseball cap: My countertop!

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

====Inside:====

Hairy: This should be enough sunscreen.

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

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

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

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

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

Ponytail but with black hair to Cueball: Nobody knows.

===Remnant:===

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

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

Spaceship captain: Oh no.

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

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

===Dogplanet:===

Cueball: I want more dogs!

dog 1: Ball! Again!

dog 2: I hope it lands soon.

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

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

===Quantz:===

Gardener: Welcome ... to Jurassic park.

===Enterprise:===

Ground text: U.S.S. Enterprise

Ground text: NCC-1701-C

===Greatattractor:===

Ground text: The Great Attractor

Ground text: The Great Attractor

Ground text: The Great Attractor

Ground text: The Great Attractor

Ground text: The Great Attractor

Ground text: The Great Attractor

Ground text: The Great Attractor

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

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

2883: Astronaut Guests

2024-01-22T15:34:38Z

172.68.34.60:

{{comic
| number = 2883
| date = January 19, 2024
| title = Astronaut Guests
| image = astronaut guests 2x.png
| imagesize = 331x391px
| noexpand = true
| titletext = They didn't bring us a gift, but considering the kinetic energy of a bottle of wine at orbital speed, that's probably for the best.
}}

==Explanation==
{{incomplete|Created by ELEVEN ASTRONAUTS OVER YOUR HEAD RIGHT NOW - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

In this comic, [[Cueball]], [[Megan]], [[Ponytail]], and [[Hairbun]] can all be seen eating dinner together. Presumably, Ponytail and Hairbun were invited over for dinner, as, to impress them, [[Cueball]] misleadingly claims that they previously "had six {{w|astronaut}}s over for dinner." Normally, this would be interpreted as the astronauts being friends with the hosts (which confers social prestige), going inside their house, and eating. As it turns out, the astronauts actually only briefly passed overhead while in {{w|orbit}}, and, by chance, this happened during dinnertime. This is a pun on the word "over", as the personnel of the {{w|International Space Station}} are overhead when it passes above you; yet they did not go "over ''to'' someone's house" in the sense that English speakers would usually assume.

Cueball may also be considering the property lines to extend up indefinitely (just like in "What If?" article "{{what if|161|Star Ownership}}"), causing the astronauts to [[1475: Technically|technically]] be at their house despite being hundreds of miles away, vertically.

The astronauts in question were presumably occupying the International Space Station, which has an orbital period of between 90 and 93 minutes (depending on its altitude) or 5400 to 5580 seconds.[https://eol.jsc.nasa.gov/Tools/orbitTutorial.htm] If the astronauts were "over" for 7½ milliseconds, that would be somewhere between 1.34x10⁻⁶ and 1.39x10⁻⁶ of an orbit. Earth's circumference (at the equator) being approximately 40,000 kilometers (24,850 miles), the station was apparently "over" for a ground distance of between 53.9 m and 55.7 m (177 to 183 feet). That would imply quite a large property, but may also take into account the locations of the astronauts within the ISS, which is 109 m (356 feet) long. (The effect of [[1276: Angular Size|angular size]] is small in this case because the ISS's elevation is small compared to the radius of the Earth. The route traced by the ISS in orbit is only slightly larger than its projection at ground level.)

The caption makes Cueball's statement even less impressive, alleging that statements like it are correct in a lot of places. This would make it not even interesting as a {{w|coincidence}}. It can only happen for latitudes of less than 51.64° north or south, which is as far as the orbital inclination of the ISS takes it, leaving almost 21.6% of the Earth's surface never directly 'over'ed. Nonetheless, these areas of the globe are, overall, significantly more sparsely populated than than those that are 'over'ed, meaning that the claim could be made in much more than 88.4% of places, assuming that by 'places' we mean 'properties where people are likely to be having dinner'.

The title text suggests that Cueball didn't want a gift (a bottle of wine) from the astronauts. The kinetic energy of a 1.2 kg (full) bottle of wine traveling at the linear velocity of the International Space Station (8000 m/s) is on the order of [https://www.wolframalpha.com/input?i=1%2F2*%288km%2Fs%29%5E2*1.2kg 40 megajoules]. For comparison, the kinetic energy of a fully loaded semi-truck (max legal weight 80,000 pounds or ~36 tonnes) at 70mph (110km/h; a typical highway speed limit for passenger cars) is around [https://www.wolframalpha.com/input?i=1%2F2*%28110km%2Fh%29%5E2*80000+pounds 17 megajoules]. A bottle with more than double the kinetic energy of that would be hard to keep on the table, and would likely do damage to people or things that tried to keep it there.{{Citation needed}}

This comic was posted the same day as the American release of a film set on the ISS (conveniently named ''{{w|I.S.S. (film)|I.S.S.}}'').

==Transcript==
:[Cueball, Megan, Ponytail, and Hairbun are eating around a table. Cueball is leaning on the back of his chair and has his palm out.]
:Cueball: We don't have houseguests often, but we once had six astronauts over for dinner.
:Hairbun: Oh, wow!
:Cueball (muttering): ''…for 7½ milliseconds in mid-August 2012.''

:[Caption below the panel:]
:If you spend enough time looking at orbital records and property lines, you can make this claim in a lot of places.

{{comic discussion}}
[[Category: Comics featuring Cueball]]
[[Category: Comics featuring Ponytail]]
[[Category: Comics featuring Megan]]
[[Category: Comics featuring Hairbun]]
[[Category: Space]]

2878: Supernova

2024-01-11T17:20:56Z

172.68.34.60: /* Explanation */

{{comic
| number = 2878
| date = January 8, 2024
| title = Supernova
| image = supernova_2x.png
| imagesize = 348x227px
| noexpand = true
| titletext = They're a little cagey about exactly where the crossover point lies relative to the likelihood of devastating effects on the planet.
}}

==Explanation==
{{incomplete|Created by A CAGEY MOSTLY HAPPY ASTRONOMER - Please change this comment when editing this page. Do NOT delete this tag too soon.}}
A {{w|supernova}} occurs when a heavy star can no longer produce enough energy to fight its own gravity, e.g. because its fuel runs out ({{w|type II supernova|type II}}) or because it has accreted too much mass from a binary companion ({{w|type Ia supernova|type Ia}}). The collapsing mass leads to a violent explosion, one of the most interesting events for astronomers to observe and one that can be used to glean information about the universe.

At first glance, the curved line on this graph might match that of the typical {{w|light curve}} of a type Ia supernova, constructed by plotting the brightness of the supernova as a function of time, with negative values indicating a logarithmic luminosity scale (below zero means a linear luminosity of less than the unit amount). In the event of a supernova, a star (which may previously have been unremarkable) becomes notably bright over a short period of time before trailing off again to leave a stellar remnant and expanding cloud of ejecta. Around the time of this comic's release new constraints on the expansion of the universe from the observation of type Ia supernovae were [https://news.fnal.gov/2024/01/final-supernova-results-from-dark-energy-survey-offer-unique-insights-into-the-expansion-of-the-universe/ published], which used the regular shape of their light curves to establish a distance scale.

However, this comic reimagines the shape of a light curve graph to depict the relationship between the distance of supernovae from Earth, and the consequent happiness of astronomers, which happens to take a similar form. The further away the supernova occurs, the less detail can be learned from it, so the graph beyond the maximum happiness distance appears to show an {{wiktionary|asymptotic}} approach to less and less astronomer happiness. On the other hand, a {{w|near-earth supernova}} close enough to flood the Earth with significant amounts of gamma and X-ray radiation might be considered ''too'' close. Its radiation could destroy life on Earth, or at least significantly harm the biosphere, which would be a bad thing.{{cn}} Astronomers (and many others) would be really unhappy if that happened, shown as a sharp drop in happiness towards smaller distances and negative happiness values for a supernova that is very close. In fact, if a supernova were to instantly destroy Earth, or kill off all life on it, astronomers may no longer be able to be happy or unhappy (depending on your theological/spiritual feelings), so distance values close to zero have undefined astronomer happiness values.

Many astronomers watch and study the stars in the night sky, even those that don't change appreciably over human timescales, but observing and recording such a huge event would be interesting for many reasons. Humans can observe some supernovae with the naked eye, especially if they occur within {{w|Milky Way|our own galaxy}}. A potential supernova in the news lately is {{w|Betelgeuse}}, a {{w|red giant}} star that is the left shoulder in the constellation Orion. About 430 light years from the Sun, it has been pulsating, dimming and brightening over exceedingly short time scales compared to the tens of millions of years such a big star is expected to burn. Betelgeuse should be far enough away from Earth that the inevitable explosion would be safe enough for life on Earth (although [https://www.skyatnightmagazine.com/space-science/earth-danger-betelgeuse-supernova some assessments] are not so sure), but it ''will'' outshine all other stars in the night sky, competing with the Moon, and could even be visible during daytime. This would be a dream come true for many astronomers and something obvious to others interested in the night sky. In the first [[:Category:Stargazing | Stargazing]] comic, [[1644: Stargazing | 1644]], the wish that it goes supernova (in [[Randall|Randall's]] lifetime) is clearly expressed.

Since this ''should'' be safe for us, and since it would be a spectacle not seen at least since the start of recorded history, and unlikely to be seen again by human eyes, this would make astronomers very happy, not just from all they could learn, but also from all the increased interest in gazing at the sky with the 'new' star (and then seeing what happens to it next).
There are thought to be about three supernovae occurring per century within our own galaxy (most of which are much further away than Betelgeuse), and many other galaxies within which a supernova explosion can be detected. These remain useful to see, and are often studied as intensively as possible, but have decreasing amounts of thrill to them and are harder to notice/record in the early stages of the explosion (or immediately before, to add even more understanding).

The title text expands upon the point of "too close" supernovae, claiming that astronomers are not quite clear or perhaps unwilling to admit how close they would like a supernova to be. If it were {{what if|73|close enough}} to severely impact the quality of human life, they would presumably not be happy, but the title text suggests that they might actually be willing to accept some trouble on Earth if they get to see a supernova comparatively close by.

This is the second comic in a row that mentions exploding stars, after [[2877: Fever]], which like this comic is also a [[:Category:Charts|Charts comic]].

==Transcript==
:[A graph is shown where the axes are labeled and arrows are pointing upward above the Y axis label and to the right above the X axis label. There is a single line on the graph that peaks close to the Y axis, where it reaches close to the top of the drawn part of the Y axis. Then the line approaches the X axis asymptotically towards the far right. But closer to the Y axis, the peak line goes almost vertically down, and continues far below the "bottom of the chart", outside of the boundary of the graph that was only supposed to be above the X axis.]
:Y axis: How happy astronomers are
:X axis: How far away the new supernova is

{{comic discussion}}

[[Category:Line graphs]]
[[Category:Astronomy]]