explain xkcd - User contributions [en]

2429: Exposure Models

2021-02-25T02:15:21Z

108.162.219.80: Formatting

{{comic
| number = 2429
| date = February 25, 2021
| title = Exposure Models
| image = exposure_models.png
| titletext = "Cumulative number of coronavirus spreadsheets created over time" is a spreadsheet I am coming dangerously close to creating.
}}

==Explanation==
{{incomplete|Created by a META-MODEL. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}
The idea is that Cueball is too busy making models in order to figure out how to lower his risk to actually go outside. This is working—but not in the intended way. [[1708: Dehydration]] also features researching something in order to prevent it affecting it—but in the opposite way, i.e. it has a detrimental effect instead of a beneficial effect.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
[Cueball is sitting at a desk. Megan walks in]

Cueball: I built another COVID exposure model to help me limit my risk

Megan: Any new insights?

Cueball: Yeah: "If you spend all day debugging models, you don't have close contact with a lot of people."

Megan: Well, I guess it worked.

Cueball: According to my meta-model, the end of the pandemic is only four more models away.

Megan: ''So close!''
{{comic discussion}}

2429: Exposure Models

2021-02-25T02:13:56Z

108.162.219.80: Transcript added

{{comic
| number = 2429
| date = February 25, 2021
| title = Exposure Models
| image = exposure_models.png
| titletext = "Cumulative number of coronavirus spreadsheets created over time" is a spreadsheet I am coming dangerously close to creating.
}}

==Explanation==
{{incomplete|Created by a META-MODEL. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}
The idea is that Cueball is too busy making models in order to figure out how to lower his risk to actually go outside. This is working—but not in the intended way. [[1708: Dehydration]] also features researching something in order to prevent it affecting it—but in the opposite way, i.e. it has a detrimental effect instead of a beneficial effect.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
[Cueball is sitting at a desk. Megan walks in]
Cueball: I built another COVID exposure model to help me limit my risk
Megan: Any new insights?
Cueball: Yeah: "If you spend all day debugging models, you don't have close contact with a lot of people."
Megan: Well, I guess it worked.
Cueball: According to my meta-model, the end of the pandemic is only four more models away.
Megan: ''So close!''
{{comic discussion}}

2428: Mars Landing Video

2021-02-23T18:05:08Z

108.162.219.80: /* Explanation */

{{comic
| number = 2428
| date = February 22, 2021
| title = Mars Landing Video
| image = mars_landing_video.png
| titletext = The best part of crashing a Mars briefing is you can get in a full 11 minutes of questions before they can start to respond.
}}

==Explanation==
{{incomplete|Created by THE WORST SKYCRANE. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}
Three days before this comic was published, NASA successfully landed a new rover, {{w|Perseverance (rover)|''Perseverance''}}, on Mars, this was also the subject of the previous comic [[2427: Perseverance Microphones]].

This comic is set at the press briefing where a video of the landing (a first ever) is presented, and was published shortly before this happened in real life.

This comic plays on the fact that if there is only one of something in a set, that one thing is the most/least in that set by lack of comparison. As there is only one full speed video of a Mars landing, that makes the video the worst one. [[Randall]], who has often been [[:Category:Banned from conferences|banned from conferences]], has also been banned from NASA's press briefings. So he decided to crash the conference (literally, see below) solely to ask the question, "is this then not also the worst video ever", flouting his ban and embarrassing NASA.

He follows up with the question if NASA is planning to make a worse Mars landing video, which is silly because people generally don't intend to make something worse. However, because this video is the worst full-speed video of a Martian landing by virtue of being the only full-speed video of a Martian landing, it is likely that if enough full-speed videos of Martian landings are made in the future, this video will not be the worst forever.

Judging by the sound effects, Randall has chosen to literally crash his way through the roof, using a "skycrane" — a general term for aerial vehicles, similar to standard cranes, that can lower or raise objects. Specifically one of these was used to land the Perseverance rover three days before.

This comic was published shortly before a [https://www.youtube.com/watch?v=gYQwuYZbA6o NASA press briefing] that showed, as mentioned in the comic, the first ever full-speed video of a Mars landing. On Earth one would likely use the {{w|Sikorsky S-64 Skycrane}} helicopter, while NASA used a custom-built skycrane delivery system for the ''Perseverance'' rover. Randall deems using a skycrane to crash a conference about a skycrane very ironic, especially since NASA's security was totally unprepared to stop him from using this particular method to crash the press-briefing.

The title text refers to the 11-minute (one-way; 23 minutes round-trip) communications delay between Mars and Earth, due to the speed of light and the distance between the planets at the time of the rover's landing. Perseverance mission control must wait this long before they can even begin to respond to anything that happens to the rover, which Randall here twists into an 11-minute delay before they can begin to answer his questions allowing him to ask questions for 11 minutes before they can intervene. This would of course only make sense if he was crashing the conference at Mars, and they were waiting for his questions here on Earth. And that would not make sense anyway. Also since the round trip is 23 minutes, he would not hear any response from them until 23 minutes after he began asking questions.

Randall copying the use of the skycrane that was used to drop the mars rover, is similar to how different groups express similar behaviors in parallel research, so as to have similar footing in the world, as if they are almost in nonverbal communication about the merits of their ways.

==Transcript==
:[Hairbun is standing, arms spread out, on a podium in front of a lectern. There is a "Crash" on the top right of the panel with several lines around to indicate the position, and an of panel voice coming from there. As indicated in the caption below the voice is from Randall.]
:Hairbun: We're excited to share the first ever full-speed video of a Mars landing.
:Sound: ''Crash''
:Randall (off-panel): Doesn't that mean it's also the ''worst'' ever full-speed video of a mars landing?
:Randall (off-panel):Do you expect that record to stand forever, or is NASA working on a worse one?

:[Caption below the comic]:
:NASA tried to ban me from their press briefings, but ironically their security was totally unprepared to deal with a skycrane.

{{comic discussion}}

[[Category:Mars rovers]]
[[Category:Comics featuring Hairbun]]
[[Category:Comics featuring Randall]]

2428: Mars Landing Video

2021-02-23T18:04:31Z

108.162.219.80: /* Explanation */

{{comic
| number = 2428
| date = February 22, 2021
| title = Mars Landing Video
| image = mars_landing_video.png
| titletext = The best part of crashing a Mars briefing is you can get in a full 11 minutes of questions before they can start to respond.
}}

==Explanation==
{{incomplete|Created by THE WORST SKYCRANE. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}
Three days before this comic was published, NASA successfully landed a new rover, {{w|Perseverance (rover)|''Perseverance''}}, on Mars, this was also the subject of the previous comic [[2427: Perseverance Microphones]].

This comic is set at the press briefing where a video of the landing (a first ever) is presented, and was published shortly before this happened in real life.

This comic plays on the fact that if there is only one of something in a set, that one thing is the most/least in that set by lack of comparison. As there is only one full speed video of a Mars landing, that makes the video the worst one. [[Randall]], who has often been [[:Category:Banned from conferences|banned from conferences]], has also been banned from NASA's press briefings. So he decided to crash the conference (literally, see below) solely to ask the question, "is this then not also the worst video ever", flouting his ban and embarrassing NASA.

He follows up with the question if NASA is planning to make a worse Mars landing video, which is silly because people generally don't intend to make something worse. However, because this video is the worst full-speed video of a Martian landing by virtue of being the only full-speed video of a Martian landing, it is likely that if enough full-speed videos of Martian landings are made in the future, this video will not be the worst forever.

Judging by the sound effects, Randall has chosen to literally crash his way through the roof, using a "skycrane" — a general term for aerial vehicles, similar to standard cranes, that can lower or raise objects. Specifically one of these was used to land the Perseverance rover three days before.

This comic was published shortly before a [https://www.youtube.com/watch?v=gYQwuYZbA6o NASA press briefing] that showed, as mentioned in the comic, the first ever full-speed video of a Mars landing. On Earth one would likely use the {{w|Sikorsky S-64 Skycrane}} helicopter, while NASA used a custom-built skycrane delivery system for the ''Perseverance'' rover. Randall deems using a skycrane to crash a conference about a skycrane very ironic, especially since NASA's security was totally unprepared to stop him from using this particular method to crash the press-briefing.

The title text refers to the 11-minute (one-way; 23 minutes round-trip) communications delay between Mars and Earth, due to the speed of light and the distance between the planets at the time of the rover's landing. Perseverance mission control must wait this long before they can even begin to respond to anything that happens to the rover, which Randall here twists into an 11-minute delay before they can begin to answer his questions allowing him to ask questions for 11 minutes before they can intervene. This would of course only make sense if he was crashing the conference at Mars, and they were waiting for his questions here on Earth. And that would not make sense anyway. Also since the round trip is 23 minutes, he would not hear any response from them until 23 minutes after he began asking questions.

Randall copying the use of the skycrane that was used to drop the mars rover, is similar to how different groups express similar behaviors in parallel research, so as to have similar footing in the world.

==Transcript==
:[Hairbun is standing, arms spread out, on a podium in front of a lectern. There is a "Crash" on the top right of the panel with several lines around to indicate the position, and an of panel voice coming from there. As indicated in the caption below the voice is from Randall.]
:Hairbun: We're excited to share the first ever full-speed video of a Mars landing.
:Sound: ''Crash''
:Randall (off-panel): Doesn't that mean it's also the ''worst'' ever full-speed video of a mars landing?
:Randall (off-panel):Do you expect that record to stand forever, or is NASA working on a worse one?

:[Caption below the comic]:
:NASA tried to ban me from their press briefings, but ironically their security was totally unprepared to deal with a skycrane.

{{comic discussion}}

[[Category:Mars rovers]]
[[Category:Comics featuring Hairbun]]
[[Category:Comics featuring Randall]]

843: Misconceptions

2021-02-16T01:50:06Z

108.162.219.80:

{{comic
| number = 843
| date = January 5, 2011
| title = Misconceptions
| image = misconceptions.png
| titletext = "Grandpa, what was it like in the Before time?" "It was hell. People went around saying glass was a slow-flowing liquid. You folks these days don't know how good you have it."
}}

==Explanation==
The Wikipedia article {{w|List of common misconceptions}} gives a list of {{tvtropes|CommonKnowledge|commonly-repeated anecdotes}} that are widely believed to be true, but actually are not.

The teacher, [[Miss Lenhart]], is announcing that since it is the first {{w|Tuesday}} in {{w|February}}, by law and custom the reading of this article is requirement to stem the repetition of these incorrect anecdotes. (Funnily enough the comic was released the first Wednesday in January, which could just as well have been written in the comic).

She continues to make it clear that this is to make the students in general a little less wrong, and the main outcome will be that the guest of any future parties the students ever attend, will not have to listen to them retell these misconceptions and for that these guest will thank those who have decided on this new law in advance.

In the caption below the comic [[Randall]] expresses his wishes that he lived in a {{w|Many-worlds interpretation|parallel universe}} where this rule had been used for many years. So he would not have to listen to all these stories at every party he goes to. Since Randall likes to correct people if they are wrong (see [[386: Duty Calls]]), not having to discuss with those that believe these misconceptions, would make his parties much better.

The title text refers to a specific one of these {{w|List_of_common_misconceptions#Materials_science|false stories about glass}}:
:''That {{w|glass}}, while seeming solid, is actually an extremely viscous liquid and will flow over time, as is seen on older buildings where the window panes are thicker at the bottom.''
In reality, older manufacturing processes did not produce glass panes with as uniform thickness as modern processes, and people tended to install the uneven panes with the thicker side at the bottom for stability. Glass simply does not flow at room temperature; it's more viscous than solid lead by a factor of over a ''billion''. The fact that glass is solid at room temperature was again referenced in a foot note, under the pipe with glass, in [[1649: Pipelines]].

It seems that Miss Lenhart has corrected her course from [[803: Airfoil]], where she taught another common misconception.

==Transcript==
:[Miss Lenhart the teacher is standing in front of a board, looking at a laptop computer she is holding in one hand while elocuting.]
:Miss Lenhart: Okay, middle school students, it's the first Tuesday in February.
:Miss Lenhart: This means that by law and custom, we must spend the morning reading through the Wikipedia article ''List of Common Misconceptions'', so you can spend the rest of your lives being a little less wrong.
:Miss Lenhart: The guests at every party you'll ever attend thank us in advance.

:[Caption below the panel:]
:I wish I lived in this universe.

{{comic discussion}}

[[Category:Comics featuring Miss Lenhart]]
[[Category:Wikipedia]]
[[Category:Physics]]

Talk:2424: Normal Conversation

2021-02-14T12:55:29Z

108.162.219.80: once recaptcha asks you to "please try again" you know you're at risk for being relegated to the cyborg camps

I told my friends that my mother tested positive for COVID-19. I noticed that I only had to say "tested positive", the rest is implicit. I think it's similar in the gay community with HIV/AIDS.{{unsigned|bubblegum}}
:...uh, interesting thing to bring up. [[Special:Contributions/108.162.215.244|108.162.215.244]] 02:11, 13 February 2021 (UTC)
:That's not specific to any gay community. You say 'tested positive' in any community and people will turn their heads. I guess the culture differentiates whether it's an STD or a child. [[Special:Contributions/108.162.219.80|108.162.219.80]] 12:55, 14 February 2021 (UTC)

As an introvert, I've found that my interactions with other humans have changed very little . . . and mostly positively, as there are fewer of them. It's also nice to have a topic ready at all times to fill those awkward silences.

"Stay Positive. Test Negative." -Norah O'Donnell [[Special:Contributions/162.158.74.239|162.158.74.239]] 11:45, 14 February 2021 (UTC)

2424: Normal Conversation

2021-02-14T12:53:29Z

108.162.219.80: I am surprised that the people editing this wiki think these traits are somehow special to randall, when the comic is designed for people who have them.

{{comic
| number = 2424
| date = February 12, 2021
| title = Normal Conversation
| image = normal_conversation.png
| titletext = "I think I'll pass. These days I have a hard time feeling comfortable in crowded bars with loud music and lots of shouting." --me, after the pandemic, but now for a second reason
}}

==Explanation==
{{incomplete|Created by a NORMAL CONVERSATION. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}
[[Randall]]/[[Cueball]] has shown in many comics the difficulty of making small talk, or having a "normal" conversation, when you spent your developing years developing work skills ([[:Category:Social interactions]]), a trait of nerds such as engineers that is frequently used as material in [https://dilbert.com/strip/1991-12-09 comics]. With the COVID-19 pandemic, he feels that others may have difficulty having normal conversations as well, and so this seems to be a "silver lining" for the pandemic. He can now use this excuse instead of having to admit that he has difficulty in social situations. Randall also uses a false but plausible excuse to cover unusual nerd behavior in [[1900: Jet Lag]]. He also uses another excuse which can get him out of life in general in [[880: Headache]].

In the title text, he shows his dislike, which existed prior to the pandemic, of going to crowded bars. In the future, even after the pandemic passes, Cueball will still have the excuse that the pandemic made him feel uncomfortable in crowded bars due to possible virus spread and that the feeling has persisted past the pandemic.

==Transcript==
:[Two Cueballs wearing face masks are facing each other and talking.]
:Cueball 1: So how's...everything.
:Cueball 1: I mean, I know everything is, um...but are you, uh...
:Cueball 1: Sorry, I feel like the pandemic has destroyed my ability to have a conversation like a normal human.
:Cueball 2: Haha, I know, right?

:Caption below the panel: I'm at least glad I have this excuse now.

{{comic discussion}}
[[Category:COVID-19]]
[[Category:Social interactions]]
[[Category:Multiple Cueballs]]
[[Category:Comics featuring face masks]]

2422: Vaccine Ordering

2021-02-09T00:12:51Z

108.162.219.80: fix

{{comic
| number = 2422
| date = February 9, 2021
| title = Vaccine Ordering
| image = vaccine_ordering.png
| titletext = You know what they say: mRNA-1273 before tozinameran, you'll have to slay a banshee in a catamaran.
}}

==Explanation==
{{incomplete|Created by the RULER OF SMYRNA. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}

Megan is reading an article on her phone to Cueball. A report from the {{w|Centers for Disease Control and Prevention|CDC}} says it's possible to get effective immunity against {{w|COVID-19}} when taking two different {{w|RNA vaccine|mRNA vaccines}}, but this practice should not be the norm. The report in question can be viewed [https://www.cdc.gov/vaccines/covid-19/info-by-product/clinical-considerations.html here]. It stresses that mixing the vaccines is acceptable only in exceptional circumstances, "like when the first-dose vaccine product cannot be determined."

Cueball wonders whether the order that you receive the vaccines matters. She and Cueball then attempt to create {{w|Mnemonic|mnemonic devices}} to help them remember which mix-and-match strategy is best for the mRNA vaccines from pharmaceutical companies Pfizer and Moderna (e.g., "Beer before wine and you'll feel fine; wine before beer and you'll feel queer"). Megan succeeds by rhyming "Pfizer" and "wiser", but struggles with finding a rhyme for "Moderna", settling for {{w|Smyrna}}, an ancient city located in what is now Turkey.

Studies have shown that the order that you have alcoholic drinks doesn't affect the severity of the hangover. The efficacy of mixing vaccines is presently unknown, which is an important reason why mixing them is discouraged.

The title text continues the theme of difficult rhymes, using the full names of both the Moderna vaccine drug ({{w|Moderna COVID-19 vaccine|mRNA-1273}}) and the Pfizer one ({{w|Pfizer–BioNTech COVID-19 vaccine|tozinameran}}).

==Trivia==

This comic image has no {{w|Spatial anti-aliasing|anti-aliasing}} (all its pixels are either fully black or fully white, with no shades of gray). This gives the smooth lines a jagged appearance when the image is displayed in something other than its native size.

==Transcript==
Megan and Cueball are talking. Megan is refering to a news story on her phone.

Megan: The CDC says it's okay to mix and match the mRNA vaccines for doses 1 and 2, but only in exceptional circumstances.

Cueball: I wonder which order works better, if either.

Megan: Well you know what they say — Moderna before Pfizer, you'll be none the wiser. Pfziser before Moderna then you'll….rule ancient Smyrna.

Cueball: Weird side effect.

Megan: A lot of hard-to-rhyme drugs have those.
{{incomplete transcript|Do NOT delete this tag too soon.}}

{{comic discussion}}

Talk:2414: Solar System Compression Artifacts

2021-01-21T17:36:22Z

108.162.219.80:

"([Compression artefacts] may become literally unnoticeable because hexadecimal color values are discrete[...]" - disagree. Artefacts exist ''because'' of a discrete nature. Either of the RGB(/HSV/whatever) granularity, the lower the colour depth, or of the method used to get around the overheads of storing literal 24+ bits of colour-depth across a given image size. TrueColo(u)r should escape ''perceived'' colour-banding, but any image editor knows (or relies upon) that any flood-fill/by-colour-selection used with an absolute drift range away from the datum spot less than that across a gradient spills away from it can highlight 'hidden' edges between (say) #789ABC and #789BBC. What we have here is low bit-depth (grey-shade or equal-RGB, apparently 4-bit(/each), counting the 16 bands thanks to the mach-banding) non-dithered band-shading of a possibly nuanced (fractal?) shade fall-off. Possibly a 2D slice through 3D (or more, e.g. if animated) of voxelated (or hypervoxelated) stored values, which use up a ''lot'' of space in the Universe Simulator. Perhaps there's also something like Discrete Cosine Transform compression for easier block/chunk storage, retrieval and/or generation-on-demand (with detailed deltas for complex overlaying features such as Voyager). Because the Creator/Programmer of the universe has limited storage/processor cycles! [[Special:Contributions/141.101.105.122|141.101.105.122]] 01:39, 21 January 2021 (UTC)
:tl;dr? — [[User:Sqrt-1|The 𝗦𝗾𝗿𝘁-𝟭]] [[User talk:Sqrt-1|talk]] [[Special:Contributions/Sqrt-1|stalk]] 13:16, 21 January 2021 (UTC)
I would suggest that more emphasis needs to be placed on 'dynamic range' and 'undetectable' in this explanation. Particularly noticeable in streaming video codecs, you often can't decipher any information in dark scenes/regions. So the joke is that the map beyond here is empty, mostly because it is too far down in the dynamic range of our lossy observations. [[Special:Contributions/108.162.219.80|108.162.219.80]] 17:36, 21 January 2021 (UTC)

2413: Pulsar Analogy

2021-01-20T20:38:25Z

108.162.219.80: /* Explanation */

{{comic
| number = 2413
| date = January 18, 2021
| title = Pulsar Analogy
| image = pulsar_analogy.png
| titletext = The #2 cause of astronomer hand injuries is trying to do vector math when the second axis points off to the right.
}}

==Explanation==
{{incomplete|Created by an INJURED ASTRONOMER - more on the injury part in the explanation. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}

{{w|Pulsar}}s are a kind of old shrunken fast-spinning star which no longer shine in all directions but instead produce beams of radiation out their magnetic poles that blip by us as they spin. Ponytail, an astronomer in this comic, explains a pulsar's fast rotation with an analogy about a tape measure retracting. Since the analogy does result in something that spins, the reader might think that, while they don't immediately see how it helps in understanding pulsars, they're willing to reserve judgment to see what is then done with the analogy; Cueball's response may suggest this sort of wait-and-see attitude. However, the analogy is likely to be useless or misleading, as the tape measure starts to rotate because the retracting tape is not moving only in a radial (in/out) direction. As a star collapses into a pulsar, its natural rotation rate is greatly amplified by its shrinking moment of inertia.

Further elaborations of the analogy, rather than clarifying matters, are successively more surreal. More misleading than the tape-measure is the idea of a laser measure being "exactly" like the emissions of a pulsar, which, although both pulse (and both for the same reason of holding pulsed light representation on our timeline in view of our deities), are produced in entirely different ways and are at best simply helping the mind hold the concept.

When a tape measure retracts, the part of the tape outside the tape measure is not going directly towards the tape measure's center but rather towards a hole in the side. This means the tape possesses some angular momentum relative to the tape measure. In addition, when the tape measure retracts, the part of the tape inside the tape measure rotates around a spool (which pulls the part of the tape outside the tape measure inside), so it also has angular momentum relative to the tape measure. When the tape is completely retracted, the tape can no longer rotate relative to the tape measure, so the entire tape measure rotates due to the conservation of angular momentum. While pulsars also rotate quickly due to the conservation of angular momentum, the exact mechanism is completely different. Pulsars are formed when stars collapse due to no longer performing enough fusion to produce enough heat and energy to cancel out gravity. This causes the star to contract, which causes its mass, on average, to be closer to its axis of rotation, which causes the rotational inertia (also called the moment of inertia) to decrease. If the star's angular velocity stayed constant, this would cause the angular momentum to decrease, so the star's angular velocity must increase in order to offset the decrease in rotational inertia, i.e. the star (which is now a pulsar) spins faster.

Some tape measures have a built-in {{w|laser line level}} and others have a built-in {{w|laser rangefinder}}. Pulsars emit electromagnetic radiation out of their magnetic poles, which is similar to a laser, but unlike the laser of a tape measure, the pulsar beam is emitted through the axis of the magnetic field. The pulsing nature of a pulsar comes from when the axis of rotation is not precisely aligned with the axis of the magnetic field, and the location of the viewer as the beam sweeps by. On the other hand, the laser of a laser rangefinder is pulsed by microcircuitry so as to measure distance by the time a reflection is received.

The title text mentions the {{w|right-hand rule}} in three-dimensional space. In a typical 3D coordinate system the Y-axis will point counterclockwise to the X-axis when looking down from the positive Z-axis. In academia, students are often taught to remember a number of mathematical conventions by using their actual physical right and left hands to align the axes. When the axes are in a different order, the left hand can be used in stead of the right, but there are a number of common operations in engineering and physics that use the {{w|cross product}} in systems where the first axis might point in absolutely any direction relative to the viewer. Using the hand rules, the thumb is aimed along the first axis, the forefinger along the second, and the middle finger along the third -- all at ninety degrees. So, when the first axis points off to the right, the right wrist is torqued to its full extension to make the thumb point that way while the other two fingers don't. During exams students can be seen performing this feat. People who learn cross products early in their life may develop other approaches for remembering these things, that don't stretch the hands as much, but then adopt the common approach once taught it.

==Transcript==
:[Cueball and Ponytail are standing next to each other.]
:Cueball: Why do pulsars spin so ''fast?''
:Ponytail: Hmm, let me think of an analogy...

:[A tape measure is retracting above Ponytail's head. To the right of her head, a tape measure is spinning rapidly.]
:Retracting tape measure: ''zzzzzzzzzzzzzzz''
:Spinning tape measure: SNAP
:Ponytail: You know how when you retract a tape measure and let go, it leaves it spinning?
:Ponytail: It's like that.
:Cueball (off-panel): Oh, I see.

:[A tape measure with a laser instead of a measuring tape is spinning slowly.]
:Cueball (off-panel): And if the tape measure is the kind with a laser level, that's the beam of radiation?
:Ponytail (off-panel): Exactly!

:[Cueball and Ponytail are walking next to each other in silhouette.]
:Ponytail: And when the tape whips around and smacks your hand, that's the neutron degeneracy shockwave.
:Cueball: Sounds painful!
:Ponytail: Top cause of astronomer hand injuries.

{{comic discussion}}
[[Category:Astronomy]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Ponytail]]

2413: Pulsar Analogy

2021-01-20T20:37:10Z

108.162.219.80: /* Explanation */

{{comic
| number = 2413
| date = January 18, 2021
| title = Pulsar Analogy
| image = pulsar_analogy.png
| titletext = The #2 cause of astronomer hand injuries is trying to do vector math when the second axis points off to the right.
}}

==Explanation==
{{incomplete|Created by an INJURED ASTRONOMER - more on the injury part in the explanation. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}

{{w|Pulsar}}s are a kind of old shrunken fast-spinning star which no longer shine in all directions but instead produce beams of radiation that blip by us as they spin. Ponytail, an astronomer in this comic, explains a pulsar's fast rotation with an analogy about a tape measure retracting. Since the analogy does result in something that spins, the reader might think that, while they don't immediately see how it helps in understanding pulsars, they're willing to reserve judgment to see what is then done with the analogy; Cueball's response may suggest this sort of wait-and-see attitude. However, the analogy is likely to be useless or misleading, as the tape measure starts to rotate because the retracting tape is not moving only in a radial (in/out) direction. As a star collapses into a pulsar, its natural rotation rate is greatly amplified by its shrinking moment of inertia.

Further elaborations of the analogy, rather than clarifying matters, are successively more surreal. More misleading than the tape-measure is the idea of a laser measure being "exactly" like the emissions of a pulsar, which, although both pulse (and both for the same reason of holding pulsed light representation on our timeline in view of our deities), are produced in entirely different ways and are at best simply helping the mind hold the concept.

When a tape measure retracts, the part of the tape outside the tape measure is not going directly towards the tape measure's center but rather towards a hole in the side. This means the tape possesses some angular momentum relative to the tape measure. In addition, when the tape measure retracts, the part of the tape inside the tape measure rotates around a spool (which pulls the part of the tape outside the tape measure inside), so it also has angular momentum relative to the tape measure. When the tape is completely retracted, the tape can no longer rotate relative to the tape measure, so the entire tape measure rotates due to the conservation of angular momentum. While pulsars also rotate quickly due to the conservation of angular momentum, the exact mechanism is completely different. Pulsars are formed when stars collapse due to no longer performing enough fusion to produce enough heat and energy to cancel out gravity. This causes the star to contract, which causes its mass, on average, to be closer to its axis of rotation, which causes the rotational inertia (also called the moment of inertia) to decrease. If the star's angular velocity stayed constant, this would cause the angular momentum to decrease, so the star's angular velocity must increase in order to offset the decrease in rotational inertia, i.e. the star (which is now a pulsar) spins faster.

Some tape measures have a built-in {{w|laser line level}} and others have a built-in {{w|laser rangefinder}}. Pulsars emit electromagnetic radiation out of their magnetic poles, which is similar to a laser, but unlike the laser of a tape measure, the pulsar beam is emitted through the axis of the magnetic field. The pulsing nature of a pulsar comes from when the axis of rotation is not precisely aligned with the axis of the magnetic field, and the location of the viewer as the beam sweeps by. On the other hand, the laser of a laser rangefinder is pulsed by microcircuitry so as to measure distance by the time a reflection is received.

The title text mentions the {{w|right-hand rule}} in three-dimensional space. In a typical 3D coordinate system the Y-axis will point counterclockwise to the X-axis when looking down from the positive Z-axis. In academia, students are often taught to remember a number of mathematical conventions by using their actual physical right and left hands to align the axes. When the axes are in a different order, the left hand can be used in stead of the right, but there are a number of common operations in engineering and physics that use the {{w|cross product}} in systems where the first axis might point in absolutely any direction relative to the viewer. Using the hand rules, the thumb is aimed along the first axis, the forefinger along the second, and the middle finger along the third -- all at ninety degrees. So, when the first axis points off to the right, the right wrist is torqued to its full extension to make the thumb point that way while the other two fingers don't. During exams students can be seen performing this feat. People who learn cross products early in their life may develop other approaches for remembering these things, that don't stretch the hands as much, but then adopt the common approach once taught it.

==Transcript==
:[Cueball and Ponytail are standing next to each other.]
:Cueball: Why do pulsars spin so ''fast?''
:Ponytail: Hmm, let me think of an analogy...

:[A tape measure is retracting above Ponytail's head. To the right of her head, a tape measure is spinning rapidly.]
:Retracting tape measure: ''zzzzzzzzzzzzzzz''
:Spinning tape measure: SNAP
:Ponytail: You know how when you retract a tape measure and let go, it leaves it spinning?
:Ponytail: It's like that.
:Cueball (off-panel): Oh, I see.

:[A tape measure with a laser instead of a measuring tape is spinning slowly.]
:Cueball (off-panel): And if the tape measure is the kind with a laser level, that's the beam of radiation?
:Ponytail (off-panel): Exactly!

:[Cueball and Ponytail are walking next to each other in silhouette.]
:Ponytail: And when the tape whips around and smacks your hand, that's the neutron degeneracy shockwave.
:Cueball: Sounds painful!
:Ponytail: Top cause of astronomer hand injuries.

{{comic discussion}}
[[Category:Astronomy]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Ponytail]]

2413: Pulsar Analogy

2021-01-20T20:35:58Z

108.162.219.80: /* Explanation */

{{comic
| number = 2413
| date = January 18, 2021
| title = Pulsar Analogy
| image = pulsar_analogy.png
| titletext = The #2 cause of astronomer hand injuries is trying to do vector math when the second axis points off to the right.
}}

==Explanation==
{{incomplete|Created by an INJURED ASTRONOMER - more on the injury part in the explanation. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}

{{w|Pulsar}}s are a kind of small old star that no longer shine in all directions but instead produce fast-spinning beams of radiation. Ponytail, an astronomer in this comic, explains a pulsar's fast rotation with an analogy about a tape measure retracting. Since the analogy does result in something that spins, the reader might think that, while they don't immediately see how it helps in understanding pulsars, they're willing to reserve judgment to see what is then done with the analogy; Cueball's response may suggest this sort of wait-and-see attitude. However, the analogy is likely to be useless or misleading, as the tape measure starts to rotate because the retracting tape is not moving only in a radial (in/out) direction. As a star collapses into a pulsar, its natural rotation rate is greatly amplified by its shrinking moment of inertia.

Further elaborations of the analogy, rather than clarifying matters, are successively more surreal. More misleading than the tape-measure is the idea of a laser measure being "exactly" like the emissions of a pulsar, which, although both pulse (and both for the same reason of holding pulsed light representation on our timeline in view of our deities), are produced in entirely different ways and are at best simply helping the mind hold the concept.

When a tape measure retracts, the part of the tape outside the tape measure is not going directly towards the tape measure's center but rather towards a hole in the side. This means the tape possesses some angular momentum relative to the tape measure. In addition, when the tape measure retracts, the part of the tape inside the tape measure rotates around a spool (which pulls the part of the tape outside the tape measure inside), so it also has angular momentum relative to the tape measure. When the tape is completely retracted, the tape can no longer rotate relative to the tape measure, so the entire tape measure rotates due to the conservation of angular momentum. While pulsars also rotate quickly due to the conservation of angular momentum, the exact mechanism is completely different. Pulsars are formed when stars collapse due to no longer performing enough fusion to produce enough heat and energy to cancel out gravity. This causes the star to contract, which causes its mass, on average, to be closer to its axis of rotation, which causes the rotational inertia (also called the moment of inertia) to decrease. If the star's angular velocity stayed constant, this would cause the angular momentum to decrease, so the star's angular velocity must increase in order to offset the decrease in rotational inertia, i.e. the star (which is now a pulsar) spins faster.

Some tape measures have a built-in {{w|laser line level}} and others have a built-in {{w|laser rangefinder}}. Pulsars emit electromagnetic radiation out of their magnetic poles, which is similar to a laser, but unlike the laser of a tape measure, the pulsar beam is emitted through the axis of the magnetic field. The pulsing nature of a pulsar comes from when the axis of rotation is not precisely aligned with the axis of the magnetic field, and the location of the viewer as the beam sweeps by. On the other hand, the laser of a laser rangefinder is pulsed by microcircuitry so as to measure distance by the time a reflection is received.

The title text mentions the {{w|right-hand rule}} in three-dimensional space. In a typical 3D coordinate system the Y-axis will point counterclockwise to the X-axis when looking down from the positive Z-axis. In academia, students are often taught to remember a number of mathematical conventions by using their actual physical right and left hands to align the axes. When the axes are in a different order, the left hand can be used in stead of the right, but there are a number of common operations in engineering and physics that use the {{w|cross product}} in systems where the first axis might point in absolutely any direction relative to the viewer. Using the hand rules, the thumb is aimed along the first axis, the forefinger along the second, and the middle finger along the third -- all at ninety degrees. So, when the first axis points off to the right, the right wrist is torqued to its full extension to make the thumb point that way while the other two fingers don't. During exams students can be seen performing this feat. People who learn cross products early in their life may develop other approaches for remembering these things, that don't stretch the hands as much, but then adopt the common approach once taught it.

==Transcript==
:[Cueball and Ponytail are standing next to each other.]
:Cueball: Why do pulsars spin so ''fast?''
:Ponytail: Hmm, let me think of an analogy...

:[A tape measure is retracting above Ponytail's head. To the right of her head, a tape measure is spinning rapidly.]
:Retracting tape measure: ''zzzzzzzzzzzzzzz''
:Spinning tape measure: SNAP
:Ponytail: You know how when you retract a tape measure and let go, it leaves it spinning?
:Ponytail: It's like that.
:Cueball (off-panel): Oh, I see.

:[A tape measure with a laser instead of a measuring tape is spinning slowly.]
:Cueball (off-panel): And if the tape measure is the kind with a laser level, that's the beam of radiation?
:Ponytail (off-panel): Exactly!

:[Cueball and Ponytail are walking next to each other in silhouette.]
:Ponytail: And when the tape whips around and smacks your hand, that's the neutron degeneracy shockwave.
:Cueball: Sounds painful!
:Ponytail: Top cause of astronomer hand injuries.

{{comic discussion}}
[[Category:Astronomy]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Ponytail]]

Talk:2413: Pulsar Analogy

2021-01-20T20:33:53Z

108.162.219.80:

I tried applying the right-hand-rule with the y-axis pointing to the right. :( I hurt my hand.
[[User:Avitzur|Avitzur]] ([[User talk:Avitzur|talk]]) 23:22, 18 January 2021 (UTC)
:Rotate your paper then do the right hand rule :)
:Hand joint exercises. Gentle motions with the wrist bent backwards, and bent forwards; 3-5 circles in both directions and both postures, twice a day. [[Special:Contributions/162.158.62.41|162.158.62.41]] 00:48, 19 January 2021 (UTC)
[[Special:Contributions/172.69.35.149|172.69.35.149]] 23:38, 18 January 2021 (UTC)

The analogy doesn't seem to be inaccurate in the way currently indicated. In both cases (tape measure and pulsar), conservation of ''angular'' momentum is what produces the result. With the tape measure, a small fast-spinning thing turns into a large slow-spinning thing; the opposite happens with a pulsar. [[Special:Contributions/172.69.35.150|172.69.35.150]] 00:05, 19 January 2021 (UTC)
:Isn't a tape measure bigger, not smaller, and slow-spinning, not fast-spinning, when it is elongated? This is very confusing. Thinking of how pulling the tape out stores energy. [[Special:Contributions/162.158.62.41|162.158.62.41]] 00:49, 19 January 2021 (UTC)
::A tape measure starts off not spinning. It's the acceleration of the tape as it moves in that starts the rotation, because the motion of the tape measure is not precisely radial. Same principle, different problem. [[User:Ltmauve|Ltmauve]] ([[User talk:Ltmauve|talk]]) 02:29, 19 January 2021 (UTC)
:::As the tape retracts, the tape inside the case is spinning. Once it is fully retracted, the case spins. Small spinny --> large spinny.
:::Of course, on a frictionless surface there's some slow retrograde rotation of the case + extended tape that speeds up as the tape retracts, but the case should completely stop spinning once the tape is fully retracted in that scenario, which is opposite of the analogy being drawn. [[Special:Contributions/172.69.34.12|172.69.34.12]] 02:43, 19 January 2021 (UTC)
::::On a frictionless surface, it would ''never'' stop spinning. Once the case starts to spin, there's nothing to slow it down. --[[Special:Contributions/172.69.63.183|172.69.63.183]] 17:45, 19 January 2021 (UTC)
:::::On a frictionless surface, before the extended tape measure is released, it has no net angular momentum. After it is released, the winding tape carries angular momentum, so the case+extended tape must spin in the opposite direction for the entire tape measure system to continue to have no net angular momentum. When the tape suddenly stops, it will no longer carry any angular momentum, so the case must stop spinning entirely for the system to continue to have no net angular momentum. Because of friction, we usually don't see the retro-rotation of the case until the tape is almost completely wound up. See also dlvozza's Impact Driver comment. [[Special:Contributions/172.69.35.85|172.69.35.85]] 21:27, 19 January 2021 (UTC)
::: It seems to me like the reason the full tape measure spins is somewhat similar to an Impact Driver. Shooting slow motion videos of retracting my tape measure I see a small rotation in the opposite direction of the rotation in the end (likely due to the device maintaining angular momentum as the spring inside spins up) and then a quick snap when the tape is fully retracted, followed by the tape spinning very quickly in the opposite direction. As for my comparison to an impact, this reminds me a lot of how those work, with some inner barrel spinning at a very high speed, and then mechanically imparting that energy onto the body of the driving head, causing it to turn with a high torque. Typically when you start an impact spinning you can feel a small torque opposite to how the driver end spins because of the inner barrel spinning up. In the tape measure the inner spinning barrel is the tape itself and the spring to retract it, the driver head is the outer shell of the tape measure. [[User:dlvozza|dlvozza]] ([[User talk:dlvozza|talk]]) 19:48, 19 January 2021 (UTC)

Currently the description starts off “Pulsars are dead stellar cores” and that phrase seems very bizarre to me, since all stellar objects are dead. Do astronomers routinely anthropomorphize to such a degree as to call some stars alive and others dead? I would think more literal language like “A pulsar is the very compact and highly magnetized remains of a star after a nova or supernova explosion” but if the acceptable astronomical parlance is to say “dead star” far be it for me to demand a change[[Special:Contributions/162.158.63.94|162.158.63.94]] 05:26, 19 January 2021 (UTC)
:I find the "dead star" also odd. Sure, I know what is meant, but in the same way I know what is meant by the tape measure analogy. Neither is accurate. Side note: I removed the part about the measures' lifespan and how you could repair it as this gives no benefit for the explanation and is totally irrelevant. [[User:Elektrizikekswerk|Elektrizikekswerk]] ([[User talk:Elektrizikekswerk|talk]]) 10:18, 19 January 2021 (UTC)
:The word "dead" can be used to refer to inactivity in an object that was never classically alive. i.e. dead volcanoes --[[Special:Contributions/188.114.102.60|188.114.102.60]] 15:55, 19 January 2021 (UTC)
:Humans aren't the only things that can be alive or dead, so calling it anthropomorphization is way off mark. But besides that, stellar objects aren't all "dead", they're non-living. You have to be alive and then die to be dead, in the biological sense. But in this case, it's called a "dead stellar core" because it no longer has sustained fusion reactions which is what stars are known for, just like a battery that's used up all of its charge is called "Dead" - not because we're assigning human qualities, but because it doesn't do what it's supposed to. Same with any non-living thing that doesn't function as expected being referred to as dead. --[[Special:Contributions/172.69.63.183|172.69.63.183]] 17:41, 19 January 2021 (UTC)
:Astronomers also ''bio''morphise stars by talking about when they are "born" – the moment sustained fusion starts in the core. [[Special:Contributions/172.69.35.7|172.69.35.7]] 21:34, 19 January 2021 (UTC)
:I think stars are alive! They're not biological but they have histories and stories and communities, they just have to do with unimaginably large atomic behaviors and orbiting patterns and stuff instead of fast food and mobile phones. [[Special:Contributions/108.162.219.80|108.162.219.80]] 20:33, 20 January 2021 (UTC)

The increased angular velocity as the star shrinks is analogous to the way an ice skater's rotational velocity changes as they draw their arms in and out, no? [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 23:59, 19 January 2021 (UTC)
:Just in, no pulsar ever managed to do "out" ... and yes, that's the analogy usually used, because it's easier to understand and considerably more fitting. Well, at least for someone who ever saw ice skating ... -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 06:24, 20 January 2021 (UTC)
:: Though they didn't use that analogy here, as they needed one that could be extended in a really ridiculous way to make the joke. It's not supposed to be the best possible analogy, but the follow up is supposed to be much worse.--[[Special:Contributions/108.162.216.118|108.162.216.118]] 17:51, 20 January 2021 (UTC)

Currently, the explanation doesn't say anything about the last panel, and should probably emphasize the core of the joke in that the explanation starts out kind of reasonable, albeit imperfect, but then gets progressively much worse when it is elaborated on in the last 2 panels (the initial analogy is a lot more reasonable than the stuff about the laser, and the fourth panel is just nonsense.)--[[Special:Contributions/162.158.74.85|162.158.74.85]] 05:01, 20 January 2021 (UTC)

2413: Pulsar Analogy

2021-01-20T20:28:16Z

108.162.219.80: /* Explanation */

{{comic
| number = 2413
| date = January 18, 2021
| title = Pulsar Analogy
| image = pulsar_analogy.png
| titletext = The #2 cause of astronomer hand injuries is trying to do vector math when the second axis points off to the right.
}}

==Explanation==
{{incomplete|Created by an INJURED ASTRONOMER - more on the injury part in the explanation. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}

{{w|Pulsar}}s are dead stellar cores that produce fast-spinning beams of radiation. Ponytail, an astronomer in this comic, explains a pulsar's fast rotation with an analogy about a tape measure retracting. Since the analogy does result in something that spins, the reader might think that, while they don't immediately see how it helps in understanding pulsars, they're willing to reserve judgment to see what is then done with the analogy; Cueball's response may suggest this sort of wait-and-see attitude. However, the analogy is likely to be useless or misleading, as the tape measure starts to rotate because the retracting tape is not moving only in a radial (in/out) direction. As a star collapses into a pulsar, its natural rotation rate is greatly amplified by its shrinking moment of inertia.

Further elaborations of the analogy, rather than clarifying matters, are successively more surreal. More misleading than the tape-measure is the idea of a laser measure being "exactly" like the emissions of a pulsar, which, although both pulse (and both for the same reason of holding pulsed light representation on our timeline in view of our deities), are produced in entirely different ways and are at best simply helping the mind hold the concept.

When a tape measure retracts, the part of the tape outside the tape measure is not going directly towards the tape measure's center but rather towards a hole in the side. This means the tape possesses some angular momentum relative to the tape measure. In addition, when the tape measure retracts, the part of the tape inside the tape measure rotates around a spool (which pulls the part of the tape outside the tape measure inside), so it also has angular momentum relative to the tape measure. When the tape is completely retracted, the tape can no longer rotate relative to the tape measure, so the entire tape measure rotates due to the conservation of angular momentum. While pulsars also rotate quickly due to the conservation of angular momentum, the exact mechanism is completely different. Pulsars are formed when stars collapse due to no longer performing enough fusion to produce enough heat and energy to cancel out gravity. This causes the star to contract, which causes its mass, on average, to be closer to its axis of rotation, which causes the rotational inertia (also called the moment of inertia) to decrease. If the star's angular velocity stayed constant, this would cause the angular momentum to decrease, so the star's angular velocity must increase in order to offset the decrease in rotational inertia, i.e. the star (which is now a pulsar) spins faster.

Some tape measures have a built-in {{w|laser line level}} and others have a built-in {{w|laser rangefinder}}. Pulsars emit electromagnetic radiation out of their magnetic poles, which is similar to a laser, but unlike the laser of a tape measure, the pulsar beam is emitted through the axis of the magnetic field. The pulsing nature of a pulsar comes from when the axis of rotation is not precisely aligned with the axis of the magnetic field, and the location of the viewer as the beam sweeps by. On the other hand, the laser of a laser rangefinder is pulsed by microcircuitry so as to measure distance by the time a reflection is received.

The title text mentions the {{w|right-hand rule}} in three-dimensional space. In a typical 3D coordinate system the Y-axis will point counterclockwise to the X-axis when looking down from the positive Z-axis. In academia, students are often taught to remember a number of mathematical conventions by using their actual physical right and left hands to align the axes. When the axes are in a different order, the left hand can be used in stead of the right, but there are a number of common operations in engineering and physics that use the {{w|cross product}} in systems where the first axis might point in absolutely any direction relative to the viewer. Using the hand rules, the thumb is aimed along the first axis, the forefinger along the second, and the middle finger along the third -- all at ninety degrees. So, when the first axis points off to the right, the right wrist is torqued to its full extension to make the thumb point that way while the other two fingers don't. During exams students can be seen performing this feat. People who learn cross products early in their life may develop other approaches for remembering these things, that don't stretch the hands as much, but then adopt the common approach once taught it.

==Transcript==
:[Cueball and Ponytail are standing next to each other.]
:Cueball: Why do pulsars spin so ''fast?''
:Ponytail: Hmm, let me think of an analogy...

:[A tape measure is retracting above Ponytail's head. To the right of her head, a tape measure is spinning rapidly.]
:Retracting tape measure: ''zzzzzzzzzzzzzzz''
:Spinning tape measure: SNAP
:Ponytail: You know how when you retract a tape measure and let go, it leaves it spinning?
:Ponytail: It's like that.
:Cueball (off-panel): Oh, I see.

:[A tape measure with a laser instead of a measuring tape is spinning slowly.]
:Cueball (off-panel): And if the tape measure is the kind with a laser level, that's the beam of radiation?
:Ponytail (off-panel): Exactly!

:[Cueball and Ponytail are walking next to each other in silhouette.]
:Ponytail: And when the tape whips around and smacks your hand, that's the neutron degeneracy shockwave.
:Cueball: Sounds painful!
:Ponytail: Top cause of astronomer hand injuries.

{{comic discussion}}
[[Category:Astronomy]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Ponytail]]

2413: Pulsar Analogy

2021-01-20T20:23:38Z

108.162.219.80: pulsing

{{comic
| number = 2413
| date = January 18, 2021
| title = Pulsar Analogy
| image = pulsar_analogy.png
| titletext = The #2 cause of astronomer hand injuries is trying to do vector math when the second axis points off to the right.
}}

==Explanation==
{{incomplete|Created by an INJURED ASTRONOMER - more on the injury part in the explanation. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}

{{w|Pulsar}}s are dead stellar cores that produce fast-spinning beams of radiation. Ponytail, an astronomer in this comic, explains a pulsar's fast rotation with an analogy about a tape measure retracting. Since the analogy does result in something that spins, the reader might think that, while they don't immediately see how it helps in understanding pulsars, they're willing to reserve judgment to see what is then done with the analogy; Cueball's response may suggest this sort of wait-and-see attitude. However, the analogy is likely to be useless or misleading, as the tape measure starts to rotate because the retracting tape is not moving only in a radial (in/out) direction. As a star collapses into a pulsar, its natural rotation rate is greatly amplified by its shrinking moment of inertia.

Further elaborations of the analogy, rather than clarifying matters, are successively more surreal. More misleading than the tape-measure is the idea of a laser measure being "exactly" like the emissions of a pulsar, which, although both pulse (and both for the same reason of holding pulsed light representation on our timeline in view of our deities), are produced in entirely different ways and are at best simply helping the mind hold the concept.

When a tape measure retracts, the part of the tape outside the tape measure is not going directly towards the tape measure's center but rather towards a hole in the side. This means the tape possesses some angular momentum relative to the tape measure. In addition, when the tape measure retracts, the part of the tape inside the tape measure rotates around a spool (which pulls the part of the tape outside the tape measure inside), so it also has angular momentum relative to the tape measure. When the tape is completely retracted, the tape can no longer rotate relative to the tape measure, so the entire tape measure rotates due to the conservation of angular momentum. While pulsars also rotate quickly due to the conservation of angular momentum, the exact mechanism is completely different. Pulsars are formed when stars collapse due to no longer performing enough fusion to produce enough heat and energy to cancel out gravity. This causes the star to contract, which causes its mass, on average, to be closer to its axis of rotation, which causes the rotational inertia (also called the moment of inertia) to decrease. If the star's angular velocity stayed constant, this would cause the angular momentum to decrease, so the star's angular velocity must increase in order to offset the decrease in rotational inertia, i.e. the star (which is now a pulsar) spins faster.

Some tape measures have a built-in {{w|laser line level}} and others have a built-in {{w|laser rangefinder}}. Pulsars emit electromagnetic radiation out of their magnetic poles, which is similar to a laser, but unlike the laser of a tape measure, the pulsar beam is emitted through the axis of the magnetic field. The pulsing nature of a pulsar comes from when the axis of rotation is not precisely aligned with the axis of the magnetic field, and the location of the viewer as the beam sweeps by. On the other hand, the laser of a laser rangefinder is pulsed by microcircuitry so as to measure distance by the time a reflection is received.

The title text mentions the {{w|right-hand rule}} in three-dimensional space. In a typical 3D coordinate system the Y-axis will point counterclockwise to the X-axis when looking down from the positive Z-axis. In a left-handed coordinate system, the Y-axis instead points clockwise. Attempting to use the right hand here to calculate a {{w|cross product}} will require a 90° backward bend of the middle finger or thumb, which hurts.{{Citation needed}}

==Transcript==
:[Cueball and Ponytail are standing next to each other.]
:Cueball: Why do pulsars spin so ''fast?''
:Ponytail: Hmm, let me think of an analogy...

:[A tape measure is retracting above Ponytail's head. To the right of her head, a tape measure is spinning rapidly.]
:Retracting tape measure: ''zzzzzzzzzzzzzzz''
:Spinning tape measure: SNAP
:Ponytail: You know how when you retract a tape measure and let go, it leaves it spinning?
:Ponytail: It's like that.
:Cueball (off-panel): Oh, I see.

:[A tape measure with a laser instead of a measuring tape is spinning slowly.]
:Cueball (off-panel): And if the tape measure is the kind with a laser level, that's the beam of radiation?
:Ponytail (off-panel): Exactly!

:[Cueball and Ponytail are walking next to each other in silhouette.]
:Ponytail: And when the tape whips around and smacks your hand, that's the neutron degeneracy shockwave.
:Cueball: Sounds painful!
:Ponytail: Top cause of astronomer hand injuries.

{{comic discussion}}
[[Category:Astronomy]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Ponytail]]

2413: Pulsar Analogy

2021-01-20T20:17:15Z

108.162.219.80: yes, it is the same reason

{{comic
| number = 2413
| date = January 18, 2021
| title = Pulsar Analogy
| image = pulsar_analogy.png
| titletext = The #2 cause of astronomer hand injuries is trying to do vector math when the second axis points off to the right.
}}

==Explanation==
{{incomplete|Created by an INJURED ASTRONOMER - more on the injury part in the explanation. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}

{{w|Pulsar}}s are dead stellar cores that produce fast-spinning beams of radiation. Ponytail, an astronomer in this comic, explains a pulsar's fast rotation with an analogy about a tape measure retracting. Since the analogy does result in something that spins, the reader might think that, while they don't immediately see how it helps in understanding pulsars, they're willing to reserve judgment to see what is then done with the analogy; Cueball's response may suggest this sort of wait-and-see attitude. However, the analogy is likely to be useless or misleading, as the tape measure starts to rotate because the retracting tape is not moving only in a radial (in/out) direction. As a star collapses into a pulsar, its natural rotation rate is greatly amplified by its shrinking moment of inertia.

Further elaborations of the analogy, rather than clarifying matters, are successively more surreal. More misleading than the tape-measure is the idea of a laser measure being "exactly" like the emissions of a pulsar, which, although both pulse (and both for the same reason of holding pulsed light representation on our timeline in view of our deities), are produced in entirely different ways and are at best simply helping the mind hold the concept.

When a tape measure retracts, the part of the tape outside the tape measure is not going directly towards the tape measure's center but rather towards a hole in the side. This means the tape possesses some angular momentum relative to the tape measure. In addition, when the tape measure retracts, the part of the tape inside the tape measure rotates around a spool (which pulls the part of the tape outside the tape measure inside), so it also has angular momentum relative to the tape measure. When the tape is completely retracted, the tape can no longer rotate relative to the tape measure, so the entire tape measure rotates due to the conservation of angular momentum. While pulsars also rotate quickly due to the conservation of angular momentum, the exact mechanism is different. Pulsars are formed when stars collapse due to no longer performing enough fusion to produce enough heat and energy to cancel out gravity. This causes the star to contract, which causes its mass, on average, to be closer to its axis of rotation, which causes the rotational inertia (also called the moment of inertia) to decrease. If the star's angular velocity stayed constant, this would cause the angular momentum to decrease, so the star's angular velocity must increase in order to offset the decrease in rotational inertia, i.e. the star (which is now a pulsar) spins faster.

Some tape measures have a built-in {{w|laser line level}}. Pulsars emit electromagnetic radiation out of their magnetic poles, which is similar to a laser, but unlike the laser of a tape measure, the pulsar beam is emitted through the axis of the magnetic field. The pulsing nature of a pulsar comes from when the axis of rotation is not precisely aligned with the axis of the magnetic field.

The title text mentions the {{w|right-hand rule}} in three-dimensional space. In a typical 3D coordinate system the Y-axis will point counterclockwise to the X-axis when looking down from the positive Z-axis. In a left-handed coordinate system, the Y-axis instead points clockwise. Attempting to use the right hand here to calculate a {{w|cross product}} will require a 90° backward bend of the middle finger or thumb, which hurts.{{Citation needed}}

==Transcript==
:[Cueball and Ponytail are standing next to each other.]
:Cueball: Why do pulsars spin so ''fast?''
:Ponytail: Hmm, let me think of an analogy...

:[A tape measure is retracting above Ponytail's head. To the right of her head, a tape measure is spinning rapidly.]
:Retracting tape measure: ''zzzzzzzzzzzzzzz''
:Spinning tape measure: SNAP
:Ponytail: You know how when you retract a tape measure and let go, it leaves it spinning?
:Ponytail: It's like that.
:Cueball (off-panel): Oh, I see.

:[A tape measure with a laser instead of a measuring tape is spinning slowly.]
:Cueball (off-panel): And if the tape measure is the kind with a laser level, that's the beam of radiation?
:Ponytail (off-panel): Exactly!

:[Cueball and Ponytail are walking next to each other in silhouette.]
:Ponytail: And when the tape whips around and smacks your hand, that's the neutron degeneracy shockwave.
:Cueball: Sounds painful!
:Ponytail: Top cause of astronomer hand injuries.

{{comic discussion}}
[[Category:Astronomy]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Ponytail]]

2406: Viral Vector Immunity

2021-01-01T21:12:15Z

108.162.219.80: /* Explanation */

{{comic
| number = 2406
| date = January 1, 2021
| title = Viral Vector Immunity
| image = viral_vector_immunity.png
| titletext = We've secretly replaced this customer's instant coffee with our patented substitute. Let's see what she ... uh oh, I think she spotted us through the window. Now she's getting something from the closet ... oh jeez, she has a sword! Run!!
}}

==Explanation==
{{incomplete|Created by a SENTIENT WOODEN HORSE. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}

The comic attempts to explain a virus vector vaccine, and one way it can fail, using the story of the {{w|Trojan Horse}} as an analogy.

A vaccine is a way to familiarize a host's immune system with a pathogen without actually causing the host to fall ill. There are many types of vaccines that have been developed, all of which are ways to present a significant segment of a molecular structure to the host body, so that the immune system recognizes the pathogen and mounts an immune response faster when a real infection happens.

A viral vector vaccine uses a modified virus, different from the pathogen being immunized against, as a carrier to deliver a molecular payload into the host body. This modified virus is called the vector because it is the method of delivery of the molecular piece of the pathogen. If the recipient has a strong immune response to the vector itself, the immunization may be less effective. It is to some degree a dice roll, with regard to whether some recipients will already be immune to a protein in a vector.

For example, a modified (to be harmless) cold virus can be used to deliver an (harmless) outer segment of another virus into the body. The ability of the vector virus to sneak into the host body and inject itself into the cell's reproductive system is used to trick the body into producing numerous copies of the recognizable piece of the other virus. That way the immune system recognizes the molecular segment of the other virus without actually being infected with that virus, which tends to significantly decrease recognition time after a real infection, leading to a less severe infection speeding up recovery.

The comic represents this idea with the Trojan horse being the (in this case) harmless vector virus, carrying, contrary to the traditional story, a beneficial payload into the cell.

In the comic the warriors recognize the shape of the delivery vehicle (the Trojan horse) as being similar to an animal that trampled one of their own earlier and therefore refuse it entry. An amusing point here is that they are not as such surprised at the arrival of a wooden vehicle at their doorstep, rather that its shape resembling an animal they have found threatening before, which is similar to how simple in its judgements the immune system can be.

The title text is a further riff on this theme, playing on an advertising campaign for freeze dried coffee. In the advertisements a narrator would claim to have secretly replaced fresh brewed coffee with that made from freeze dried to see if subjects could tell the difference. The contents of the coffee cup being the payload and the narrator the virus vector.

==Transcript==
:[A large wooden horse statue on wheels stands before a city wall, upon which are standing several warriors who are shouting and brandishing spears.]
:Warrior 1: Look! It's a statue of that horrible animal that trampled Steve!
:Warrior 2: Burn it!
:Warrior 3: Smash it!
:Warrior 4: Push it into the gorge!

:[Caption below the panel:]
:How vaccine failure due to viral vector immunity works
{{comic discussion}}
[[Category:COVID-19]]

2404: First Thing

2020-12-29T05:28:58Z

108.162.219.80:

{{comic
| number = 2404
| date = December 28, 2020
| title = First Thing
| image = first_thing.png
| titletext = Then I'm going to go on a weeks-long somatic hypermutation bender, producing ever-more targeted antibodies, while I continue to remain distanced and follow guidance from public health authorities.
}}

==Explanation==
{{incomplete|Created by a SPIKED PROTEIN. Needs a better explanation of the science and the title text. Do NOT delete this tag too soon.}}

This comic, somewhat like [[2402: Into My Veins]], references both the {{w|COVID-19 vaccine}} and a common Internet trend.

The {{w|COVID-19 pandemic}} has been one of the most consequential and broadly unpleasant events in living memory{{Citation needed}}. As of the publication of this strip, it is estimated to have caused over 1.5 million deaths worldwide, with over 300,000 deaths in the United States, with many more cases that have not resulted in fatality but far too often needing serious medical support and/or with lasting implications. Even for those who have been spared infection, measures to slow the spread of the virus have been highly impactful, and have been ongoing for nearly a year.

In consequence of all of this, many people are excited for the vaccine (which will hopefully end the pandemic). Many people online have been sharing plans for what they'll do after getting the vaccine, like "see my friends" or "travel the world." In this comic, Ponytail takes the trend literally, listing instead what will happen in her body immediately after getting the vaccine.

The title text emphasizes the real danger for and from people planning what they'll "do first": they won't have immunity immediately after receiving the vaccine. Developing immunity takes weeks to be effective. The first few vaccines likely to be approved will require a second dose 3 or 4 weeks after the first. Moreover, a person with immunity might still be able to spread the virus even if they don't get sick themselves.

==Transcript==
:[Ponytail and Cueball are walking toward the right side of a single panel. Ponytail is gesturing with one arm.]

:Ponytail: The ''first'' thing I'm going to do after I get the vaccine?
:Ponytail: Definitely make a bunch of spike proteins and engulf them with dendritic cells.
:Ponytail: Then I'll probably display the antigens to my T-cells...

{{comic discussion}}
[[Category:COVID-19]]
[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring Cueball]]
[[Category:Biology]]

Talk:357: Flies

2020-08-12T14:59:35Z

108.162.219.80: Use apple cider vinegar, not white vinegar

Actually, the saying was originally “A watched pot never boils ''over''.” This means that you should watch a pot to make sure the water doesn't spill out.[[Special:Contributions/68.195.76.173|68.195.76.173]] 17:57, 8 March 2013 (UTC)
:Nope. The phrase did not originate with the word "over", which makes less sense anyway, defeating the purpose.<ref>[https://knowyourphrase.com/a-watched-pot-never-boils The Origin Of ‘A Watched Pot Never Boils’]</ref> — [[User:Kazvorpal|Kazvorpal]] ([[User talk:Kazvorpal|talk]]) 05:27, 10 November 2019 (UTC)

Pretty sure that '''A watched pot never boils''' is an expression unto its own. If you sat and watched a pot long enough it would still boil over, on the macro scale there is no effect on observing something. [[Special:Contributions/108.162.246.117|108.162.246.117]] 09:10, 1 November 2013 (UTC)

I thought that this expression meant that the water boiling process have a Murphy law like property in it: that the pot tends to boil over when you turn away from it. [[Special:Contributions/108.162.212.196|108.162.212.196]] 21:59, 30 November 2013 (UTC)

CLEARLY the idea is that you are waiting for the pot to boil so that you can add something to it. You are not waiting for it to boil over; you are waiting for it to boil. The point is that many things that you want in life take longer to eventuate than you think, and sitting there fixating on them doesn't actually help and is a waste of time. Do something else useful in the meantime; the pot will boil when it's ready. [[Special:Contributions/108.162.219.58|108.162.219.58]] 19:48, 5 February 2014 (UTC)

Honey has a much higher sugar content than Balsamic vinegar. My hypothesis for this is that the real draw fro the flies is related to fragrance [[Special:Contributions/108.162.219.52|108.162.219.52]] 19:18, 3 April 2014 (UTC)
: I agree on this and updated the explanation. [[User:Mumiemonstret|Mumiemonstret]] ([[User talk:Mumiemonstret|talk]]) 14:10, 5 June 2014 (UTC)

Could this be a metaphor for trolling?
[[User:Richmond tudor|Richmond tudor]] ([[User talk:Richmond tudor|talk]]) 00:24, 18 February 2015 (UTC)

I was actually waiting for the day I'd be able to use the knowledge this strip has bestowed onto me. Unfortunately I'm such a slob that there are just WAY too many. But it *certainly* seems to be working so far! I also did some research and found out the flies I'm having are called vinegar flies. What's funny is that when I searched for Florida [insert insect name here], it turns out my college (UF) has pretty much the entire field of Florida entomology covered, and I doubt it's because I'm using the school network.

But I've been living in a dumpster-quality environment for weeks and haven't gotten remotely sick. My immune system is *crazy* good, haha! But there comes a point where it's just plain disgusting and the flies get annoying, so I am in the process of cleaning up, not so much because of the health hazard as much as it is just the smell and how I'm tired of getting hundreds of flies in my face. Also a few of them bite, and they're starting to spread throughout the rest of the dorms so... yeah. If UF's Lakeside building 3 dorm ends up getting fumigated... it's my fault entirely.

STILL I CAN'T BELIEVE HOW CRAZY MY IMMUNE SYSTEM IS.

Also I don't want to wake up to find my bed crawling with maggots. IDK where they laid eggs and the RA is forbidding me to use Raid. IDK why they'd sell it in the PODs (UF's convenience store) if we're not allowed to use them. [[User:International Space Station|International Space Station]] ([[User talk:International Space Station|talk]]) 07:04, 28 October 2015 (UTC)

--- Is an ''unwatched'' pot in a superposition of boiling and not boiling? --- [[User:Ruffy314|Ruffy314]] ([[User talk:Ruffy314|talk]]) 01:56, 20 November 2015 (UTC)

In English, the acid in vinegar is called "acetic acid". IIRC, "ethanoic acid" makes sense from the IUPAC rules for forming chemical names, so perhaps the writer speaks a language that uses that term.
[[Special:Contributions/108.162.241.123|108.162.241.123]] 20:27, 3 October 2016 (UTC)

Just a note - white vinegar doesn't work well. Apple cider vinegar is much more effective. Add a little dish soap, put it in a narrow-mouth bottle (like 20oz soda bottle), and it'll catch a LOT of gnats or fruit flies. [[Special:Contributions/108.162.219.80|108.162.219.80]] 14:59, 12 August 2020 (UTC)

==References==

2288: Collector's Edition

2020-04-03T17:16:34Z

108.162.219.80: Added unlocked item source for "Take it from the top"

{{comic
| number = 2288
| date = April 3, 2020
| title = Collectors Edition
| image = collectors_edition.png
| titletext = I'm sure you can find some suitable worldbuilding material if you scavenge through the archives.
}}

==Explanation==
{{incomplete|Created by TECHNICAL DIFFICULTIES. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}

This is an April 1st comic. It is a large image, of which only part is visible, but it can be dragged around. This Space acts as a virtual common sandbox where viewers can interact. "Items" (small, often humorous images) can be 'collected' from other comics and then placed in this image by viewers. The collection then updates for all viewers in real-time. Multiples of the same item are often seen.

There is a "backpack" at the bottom, similar to "backpacks" in video games containing items collected by the player. Items can be found by visiting different XKCD comics/pages. Randomly, some pages will have a treasure chest which will contain the sticker related to the page. It is believed that the hint represents what page currently has a chest.

The sticker images can be seen at https://xkcd.com/2288/collectors/static/loot/loot_XXX.png, where XXX is a number from 001-253. Additionally, some images can be found at custom urls, for example the periodic elements can be found at https://xkcd.com/2288/collectors/static/loot/element-XX.png, where XX is the element, and text loot at https://xkcd.com/2288/collectors/static/loot/loot-words-X.png, where X is the sentence.

===Hints===

{| class="wikitable"
!Hint
!Comic
!Unlocked item
!Item image
!Notes
|-
|Doctors in a row||[[1529: Bracket]] ||Cory Doctorow || loot_019.png ||
|-
|Get out the (US) vote|| [[2224: Software Updates]] || Statue of liberty || loot_246.png ||
|-
|Find a box of nice stuff on a picture with words like these|| [[1133: Up Goer Five]] || Signpost || loot_126.png ||
|-
|Plug in or find another power source||[[1373: Screenshot]] || || loot_228.png ||
|-
|Sweet dreams, kitty||[[729: Laser Pointer]] || Cat licking laser point || ||
|-
|What is this hint pointing to? Hell if I know.||[[28: Elefino]] || || ||
|-
|Somebody set up us the bomb||[[286: All Your Base]] ||Exploding rock || ||
|-
|Cowabunga||[[1412: Teenage Mutant Ninja Turtles]] ||Women Science Fiction Authors || loot_175.png || [[197: Ninja Turtles]] also works
|-
|I want to believe||[[2156: Ufo]] ||Ufo || ||
|-
|Bleeped|| || || ||
|-
|why waste time say few word when lot word do trick||[[1022: So It Has Come To This]] || First Annual Award for Excellence in Being Very Smart || ||
|-
|Cooler than electric scooters||[[409: Electric Skateboard (Double Comic)]]||An electric scooter|| loot_006.png ||
|-
|Take it from the top||[[1: Barrel - Part 1]] ||I am a turtle from [[889: Turtles]] || loot_095.png ||
|-
|I accept the yucca gnocchi, this meal is a success!||[[1713: 50 ccs]] ||Man carrying parentheses from [[297: Lisp Cycles]] || loot_031.png ||
|-
|Catch up on the news|| [[1699: Local News]] || || ||
|-
|Participation trophy|| [[2288: Collectors Edition]] || Server rack || ||
|-
|Find an opportunity for a sojourn||[[1504: Opportunity]] ||Opportunity Mars rover || ||
|-
|Tastier than tau day||[[179: e to the pi times i]] ||First annual award for excellence in being very smart || ||
|-
|418 I'm a teapot||[[1866: Russell's Teapot]] ||S.S. NASA: Space is Hard || ||
|-
|26th September, 1983||[[2052: Stanislav Petrov Day]] ||White dove || ||
|-
|There are 4241 as of Apr 1, 2020|| [[1071: Exoplanets]] || Little girl from [[2264: Satellite]] || ||
|-
|asableiK|| [[645: RPS]] || A reverse Polish hotdog || || "Kielbasa" backwards, which is "sausage" in Polish
|-
|Critical mass elements|| [[235: Kite]] || || loot_203.png ||
|-
|Some Februarys are more equal than others|| [[390: Nightmares]]? || Cueball wheelie from [[272: Linux User at Best Buy]] || || Comic-hint connection largely conjectural; 390 was the first comic published on a leap day.
|-
|Five spice||[[1554: Spice Girls]]|| Rock guitarist || ||
|-
|Call the plumber|| [[290: Fucking Blue Shells]] || || loot_058.png ||
|-
|Was it a rat I saw?|| [[1632: Palindrome]] || Cueball with a large sack, pulling a wagon || || or [[1503: Squirrel Plan]] for cueball holding a balloon caught in a ceiling fan.
|-
|Churchill's gonna have to seriously rehydrate||[[1148: Nothing to Offer]]|| Bottle of soda || loot_045.png ||
|-
|Keep coming back|| || || ||
|-
|A new model released each year|| || || || https://xkcd.com/1363/ ? and/or other XKCD Phone comics?
|-
|Tea Time||[[581: The Race: Part 5]] ||Floor tea ||loot_232.png|| Also [[479: Tones]] ? Also [[578: The Race: Part 2]] ?
|-
|Try pattern-matching! Look for comic 'bout alphabet?||[[1045: Constraints]] || || ||
|-
|Where's Hilbert?||[[195: Map of the Internet]] || Hilbert Curve || loot_021.png ||
|-
|Science fiction fetish|| || || ||
|-
|The first one was funnier||[[11: Barrel - Part 2]]||Falling feather || ||
|-
|It's up to over 260 million cycles!|| || || ||
|-
|Sleeping Beauty is the same everywhere though||[[2233: Aurora Meaning]] || || ||
|-
|On the internet, nobody knows you're an arachnid|| [[1530: Keyboard Mash]] || Cobwebbed frame || ||
|-
|Did James Cameron pay for the rice cooker too?||[[1598: Salvage]] ||Rice bowl || ||
|-
|Never going to give you up||[[351: Trolling]] || || ||
|-
|If red touches yellow, that's 24 ohms||[[1604: Snakes]]|| Yoda with an mp3 player from What If || ||
|-
|An enthusiastic but questionable business opportunity||[[1533: Antique Factory]] or [[1021: Business Plan]]|| Beret guy with a goat on leash || ||
|-
|Read the fine manual|| [[1343: Manuals]] or [[293: RTFM]] || "Configure the network" window with a prompt for hostname || ||
|-
|That thing's undecimodal!||[[1347: t Distribution]] || Floating tentacled alien || ||
|-
|Actually, it's Myanmar-Shave now||[[491: Twitter]]||Expensive bottle || ||
|-
|You don't have to find all 99|| [[121: Balloon]] ||Balloon copter || loot_002.png || Or [[51: Malaria]] ?
|-
|Going in circles|| || || ||
|-
|Couldn't you try knitting, or maybe stamp collecting?||[[2123: Meta Collecting]]||Phishing License sign|| loot_158.png ||
|-
|It's the ciiiiircle of HONK||[[537: Ducklings]] ||DUCKLOOP'D? || ||
|-
|Fool me twice|| [[880: Headache]] || Raptor Attack || loot_033.png ||The second April fools' comic
|-
|oOOOoooo|| || || || https://xkcd.com/316/ ? definitely not https://xkcd.com/1393/- I got that hint while On that page. ?
|-
|Maybe we can ask for new wishes||[[879: Lamp]] ||Genie and his bottle ||loot_004.png ||
|-
|HACK THE PLANET||[[1337: Hack]] || || ||
|-
|Monetization haute couteur||[[20: Ferret]]||Two bags of money ||loot_162.png||
|-
|Maybe writing a script would help||[[1319: Automation]]|| || ||
|-
|Go big to go small|| [[1365: Inflation]] || || loot_245.png ||
|-
|Are you projecting||[[850: World According to Americans]] or [[977: Map Projections]]||Squirrel on a gun||loot_237.png||
|-
|Do spiders really have six legs||[[8: Red spiders]] || || ||
|-
|Istanbul or Constantinople or St. Trimble's Island?||[[1688: Map Age Guide]] ||Cephalopod || ||
|-
|Another rulebook?||[[393: Ultimate Game]]||Wizard in a chair || loot_037.png ||
|-
|Moooooon|| [[1300: Galilean Moons]] || MOOOOOON || ||
|-
|Take a flight from LOL to FFS|| [[1937: IATA Airport Abbreviations]] || || ||
|-
|Everyone deserves a second chnace|| || || ||
|-
|Community contribution|| [[826: Guest Week: Zach Weiner (SMBC)]] || [Citation Needed] protester from [[285: Wikipedian Protester]] || loot_035.png ||
|-
|On the other side of the wardrobe|| [[665: Prudence]] or [[969: Delta-P]] or [[2218: Wardrobe]] ||Authentic Reindeer pulling sled || ||
|-
|Today's your lucky day|| [[1053: Ten Thousand]] || Ms. Frizzle || loot_105.png ||
|-
|[This hint has been redacted due to a copyright claim]|| [[1005: SOPA]] || || ||
|-
|Try a different approach|| [[55: Useless]] || || loot_times.png ||
|-
|The cake is a lie!|| [[606: Cutting Edge]] || Cake || ||
|-
|Joanna, fire.||[[322: Pix Plz]] || Joanna with EMP cannon || loot_026.png ||
|-
|Everything changes from time to time when the fire nation attacks|| [[965: Elements]] || Symposium || ||
|-
|90KG x 300M|| [[382: Trebuchet]] || Trebuchet || ||
|-
|Copyright Enforcement Brigade|| [[344: 1337: Part 4]] || || loot_046.png ||
|-
|Where Cape Town meets Chukotka||[[1500: Upside-Down Map]] || || ||
|-
|Take a ride in a barrel|| || || || ('''not''' any of the comics in the barrel series)
|}

==Trivia==
* This comic is the 2020 April Fools comic and was supposed to be released April 1st. However, the below message was displayed on the top of the page until early Friday (April 3rd) morning, when the comic finally went live. It remains to be seen if Friday's intended comic will be published later.
<blockquote>
Note: For technical reasons Wednesday's comic will be posted Thursday instead. Apologies for the delay!
</blockquote>
* Placement is limited to 10,000 units from the origin. Users will receive no messages if they try placing something outside the boundary.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:[Cueball stands to the left of a vibrating box.]
:[The words "Collector's Edition" are written above him and boxed.]

{{comic discussion}}

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

Talk:2288: Collector's Edition

2020-04-03T12:08:31Z

108.162.219.80:

... is this going to be like [[1190: Time]]? [[Special:Contributions/162.158.74.63|162.158.74.63]] 04:08, 3 April 2020 (UTC)
: I hope so, otherwise I don't get the joke [[User:Forresthopkinsa|Forresthopkinsa]] ([[User talk:Forresthopkinsa|talk]]) 04:15, 3 April 2020 (UTC)
: The page just went down for me so maybe what we've seen isn't what it's supposed to be? [[User:Avi m|avis_magpie]] ([[User talk:Avi m|talk]]) 04:20, 3 April 2020 (UTC)
Looks like the whole comic was just taken down. [[User:Parzivail|Parzivail]] ([[User talk:Parzivail|talk]]) 04:27, 3 April 2020 (UTC)
: Can confirm - the most recent comic is Pathogen again [[Special:Contributions/162.158.187.207|162.158.187.207]] 04:26, 3 April 2020 (UTC)
It is still up on the mobile website, but only if you directly go to comic page https://m.xkcd.com/2288 [[Special:Contributions/172.69.22.146|172.69.22.146]] 05:10, 3 April 2020 (UTC)
: Perhaps this is a collector's edition because it was only up for a limited amount of time? {{unsigned ip|108.162.219.60|05:12, 3 April 2020}}
:: That was my immediate assumption. The title text says, "I'm sure you can find some suitable worldbuilding material if you scavenge through the archives." And I was viewing the comic by using the Internet Archive's Wayback Machine — which, wouldn't you know it, captured the page exactly once before it went down. Between that and the title "Collector's Edition", I can't help thinking that the comic was actually intended to be viewed this way. Though for what reason, and what intended meaning, I couldn't tell you. …And jeez, in the time it took me to type this, the comic is back, but changed! Oy vey. [[User:NoriMori|NoriMori]] ([[User talk:NoriMori|talk]]) 06:42, 3 April 2020 (UTC)

Maybe it's called collectors edition, because it was only available quite limited and to an unusual time? But that logic doesn't fit with the title text. --[[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 05:14, 3 April 2020 (UTC)
:I doubt that could be caused by "technical difficulties". [[Special:Contributions/172.69.34.186|172.69.34.186]] 06:14, 3 April 2020 (UTC)

It looks like it went back up about 5 minutes age. I can't figure out if it's possible to do more than pan right now though. [[Special:Contributions/108.162.215.120|108.162.215.120]] 06:39, 3 April 2020 (UTC)
:Yeah I see the same thing, looks like they're just testing it live. What a shame :(--[[Special:Contributions/108.162.215.242|108.162.215.242]] 06:47, 3 April 2020 (UTC)
::what makes you assume that this is testing right now? however it doesn't seem to be very interactive apart from panning through it, and that it seems to chagne over time (the moon from [[1300]] wasn't there a few minutes ago, was it? --[[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 06:49, 3 April 2020 (UTC)

:It's a giant pan similar to [https://xkcd.com/1110], although it's mostly empty, with some content at [https://xkcd.com/2288/#-361,-161]
. The title reads that you can find world building material, if you scavenge through the archives. I assume, more content will be unlocked as you read through past comics. [[User:Goatfryed|Goatfryed]] ([[User talk:Goatfryed|talk]]) 06:52, 3 April 2020 (UTC)
::That would mean it is individual? That everyone gets their own picture? --[[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 07:03, 3 April 2020 (UTC) Edit: I can kinda rule that out. I get the same picture on my phone and my work laptop, the work laptop is in a different country via vpn, and doesn't share any logins/advertisement ID's apart from explain xkcd with my phone... --[[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 07:05, 3 April 2020 (UTC)

Yeah, it definitely changes. The orange swimming pool just showed up now. Also, at the bottom of the page, it says something about "backpack", and what appears to be a reference to some other xkcd comic. For example, "Hint: why waste time say few word when lot word do trick", which I think refers to Up Goer Five. But I have no idea what to do with that info. [[Special:Contributions/172.68.141.190|172.68.141.190]] 06:55, 3 April 2020 (UTC)
:and the content seems to be related to previous comics and what-ifs... but still no clue what to do apart from exploring the page. --[[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 06:57, 3 April 2020 (UTC)

So I just stumbled upon this and it seems to be exactly as other commentors have theorised: as you read previous comics more stuff gets added to the page. There seems to be some kind of backpack mechanic where you collect items from previous ones somehow, but, perhaps because I've already read all previous comics, that didn't seem to work for me. Instead I just had to click the link above the backpack, which opened the comic in a new tab, and it had a bunch of stuff there. We may need to co-ordinate to figure out if different people end up with different sets of items, and to ensure we have all of them, but I think other than that it should be just a cut and dry thing of making a table with every item in it. [[Special:Contributions/162.158.34.202|162.158.34.202]] 07:12, 3 April 2020 (UTC)
:Hang on, mine just changed: before there was only 1 pool on the left, now there are two. I only went back to pathogens and then forwards agin. This may be harder than I thought, I'm going to start keeping a screenshot log of actions vs. results. [[User:Benkor42|Benkor42]] ([[User talk:Benkor42|talk]]) 07:17, 3 April 2020 (UTC)
:You may need to try xkcd.com instead of www.xkcd.com - there seems to be an issue with the latter at the moment. [[Special:Contributions/162.158.255.216|162.158.255.216]] 07:18, 3 April 2020 (UTC)
::Hold up it changed again! This time without a reload! [[User:Benkor42|Benkor42]] ([[User talk:Benkor42|talk]]) 07:28, 3 April 2020 (UTC)
:::It seems to change periodically, the url does change everytime. New stuff always seems to be added, not old stuff rremoved. [[User:Benkor42|Benkor42]] ([[User talk:Benkor42|talk]]) 07:28, 3 April 2020 (UTC)
::::The URL is related to the coordinates, it changes when you pan the image. --[[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 07:34, 3 April 2020 (UTC)
::::Timings seem to be random, working on double checking that rn. Highest first number so far is 1127, once it switches agin I'm going to experiement with manually editing the url.

I was briefly able to do things. Open the archieve, navigate it to one of the comics, that are hinted for (e.g. compiling or iata) and when viewing that comic I get a lootbox, with an image I can then place in the 2288. It worked twice, and now it doesn't again... neither with those that have worked before, nor with others I am fairly sure have been placed by other people. (such as galilean moons) --[[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 07:21, 3 April 2020 (UTC)
:I'm working on assembling an image log, wonder if we could compare? Also, the two number url could be useful, rn I'm on -1378, -152 [[User:Benkor42|Benkor42]] ([[User talk:Benkor42|talk]]) 07:25, 3 April 2020 (UTC)
::What do you mean by compare? Also the URL is related to the coordinates, it changes when you pan the image. --[[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 07:34, 3 April 2020 (UTC)
:::Yh just got that, is that the same for other panning comics (I'm a little new)? And I was wondering if the comic changed per person/system like certain previous comics. [[User:Benkor42|Benkor42]] ([[User talk:Benkor42|talk]]) 07:40, 3 April 2020 (UTC)
::::Just seen a previous comment from you saying it doesn't change cross-system. However, it definetely changes with time, so the question is whether that's per user or done on a sort of universal clock, so we all unlock the same new content at the same time.
:::::I didn't complete writing up the thing I was able to do above... after opening the lootbox I got one image related to the comic I opened in my backpack and was able to place that in the actual 2288, where it now is placed. --[[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 07:50, 3 April 2020 (UTC)
::::::For me that didn't happen, it started with a loading screen type thing, and then objects just started appearing seemingly at random. I've also noticed some of them dissapear. I feel like the best course of action would be to start with a table of all the different objects, and then see if we can figure out when/why they appear later.
::::::: At least 2 objects appeared, because I placed them. It is a colaboration of many xkcd readers to do this world building here. I placed one of the sword fights around #439,-181 and the non-inverted kite at #-1679,-290 . --[[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 07:55, 3 April 2020 (UTC)
::::::::Do you agree that the best course of action would therefore be a table with all the items? [[User:Benkor42|Benkor42]] ([[User talk:Benkor42|talk]]) 08:03, 3 April 2020 (UTC)
:::::::::Not a big fan of tables, unless there really is content of muliple categories to be entered for one line. A list would do fine I guess? Also I find lists easier to work with. Or what would be the columns you'd set up? --[[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 08:08, 3 April 2020 (UTC)
::::::::::Something along the lines of the comic that it's a reference to, an image, and an explanation. Do we know if you find the same sticker at the same comic every time? If so, then that. A list would work well too. [[User:Benkor42|Benkor42]] ([[User talk:Benkor42|talk]]) 08:12, 3 April 2020 (UTC)
::::::::::From looking at what image URLs don't 404, it looks like there are 253 stickers, which is quite a lot for a table.[[User:Matthias1|Matthias1]] ([[User talk:Matthias1|talk]]) 10:03, 3 April 2020 (UTC)
:::::I think we can unlock new elements by reading older comics (seemingly at random, it doesn't work with every comic read) and that everyone can see the changes once they are put on the global picture. If someone could check, I have put berret guy and his goat around (5000,0)
::::::Yep, he's there. [[User:Benkor42|Benkor42]] ([[User talk:Benkor42|talk]]) 08:01, 3 April 2020 (UTC)

I almost feel like someone needs to show them this xkcd... https://xkcd.com/169/

It seems to be an interactive canvas. You can find stickers in chests on specific comics and put them in your backpack, and then when you come back here you can choose where to put them on the canvas. The hints in the empty backpack are cryptic references to comics. {{unsigned ip|162.158.107.85}}
:Yep, I figured the same thing, but for me it only worked twice (fly from wtf to lol was a reference to the iata thing and compiling was a reference to the compiling one) - but it didn't work again. Also: Some of the placed images are clearly references to what-if. Like the squirrel on top of an AK47 or the yoda powering an IPOD. --[[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 07:59, 3 April 2020 (UTC)

I've made a catalog of the stickers but it's only partial because stuff keeps appearing: https://photos.app.goo.gl/dPYeYVpGqu5tqGTt5 [[User:Lev|Lev]] ([[User talk:Lev|talk]]) 08:02, 3 April 2020 (UTC)

I got it. I wrote the steps on reddit and included some screenshots. Feel free to use it to edit this page https://old.reddit.com/r/xkcd/comments/fu1dt0/xkcd_2288_collectors_edition/fmaqp1w/ [[User:Ufolicker|Ufolicker]] ([[User talk:Ufolicker|talk]]) 09:27, 3 April 2020 (UTC)

Am I too late to participate in this or am I doing something wrong? Where is this hint supposed to appear? I only see an empty backpack and the canvas on which references to different comics are placed. No comic I've visited, either inspired by references on the canvas, nor by random selection has any chest or other interactive components to it. [[User:Bischoff|Bischoff]] ([[User talk:Bischoff|talk]]) 09:53, 3 April 2020 (UTC)
:No, you're doing it right. Hints show up in the backpack area. Obviously no one is sure of anything, but even users who have seen hints have reported not seeing hints on a different browser/device. I suspect something similar to [https://xkcd.com/1037/ Umwelt], where different hints are shown to different people. And I think once a chest is picked up, it stops appearing to everyone that could see it, but that's a guess.[[User:Matthias1|Matthias1]] ([[User talk:Matthias1|talk]]) 10:03, 3 April 2020 (UTC)
::Ok, I was unsure because on my windows 10 laptop I have yet to see a hint. I've tried chrome, firefox and internet explorer. [[User:Bischoff|Bischoff]] ([[User talk:Bischoff|talk]]) 11:09, 3 April 2020 (UTC)
:::Finally got it to work in Safari in iOS [[User:Bischoff|Bischoff]] ([[User talk:Bischoff|talk]]) 11:13, 3 April 2020 (UTC)

When I view the comic, I don't see the closed box - the screen is absolutely full of stickers. I've not done any scavenger hunting (I'd upload an image, but I don't have permissions to do so) [[User:Kvetch|Kvetch]] ([[User talk:Kvetch|talk]]) 11:10, 3 April 2020 (UTC)

Hints I've seen so far: "The first one was funnier" (chest appeared in comic 1, contained I'm a turtle);
"418 I'm a teapot"
"26th September, 1983" (comic 2052, Stanislav Petrov Day, white dove); [[Special:Contributions/172.69.134.135|172.69.134.135]] 11:20, 3 April 2020 (UTC)

Perhaps a table for found chests with no attached hints? I've stumbled across a few but don't know if they're hinted at or not :). [[User:Deranged|Deranged]] ([[User talk:Deranged|talk]]) 11:54, 3 April 2020 (UTC)

"Churchill's gonna have to rehydrate" is Nothing to Offer. Can't remember what number, I think 1148?

1732: Earth Temperature Timeline

2020-03-26T20:49:05Z

108.162.219.80: /* Popularity of comic */ Changed climate skeptics to the more accurate climate change deniers, see the Wikipedia talk page for climate change denial

{{comic
| number = 1732
| date = September 12, 2016
| title = Earth Temperature Timeline
| before = [[#Explanation|↓ Skip to explanation ↓]]
| image = earth_temperature_timeline.png
| titletext = [After setting your car on fire] Listen, your car's temperature has changed before.
}}

==Explanation==
{{TOC}}
This comic is a [[:Category:Timelines|timeline]] on how the temperature has changed from 20,000 BCE (Before {{w|Common Era}}) to the present day (2016), with three predictions for the rest of the 21st century depending on what actions are taken (or not taken) to stop CO₂ emission. This comic is a direct, but much more thorough, follow up on the previous global warming comic: [[1379: 4.5 Degrees]]. By having readers scroll through millennia of slow-paced natural changes, Randall uses the comic to confront the rapid temperature rise in recent years.

Over the past 100 years, human action has produced a large amount of {{w|CO₂ emissions}}, which have caused a rise in average global temperature through the {{w|greenhouse effect}}. This is called {{w|global warming}} and is part of a {{w|climate change}}, a subject that has become a [[:Category:Climate change|recurrent subject]] on xkcd. There are still many people who claim that this is not happening, or at least that it is not caused by any human actions, called {{w|Climate change denial|climate change deniers}}. One argument of theirs is that global warming is happening for natural causes, summarized with the phrase "temperature has changed before".

This comic shows that while temperature changes have indeed occurred before, the speed of the current temperature rise is much, much faster than those measured for many previous thousands of years. The comic became so popular that [[Randall]] [[#Popularity_of_comic|postponed the release]] of his next comic to keep this one on the front page one day longer.

The temperature curve is a dotted line most of the time, but from about 1850 to 2016 the measurement data is good enough to let the curve become a solid line indicating that this is not an estimate. Before 1850 the temperature is an estimate based on the [[#Sources|sources]] given. And likewise into the future the three possible curves are also dotted to show that they are predictions, based on how seriously the population of Earth takes knowledge (and comics) like this.

Although this is a topic Randall obviously takes very seriously, and by far most of the facts fit with known history, he still includes several [[#Jokes in the comic|jokes in the comic]]. See also the [[#Table of all elements|table]] explaining each item in the comic. After the election of {{w|Donald Trump}} for president later the year of this comic's release, several [[Sad comics]] have been posted. Some of the reason could be that Randall no longer believes that even his worst fears (as expressed by the current path at the bottom) will hold up, with the actions taken by the new president.

The title text compares the saying that "the temperature has changed before" comparing temperature changes over thousands of years to the rapid global warming over the last century with saying that the "small" changes to the temperature a car experiences over the years of normal usage should not make you worried over the rapid temperature increase that happens when someone sets your car on fire. Randall previously used this joke in [[1693: Oxidation]].

===Jokes in the comic===
* By placing the invention of the internet at 1980 in the chart, just where the temperature curve starts its most rapid increase, Randall humorously implies that the internet caused the rise in temperature.
* At 13600 BCE a glacier is shown retreating from New York because of the warm up. It is disgusted by the new changes and proclaims: ''That’s it! I’m moving to Canada!'' This is a joke on [https://www.rollingstone.com/politics/politics-news/want-to-move-to-canada-if-trump-wins-not-so-fast-100658/ an idiom said by US citizens] to protest against changes in their country. As shown in the chart, the glacier takes 5000 years (13600-8400 BCE) to cross what would become the Canadian border (neither the United States nor Canada existed yet). Also, glaciers don't speak English.
* At 13400 BCE it is mentioned that {{w|origin of the domestic dog|humans domesticate dogs}}. [[Megan]] talks to a wolf about to be tamed making a deal with it, that it can eat and sleep with the humans as long as they can yell at it for pooping indoors. This sounds like a sweet deal for the wolf until [[Cueball]] mentions that they will {{w|Dog breeding|breed}} it to be {{w|Chihuahua (dog)|very small}} and then dress it up in small {{w|Dog's fashion|costumes}}. The wolf says wait, but it is already too late...
* The {{w|Pokémon}} reference at 9000 BCE about them going extinct in North America (although Megan does proclaim that this is not a real fact). As the writing stated that ''Pokémon go extinct'' this can also be seen as a reference to a popular video game called {{w|Pokémon Go}} and hence also the comic [[1705: Pokémon Go]].
* At 4500 BCE, next to "{{w|Proto-Indo-European language}} develops", [[Ponytail]] gets the idea to develop the language heavily inflected to make it difficult to remember all the verb endings for future students. This is a direct reference to the comic [[1709: Inflection]].
* The reference to the 1984 {{w|mockumentary}} about the fake rock band {{w|This Is Spinal Tap}} in conjunction with {{w|Stonehenge}} at 2200 BCE. In the movie the band ordered a giant 18 feet Stonehenge megalith but a writing mistake gives them one that is only 18 inches high.
**Another real band {{w|Nine Inch Nails}} is referenced 16000 BCE where Megan writes the bands stylized name NIИ on the wall next to [[Hairy]] who is in the process of painting the {{w|cave painting}} at {{w|Lascaux}} in France.
* Around the setting of the {{w|Iliad}} and the {{w|Odyssey}} (1200 BCE) a drawing of the {{w|Trojan Horse}} has writing on it that states: ''Not a trap''.
* Just below the previous entry also at 1200 BCE is the mentioning of the invasion of the {{w|Sea Peoples}}. This sounds so much like a reference to {{w|Mermaid|mermaids}}, often called {{w|Mermaid#One_Thousand_and_One_Nights|sea people}} that Randall feels the need to note that this invasion and these sea people is ''a real thing'' in a footnote. This is opposed to the Pokémon reference above where he notes that it is ''not a real fact''. The sea people was a seafaring confederation of groups known to have attacked ancient Egypt and other Bronze age civilizations around this time. It is widely regarded to be one of the major causes of the {{w|Late Bronze Age Collapse|Bronze Age Collapse}}.
* The reference at 450 BCE compares the {{w|Battle of Thermopylae}} (also known as 300 Spartans) with the dramatized 2007 movie ''{{w|300 (film)|300}}'', but in the real world the fighting of course occurred [https://youtu.be/FCfdyroV7kc?t=12 at regular speed and with more clothing].
*There are other minor jokes but this list mentions all the major jokes.

===Table of all elements===
*Here is table including all elements in the chart with explanations including reading off temperature and year for each event from the curve.
**The year group is just an easy way to find the section.
**Element is a description mainly taken from the transcript.
**The actual year of an event has been read off more precisely on the chart.
***The central part of the element has mainly been used.
***Only rarely has ranges below 100 years been used but if a location is clearly midway between two hundred years intervals 50 year range has been used.
***Only when there are several posts close to each other has smaller range been used a few times.
**T (°C) is the number of degrees Celsius above or below the 1961-1990 average, which on this graph is set to zero, (i.e. not the number of physical degrees above or below this 0°C).
***These have been read of to 0.1°C rounding up or down. Lines have been inserted over the chart, 10 for each degree, to make this as accurate as possible.
***In a few cases where a maximum is reached 0.05°C has been used
**Explanation of each element.
{| class="wikitable"
!Year group
!Element
!Year
!T (°C)
!Explanation
|-
| rowspan="2"| 20000 BCE
| [An arrow goes from the dotted line to the central line at 0°C (representing the 1961-1990 average). In the middle of the line there is a temperature label:] 4.3°C At the start of our timeline, 22,000 years ago, Earth is 4°C colder than during the late 20th century. || 20000 BCE || -4.3 || The scale here is relative, showing the magnitude of change rather than an absolute temperature reading. As a rule, {{w|climate}} changes are compared with a 30 year interval, and the 1961-1990 average was {{w|Climate#Definition|chosen for convenience}} as the "normal" to compare temperature changes with, but any other choice of baseline would show the exact same changes. The {{w|Last glacial period}} (aka ice age) reached its {{w|Last Glacial Maximum|maximum extent}} approximately 22 to 24 thousand years ago.
|-

| {{w|Boston}} is buried under almost a mile of ice, and the {{w|glaciers}} reach as far south as {{w|New York City}}. [The Statue of Liberty is shown in front of a glacier front. A guy with a white {{w|knit cap}} is seen walking in a snowy landscape. The skyline of Boston is shown under a half a mile of ice.] || 19700 BCE || -4.3 || This shows what a difference 4 degree in global temperature means (massive effect), as opposed to four degrees on a daily weather wise scale (trivial). The Boston image is directly taken from [[1225: Ice Sheets]] about the ice age glacier coverage; it was also shown buried in ice in [[1379: 4.5 Degrees]]. The guy with the white knit cap could be the guy from [[1321: Cold]] also about global warming. Knit caps have only been used a few times in xkcd, most prominently on [[1350:_Lorenz#Knit_Cap_Girl|Knit Cap Girl]] in [[1350: Lorenz]].

|-
| rowspan="3"| 19500 BCE
| But the world is about to warm up. || 19500 BCE|| -4.3 || The warming process actually takes thousands of years, which this comic will portray down thousands of pixels to come. This is not a fast warm up, especially not compared to the one we are currently experiencing (at the bottom of the chart).
|-
| By this time, humans have already spread across {{w|Africa}}, {{w|Eurasia}}, and {{w|Australia}}. || 19300 BCE || -4.3 || {{w|Homo Sapiens}} successfully {{w|Recent_African_origin_of_modern_humans#Movement_out_of_Africa|migrated out of Africa}} somewhere between {{w|Recent_African_origin_of_modern_humans#Dating:_pre-or_post-Toba|130,000}} and {{w|Recent_African_origin_of_modern_humans#Coastal_route|70,000}} BCE.
|-
| They’ve created {{w|painting}}, {{w|pottery}}, {{w|rope}}, and {{w|Bow and arrow|bows and arrows}}, but haven’t developed {{w|writing}} or {{w|farming}}. || 19100 BCE || -4.3 || The {{w|History of painting#Pre-history|oldest known paintings}} date back to about 38,000 BCE. The {{w|Ceramic_art#History|oldest known pottery}} date back to about 20,000 BCE. The {{w|Rope#History|oldest known rope}} date back to about 26,000 BCE. The {{w|History_of_archery#Stone_Age_and_Bronze_Age_archery|oldest known arrows}} date back to about 70,000 BCE, but Randall seems to be mistaken about the bows which seems to be {{w|History_of_archery#Stone_Age_and_Bronze_Age_archery|at most 10,000 years old}}. Writing is mentioned again at 3500 BCE and farming at 10,000 BCE.

|-
| rowspan="2"| 19000 BCE
| Changes in the Earth’s orbit mean that more sunlight reaches the polar ice… || 18600 BCE || -4.2 ||{{w|Milankovitch cycles}} are repeated climate variations on a timescale of tens of millennia caused by cyclic variations in {{w|Orbital eccentricity|eccentricity}}, {{w|axial tilt}}, and {{w|precession}} of the {{w|Earth's orbit}}, which thus then determined climatic patterns on Earth. The Milankovitch cycles are referenced again around 4700 BCE.

|-
| [A line chart with a labeled Y-axis "Summer sun W/m2 at 60°N" with three labeled ticks ranging from 450-550. The curve starts up and then goes down five times and up four times ending down. There is one plateau towards the end compared to the rest of the curve where the ups and downs are quite alike.] || 18600 BCE || -4.2 || The chart shows the input of sun during summer time in the {{w|Northern hemisphere}} (at {{w|60° northern latitude}}) as the effect (W) per square meter (m2) which fluctuated in the range from 450-550 during the time shown in the chart. There is, however, no scale for the time between the peaks. This chart relates to the text about increasing sun to the polar ice in the entry above.

|-
| rowspan="1"| 18500 BCE
| [A map of the world. At the top is a light gray area covering {{w|North America}}, {{w|Greenland}} and northern {{w|Europe}} and most of the northern part of {{w|Russia}}. A similar gray area covers {{w|Antarctica}}. The gray areas are labeled as ice.] || 18300 BCE || -4.2 || This [[:Category:Maps|map]] shows where the ice covered the {{w|northern hemisphere}} (and Antarctica) during the {{w|Last Glacial Maximum}}. The continents have not moved much since then, but the lower water level caused by the amount of water bound up in the ice, can clearly be seen in several locations. For instance, the {{w|British islands}}, Greenland, and {{w|Papua New Guinea}} are connected to their respective neighboring continents. Also {{w|Alaska}} and Russia are connected through the ice sheets covering the northern part of the Earth.
|-
| rowspan="1"| 18000 BCE
| …And the ice sheets start to melt. || 17900 BCE || -4.1 || This was a slow process that takes 10,000 years. The ice is mentioned again at 13,600 and 8400 BCE.

|-
| rowspan="1"| 17500 BCE
| Temperatures have been creeping upward, but around this point, CO2 levels start to climb…|| 17300 BCE || -4.1 || Due to the release of gasses from various sources (dissolved in the ocean, trapped in {{w|permafrost}}, etc), {{w|Carbon dioxide in Earth's_atmosphere#Measuring ancient-Earth carbon dioxide concentration|atmospheric CO2 levels}} increased by 100 parts per million over a span of thousands of years. Modern civilization has added the same amount in a single century.

|-
| rowspan="1"| 17000 BCE
| …And then the warming speeds up. || 16700 BCE || -4.1 || It took 3000 years for the temperature to increase with one degree. So this sentence can be seen as sarcasm about the rate of natural climate change compared to modern {{w|anthropogenic}} (human caused) warming.

|-
| rowspan="1"| 16500 BCE
| [Cueball is standing with a spear just the right of the graph talking to a rabbit.] Cueball: Still pretty cold. || 16200 BCE || -4.0 || True, because although the temperature has risen with 0.3°C over the last 4000 years, it's still 4°C below the 1961-1990 average.

|-
| rowspan="2"| 16000 BCE
| [Megan touches the dotted line to the right of her, with Ponytail standing on the other side. The graph has finally passed the -4°C line below the 1961-1990 average.] || 15600 BCE || -3.9 || Megan is the first drawing on the left side of the curve. She seems to be pushing the temperature up.
|-
| [In the right part of the chart is an explanation of the data. Below the first two lines there are four drawings each showing possible temperature swings in reality compared to the smoothed data that represents the dotted curve of the entire chart. The dotted curve is shown in all four drawings and a thin line is shown running along it but with much more fluctuation left and right on the first two, a large spike right on the third and a large bump way right on the fourth. Above these there are two labels. The first labels is inside a bracket that covers the first three, and the last label is for the last drawing. Below is a list of sources.] Limits of this data: Short warming or cooling spikes might be “smoothed out” by these reconstructions but only if they’re small or brief enough. Possible Unlikely Reconstructions are from Shakun (2012) and Marcott (2013), scaled to Annan + Hargreaves (2013) estimate for the last glacial period. || 15600 BCE || -3.9 || This is Randall's pre-emptive response to skepticism about the accuracy of prehistoric data. {{w|Ice cores}} and similar records might miss individual year-to-year variation, but should catch sustained changes lasting many decades, which is the time scale that matters for climate. See links to the [[#Sources|sources below]].

|-
| rowspan="1"| 15500 BCE
| In what is now {{w|France}}, humans paint murals on the walls of the {{w|Lascaux}} caves [Hairy paints three animals, two with horns, and two humans, Cueball holding hand with Hairy who has a spear. On the other side of the central line Megan writes three letters, the last of which is reversed:] NIИ || 15200 BCE || -3.8 || A reference to the industrial techno band {{w|Nine Inch Nails}} as Megan writes the bands stylized name NIИ on the wall next to Hairy who is in the process of painting part of the {{w|cave paintings}} at Lascaux in France.

|-
| rowspan="1"| 15000 BCE
| Ice sheets around {{w|Alaska}} shrink, exposing a land bridge between Asia and North America [From around the bottom if this section and down to 11500 BCE the dotted curve moved steadily to the right towards warmed temperature peaking close to 1.5°C below the 1961-1990 average. Before this the temperature had not moved much away from that at the start.] || 14600 BCE || -3.5 || This land bridge is known as {{w|Beringia}}. It is mentioned again at 8300 when it disappears due to the rising seas.
|-
| rowspan="1"| 14500 BCE
| [Cueball walks right looking back at the graph behind him. Megan walks in front of him pointing further right.] Cueball: Cool. Humans reach {{w|North America}}. || 14200 BCE || -3.3 || This is approximately when the humans from {{w|Asia}} crossed the land bridge mentioned in the previous entry, from what is now {{w|Siberia}} to what is now {{w|Alaska}}. {{w|Settlement of the Americas}} occurred around the time shown in the chart, although {{w|Settlement_of_the_Americas#Chronology|it's possible}} that earlier humans did so by boat prior to the formation of the land bridge. Cueball's comment is a double entendre; it was figuratively "cool" that early people migrated this far, and the climate was literally cool compared to modern times.

|-
| rowspan="2"| 14000 BCE
| The edge of the ice withdraws from {{w|New York City}} and retreats north. || 13700 BCE || -3.1 || Even though the ice began to melt 4000 years before (at 18,000 BCE in the chart) it is first now that New York City is free of ice.
|-
| [A large glacier front speaks in a speech bubble with an arrow pointing at it. Behind is there are four peaks in the horizon and in front of it three small melting pools and some rocks on the ground.] Glacier: ''That’s it! I’m moving to Canada!'' || 13600 BCE || -3.0 || When US citizens are unhappy with changes in their country, they sometimes say they will move to Canada in protest. Here it is the glacier that is anthropomorphically unhappy with the climate changes. However this is a slow process; it crosses the Canadian border more than 5000 years later.

|-
| rowspan="2"| 13500 BCE
| Humans domesticate dogs (Date uncertain, may be much earlier) || 13400 BCE || -3.0 || See {{w|Origin of the domestic dog}}. This timeline event is not quite accurate. The first dogs differentiated from {{w|Gray wolf|wolves}} about {{w|Origin_of_the_domestic_dog#Time_of_domestication|23,500 years ago}}, but there was an event around 13500 BCE that increased the population size and may be attributable to domestication events.
|-
|| [Megan and Cueball is watching a wolf looking at them.] Megan: Okay, you can live in our homes and we’ll feed you, but we’ll still get mad if you poop on the floor. Wolf: Deal. Cueball: And we get to breed you to be tiny and dress you in little costumes. Wolf: …Wait. || 13100 BCE || -2.8 || Megan is making a deal with the wolf that it can eat and sleep with the humans as long as they can yell at it for pooping indoor. This sounds like a sweet deal for the wolf until Cueball mentions that they will {{w|Dog breeding|breed}} it to be {{w|Chihuahua (dog)|very small}} and then dress it up in small {{w|Dog's fashion|costumes}}. The wolf says wait, but it is already too late...

|-
| rowspan="2"| 13000 BCE
| {{w|Woolly Rhino}} goes extinct || 12900 BCE || -2.7 || Mainland woolly rhinos died in the {{w|Quaternary extinction event}}, but a small island population survived until {{w|Woolly_rhinoceros#Extinction|around 8000 BCE}}. Woolly rhinos likely became extinct in part due to {{w|Holocene extinction|over-hunting}}. Randall's choice of species on this chart seems to focus on animals that were greatly affected by humans, for good or ill.
|-
| {{w|Oregon}} is scoured by huge floods as glacial dams burst and lakes of meltwater flow to the sea || 12600 BCE || -2.2 || This is a reference to the {{w|Missoula Floods}} several cataclysmic floods that swept periodically across eastern {{w|Washington}} and down the {{w|Columbia River Gorge}} flooding much of eastern Washington and the {{w|Willamette Valley}} in western Oregon at the end of the last ice age. During the last {{w|deglaciation}} ice dams formed then burst several times between 13,000 and 11,000 BCE.

|-
| rowspan="1"| 12500 BCE
| Ice sheets withdraw from Chicago || 12200 BCE || -1.8 || The next step towards the Canadian border, after they left New York at 13,600 BCE.

|-
| rowspan="1"| 12000 BCE
| Humans settle {{w|Abu Hureyra}} in {{w|Syria}} || 11550 BCE || -1.6 || A well-preserved prehistoric village that existed from 11,000 to 7000 BCE (a little later than noted in the chart), allowing archaeologists to study how their culture developed.

|-
| rowspan="1"| 11500 BCE
| [An arrow on the left side of the dotted curve is pointing down along the dotted curve and to the left indicate temperature is declining again, meaning the dotted curve now moves left to colder temperatures. This only continues until 10500 BCE. It is only the second time something is noted on the left side after Megan at 16000 BCE] Temperatures start to decline, mainly in the Northern hemisphere This may be caused by changes in ocean circulation due to the floods of cold fresh meltwater flowing into the Atlantic as the North American ice sheet melts. This cooler period is called the {{w|Younger Dryas}} || 11300 BCE || -1.6 || In the Younger Dryas, the Earth cooled by almost one degree over 1000 years. There were {{w|Outburst flood#Glacial_floods_in_North_America_.288.2C000_to_15.2C000_years_ago.29|several floods}} during the end of the ice age but the most famous is the one from {{w|Lake Agassiz}}. A similar but less global effect could occur if the ice on {{w|Greenland}} melts too quickly and causes a {{w|shutdown of thermohaline circulation}}. Without the {{w|Gulf Stream}}, hot water would remain in the Gulf of Mexico and the Caribbean instead of warming the {{w|North Atlantic}} and Europe. The movie {{w|The Day After Tomorrow}} dramatized a worse-than-worst-case version of this, happening in days instead of centuries.

|-
| rowspan="1"| 11000 BCE
| [This is the first text to the left of the dotted curve:] Humans reach {{w|Argentina}} || 10900 BCE || -1.8 || The earliest evidence of {{w|Indigenous_peoples_in_Argentina#Prehistory|humans in Argentina}}. Finally the temperature graph has risen enough that there is space to write text on the left side of the curve.

|-
| rowspan="2"| 10500 BCE
| [An arrow pointing down along the right side of the dotted curve and to the right indicate temperature is increasing again, meaning the dotted curve now moves right to hotter temperatures. This continues until 8000 BCE where it levels out just above the 1961-1990 average.] Warming resumes || 10500 BCE || -1.8 || After 1000 years of slightly decreasing temperatures the warm up of Earth resumes. Over the next 3000 years the temperature increases 2.5°C, reaching a long plateau about 0.5°C above the 1961-1990 average around 7500 BCE.
|-
| Human settlements at {{w|Jericho}} ||10050 BCE || -1.4 || The {{w|Jericho#Pre-Pottery_Neolithic.2C_c._9500_BCE|first permanent settlement}} on the site of Jericho occurred around 9500 BCE, but there is evidence of {{w|Jericho#Natufian_hunter-gatherers.2C_c._10.2C000_BCE|non permanent settlement}} during this period, when cold and drought made permanent habitation in that region difficult.

|-
| rowspan="1"| 10000 BCE
| First development of {{w|farming}} || 9750 BCE || -1.1 || This is now called the {{w|Neolithic Revolution}}, i.e. the wide-scale transition of many human cultures from a lifestyle of {{w|Hunter-gatherer|hunting and gathering}} to one of {{w|agriculture}} and settlement. The {{w|history of agriculture}} began independently in several locations with both {{w|domestication}} of animals and the farming of different {{w|cereals}}. One of the first regions to develop farming was the {{w|Fertile Crescent}}. This is also around this time that the last ice age is said to have ended.

|-
| rowspan="2"| 9500 BCE
| {{w|Saber-toothed cat}} goes extinct || 9200 BCE || -0.3 || Although one of these (Smilodon) was known as the {{w|saber-toothed tiger}}, most saber-toothed "cats" are not related to tigers, or any modern {{w|cats}} at all, but can be viewed as examples of convergent evolution. {{w|Smilodon}} became extinct around 8000 BCE, and the last Saber-toothed cat first became extinct around 7000 BCE, which does not fit very well with Randall's range. Indirectly humans may have caused the extinction of the Saber-toothed cat by over-hunting their {{w|megafauna}} prey, depriving the cats of food sources.

|-
| {{w|Horses}} disappear from {{w|North America}} || 9100 BCE || -0.2 || The {{w|evolution of the horse}} began millions of years ago in North America; early species {{w|Evolution_of_the_horse#Miocene_and_Pliocene:_true_equines|migrated across Beringia into Eurasia}} before their predecessors {{w|Evolution_of_the_horse#Pleistocene_extinctions|died out}}.

|-
| rowspan="4"| 9000 BCE
| | Last North American {{w|Pokémon}} go extinct [Cueball with a spear and Megan is looking up at this last “fact”.] Megan: That is not a real fact. || 8900 BCE || -0.1 || Pokemon are not real. This faux-extinction is likely a reference to the {{w|Pokémon Go}} game, which Randall spoofed in [[1705: Pokémon Go]]. Virtual Pokémon now thrive throughout the entire world, and are most commonly found near [http://time.com/4443225/pokemon-go-affluent-white-neighborhoods-report/ affluent first world neighborhoods].

|-
| Temperatures reach modern levels || 8800 BCE || 0.0 || It took 11,200 years for the temperature to increase 4.3°C. It's possible that human-created effects will produce an equal change in a few hundred years.
|-
| Rising seas cut off the {{w|land bridge}} between North America and Asia || 8700 BCE || 0.1 || {{w|Beringia}} was freed of ice in 15,000 BCE. This is an example of what happens when the temperature rises and glaciers melt. Sea levels are rising again as ice on {{w|Greenland}} and {{w|Antarctica}} continues to melt.

|-
| {{w|Cattle}} domesticated || 8500 BCE || 0.2 || Cattle feature prominently in the comic [[1338: Land Mammals]].

|-
| rowspan="2"| 8500 BCE
| Ice sheets retreat across the Canadian border || 8400 BCE || 0.3 || Finally the glacier that began retreating from New York around 13,600 BCE succeeded in moving to Canada as it had threatened to do...
|-
| Temperatures start to level out slightly above 1961-1990 levels || 8050 BCE || 0.4 || The next 3000 years the temperature stays within 0.2°C degree of a temperature 0.5°C above the 1961-1990 average. A very long and stable period.

|-
| rowspan="1"| 8000 BCE
| [The above sentence breaks over the 8000 BCE line. From here a maximum in temperature on the chart is reached at 0.5°C above the 1961-1990 average, which will not be overtaken until 2000 CE. It stays almost constant here until 5000 BCE where a slight cooling begins.] || 8000 BCE || 0.4 || This is the only five hundred year span with no events listed fully inside. Maybe because nothing happens with the temperature.

|-
| rowspan="2"| 7500 BCE
| This warm, stable period is called the {{w|Holocene Climate Optimum}} || 7400 BCE || 0.5 || Some skeptics like to say "[http://www.skepticalscience.com/10000-years-warmer.htm it was warmer in the Holocene]." This is no longer true. Global temperature began encroaching Holocene levels in 1998, and has equaled or possibly exceeded them since 2014.
|-
| {{w|Jiahu}} settled in China || 7050 BCE || 0.5 || Jiahu is another prehistoric settlement, similar to Abu Hureyra (12000 BCE), that was extensively studied by archaeologists.

|-
| rowspan="2"| 7000 BCE
| Final collapse of the North American ice sheet leads to rapid 2-4m sea level rise… || 6800 BCE || 0.55 || The temperature almost reached 0.6°C above the 1961-1990 average before this happened and caused the slight decrease in temperature mentioned below.
|-
| [A small arrow points down and left to the right of the dotted curve. There is a small decrease in temperature but it is very small and would have been missed without the arrow and label.] …And a period of cooling in the Northern hemisphere || 6550 BCE || 0.5 || A 0.05 degree decrease in 200 years again refers to the theme of slow natural climate change.

|-
| rowspan="1"| 6500 BCE
| As seas rise to near their modern levels, Britain is cut off from mainland Europe || 6300 BCE || 0.45 || This is a reference to the flooding of {{w|Doggerland}}.

|-
| rowspan="1"| 6000 BCE
| Humans develop copper metalworking || 5600 BCE || 0.5 || The {{w|copper age}} was relatively brief before humans discovered how to make {{w|bronze}}.

|-
| rowspan="2"| 5500 BCE
| Massive volcanic eruption in {{w|Oregon}} creates crater lake || 5300 BCE || 0.55 || {{w|Crater Lake}} is the caldera at the top of Mount Mazama, a collapsed stratovolcano. If it erupted again, it could become a Somma volcano (see [[1714: Volcano Types]]).
|-
| {{w|Gold}} metalworking || 5050 BCE || 0.6 || The temperature peaks here at just a bit more than 0.6°C above the 1961-1990 average. It will not rise above this level until the global warming sets in in the 1900s.

|-
| rowspan="2"| 5000 BCE
| {{w|Invention of the wheel}} || 4900 BCE || 0.6 || Wheels are one of the most important inventions of humanity. They feature in many xkcd comics, such as [[1075: Warning]].
|-
| [To the right of the dotted curve is an arrow pointing down and slightly left. From here temperature decreases very slowly but steadily from 0.5°C above the 1961-1990 average until 1000 BCE where a stable plateau is reached around the 1961-1990 average.] Earth begins to cool slowly mainly due to regular cycles in its orbit || 4800 BCE || 0.5 || Again a reference to the {{w|Milankovitch cycles}} mentioned in detail at 18,600 BCE. Here they cause a cooling rather than a heating as they did back then.

|-
| rowspan="3"| 4500 BCE
| {{w|Proto-Indo-European language}} develops || 4400 BCE || 0.5 || Most of the languages in Europe, the Middle East, and India share a surprising number of common roots. PIE is the theoretical ancestor from which they descend. Randall mentions this language family in many comics, such as [[890: Etymology]].
|-
| [To the right of the curve Ponytail holds up a hand towards Cueball.] Ponytail: Let’s make our language heavily inflected, so future students have to memorize a zillion verb endings! Cueball: Okay! || 4400 BCE || 0.5 || Ponytail gets the idea to develop the language heavily inflected to make it difficult to remember all the verb endings for future students and Cueball is okay with that. This is a direct reference to the comic [[1709: Inflection]].
|-
| Permanent settlements in the {{w|fertile crescent}} || 4200 BCE || 0.5 || The Fertile Crescent is one of those things you're supposed to remember from grade school. A lot of historic milestones happened there, such as the pyramids of Giza, the code of Hammurabi, and the Abrahamic religions.

|-
| rowspan="2"| 4000 BCE
| Horses domesticated || 3950 BCE || 0.5 || Horse riding was the greatest advance in land travel until the invention of engines. Horses appear in many xkcd comics, such as [[936: Password Strength]].
|-
| {{w|Minoan culture}} arises on Crete || 3700 BCE || 0.5 || Minoan culture invented many strange and wonderful things, such as the Labyrinth at Knossos and {{w|Bull-leaping}}.

|-
| rowspan="4"| 3500 BCE
| {{w|Egyptian mummification}} || 3500 BCE || 0.5 || xkcd has discussed mummification in {{what if|134|What If? 134: Space Burial}}.
|-
| Rise of the {{w|Indus Valley civilization}} || 3300 BCE || 0.5 || The largest bronze-age civilization.
|-
| Invention of {{w|writing}} in {{w|Sumer}} “{{w|prehistory}}” ends, “{{w|history}}” begins || 3200 BCE || 0.5 || Our knowledge of prehistoric events must rely on digging up artifacts and making inferences. After this time, it became possible to find descriptions of past people and events, which is the definition of history. (Old guy in Sumer: Kids these days with their new-fangled stone tablets, instead of using their memory...)
|-
| Earliest human whose name we know (Pharaoh {{w|Iry-Hor}} in Egypt) || 3100 BCE || 0.5 || The first named person we know of today! This was also mentioned as a "cool fact" in the title text of [[1355: Airplane Message]].
|-
| rowspan="5"| 3000 BCE
| {{w|Three Sovereigns and Five Emperors}} period in China || 2800 BCE || 0.4 || The temperature has finally dropped below 0.5°C above the 1961-1990 average after almost 2000 years of cooling from 0.6°C above the 1961-1990 average.
|-
| {{w|Gilgamesh}} || 2700 BCE || 0.4 || Gilgamesh was probably a Sumerian king whose tales were exaggerated into mythology.
|-
| {{w|Imhotep}} || 2600 BCE || 0.4 || Imhotep was not a pharaoh, but a wise commoner who was elevated to chancellor, high priest, and post-mortem divinity.
|-
| {{w|Maya civilization|Mayan}} culture emerges || 2600 BCE || 0.4 || Like the ancient Egyptians, Mayans are remembered for pyramids and {{w|logograph}}s.
|-
| {{w|Great Pyramid}} constructed || 2650 BCE || 0.4 || xkcd has discussed pyramids in [[1717: Pyramid Honey]] and {{what if|95|What If? 95: Pryamid Energy}}.

|-
| rowspan="3"| 2500 BCE
| {{w|Corded Ware culture}} in Europe || 2500 BCE || 0.3 || The term Corded Ware was invented by an archaeologist; no civilization actually called themselves that.
|-
| [To the left of the curve two rock musicians with long hair and electrical guitars are standing on either side of a small gate made of three slabs of stone, one on top of the other two standing stones.] {{w|Stonehenge}} completed || 2200 || 0.3 || This is a reference to the 1984 {{w|mockumentary}} about the fake rock band {{w|This Is Spinal Tap}}. In the movie the band wanted a giant Stonehenge prop 18 feet high, but a writing mistake gives them one that is only 18 inches.
|-
| {{w|Chariots}} developed || 2000 BCE || 0.3 || But {{w|Chariots of Fire}} came much later.

|-
| rowspan="3"| 2000 BCE
| {{w|Alphabetic writing}} developed in Egypt || 1750 BCE || 0.2 || Obligatory reference to xkcd [[1069: Alphabet]].
|-
| Last {{w|mammoth}}s on a tiny Siberian island go extinct || 1650 BCE || 0.2 || Many of the {{w|Pleistocene megafauna}} died in the {{w|Quaternary extinction event}}. Like the {{w|woolly rhino}} (see 12900 BCE) these animals likely became extinct in part due to {{w|Holocene extinction|humans hunting them}}, which may be why Randall included them in the chart. Most of the mammoths died out before 8000 BCE but {{w|Woolly_mammoth#Extinction|some survived in remote areas}} and the last known population died on {{w|Wrangel Island}} in the {{w|Arctic Ocean}} around 2000 BCE, slightly earlier than Randall shows here.
|-
| {{w|Minoan eruption}} || 1600 BCE || 0.2 || This volcano may have led to the downfall of Minoan civilization.

|-
| rowspan="5"| 1500 BCE
| {{w|Iron smelting}} || 1400 BCE || 0.1 || The beginning of the {{w|Iron Age}}.
|-
| {{w|Olmec}} civilization develops in Central America || 1350 BCE || 0.1 || No, Maggie, not Aztec, [http://vimeo.com/34002760 Olmec].
|-
| [A Trojan horse with two Cueball-like guys in front and a third standing on its back. Its back is at three Cueball’s height and its head rises to the level of the Cueball on its back. It stands on a platform with four wheel on the visible side. There is text on the horse] Setting of the ''{{w|Iliad}}'' and the ''{{w|Odyssey}}'' Text on horse: Not a trap || 1250 BCE || 0.1 || A reference to the {{w|Trojan War}} qua the drawing of the {{w|Trojan Horse}}. The horse was a big trap letting the soldiers hidden inside it into {{w|Troy}}. This explains why it has ''Not a trap'' written on it. Else they would not have taken the giant wooden horse present from their sworn enemies into their city just like that... Note that the Trojan horse isn't mentioned in the Iliad, and only recalled in passing by the characters in the Odyssey.
|-
| Invasion of the {{w|Sea peoples}}* * A real thing || 1200 BCE || 0.1 || {{w|Mermaid#One_Thousand_and_One_Nights|Sea people}} might sound like a reference to mythical {{w|mermaid}}s, so Randall feels the need to footnote that this event was ''a real thing'' (as opposed to his Pokémon reference, which he notes is ''not a real fact''). The sea peoples were a seafaring confederation of groups known to have attacked ancient Egypt around this time.
|-
| {{w|Polynesians}} explore the Pacific Ocean || 1000 BCE || 0.1 || {{w|Polynesian navigation}} was surprisingly widespread.

|-
| rowspan="8"| 1000 BCE
| [From 1000 BBC to 1000 CE the temperature is stable and very close to the 1961-1990 average.] || 1000 BCE || 0.1 || The temperature has fallen from the Holocene Optimum by half a degree to just a bit above the the 1961-1990 average. It will stay in this range for the next 2000 years.
|-
| {{w|Solomon}} || 1000 BCE || 0.1 || Solomon may have been a real historical king, but he probably did not threaten to chop a baby in half.
|-
| {{w|Iliad}} and {{w|Odyssey}} composed || 900 BCE || 0.1 || These classic myths were written more than 300 years after their supposed events. Archaeologists believe the city of {{w|Troy}} existed (and was destroyed by war around the right time period), but characters like Helen, Odysseus, and Achilles did not.
|-
| Rise of {{w|Greek city-states}} || 800 BCE || 0.1 || This is ''Sparta'', along with Athens and several others.
|-
| {{w|Neo-Assyrian Empire}} || 800 BCE || 0.1 || Hi, you may remember us from such kings as Adad-nirari and Sennacherib.
|-
| {{w|Ancient Olympic Games|First Olympics}} || 750 BCE || 0.1 || The first of the ancient Olympic Games is traditionally dated to 776 BC.
|-
| {{w|Zapotec civilization|Zapotec}} writing in modern Mexico || 600 BCE || 0.0 || Another Central American culture that fell to the Spanish invasion.
|-
| {{w|Confucius}} || 550 BCE || 0.0 || "He who knows all the answers has not been asked all the questions."

|-
| rowspan="10"| 500 BCE
| The stuff in the {{w|300 (film)|movie ''300''}}, but regular speed and with more clothing || 450 BCE || 0.0 || A reference to the {{w|Battle of Thermopylae}} by comparison with the 2007 movie ''300'' about this battle. The real Spartans wore armor, and real humans don't [http://www.google.com/search?q=300+slow-motion fly through the air in slow motion when struck].
|-
| {{w|Buddha}} || 450 BCE || 0.0 || Randall also mentions other religious figures like {{w|Jesus}} and {{w|Muhammad}}.
|-
| {{w|Nazca Lines}} || 350 BCE || 0.0 || These huge ancient drawings are difficult to see from ground level, leading some people to believe that they were intended for aliens.
|-
| {{w|Alexander the Great}} || 350 BCE || 0.0 || One of the most successful conquerors of the iron age, known for supposedly cutting the {{w|Gordian Knot}}.
|-
| {{w|Mayan hieroglyphics}} || 250 BCE || 0.0 || The {{w|Maya Calendar}} was probably created hundreds of years later.
|-
| {{w|Ashoka the Great}} || 250 BCE || 0.0 || The {{w|Edicts of Ashoka}} proselytized Buddhism across the continent.
|-
| {{w|Paper}} invented || 200 BCE || 0.0 || A significant step up from stone tablets or even papyrus.
|-
| {{w|Asterix}} || 100 BCE || 0.0 || Fictional main character in ''The Adventures of Asterix'', a comic series set around 50 BCE when {{w|Julius Caesar}} conquered {{w|Gaul}}.
|-
| {{w| Teotihuacan|Teotihuacán}} metropolis || 100 BCE || 0.0 || Another ancient city much beloved by archaeologists, even though they don't know who built it.
|-
| {{w|Julius Caesar}} || 50 BCE || 0.0 || Aside from being a conqueror, dictator, and deity, Julius had a big impact on {{w|Julian Calendar|calendars}}. The month of Quintilis was renamed July to honor him, and he was famously assassinated on the ides (middle day) of March.
|-

|-
| rowspan="8"|1 BCE 1 CE
| [Instead of a zero, there are two numbers for each of the two scales before (1 BCE) and after Christ (1 CE)] || 0 CE || -0.1 || Originally the year range went directly from 1 BC to 1 AD. The year zero has since been added for ease of mathematical and astronomical calculations.
|-
| {{w|Roman Empire}} || 1 CE || -0.1 || Julius never held the title "Emperor"; his adoptive son Augustus was the first to do so.
|-
| {{w|Jesus}} || 1 CE || -0.1 || Randall also mentions other religious figures like {{w|Buddha}} and {{w|Muhammad}}.
|-
| [To the left and erupting volcano.] {{w|Pompeii}} || 100 CE || -0.1 || The volcano is {{w|Mount Vesuvius}} which exploded in 79 CE and is famous for burying everyone in the close by city Pompeii preserving peoples bodies inside the huge amount of ash that swallowed the city very rapidly. Today it has given the archeologist lots of knowledge about the culture of that time.
|-
| {{w|Three Kingdoms}} period || 250 CE || -0.1 || Not just a series of movies and video games, but an actual thing that happened in China.
|-
| {{w|Gupta empire}} || 700 CE || -0.1 || Not as great as Ashoka, but still a pretty important time in the history of India.
|-
| Various groups take turns sacking {{w|Rome}} || 550 CE || -0.1 || 500 years is a pretty successful span for an empire.
|-
| {{w|Attila the Hun}} || 550 CE || -0.1 || He probably would not mind being remembered as one of the most infamous barbarians in history.

|-
| rowspan="4"| 500 CE
| {{w|Muhammad}} || 600 CE || 0.0 || Randall also mentions other religious figures like {{w|Buddha}} and {{w|Jesus}}
|-
| {{w|Tang Dynasty}} || 750 CE || 0.0 || A golden age in China, responsible for the development of printing, gunpowder, and many other advances.
|-
| [An arrow to the right of the dotted curve pointing down, takes a swing far out from the curve and then bends back again. The text label next to it breaks into the next 500 period. The dotted curve stays stable at the 1961-1990 average along this arrow.] {{w|Medieval warm period}} in Europe and some northern regions (too regional to affect the global average much) || 900 CE || 0.0 || Changes in ocean currents caused various regions to warm up while others cooled.
|-
| {{w|Leif Eriksson}} || 950 CE || 0.0 || Probably the first European explorer to reach North America.

|-
| rowspan="7"| 1000 CE
| [To the left a drawing of a compass with needle pointing the black end towards north east. There are labels for the four main directions (N, S, W, E) and a label next to it:] {{w|Magnetic compass}} navigation || 1050 CE || 0.0 || It's much easier to sail to the Orient when you can orient yourself.
|-
| [The dotted curve moves to the left towards lower temperature reaching a minimum around 1650 CE of about 0.6°C below the 1961-1990 average at the {{w|Little Ice Age}}.] || 1150 CE || -0.1 || This less than half a degree drop in temperature over 500 years was enough to cause the "Little Ice Age" which resulted in extended ice coverage in the winters in instance Europe. See more below at the entry for the Little Ice Age.
|-
| {{w|Ghengis Khan}} || 1200 CE || -0.2 || Mongol emperor. {{w|Gengar}} is not named after him, but [http://bulbapedia.bulbagarden.net/wiki/Kangaskhan_(Pokémon) Kangaskhan] and [http://awoiaf.westeros.org/index.php/Khal the Khals] are.
|-
| {{w|Zheng He}}’s fleet explores Asia and Africa || 1400 CE || -0.3 || He explored farther than European contemporaries like Dias or de Gama.
|-
| {{w|Aztec Empire|Aztec Alliance}} || 1400 CE || -0.3 || Aztec dominance only lasted a century until Cortes arrived, but their cultural legacy is indisputable.
|-
| {{w|Printing press}} || 1450 CE || -0.3 || {{w|Johannes Gutenburg}} ushered in the {{w|Age of Enlightenment}}.
|-
| {{w|Christopher Columbus|Columbus}} || 1490 CE || -0.3 || The time given here references when Christopher Columbus reached the {{w|Americas|New World}} in 1492. The five events around 1500 CE lies very close together but it fits with Columbus fitted in just before 1500.

|-
| rowspan="2"| 1500 CE
| {{w|European Renaissance}} || 1500 CE || -0.3 || From here on, the chart has labels for each 100 year increment instead of 500, but the scale stays the same. Important events happens so much faster in these last five hundred years, there isn't enough space to write all of them, so Randall has had to be selective. He includes {{w|Isaac Newton}} but leaves out {{w|Albert Einstein}}, includes {{w|airplane}}s but leaves out {{w|car}}s, etc.
|-
| {{w|Shakespeare}} || 1600 CE || -0.4 || xkcd references Shakespeare many times, such as [[79: Iambic Pentameter]] and [[1026: Compare and Contrast]].

|-
| rowspan="2"| 1600
| {{w|Isaac Newton|Newton}} || 1650 CE || -0.4 || Isaac Newton appears in various xkcd comics, such as [[626: Newton and Leibniz]].
|-
| [To the right of the dotted curve there is an arrow pointing down that makes a swing in towards the curve and then back out again. This is the coldest it has been since 9500 BCE. It is labeled:] ”{{w|Little Ice Age}}” || 1650 CE || -0.4 || This was not a true geologic Ice Age, just a slightly chilly period when the temperature fell a fraction of a degree, but still colder than it had been through 11,000 years of human civilization. In Europe the winters were so cold that the river {{w|Thames}} {{w|Little_Ice_Age#Europe|froze over}} hard enough to hold {{w|River Thames frost fairs}} between 1607 and 1814. And in 1658 {{w|Sweden}} crossed the {{w|Danish Straits}} on foot to invade {{w|Copenhagen}} in the {{w|March Across the Belts}}. It was only possible due to the harsh winters of the Little Ice Age, demonstrating how much half a degree of climate change can mean.

|-
| rowspan="2"| 1700
| {{w|Steam engines}} || 1750 CE || -0.4 || The {{w|Age of Steam}} heralded the upsurge of human CO2 emissions.
|-
| {{w|United States Declaration of Independence|Unites States Independence}} || 1770 CE || -0.3 || On July 4, 1776.

|-
| rowspan="3"| 1800
| {{w|Industrial Revolution}} || 1825 CE || -0.3 || Not to be confused with {{w|Industrial music}} such as Nine Inch Nails.
|-
| {{w|Electrical telegraph|Telegraphs}} || 1830 CE || -0.3 || [https://youtu.be/gEGQUgWBQL4?t=56s -. --- .-- --..-- / - .... . / -- --- - .... . .-. / --- ..-. / ... .- -- ..- . .-.. / -- --- .-. ... . / .- .-.. .-- .- -.-- ... / ... . -. - / - .... . / .-.. .- -.. / --- ..- - / --- -. / .- / .... --- .-. ... .]
|-
| [After this the dotted curve becomes solid.] || 1850 CE || -0.3 || From 1850 weather records became sufficiently accurate and widespread to greatly improve the precision of climate measurements. Hence the curve stops being an estimate and thus also stops being a dotted curve and becomes solid.

|-
| rowspan="6"| 1900
| {{w|Airplane}}s || 1900 CE || -0.3 || xkcd discusses airplanes many times, such as [[726: Seat Selection]] and {{what if|30|30: Interplanetary Cessna}}.
|-
| {{w|World Wars}} || 1930 CE || -0.2 || Likewise, there are many xkcds on this topic, such as [[261: Regarding Mussolini]] and {{what if|100|100: WWII Films}}.
|-
| [The solid line takes a step to the right close to the 1961-1990 average. Over the rest of the 1900s it moves closer to the 1961-1990 average, crossing it before 2000 where it almost reaches the maximum temperature of 0.5 °C above the 1961-1990 average from earlier in 8000 BCE.] || 1940 CE || -0.2 || This is what the previous 14000 pixels of comic has been leading up to. After a laborious 20 millennia of gradual and meandering climate change, it should be clear that a full degree of warming in a single century is unprecedented in human history, and very unlikely to be natural variation.
|-
| {{w|Fossil fuel}} CO2 emissions start rapidly increasing || 1950 CE || -0.1 || The infamous [http://www.skepticalscience.com/Hockey-stick-or-hockey-league.html "hockey stick"] starts around here.
|-
| {{w|Nuclear weapons}} || 1950 CE || -0.1 || The Working Group on the 'Anthropocene' suggests dating the {{w|Anthropocene}} epoch from ~1950. The week after this comic [[1736: Manhattan Project]] with a mushroom cloud was released.
|-
| {{w|Internet}} || 1980 CE || 0.1 || The origin of the internet dates back to 1960 but it began growing rapidly in 1980. By placing the invention of the {{w|internet}} at 1980 in the chart, just where the temperature curve starts its most rapid increase, Randall uses this [[552: Correlation|correlation]] to humorously imply that the internet caused the rise in temperature. This is also where the temperature crosses the 1961-1990 average, which has to happen somewhere due to the {{w|Intermediate Value Theorem}}.

|-
| rowspan="2"| 2000
| {{w|Northwest Passage}} opens || 2000 CE || 0.4 || This was dramatic evidence that the climate had changed. When global warming removes enough sea ice to create shipping routes that never existed before, then it is clear to people that ''something'' is changing, even if they disregard who/what is responsible for the change.
|-
|[From here to present day the solid line increases rapidly and in 2016, present day, is almost reaches 1°C above the 1961-1990 average, with about 0.8°C above the 1961-1990 average.] || 2016 CE || 0.8 || '''Notice''': [http://www.skepticalscience.com/argument.php?a=11&p=2 Warming did not stop] in 1998.

|-
| rowspan="3"| 2016
| | Present day || 2016 CE || 0.8 || Today, just after the two hottest months ever measured since 1850 had ended (July and August 2016), this comic was released with the message displayed very clearly here below. Act now or fry...
|-
| [From here the curve once again becomes dotted as this is the future. After one dot it splits in two and after the first two dots another split between them occurs forming three possible future dotted curves.] || 2016 CE || 0.8 || Here stops the data and the projection into the future begins so the curve again becomes dotted. Three different scenarios are depicted.
|-
|The first curve bending down before the others, and thus to the right of the other two reaches about 1.2°C above the 1961-1990 average and then goes straight down and stops at the 2100 line. An arrow points to it from the left and a label is written partly before and the rest after the 2100 line to the left of the curve:] Best-case scenario assuming immediate massive action to limit emissions || 2100 CE || 1.2 || If humanity does all in its power to stop global warming we might be able to halt the global warming already before 2050 keeping the maximum temperature to just 1.2°C above the 1961-1990 average. Only 0.4°C above today's temperature. (Note that this is not, in fact, the absolute best-case scenario, as it assumes that no new greenhouse gasses are either added to or removed from the atmosphere in the future; the temperature rise could be kept to an even lower level if some or all of the already-emitted greenhouse gasses were removed from the atmosphere.)

|-
| rowspan="2"| 2100
| [The middle curve bends a little down after reaching 1.3°C above the 1961-1990 average, and then continues this path reaching 2°C above the 1961-1990 average in 2100. An arrow point from below to it and a label is written below the curve and below 2100 line:] Optimistic scenario|| 2100 CE || 2.0 || If all the current realistic preventions are implemented, which might not be so realistic, then we may not even stop the warming but slow it down so we "only" reach 2°C above the 1961-1990 average in 2100 CE but it would not stop there. This is half the temperature change experienced since the ice age, but the other way. This was directly referenced in the title text of [[1379: 4.5 Degrees]]: ''That's only HALF an ice age unit (IAU), which is probably no big deal.''
|-
| [The last line continues along the path from the last 16 years of the solid line reaching 4.2°C above the 1961-1990 average at 2100, almost as far on the other side of the 1961-1990 average in 150 years as it took 14,000 years to move from the other side from the start of the chart. Another arrow point to this from below with a label below the curve and below 2100 line:] Current Path || 2100 CE || 4.2 || In this last scary scenario Randall assumes the temperature keeps rising steadily by extrapolating along the slope of the last two to three years. Randall has warned about the hazards of [[Extrapolating]], but this line is in fact [http://www.skepticalscience.com/climate-best-to-worst-case-scenarios.html below the worst case predictions]. If this comes true we will reach a temperature increase taking us from the 1961-1990 average and in just 125 years to 4.2°C above this average. That is just as far above this average in that short time span as the ice age temperature was below. And it took more than 11,000 years for nature to reach such an increase. Randall already contemplated what this would be like in the +1 ice age unit (IAU) panel of [[1379: 4.5 Degrees]] two years ago, as well as in [[164: Playing Devil's Advocate to Win]] almost 10 years ago. He may get to ''enjoy quite a ride'' as he "wished" for back then.

There is no reason to assume the temperature will not keep rising past 2100 CE, so the {{w|Cretaceous Thermal Maximum|"Hothouse Earth"}} of the early {{w|Cretaceous period}} mentioned in the 4.5 degree comics +2 IAU panel might come to pass in future centuries if we continue on our current path. On the bright side, modern civilization might collapse if this trend keeps up, which would drastically cut our releases of carbon dioxide and other greenhouse gasses into the atmosphere. But then again, positive feedback from methane in melting {{w|permafrost}} might take over... Good luck Earth.
|}

===Sources===
The image attributes climate data sources as "Shakun et al. (2012), Marcott et al. (2013), Annan and Hargreaves (2013), HadCRUT4, IPCC":
* Shakun et al. (2012) - [http://www.nature.com/nature/journal/v484/n7392/full/nature10915.html Nature], [http://www.atm.damtp.cam.ac.uk/mcintyre/shakun-co2-temp-lag-nat12.pdf (pdf)]
* Marcott et al. (2013) - [http://science.sciencemag.org/content/339/6124/1198 Science], [http://content.csbs.utah.edu/~mli/Economics%207004/Marcott_Global%20Temperature%20Reconstructed.pdf (pdf)]
* Annan and Hargreaves (2013) - [http://www.clim-past.net/9/367/2013/cp-9-367-2013.html Climate of the Past] [http://www.jamstec.go.jp/frsgc/research/d5/jdannan/LGM_temp.pdf (pdf)]
* {{w|HadCRUT}} - [http://www.metoffice.gov.uk/hadobs/hadcrut4/ Official site]
* {{w|Intergovernmental_Panel_on_Climate_Change|IPCC}} -[http://www.ipcc.ch/ Official site]

==Transcript==
'''Note''' there are several spelling errors in the comic, so please do only correct spelling errors that are not part of the comic! See more in the [[#Trivia|trivia section]].
:[A large heading, followed by a sub-caption. Below that two lines with a statement in between:]
:<big>A timeline of Earth’s average temperature</big>
:since the last ice age glaciation
:When people say “The climate has changed before,” these are the kinds of changes they’re talking about.

:[A very long chart below the headings above is headed with a label for the scale of the X-axis above the chart. Below that a sub-caption. To the left an arrow down to the top of the chart pointing to the dotted curves starting point (at -4.3°C below the 1961-1990 average) with a label above the arrow. And arrow pointing left to the left of the center and another pointing right to the right of the center has labels. Below these is the temperature scale of the X-axis, with 9 ticks between the borders each with a label ranging from -4 to +4°C compared to the 1961-1990 average, but with another step in each direction not labeled towards to axis so the chart covers -5 to +5°C compared to the 1961-1990 average.]
:'''Temperature'''
: Compared to the 1961-1990 average
:Start
:Colder
:Warmer
:-4°C -3°C -2°C -1°C 0°C +1°C +2°C +3°C +4°C

:[To the right of the chart is a gray text standing on the side down along the outer boarder of the chart with the sources for the chart:]
: Source: Shakun et. al. (2012) , Marcott et. al. (2013), Annan and Hargreaves (2013) , HadCRUT4, IPCC 

:[The chart is split in 10 columns by the temperature scale and the borders. The two central columns are white, and then from there to the left the background becomes a faded color that changes from light blue to blue at the edge in four steps. Similarly to the right the color changes from light red to red. To the left there is a time scale taking 500 years leaps from 20,000 BCE all the way to year 1, where there are two years, one for BBC and one for CE. The 500 year leaps continue until 1500 CE and from there the steps are down to 100 years until 2100 with also present day 2016 labeled. After 1500 the CE is omitted. The labels stop there, but there is space below covering down to 2200 CE. There is clearly visible division line across the chart on the level of each of the 500 step, and fainter lines for each of the 100 steps all the way even though only the last 5 of these 100 steps are labeled. There is a similar clear line at 2016. Below each step on the Y-axis is noted, and then any text starting before the next step is noted below indented. If there are extra image belonging to text this is indented once more. The graph that the whole chart is about is a dotted line that begins at the “start” point mentioned above at -4.3°C and then begins to go straight down. It will change left and right all the way down. To being with all text and most drawings are to right of the dotted curve. Whenever something is to the left it will be noted. When it says to the left above something, and then nothing over the next, then the next will be to the right. Only at the very bottom are there more entries to the left than right. ]
:20000 BCE
::[An arrow goes from the dotted line to the central line at 0°C. In the middle of the line there is a temperature label:]
::4.3°C
::At the start of our timeline, 22,000 years ago, Earth is 4°C colder than during the late 20th century.
::Boston is buried under almost a mile of ice, and the glaciers reach as far south as New York City.
:::[The Statue of Liberty is shown in front of a glacier front. A very tiny Cueball is on top of the glacier. The drawing is labeled and so is also the glacier.]
:::New York
:::Ice
:::[A guy with a white knit cap is seen walking in a snowy landscape leaving black footprints behind him. He walks through the white central part of the chart.]
:::[The skyline of Boston is shown with two clear buildings among all the other. Above it is a line and in between this area has been filled with thin lines. The drawing is labeled and so is this area. Also the skyline has an arrow pointing at it with a label:]
:::Boston
:::Ice
:::Modern skyline

:19500 BCE
::But the world is about to warm up.
::By this time, humans have already spread across Africa, Eurasia, and Australia.
::They’ve created painting, pottery, rope, and bows and arrows, but haven’t developed writing or farming.

:19000 BCE
::Changes in the Earth’s orbit mean that more sunlight reaches the polar ice…
:::[A line chart with a labeled Y-axis with three labeled ticks. The curve starts up and then goes down five times and up four times ending down. There is one plateau towards the end compared to the rest of the curve where the ups and downs are quite alike.]
:::Summer sun W/m2 at 60°N
:::550
:::500
:::450

:18500 BCE
::[A map of the world. At the top is a light gray area covering North America, Greenland and northern Europe and most of the northern part of Russia. A similar gray area covers Antarctica. There are two labels in the gray area above and one in the gray area below:]
::Ice Ice
::Ice

:18000 BCE
::…And the ice sheets start to melt.

:17500 BCE
::Temperatures have been creeping upward, but around this point, CO2 levels start to climb…

:17000 BCE
::…And then the warming speeds up.

:16500 BCE
::[Cueball is standing with a spear just the right of the graph talking to a rabbit.]
::Cueball: Still pretty cold.

:16000 BCE
::[Megan points to the graph to the right of her and between her and Ponytail standing on the other side. Mean is the first drawing on the left side of the dotted curve, which has hardly moved since the beginning, only to just on the other side of 4°C.]
::[In the right part of the chart is an explanation of the data. Below the first two lines there are four drawings each showing possible temperature swings in reality compared to the smoothed data that represents the dotted curve of the entire chart. The dotted curve is shown in all four drawings and a thin line is shown running along it but with much more fluctuation left and right on the first two, a large spike right on the third and a large bump way right on the fourth. Above these there are two labels. The first labels is inside a bracket that covers the first three, and the last label is for the last drawing. Below is a list of sources.]
::Limits of this data:
::Short warming or cooling spikes might be “smoothed out” by these reconstructions but only if they’re small or brief enough.
:::Possible Unlikely
::Reconstructions are from Shakun (2012) and Marcott (2013), scaled to Annan + Hargreaves (2013) estimate for the last glacial period.

:15500 BCE
::In what is now France, humans paint murals on the walls of the Lascaux caves
::[Hairy paints three animals, two with horns, and two humans, Cueball holding hand with Hairy who has a spear. On the other side of the central line Megan writes three letters, the last of which is reversed.]
:::NIИ

:15000 BCE
::Ice sheets around Alaska shrink, exposing a land bridge between Asia and North America
::[From around the bottom if this section and down to 11500 BCE the dotted curve moved steadily to the right towards warmed temperature peaking close to -1.5°C. Before this the temperature had not moved much away from that at the start.]

:14500 BCE
::[Cueball walks right looking back at the graph behind him. Megan walks in front of him pointing further right.]
::Cueball: Cool.
::Humans reach North America.

:14000 BCE
::The edge of the ice withdraws from New York City and retreats North.
::[A large glacier front speaks in a speech bubble with an arrow pointing at it. Behind is there are four peaks in the horizon and in front of it three small melting pools and some rocks on the ground.]
::Glacier: ''That’s it! I’m moving to Canada!''

:13500 BCE
::Humans domesticate dogs
::(Date uncertain, may be much earlier)
::[Megan and Cueball is watching a wolf looking at them.]
::Megan: Okay, you can live in our homes and we’ll feed you, but we’ll still get mad f you poop on the floor.
::Wolf: Deal.
::Cueball: And we get to breed you to be tiny and dress you in little costumes.
::Wolf: …Wait.

:13000 BCE
::[Randall did not use the normal spelling for Woolly Rhino, but this is an accepted alternative spelling:]
::Wooly Rhino goes extinct
::Oregon is scoured by huge floods as glacial dams burst and lakes of meltwater flow to the sea

:12500 BCE
::Ice sheets withdraw from Chicago

:12000 BCE
::Humans settle Abu Hureyra in Syria

:11500 BCE
::[An arrow on the left side of the dotted curve is pointing down along the dotted curve and to the left indicate temperature is declining again, meaning the dotted curve now moves left to colder temperatures. This only continues until 10500 BCE. It is only the second time something is noted on the left side after Megan at 16000 BCE]
::Temperatures start to decline, mainly in the Northern hemisphere
::This may be caused by changes in ocean circulation due to the floods of cold fresh meltwater flowing into the Atlantic as the North American ice sheet melts.
::This cooler period is called the Younger Dryas

:11000 BCE
::[This is the first text to the left of the dotted curve:]
::Humans reach Argentina

:10500 BCE
::[An arrow pointing down along the right side of the dotted curve and to the right indicate temperature is increasing again, meaning the dotted curve now moves right to hotter temperatures. This continues until 8000 BCE where it levels out just above 0°C.]
::Warming resumes
::Human settlements at Jericho

:10000 BCE
::First development of farming

:9500 BCE
::Saber-toothed cat goes extinct
::[To the left:]
::Horses disappear from North America

:9000 BCE
::[To the left, Randall spelled Pokémon wrong:]
:::Last North American Pokemon go extinct
:::[Cueball with a speak and Megan is looking up at this last “fact”.]
:::Megan: That is not a real fact.
::Temperatures reach modern levels
::Rising seas cut off the land bridge between North America and Asia
::Cattle domesticated

:8500 BCE
::Ice sheets retreat across the Canadian border
::Temperatures start to level out slightly above 1961-1990 levels

:8000 BCE
::[The above sentence breaks over the 8000 BCE line. From here a maximum in temperature on the chart is reached at 0.5°C which will not be overtaken until 2000 CE. It stays almost constant here until 5000 BCE where a slight cooling begins.]

:7500 BCE
::[To the left:]
::This warm, stable period is called the Holocene Climate Optimum
::[To the left:]
::Jiahu settled in China

:7000 BCE
::Final collapse of the North American ice sheet leads to rapid 2-4m sea level rise…
::[A small arrow points down and left to the right of the dotted curve. There is a small decrease in temperature but it is very small and would have been missed without the arrow and label.]
::…And a period of cooling in the Northern hemisphere

:6500 BCE
::[To the left:]
::As seas rise to near their modern levels, Britain is cut off from mainland Europe

:6000 BCE
::Humans develop copper metalworking

:5500 BCE
::[To the left:]
::Massive volcanic eruption in Oregon creates crater lake
::Gold metalworking

:5000 BCE
::[To the left:]
::Invention of the wheel
::[To the left. To the right of the dotted curve is an arrow pointing down and slightly left. From here temperature decreases very slowly but steadily from 0.5°C until 1000 BCE where a stable plateau is reached around 0°C.]
::Earth begins to cool slowly mainly due to regular cycles in its orbit

:4500 BCE
::[To the left:]
:: Proto-Indo-European language develops
:::[To the right of the curve Ponytail holds up a hand towards Cueball.]
:::Ponytail: Let’s make our language heavily inflected, so future students have to memorize a zillion verb endings!
:::Cueball: Okay!
::[To the left:]
::Permanent settlements in the fertile crescent

:4000 BCE
::Horses domesticated
::[To the left:]
::Minoan culture arises on Crete

:3500 BCE
::Egyptian mummification
::Rise of the Indus Valley civilization
::[To the left:]
::Invention of writing in Sumer “prehistory” ends, “history” begins
::Earliest human whose name we know
::(Pharaoh Iry-Hor in Egypt)

:3000 BCE
::''Three Sovereigns and five emperors'' period in China
::Gilgamesh
::[To the left:]
::Imhotep
::Mayan culture emerges
::[To the left:]
::Great Pyramid constructed

:2500 BCE
::Corded Ware culture in Europe
::[To the left of the curve two rock musicians with long hair and electrical guitars are standing on either side of a small gate made of three slabs of stone, one on top of the other two standing stones.]
::Stonehenge completed
::Chariots developed

:2000 BCE
::[To the left:]
::Alphabetic writing developed in Egypt
::Last mammoths on a tiny Siberian island go extinct
::[To the left:]
::Minoan eruption

:1500 BCE
::[To the left:]
::Iron smelting
::Olmec civilization develops in Central America
::[A Trojan horse with two Cueball-like guys in front and a third standing on its back. Its back is at three Cueball’s height and its head rises to the level of the Cueball on its back. It stands on a platform with four wheel on the visible side. There is text on the horse]
:::Setting of the ''Iliad'' and the ''Odyssey''
:::Text on horse: Not a trap
::[To the left:]
::Invasion of the Sea peoples*
::* A real thing
::Polynesians explore the Pacific Ocean

:1000 BCE
::[From 1000 BBC to 1000 CE the temperature is stable and very close to 0°C.]
::[To the left:]
::Solomon
::[Randall spelled Iliad wrongly this time:]
::Illiad and Odyssey composed
::[To the left:]
::Rise of Greek city-states
::Neo-Assyrian empire
::[To the left:]
::First Olympics
::Zapotec writing in modern Mexico
::[To the left:]
::Confucius

:500 BCE
::[To the left:]
::The stuff in the 300 (film)|movie ''300'', but regular speed and with more clothing
::Buddha
::Nazca Lines
::[To the left:]
::Alexander the Great
::[To the left:]
::Mayan hieroglyphics
::Ashoka the Great
::[To the left:]
::Paper invented
::[To the left:]
::Asterix
::Teotihuacán metropolis
::[To the left:]
::Julius Caesar

:[At the year 0, there is instead two numbers for each of the two scales before and after Christ:]
:1 BCE
:1 CE
::[To the left:]
::Roman Empire
::Jesus
::[To the left and erupting volcano.]
::Pompeii
::Three Kingdoms period
::[To the left:]
::Gupta empire
::[To the left:]
::Various groups take turns sacking Rome
::[Randall spelled Attila wrong:]
::Atilla the Hun

:500 CE
::Muhammad
::[To the left:]
::Tang Dynasty
::[An arrow to the right of the dotted curve pointing down, takes a swing far out from the curve and then bends back again. The text label next to it breaks into the next 500 period. The dotted curve stays stable at 0°C along this arrow.]
::Medieval warm period in Europe and some northern regions (too regional to affect the global average much)
::[To the left:]
::Leif Eriksson

:1000 CE
::[The dotted curve moves to the left towards lower temperature reaching a minimum around 1650 of about -0.6°C at the Little Ice Age.]
::[To the left a drawing of a compass with needle pointing the black end towards north east. There are labels for the four main directions and a label next to it:]
:::N
:::W E
:::S
:::Magnetic compass navigation
::[To the left:]
::Ghengis Khan
::Zheng He’s fleet explores Asia and Africa
::[To the left:]
::Aztec Alliance
::[To the left:]
::Printing press
::[To the left:]
::Columbus

:1500 CE
::European Renaissance
::[To the left:]
::Shakespeare

:1600
::[To the left:]
::Newton
::[To the right of the dotted curve there is an arrow pointing down that makes a swing in towards the curve and then back out again. At -0.6°C this is the coldest it has been since 9500 BCE. It is labeled:]
::”Little Ice Age”

:1700
::Steam engines
::[To the left:]
::Unites States Independence

:1800
::Industrial Revolution
::[To the left:]
::Telegraphs
::[After this the dotted curve becomes solid.]

:1900
::[To the left, and on the line for 1900:]
::Airplanes
::[To the left:]
::World Wars
::[The solid line takes a step to the right close to 0°C. Over the rest of the 1900s it moves closer to 0°C crossing it before 2000 where it almost reaches the maximum temperature of 0.5 °C from earlier in 8000 BCE.]
::Fossil fuel CO2 emissions start rapidly increasing
::[To the left:]
::Nuclear weapons
::[To the left:]
::Internet

:2000
::Northwest Passage opens
::[From here to present day the solid line increases rapidly and in 2016 present day is almost reaches 1°C, with about 0.8°C.]

:2016
::[To the left on the line for 2016:]
::Present day
::[From here the curve once again becomes dotted as this is the future. After one dot it splits in two and after the first two dots another split between them occurs forming three possible future dotted curves. The first curve bending down before the others, and thus to the right of the other two reaches about 1.2°C and then goes straight down and stops at the 2100 line. An arrow points to it from the left and a label is written patly before and the rest after the 2100 line to the left of the curve:]
::Best-case scenario assuming immediate massive action to limit emissions

:2100
::[The middle curve bends a little down after reaching 1.3°C and then continues this path reaching 2°C in 2100. An arrow point from below to it and a label is written below the curve and below 2100 line:]
::Optimistic scenario
::[The last line continues along the path from the last 16 years of the solid line reaching 4.2°C at 2100, almost as far on the other side of 0°C in 150 years as it took 14000 years to move from the other side from the start of the chart. Another arrow point to this from below with a label below the curve and below 2100 line:]
::Current Path

==Trivia==
*There have been several ''[[:Category:Large drawings|large drawings]]'' in the history of xkcd, some of which are bigger than this one (for instance [[1110: Click and Drag]]).
**Among those that can be viewed in one go, without downloading a larger file or moving around, this is by far the longest.
**The next longest is probably [[482: Height]].
*The timeline starts at 20,000 BCE (22,000 years ago) and ends at 2100 CE, thus covering 22,100 years.
*There are several spelling mistakes.
**Most obvious is the second time Randall wrote the word "Iliad," because he just spelled it correctly at 1500 BCE and then spelled it ''Illiad'' at 1000 BCE with two "L"s.
**Attila the Hun becomes ''Atilla the Hun'' with ''one'' T and ''two'' L's.
**Pokémon is spelled ''Pokemon'', but then again, that is not so strange for Randall (see [[1647: Diacritics]]). Despite that, he usually spells it correctly, as in [[1705: Pokémon Go]].
**Note that the fact that woolly rhinoceros becomes ''Wooly rhino'' with only one l is not a spelling mistake but an alternative spelling of the word.
*The following notable facts are absent
**1850: methodical temperature record begins. However, this fact is indirectly indicated when the temperature curve becomes solid around 1850 and until present day.
**The entire swing period between 20 and 200 thousand years prior to now would depict temperature swings with increasing frequency and amplitude (ref geological record). But of course, this could not be included in a comic that only goes back to 20,000 BCE.
**During much of the 300 million years prior to that, the Earth was significantly warmer than now. However, the data's temporal precision decreases with age; seemingly abrupt changes millions of years ago might have happened over centuries or millennia. Hence, the older data is not usable to compare rates of change.

===Popularity of comic===
*This comic became popular with a much broader audience than most xkcd comics. It was discussed admiringly by news sites such as [http://www.popsci.com/xkcd-earth-average-temperature-timeline Popular Science], [http://reason.com/blog/2016/09/14/send-around-this-xkcd-climate-change-web Reason], [http://www.slate.com/blogs/bad_astronomy/2016/09/13/xkcd_takes_on_global_warming.html Slate], [http://www.smithsonianmag.com/smart-news/new-comic-masterfully-shows-how-climate-has-changed-through-time-180960451/ Smithsonian], and [http://www.forbes.com/sites/ericmack/2016/09/13/heres-22000-years-of-climate-changes-in-a-single-comic/ Forbes]. It was promoted by famous individuals such as [http://www.ecowatch.com/xkcd-climate-change-2003991855.html Elon Musk and John Green], and of course criticized by climate change deniers such as [http://wattsupwiththat.com/2016/09/20/josh-takes-on-xkcds-climate-timeline/ Anthony Watts] and [http://joannenova.com.au/2016/09/how-to-make-climate-graphs-look-scary-a-reply-to-xkcd/ Joanne Nova].
*Due to increased interest, Randall decided to push the release of the next comic [[1733: Solar Spectrum]] one day back for a rare [[:Category:Thursday comics|Thursday release]] instead of the scheduled [[:Category:Wednesday comics|Wednesday release]].
**He [http://web.archive.org/web/20160915101125/http://xkcd.com/ noted this] above [[:image:1732_Earth_Temperature_Timeline_header_text_changed_for_all_comics.png|all the comics]] in the [[:image:1732_Earth_Temperature_Timeline_header_text_changed.png|header text on xkcd]]:
::''Note: Since a lot of new people are here looking for this chart today,''
::''I'll be posting Wednesday's comic on Thursday instead.''
:*Before that, the [http://web.archive.org/web/20160912181546/https://xkcd.com/ normal heading] with the release day of xkcd was shown.
:*This was (of course) still there Tuesday the [http://web.archive.org/web/20160913231501/http://xkcd.com/ day after] the release, because it was first on Wednesday there were reason to note the delay.
:*It stayed in place even [[:image:1732_Earth_Temperature_Timeline_header_text_changed_also_when_next_comic_was_released.png|for some time after]] the "Wednesday" comic was released on Thursday, but was [http://web.archive.org/web/20160915154605/http://xkcd.com/ then removed] before [[:image:1732_Earth_Temperature_Timeline_header_text_back_to_normal_shortly_after_next_comic_was_released.png|noon (EST)]] on Thursday.
:**Randall did thus not post a link to this comic in the header text for new visitors to use, only giving them that one extra day.
:*Even though the next comic was released on a Thursday, the scheduled Friday comic [[1734: Reductionism]] was still released as planned.
:**This was also the first time this occurred on xkcd - see [[1734:_Reductionism#Trivia|this trivia item]] from the Friday comic.
*On 2019-3-1, this comic became one of the six [[Design of xkcd.com|footer]] comics.
==== Removal of warning and footnote ====
*This comic's popularity was possibly the reason that both the more-than-10-year-old [[xkcd warning]] as well as the [[footnote#Original_footnote|original footnote]] was [[footnote#Removal_of_original_footnote|removed]] on the day of this comic's release.
**The next footnote was added 22 days later.

{{comic discussion}}

[[Category:Comics with color]]
[[Category:Large drawings]]
[[Category:Charts]]
[[Category:Timelines]]
[[Category:Line graphs]]
[[Category:Maps]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring Hairy]]
[[Category:Comics featuring real people]] 
[[Category:Multiple Cueballs]]
[[Category:Climate change]]
[[Category:Science]]
[[Category:Animals]]
[[Category:Music]] 
[[Category:Fiction]] 
[[Category:Sport]] 
[[Category:Religion]] 
[[Category:Internet]]
[[Category:Pokémon]]
[[Category:Footer comics]]
[[Category:Puns]] 
[[Category:Volcanoes]]
[[Category:Nuclear weapons]]

1759: British Map

2016-11-16T16:20:41Z

108.162.219.80: /* Explanation */ Minor edit: two rows in the table had extra blank cells added at the very right side, so I removed them.

{{comic
| number = 1759
| date = November 14, 2016
| title = British Map
| image = british_map.png
| titletext = West Norsussex is east of East Norwessex, but they're both far north of Middlesex and West Norwex.
}}

==Explanation==
{{incomplete|Started the table, editing it now.}}

This comic is a joke similar to [https://www.google.com/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8&safe=active&ssui=on#q=how%20americans%20see%20the%20world&safe=active&ssui=on "How Americans see the world"] showing how the average American has opinions on the world, often including jokes such as a lack of {{w|Africa}}, etc. This has been used before in [[850: World According to Americans]].

Many areas of the UK are most familiar to foreigners thanks to their depiction in various fantasy novels and TV series. This map labels some of these, as well as including many silly names that simply sound like real British towns to an American ear. A protractor is shown off the coast of the {{w|Mull of Kintyre}} in reference to the "{{w|Mull of Kintyre test}}" - according to urban legend, the angle of the Mull defines the maximum allowed erectness for a man on films and home video releases in the UK.

Note that in British English, the correct spelling of “labeled” is ‘labelled’.

The title text plays around with the concept of the compass directions and how numerous regions (such as South "Sussex" and West "Wessex") incorporate such literal names in their description. Randell is creating similar sounding names which are nonsense-ish ("Norsussex" would be the region of the Northern-Southern Saxons), and placing them in relation to each other in ways which would be geographically implausible, similar to this [http://www.netfunny.com/rhf/jokes/92q3/xx19.html old joke about Boston]. However, in Germany there exists the region called ''Westphalia'' (''Westfalen''), and the eastern part of it is often referred to as ''East-Westphalia'' (''{{w|Ostwestfalen}}''), which sounds somewhat ridiculous. Part of the joke in the title text could be the fact that while three of the locations are fictional, Middlesex does actually exist.

{| border =1 width=100% cellpadding=5 class="wikitable sortable"
!Label on the map !! Explanation !! Actual location !! Notes
|-
| Helcaraxë
|| The "[http://lotr.wikia.com/wiki/Helcarax%C3%AB Grinding Ice]", an area of {{w|Middle-Earth}}. Like Helcaraxë, northern Scotland is cold, mountainous and in many areas inhospitable.
|| The {{w|Grampian}} region
||
|-
| Blick
||
||Near {{w|Rhynie, Aberdeenshire}}
|| This is the name of a goblin in the movie "Legend" starring Tim Curry.
|-
| Everdeen
|| {{w|Katniss Everdeen}} is the heroine of ''{{w|The Hunger Games}}'' series of novels and films
|| {{w|Aberdeen}}
|| In colloquial Scots, its pronunciation is very similar to "Everdeen."
|-
| Highlands
|| {{w|Scottish Highlands|No joke}}
|| {{w|Scottish Lowlands}}
|| Maybe deliberate trolling - Scots have strong feelings about where the Highland-Lowland border is
|-
| Norther Sea
|| Pun on the {{w|North Sea}}
|| {{w|Sea of the Hebrides}}
||
|-
| Loch Lomond
|| {{w|Loch Lomond|No joke}}
|| Loch Lomond
|| Loch Lomond is the largest lake in Great Britain, and the third largest lake in the UK. It is the subject of a well-known {{w|The_Bonnie_Banks_o%27_Loch_Lomond|traditional song}}, and was referenced in the "beaming" (teleporter) bit in the movie Spaceballs by the Scotty expy 'Snotty'. It also houses a distillery producing a whisky appreciated by Captain Haddock in ''{{w|The Adventures of Tintin}}''.
|-
| Fjordham
|| {{w|Fjords}} are glacial valleys. "-ham" is a common English placename suffix from Old English, related to the modern {{w|Hamlet (place)|hamlet}}. There are several villages in England named {{w|Fordham}}.
|| Near {{w|Oban}} on the {{w|Firth of Lorn}}
|| The Scottish word "Firth" is related to "Fjord", although Lorn is not a fjord in the strict scientific sense - it was formed along the {{w|Great Glen Fault}} by tectonics, rather than glaciers
|-
| Glassdoor
|| {{w|Glassdoor}} is a website where employees can review their employers
|| {{w|Stirling}}
|| Although it's shown near Stirling, the reference seems to be to {{w|Glasgow}}
|-
| Eavestrough
|| A dialectal word for {{w|rain gutter}}
|| {{w|Edinburgh}}
||
|-
| Seasedge
|| Procan's realm in ''Dungeons & Dragons''
|| Somewhere near the Scotland-England border
||
|-
| Chough
|| A {{w|Chough|species of bird in the crow family}}
|| The {{w|Scottish Borders}}
||
|-
| Meowth
|| {{w|Meowth}} is a cat-like Pokémon. Name may allude to {{w|Howth}}.
|| {{w|Ayr}}
||
|-
| Glutenfree
|| {{w|Gluten-free}} food lacks the protein {{w|gluten}}. This allows {{w|coeliac disease}} sufferers to enjoy it, but has also become a dietary fad in itself.
|| {{w|Cairnryan}}, {{w|Dumfries and Galloway}}
||
|-
| Blighton
|| A mashup of {{w|Brighton}} and {{w|Blighty}}
|| The {{w|Scottish Borders}}
|| The real Brighton is much further south, on the south coast.
|-
| North Sea
|| {{w|North Sea|No joke}}
|| North Sea
||
|-
| Eyemouth
|| {{w|Eyemouth|Not a joke}}
|| near {{w|Newcastle-upon-Tyne}}
|| The real Eyemouth is further north, where "Seasedge" is marked on the map.
|-
| Earhand
|| A pun on Eyemouth
|| {{w|Carlisle}}
||
|-
| Hairskull
|| A pun on Eyemouth
|| {{w|Teesside}}
||
|-
| Belfast DeVoe
|| {{w|Belfast}}, capital of Northern Ireland, mashed up with the rock band {{w|Bell Biv DeVoe}}
|| {{w|Belfast}}
||
|-
| Lakebottom
|| The {{w|Lake District}}. "-bottom" is a common placename across Northern England, and refers to a town in a valley.
|| {{w|Lake District}}
|| Below Lakebottom is a sketch of lake with yachts on it. This is {{w|Windermere}}, the largest lake in England, where many boating speed records were set.
|-
| Braintree
|| {{w|Braintree, Essex|Not a joke}}
|| {{w|North Yorkshire}}
|| The real Braintree is much further south, near where "Paulblart" is on the map. Also a possible reference to the Braintree stop at the end of the Red Line in Boston?
|-
| Skinflower
|| A pun on Braintree
|| {{w|Yorkshire Dales}}
||
|-
| Bjork
|| {{w|Björk}} is an Icelandic singer
|| {{w|East Riding of Yorkshire}}
|| The reference is presumably to York (historically known as Jórvík), although it's a bit too far east.
|-
| Weedle
|| {{w|Weedle}} is a Pokémon, and also a word meaning "to obtain by trickery or persuasion"
|| {{w|Forest of Bowland}}
|| In the original Pokémon Red and Blue games Weedle is most notably found in '{{w|Viridian Forest}}' which - like the real-life Forest of Bowland - is known for its diverse wildlife.
|-
| Eeugh
|| An expression of disgust
|| {{w|Kingston-upon-Hull}} (generally just "Hull")
|| Pronounced 'ull by locals
|-
| Crewneck
|| A shirt with a {{w|Crewneck|simple round collar}}.
|| {{w|Blackpool}}
|| There is a town called {{w|Crewe}} somewhat further south than shown in Cheshire.
|-
| Paisley
|| {{w|Paisley, Renfrewshire|No joke}}. It sounds funny to Americans because it's associated with {{w|Paisley (design)|paisley}} fabric, a Persian-style print invented in the town. Possibly a pun on {{w|Parsley|parsley}}, a herb.
|| {{w|Burnley}}
|| The real Paisley is in Scotland, near Glasgow.
|-
| Basil
|| Also {{w|Basil|a herb}}, and {{w|Basil Fawlty|one of the most famous British TV characters}}.
|| {{w|Scunthorpe}}
||
|-
| Aidenn
|| An apparent pun on the {{w|Scouse}} accent: {{w|h-dropping}} and {{w|th-fronting}} mean the common "hey, then" would be pronounced "ai denn".
|| {{w|Merseyside}}
||
|-
| Hillfolk
|| {{w|Hillfolk}} is an RPG. "-hill" (referring to, well, a hill) is common in British placenames, and "-folk" (referring to a tribe or culture) is seen in ''Suffolk'' and ''Norfolk''. Possibly also a reference to {{w|Hobbits}}, a race of little people that live under hills in The Lord of the Rings.
|| {{w|Manchester}}
|| Manchester's name does in fact reference hills: it means "castle on the {{w|breast-shaped hill}}"
|-
| Waterdown
|| To "water something down" is to weaken it. "-down" is common in British placenames and refers to {{w|Downland|chalk hills}}. Possibly a contraction from the book and movie: Watership Down.
|| Near {{w|Grimsby}}
||
|-
| Dubstep
|| {{w|Dubstep}} is a genre of electronic music with a heavy bass line.
|| {{w|Dublin}}
|| Dublin is the only non-UK settlement in the map, and one of two on the island of Ireland.
|-
| Borough-upon-Mappe
|| By being recorded here, this is literally a borough upon a map. The "-upon-" is a common element of placenames for towns on rivers, although there's no River Mappe. Possibly referencing the fact that the town is on a "mappe" (map)?
|| {{w|Lincolnshire Wolds}}
||
|-
| Fhqwhgads
|| "[http://www.hrwiki.org/wiki/Fhqwhgads Fhqwhgads]" is a joke from the Homestar Runner internet cartoon.
|| {{w|Wrexham}}
|| This is on the Welsh border; Welsh names often look like a mish-mash of consonants to English speakers, although "Wrexham" is Anglo-Saxon and in Welsh is spelled "Wrecsam" .
|-
| Cadbury
|| {{w|Cadbury}} is a British chocolate company
|| Near {{w|Boston, Lincolnshire}}
|| Cadbury actually built a town for its workers... but it's called {{w|Bournville}}. There are several towns called "Cadbury" in the UK (where the Cadbury family presumably got its name), but none are near here.
|-
| Cabinetry
|| The art of making {{w|cabinets}}.
|| Near {{w|Oswestry}}
||Several towns in the English Midlands have names ending in -try, including Oswestry. "Cabinetry" could be a pun on {{w|Coventry}}, which lies further to the east.
|-
| The Shire
|| {{w|Shire (Middle-earth)|The Shire}} is home to the {{w|Hobbits}} in {{w|Middle-Earth}}
|| {{w|Midlands}}
|| Tolkien drew inspiration for the Shire from the {{w|West Midlands (region)|West Midlands}}, although Tolkien was from the southern part of the Midlands (roughly where Dampshire is on the map)
John Cleese recently posted the following, which could have been inspiration for this map (in a blog called "A Letter to the U.S" after the 2016 Presidential Election), "3. You should learn to distinguish English and Australian accents. It really isn't that hard. English accents are not limited to cockney, upper-class twit or Mancunian (Daphne in Frasier). Scottish dramas such as 'Taggart' will no longer be broadcast with subtitles.You must learn that there is no such place as Devonshire in England. The name of the county is "Devon." If you persist in calling it Devonshire, all American States will become "shires" e.g. Texasshire Floridashire, Louisianashire." at http://cogink.com/cleese/
|-
| Landmouth
|| Literal description
|| {{w|The Wash}}
||
|-
| Brandon
|| {{w|Brandon#United Kingdom|Not a joke}}
|| {{w|The Fens}}
|| There are several Brandons in the UK, the nearest being where "Keebler" is on the map. The area shown is borderline-uninhabitable, as it is marshland and lies mostly below sea-level. Only a few farms and isolated hamlets exist here.
|-
| Hamwich
|| A ham sandwich. Both "-ham" and "-wich" are common generic placenames. The village called simply "Ham" and the other called "Sandwich" are fairly close to each other, with a famous roadsign that points to "Ham Sandwich" between them.
|| {{w|Norwich}}
|| Likely to be coincidence but the "Cheese Hamwich" is a breaded cheese and turkey food product sold by {{w|Bernard_Matthews_Ltd}} whose food processing facility is based not far from this map location.
|-
| West Norsussex
|| Mash-up of {{w|Sussex}} ("South Saxons") with the obsolete {{w|Wessex}} ("West Saxons") and never extant {{w|Norsex}} ("North Saxons")
|| {{w|Midlands}}
||
|-
| Redsox
|| The {{w|Boston Red Sox}} are a baseball team
|| {{w|The Fens}}
|| The Boston Red Sox play at Fenway Park. The map location is not far from the British {{w|Boston, Lincolnshire|Boston}}
|-
| Keebler
|| The {{w|Keebler Elves}} advertise cookies in the US
|| {{w|Elveden}}
|| The name of this village in Thetford Forest means "valley of the elves".
|-
| Bloughshire
|| Most British counties have "-shire" in their name. Originally it meant they were administered by a {{w|sheriff}}. However, they are usually no longer known by those names in Wales.
|| {{w|Powys}}
||
|-
| Lionsgate
|| {{w|Lionsgate|A film studio}}
|| {{w|Leicester}}
||
|-
| Kingsbottom
|| Another "-bottom". A possible reference to {{w|King's Landing}}, the capital of the Seven Kingdoms of {{w|Westeros}} and one of its districts Fleabottom.
|| {{w|Suffolk Coast National Nature Reserve|Suffolk Coast}}
|| Possibly named for the town of {{w|King's Lynn}}, also located in East Anglia but close to its north coast.
|-
| Aberforth
|| {{w|Aberforth Dumbledore}} is {{w|Albus Dumbledore}}'s brother in the ''Harry Potter'' series. The name is sometimes translated as "from the river", but without any etymological references. "Aber" is Welsh for a "river mouth" or estuary, and is widespread in Wales, and occasionally found due to Celtic influence in other parts of the UK (such as {{w|Aberdeen}}).
|| {{w|Aberystwyth}}
|| {{w|Aberporth}} ("Mouth [of the] port" - the Welsh equivalent of the the English name Portsmouth) is a real town located a little further southwest along the Welsh coast. {{w|Forth}} may be a reference to the {{w|Firth of Forth}} in Scotland, where "Firth" means estuary or fjord, and "Forth" is thought to mean "the open air". Aberforth would literally mean "the mouth of the river Forth", which is the location of {{w|Edinburgh}} in Scotland. Alternatively, "forth" in Welsh could be a soft mutated form of the Welsh name "{{w|Borth}}" (the name of a town - but not a river - a little further north along the coast), which is itself a soft mutated form of the word "porth" meaning port.
|-
| South Norwessex
|| Another mash-up of {{w|Sussex}} ("South Saxons") with the obsolete {{w|Wessex}} ("West Saxons") and never extant {{w|Norsex}} ("North Saxons"). Also southwest of West Norsussex.
|| {{w|Birmingham}}
||
|-
| Dryford
|| Would refer to a river crossing without water. "{{w|Ford (crossing)|-ford}}" is a common placename element.
|| {{w|Shropshire Hills}}
||
|-
| Frampton
|| There are many {{w|Frampton}}s in the UK. It means "town on the river Frome" - and there are also several {{w|River Frome}}s. The name is famous thanks to rock musician {{w|Peter Frampton}}
|| {{w|Bury St Edmunds}}
||see also "Southframpton"
|-
| Cambridge
|| {{w|Cambridge|No joke}}
|| {{w|Cambridge}}
|| Cambridge and Oxford, the two most prestigious university towns, are correctly marked. Together, they form {{w|Oxbridge}}
|-
| Kingsfriend
|| Possibly a joke about the royal patronage given to certain towns - for instance, {{w|Bognor Regis}} and {{w|Royal Wootton Bassett}}. Also {{w|Knighton, Powys|Knighton}} (a King's friend?) is very close to this locale, and so is {{w|Kington, Herefordshire|Kington}}.
|| Near the England-Wales border
||
|-
| Cair Paravel
|| {{w|Cair Paravel}} is the castle where the ruler of {{w|Narnia}} lives in the ''Narnia'' series.
|| {{w|Dedham Vale}}
||
|-
| Camelot
|| {{w|Camelot}} was (in legend) {{w|King Arthur}}'s court.
|| Near the England-Wales border
|| The King Arthur myth did in fact originate in the Welsh culture. However, most sites associated with Camelot, such as {{w|Winchester}}, {{w|Glastonbury}} and {{w|Cadbury Castle}}, are in England.
|-
| Nothingham
|| A pun on {{w|Nottingham}}, famous for {{w|Sherwood Forest}}, the legendary home of {{w|Robin Hood}}.
|| Near {{w|Northampton}}
||
|-
| Cumberbatch
|| A surname, best known as that of actor {{w|Benedict Cumberbatch}}.
|| {{w|Harlow}}
|| The surname of a famous actress is replaced with that of a famous actor
|-
| Dampshire
|| A pun on the county of {{w|Hampshire}}. Generically a joking reference to any county, particularly of the {{w|West Country}}, to imply it is particularly prone to rain.
|| Gloucestershire
||
|-
| The CW
|| {{w|The CW|An American TV channel}}.
|| {{w|Pembrokeshire}}
|| Presumably the placement is a reference to Welsh words such as "cwm" which use W as a vowel.
|-
| Whaling
|| The practice of hunting whales. May be a reference to other -ing towns like {{w|Reading, Berkshire|Reading}} (which is actually pronounced "redding", not "reeding"), and also to its location in Wales.
|| {{w|Merthyr Tydfil}}
||
|-
| Paulblart
|| ''{{w|Paul Blart: Mall Cop}}'' is a 2009 comedy film starring Kevin James
|| Near {{w|Chelmsford}}
||
|-
| Oxford
|| {{w|Oxford|No joke}}
|| {{w|Oxford}}
|| See Cambridge. Surprisingly, Randall made no attempt to troll readers by switching the locations of Cambridge and Oxford.
|-
| Moorhen
|| The {{w|moorhen}} is a waterfowl.
|| {{w|Gower Peninsula}}
|| Possibly punning on nearby {{w|Swansea}}.
|-
| Cardigan
|| {{w|Cardigan, Ceredigion|No joke}} - it seems funny to Americans because of the {{w|Cardigan (sweater)|knitted sweater}} popularised by the {{w|James Brudenell, 7th Earl of Cardigan|Earl of Cardigan}}
|| {{w|Newport, Wales}}
|| The actual Cardigan is on the west coast. The name may be punning on the city of {{w|Cardiff}}, capital of Wales, which is further south-west.
|-
| BBC Channel 4
|| A composite of {{w|Channel 4}} and the {{w|BBC}} (UK TV operators) confusing the meaning of TV channel with a geographic channel.
|| {{w|Bristol Channel}}
||
|-
| London
|| {{w|London|No joke}}.
|| London
||
|-
| GMT
|| A reference to {{w|Greenwich Mean Time}}. Shown on the map near the London bourough of Greenwich through which the GMT meridian passes.
|| {{w|Greenwich}} (roughly)
||
|-
| Corbyn
|| A reference to leader of the UK {{w|Labour Party (UK)|Labour Party}} {{w|Jeremy Corbyn}}.
|| {{w|The Cotswolds}}
|| May be a confusion with the town of {{w|Corby}} although it is not near the location shown.
|-
| Tems-upon-Thames
|| A joke about the counter-intuitive pronunciation of {{w|Thames}}.
|| {{w|Rochester}}
||
|-
| Minas Tirith
|| {{w|Minas Tirith}} is the capital of Gondor in ''Lord of the Rings'' and is built on the side of a mountain.
|| {{w|Bristol}}
|| Clifton Village, in Bristol, is built on the side of the Avon Gorge so could be compared to {{w|Minas Tirith}}. Nearby {{w|Cheddar Gorge}} is famous for its steep cliffs that resemble the landscape from Lord of the Rings.
|-
| Hogsmeade
|| {{w|Hogsmeade}} is the nearest village to Hogwarts in the ''Harry Potter'' books.
|| {{w|Dover}}
|| The fictional Hogsmeade was in Scotland. Randall shows the {{w|Channel Tunnel}} running from there, a possible reference to Hogsmeade's secret connections to Hogwarts.
|-
| Tubemap
|| The {{w|Tube Map}} is the map of the {{w|London Underground}}, widely considered a masterpiece of design.
|| {{w|Outer London}}
||
|-
| Cambnewton
|| {{w|Cam Newton}} is quarterback for the {{w|Carolina Panthers}}. "Cam-" is common for placenames on any of the several British rivers called "{{w|Cam River|Cam}}", while "Newton" means "new town". Also possibly a pun on Camden Town, a touristic district in North London, although not its actual location on the map.
|| {{w|West Country}}
||
|-
| Efrafa
|| Efrafa is a rabbit warren in the story ''{{w|Watership Down}}''.
|| {{w|Chidden}}
|| According to the story, the warren is located roughly here - the real {{w|Watership Down, Hampshire|Watership Down}} is in Hampshire.
|-
| Chansey
|| {{w|Chansey|Another Pokémon}}. "-sey" is a common suffix meaning "island".
|| {{w|Dungeness (headland|Dungeness}}
||
|-
| Oughghough
|| Playing on common place name elements, "oughghough" has no clear pronunciation under the rules of English. It could be "Uff-guff", "Oo-gow", "Uh-guh" or any combination of these sounds. The name looks similar to the real {{w|Loughborough}} ("Luff-bruh")
|| {{w|Barnstaple}}
|| Legend has it that Loughborough was once pronounced 'Loogabarooga' by a visiting Australian.
|-
| Sundial
|| A {{w|sundial}} is a clock using a shadow to tell the time.
|| {{w|Wiltshire}}
|| The location roughly corresponds with {{w|Stonehenge}}, an ancient stone circle that was likely used to track the sun (though as a ritual calendar, rather than a clock)
|-
| Dobby
|| {{w|Magical_creatures_in_Harry_Potter#Dobby|Dobby}} is a character in {{w|Harry Potter}}.
|| {{w|Southampton}}
|| Similar to {{w|Derby}}.
|-
| Lower Bottom
|| Another -bottom. Also a redundancy, as the "bottom" is the lowest place by definition.
|| {{w|Devon}}
||
|-
| Southframpton
|| A confusion with {{w|Southampton}} which is nearby the location shown. The use of the postfix "frampton" may be a reference to the "Frampton" elsewhere on the map.
|| {{w|Milford on Sea}}
|| Frampton happens to be a common surname in the area.
|-
| Blandford
|| {{w|Blandford|No joke}}
|| {{w|Cornwall}}
|| The real Blandford is a bit further east, in Dorset, roughly under the m in 'Southframpton'.
|-
| Menthol
|| {{w|Menthol}} is a chemical with minty taste that produces a cooling sensation, and is used in mints and flavoured cigarettes.
|| {{w|Eastbourne}}
||
|-
| West Sea
|| Literal description.
|| {{w|Atlantic Ocean}}
|| Historically, this was the name for the ocean off the UK's west coast. According to the {{w|Shipping Forecast#Region names|list of sea areas}} used in the UK's {{w|Shipping Forecast}}, that region of sea is called "Lundy"
|-
| Tarp
|| Tarp, short for {{w|tarpaulin}}, is a waterproof sheet for storage and weather protection.
|| {{w|Teignmouth}}
||
|-
| Longbit
|| Literal description.
|| {{w|Cornwall}}
||
|}

==Transcript==
{{incomplete|There NEEDS to be a better way to do this.}}

: [A black-and-white map of Great Britain. The detail on the map is minimal, showing mainly the outlines of the land, upward-pointing angles representing mountains, and points representing cities. The only other features are a small drawing of a protractor south of one peninsula, and a lake with two small sailboats on the west side of the largest landmass. The caption in the upper-right states in large letters "A BRITISH MAP," then in smaller letters underneath, "LABELED BY AN AMERICAN." Most of the map's area is covered by labels for various features. The labels and their pixel coordinates are listed in the table below.]

{| border =1 width=100% cellpadding=5 class="wikitable sortable"
|-
! X !! Y !! Label
|-
| 258 || 32 || Helcaraxë
|-
| 244 || 55 || Blick
|-
| 294 || 80 || Everdeen
|-
| 34 || 89 || Norther Sea
|-
| 238 || 119 || Highlands
|-
| 144 || 151 || Loch Lomond
|-
| 83 || 172 || Fjordham
|-
| 440 || 184 || A British Map Labeled by an American
|-
| 164 || 192 || Glassdoor
|-
| 250 || 219 || Eavestroughs
|-
| 312 || 237 || Seasedge
|-
| 260 || 262 || Chough
|-
| 148 || 267 || Meowth
|-
| 76 || 298 || (A picture of an upsidedown protractor)
|-
| 256 || 303 || Blighton
|-
| 344 || 309 || Eyemouth
|-
| 124 || 320 || Glutenfree
|-
| 486 || 320 || North Sea
|-
| 254 || 329 || Earhand
|-
| 353 || 347 || Hairskull
|-
| 38 || 362 || Belfast DeVoe
|-
| 224 || 365 || Lakebottom
|-
| 411 || 389 || Braintree
|-
| 335 || 408 || Skinflower
|-
| 430 || 431 || Bjork
|-
| 279 || 432 || Weedle
|-
| 440 || 451 || Eeugh
|-
| 258 || 453 || Crewneck
|-
| 310 || 454 || Paisley
|-
| 414 || 473 || Basil
|-
| 259 || 479 || Aidenn
|-
| 461 || 496 || Waterdown
|-
| 288 || 499 || Hillfolk
|-
| 31 || 509 || Dubstep
|-
| 464 || 517 || Borough-Upon-Mappe
|-
| 269 || 535 || Fhqwhgads
|-
| 490 || 537 || Landmouth
|-
| 461 || 539 || Cadbury
|-
| 237 || 554 || Cabinetry
|-
| 360 || 355 || The Shire
|-
| 464 || 562 || Brandon
|-
| 567 || 567 || Hamwich
|-
| 356 || 577 || West Norsussex
|-
| 420 || 578 || Redsox
|-
| 502 || 590 || Keebler
|-
| 372 || 597 || Lionsgate
|-
| 229 || 597 || Bloughshire
|-
| 573 || 609 || Kingsbottom
|-
| 182 || 613 || Aberforth
|-
| 328 || 615 || South Norwessex
|-
| 244 || 617 || Dryford
|-
| 495 || 630 || Frampton
|-
| 477 || 634 || Cambridge
|-
| 251 || 635 || Kingsfriend
|-
| 539 || 652 || Cair Paravel
|-
| 235 || 655 || Camelot
|-
| 408 || 655 || Nothingham
|-
| 429 || 673 || Cumberbatch
|-
| 121 || 673 || The CW
|-
| 303 || 674 || Dampshire
|-
| 210 || 676 || Whaling
|-
| 511 || 690 || Paulblart
|-
| 397 || 693 || Oxford
|-
| 169 || 695 || Moohren
|-
| 255 || 706 || Cardigan
|-
| 462 || 710 || GMT
|-
| 445 || 711 || London
|-
| 308 || 716 || Corbyn
|-
| 507 || 729 || Tems-Upon-Thames
|-
| 161 || 737 || BBC Channel 4
|-
| 267 || 737 || Minas Tirith
|-
| 560 || 746 || Hogsmeade
|-
| 454 || 748 || Tubemap
|-
| 296 || 756 || Cambnewton
|-
| 398 || 765 || Efrafa
|-
| 186 || 767 || Oughghough
|-
| 536 || 767 || Chansey
|-
| 351 || 777 || Sundial
|-
| 370 || 782 || Dobby
|-
| 162 || 784 || Lower Bottom
|-
| 496 || 784 || Menthol
|-
| 362 || 796 || Southframpton
|-
| 56 || 800 || West Sea
|-
| 154 || 804 || Blandford
|-
| 216 || 824 || Tarp
|-
| 123 || 846 || Longbit
|}


{{comic discussion}}

291: Dignified

2016-10-21T14:48:58Z

108.162.219.80: /* Explanation */

{{comic
| number = 291
| date = July 18, 2007
| title = Dignified
| image = dignified.png
| titletext = 'I don't know, why is your beret staying on your head?' 'Staples.'
}}

==Explanation==
[[Beret Guy]] is hanging upside down a tree, usually something you might have done in your a childhood. As an adult it is not very dignified. [[White Hat]] probably made a comment on this and the fact that Beret Guy has his head down. But then Beret Guy gives him an answer, regarding where White Hat's head once came through, and asks him why he is still acting so {{w|dignified}}.

Here, Beret Guy is referring to the process of {{w|childbirth}}. Put in the way he mentions said process, the fact that White Hat came into this world in such a fashion would be very humiliating.

In the title text White Hat replies that he does not know, but then continues to ask why Beret Guy's beret stays on his head, even when upside down (in which gravity would tend to make a beret fall off{{Citation needed}}). Beret Guy explains that he has stapled the beret onto his head.

Such a process is similar to that of closing a wound after major head surgery, using {{w|surgical staples}}. Normally, the stapling of the head would be conducted with anesthetic and removed after the incision has healed, and only an insane person would do this to himself.

Beret Guy is never seen without his hat (although it has been hidden under a green helmet once in [[769: War]]). And later in [[478: The Staple Madness]] it turns out that he likes to staple anything to everything, so maybe also his hat to his head. The staple madness comic may very well be a sequel to this comic.

In the teaser trailer of Indiana Jones And The Last Crusade, Indy [http://youtu.be/DZNlwJV5RRo?t=32s staples a hat to his head] (or at least pretends to) to prevent it from blowing off, a similar situation to the one Beret Guy is in here.

==Transcript==
:[Beret Guy swinging upside-down from tree branch talking to White Hat walking by.]
:Beret Guy: You were once shoved headfirst through someone's vagina. Why are you acting so dignified?

{{comic discussion}}
[[Category:Comics featuring Beret Guy]]
[[Category:Comics featuring White Hat]]

1733: Solar Spectrum

2016-09-15T13:22:36Z

108.162.219.80:

{{comic
| number = 1733
| date = September 15, 2016
| title = Solar Spectrum
| image = solar_spectrum.png
| titletext = I still don't understand why the Sun paid the extra money for Transitions lenses.
}}

==Explanation==
{{incomplete|Examples of such advertisements needed}}
This is a reference to pictures / clipart of the sun wearing sunglasses, often used to denote good weather. The title text is most likely a reference to a specific advert using this image.

Transitions are a type of coating used prescription spectacles that allow the lens to turn dark when exposed to UV light such as that found in sunlight. The sun choosing to get transition lens would prove a waste of money as the lenses would be permanently transitioned to be dark, so a pair of ordinary sunglasses would likely have proved more cost effective.

==Transcript==
{{incomplete transcript}}
[A graph, showing the sun's spectral lines. The graph is a typical spectral lines chart, with a long rainbow band (from purple on the left to red on the right) with black lines in it, indicating the traces of different elements.]

[The labels match these lines from left to right:]

*Calcium
*Calcium
*Hydrogen
*Calcium
*Iron
*Hydrogen
*Iron
*Iron
*Unlabeled
*Hydrogen
*Iron
*Unlabeled
*Magnesium
*Magnesium
*Iron
*Unlabeled
*Unlabeled
*Unlabeled
*Those giant sunglasses
*Sodium
*Sodium
*Oxygen
*Those giant sunglasses
*Those giant sunglasses
*Unlabeled
*Those giant sunglasses
*Oxygen
*Those giant sunglasses

{{comic discussion}}

1733: Solar Spectrum

2016-09-15T13:21:55Z

108.162.219.80:

{{comic
| number = 1733
| date = September 15, 2016
| title = Solar Spectrum
| image = solar_spectrum.png
| titletext = I still don't understand why the Sun paid the extra money for Transitions lenses.
}}

==Explanation==
{{incomplete|Examples of such advertisements needed}}
This is a reference to pictures / clipart of the sun wearing sunglasses, often used to denote good weather. The title text is most likely a reference to a specific advert using this image. Transition glasses darken when exposed to UV light, such as when you walk outdoors. When you are no longer exposed to the effects of UV, (i.e. walk indoors), the lenses return to their clear state. As a source of UV light, the Sun would have been wise to just buy sunglasses.

Transitions are a type of coating used prescription spectacles that allow the lens to turn dark when exposed to UV light such as that found in sunlight. The sun choosing to get transition lens would prove a waste of money as the lenses would be permanently transitioned to be dark, so a pair of ordinary sunglasses would likely have proved more cost effective.

==Transcript==
{{incomplete transcript}}
[A graph, showing the sun's spectral lines. The graph is a typical spectral lines chart, with a long rainbow band (from purple on the left to red on the right) with black lines in it, indicating the traces of different elements.]

[The labels match these lines from left to right:]

*Calcium
*Calcium
*Hydrogen
*Calcium
*Iron
*Hydrogen
*Iron
*Iron
*Unlabeled
*Hydrogen
*Iron
*Unlabeled
*Magnesium
*Magnesium
*Iron
*Unlabeled
*Unlabeled
*Unlabeled
*Those giant sunglasses
*Sodium
*Sodium
*Oxygen
*Those giant sunglasses
*Those giant sunglasses
*Unlabeled
*Those giant sunglasses
*Oxygen
*Those giant sunglasses

{{comic discussion}}

1721: Business Idea

2016-08-17T15:05:38Z

108.162.219.80: /* Explanation */ As far as I can tell, the page now shows the correct image, so I removed the warning.

{{comic
| number = 1721
| date = August 17, 2016
| title = Business Idea
| image = business_idea2.png
| titletext = Then we move to phase two. Gas stations store fuel in underground tanks. Normally, these are inaccessible except via the pump. However, with hydraulic fracturing, we-- Wait! Come back!
}}

==Explanation==
{{incomplete|May require further editing to meet wiki standards}}
In this comic, Cueball announces he has "an exciting business opportunity to share". After hearing discouragement from an off-panel voice, he promises that "this time it's a good one", and goes on to explain his plan.

Cueball's plan involves the premise that a small amount of premium gas is left in a fuel pump hose after a car driver fills their car up with premium. He states that even if the next customer only pays for regular, that they are still getting a small amount of the premium. Though he does not finish saying the outline for his plan, one can assume he planned to get premium fuel at regular prices, so he could then sell it for profit. After hearing the first part of his plan, two off-panel voices announce they are leaving, clearly and correctly thinking that Cueball's idea is stupid and impractical.

In reality, this would be an impossible business venture to execute. While in the United States often the same hose is used for the various octane fuels, the amount of fuel contained in the hose is relatively small (about [http://www.wsj.com/articles/SB122944043385810527 a third of a gallon], or [http://www.metronews.ca/drive/2012/05/08/one-pump-three-grades-how-does-it-know.html half a liter])compared to the amount that is generally purchased, though [http://www.wsj.com/articles/SB122944043385810527 for motorcycles the ratio is more significant]. It is also illegal to resell fuel without the correct licences [citation needed], and it would be difficult, bordering on impossible, to have the fuel pump run to ''just'' the premium fuel out, and driving to each gas station would use more money to buy more fuel than any money that could be made back. This is not to mention trying to keep track of when someone purchased premium so as to be the next person to use that pump to extract those precious drops.

Comic [[1499]] implies similar plan to extract wealth out of a small market inefficiency that, in reality, would be far too onerous to exploit.

The title text is another one of Cueball's fuel-based business ventures, as he says he plans to dig up fuel stations underground fuel storage tanks, to then sell the contents of. Again, illegal/theft, impractical, don't try it (though it would be much more profitable than his previous plan). The punchline is that a gas station's underground tank is "inaccessible" from the outside, just as there are some oil deposits that are inaccessible to traditional oil production techniques because no sufficient natural flow towards a well can be obtained. In the case of oil deposits, high-pressure fluids are pumped into the rock to break it up ("fracturing") and allow the oil to reach the well. Oil tanks, on the other hand, can be made accessible by puncturing them using (presumably) hydraulically powered tools (electrical power is inadvisable in the presence of high-vapor-pressure hydrocarbons due to the significant risk of fire and explosion caused by electrical sparking).

==Transcript==
:[Cueball is standing next to a rolled down projector screen holding a hand up towards his off-panel audience, one from the audience speaks. It's is impossible to say if there are more than two persons off-panel, but it's also impossible to say if a person who speaks in one panel also speaks in one of the next, hence the numbering.]
:Cueball: Thank you all for coming.
:Cueball: I have an exciting business opportunity to share.
:Off-panel voice #1: Oh no.

:[Zoom in on Cueball's head. An off-panel person speaks twice.]
:Cueball: Now hear me out-
:Off-panel voice #2: Your ideas are always the worst.
:Cueball: No, no, this time it's a good one! I promise.
:Off-panel voice #2: Uh huh...

:[Front view of the screen with an image of a black gas pump, with the white hose snaking it's way up to the black handle. And arrow points to the middle of the hose where it is at it's highest point before the turn that goes to the handle. Cueball is pointing at the hose with a stick. Two different off-panel persons speaks to him.]
:Cueball: When someone fills their car with premium gas, some of it is left in the hose, and is dispensed to the next customer even if they've only paid for regular. If we create a network of-
:Off-panel voice #3: I'm leaving.
:Off-panel voice #4: Me too.

==Trivia==
*Because this comic had the same title (and filename) as comic [[827: Business Idea]], Randall inadvertently broke both xkcd.com and explainxkcd.com when it went up.
**The main xkcd.com site showed this comic for both numbers, while explainxkcd.com showed 827 for both. **As of 11:35am UTC Randall has fixed this by renaming the old comic to [[827: My Business Idea]], which has now been implemented also here on xkcd.
**On this page it will take a while before the new image is shown correctly, even though the error has been fixed.
*This is the third time Randall releases a comic with a [[:Category:Comics sharing name|name exactly the same]] as a previous comic.
**But for some reason this time it gave problems to the xkcd site, which did not occur the last two times.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics sharing name|Business Idea2]]

1709: Inflection

2016-07-20T15:00:04Z

108.162.219.80: /* Explanation */

{{comic
| number = 1709
| date = July 20, 2016
| title = Inflection
| image = inflection.png
| titletext = "Or maybe, because we're suddenly having so many conversations through written text, we'll start relying MORE on altered spelling to indicate meaning!" "Wat."
}}

==Explanation==
Pictographic languages are written using graphics in place of words, so are not usually suitable for "spelling" changes to show slight variance in meanings. Examples of pictographic languages include ancient Egyptian, Chinese (ancient and modern), and Japanese Kanji (which uses Chinese characters).

Early modern English (think Shakespeare or the KJV Bible) used more forms for the tenses than we do today, which can help illustrate the trend away from inflected forms. In contrast, verbs in English today are often conjugated with auxiliary verbs. Here a sample of a modern verb conjugation in English:

{| class="wikitable"
|+ Verb: Walk
!Voice->
!colspan="2"|Active
!colspan="2"|Passive
|-
!Tense
!Singular (He/She/It)
!Plural (They)
!Singular (He/She/It)
!Plural (They)
|-
|Present
|walks
|walk
|is walked
|is walked
|-
|Present Progressive
|is walking
|are walking
|is being walked
|are being walked
|-
|Past
|walked
|walked
|was walked
|was walked
|-
|Past Perfect
|had walked
|had walked
|had been walked
|had been walked
|-
|Past Perfect Progressive
|had been walking
|had been walking
|had been being walked
|had been being walked
|-
|Future
|will walk
|will walk
|will be walked
|will be walked
|-
|Future Perfect
|will have walked
|will have walked
|will have been walked
|will have been walked
|-
|Future Perfect Progressive
|will have been walking
|will have been walking
|will have been being walked
|will have been being walked
|}

==Transcript==
:[Megan and Cueball are walking together.]
:Megan: Inflected languages change words to add meaning, like "-s" for plurals or "-ed" for past tense. Alphabets—where symbols stand for sound instead of words—work well for them, since you can show the changes through spelling.

:Megan: Our language family is inflected, but the English branch has lost most of its inflection over the millennia. It's why we don't have all those Latin conjugations.

:Cueball: Could that mean English writing is ripe to become more pictographic?
:Megan: 👍 [Thumbs Up Sign] 👏 [Clapping Hands Sign] 😄 [Smiling Face With Open Mouth and Smiling Eyes]

{{comic discussion}}

[[Category:Comics with color]]
[[Category:Language]]

1132: Frequentists vs. Bayesians

2016-06-24T17:42:08Z

108.162.219.80:

{{comic
| number = 1132
| date = November 9, 2012
| title = Frequentists vs. Bayesians
| image = frequentists_vs_bayesians.png
| titletext = 'Detector! What would the Bayesian statistician say if I asked him whether the--' [roll] 'I AM A NEUTRINO DETECTOR, NOT A LABYRINTH GUARD. SERIOUSLY, DID YOUR BRAIN FALL OUT?' [roll] '... yes.'}}

==Explanation==
This comic is a joke about jumping to conclusions based on a simplistic understanding of probability. The "{{w|base rate fallacy}}" is a mistake where an unlikely explanation is dismissed, even though the alternative is even less likely. In the comic, a device tests for the (highly unlikely) event that the sun has exploded. A degree of random error is introduced, by rolling two {{w|dice}} and lying if the result is double sixes. Double sixes are unlikely (1 in 36, or about 3% likely), so the statistician on the left dismisses it. The statistician on the right has (we assume) correctly reasoned that the sun exploding is ''far more'' unlikely, and so is willing to stake money on his interpretation.

The labels given to the two statisticians, in their panels and in the comic's title, are not particularly fair or accurate, a fact which [[Randall]] has acknowledged:<ref name="munroe-on-gelman">[http://web.archive.org/web/20130117080920/http://andrewgelman.com/2012/11/16808/#comment-109366 Comment by Randall Munroe] to "I don’t like this cartoon", blog post by Andrew Gelman in ''Statistical Modeling, Causal Inference, and Social Science''. Archived Jan 17 2013 by the Wayback Machine.</ref>
<blockquote>I seem to have stepped on a hornet’s nest, though, by adding “Frequentist” and “Bayesian” titles to the panels. This came as a surprise to me, in part because I actually added them as an afterthought, along with the final punchline. … The truth is, I genuinely didn’t realize Frequentists and Bayesians were actual camps of people—all of whom are now emailing me. I thought they were loosely-applied labels—perhaps just labels appropriated by the books I had happened to read recently—for the standard textbook approach we learned in science class versus an approach which more carefully incorporates the ideas of prior probabilities.</blockquote>

The "frequentist" statistician is (mis)applying the common standard of "{{w|P-value|p}}<0.05". In a scientific study, a result is presumed to provide strong evidence if there is less than a 5% chance that the result was merely random. (More formally, this probability is defined in terms of the {{w|null hypothesis}}, or a default position that the observations are unrelated. The null hypothesis was also referenced in [[892: Null Hypothesis]].)

Since the likelihood of rolling double sixes is below this 5% threshold, the "frequentist" decides (by this rule of thumb) to accept the detector's output as correct. The "Bayesian" statistician has, instead, applied at least a small measure of probabilistic reasoning ({{w|Bayesian inference}}) to determine that the unlikeliness of the detector lying is greatly outweighed by the unlikeliness of the sun exploding. Therefore, he concludes that the sun has ''not'' exploded and the detector is lying.

The line, "Bet you $50 it hasn't", is a reference to the approach of a leading bayesian scholar, {{w|Bruno de Finetti}}, who made extensive use of bets in his examples and thought experiments. See {{w|Coherence (philosophical gambling strategy)}} for more information on his work. In this case, however, the bet is also a joke because we would all be dead if the sun exploded. If the Bayesian wins the bet, he gets money, and if he loses, they'll both be dead before money can be paid. This underlines the absurdity of the premise and emphasizes the need to consider context when examining probability.

The title text refers to a classic series of logic puzzles known as {{w|Knights and Knaves#Fork in the road|Knights and Knaves}}, where there are two guards in front of two exit doors, one of which is real and the other leads to death. One guard is a liar and the other tells the truth. The visitor doesn't know which is which, and is allowed to ask one question to one guard. The solution is to ask either guard what the other one would say is the real exit, then choose the opposite. Two such guards were featured in the 1986 Jim Henson movie ''[[246|Labyrinth]]'', hence the mention of "A LABYRINTH GUARD" here.

===Mathematical and scientific details===
As mentioned, this is an instance of the {{w|base rate fallacy}}. If we treat the "truth or lie" setup as simply modelling an inaccurate test, then it is also specifically an illustration of the {{w|false positive paradox}}: A test that is rarely wrong, but which tests for an event that is even rarer, will be more often wrong than right when it says that the event has occurred.

The test in this case is a neutrino detector. It relies on the fact that neutrinos can pass through the earth, so a neutrino detector would detect neutrinos from the sun at all times, day and night. The detector is stated to give false results ("lie") 1/36th of the time.

There is no record of any star ever spontaneously exploding—they always show signs of deterioration long before their explosion—so the probability is near zero. For the sake of a number, though, consider that the sun's estimated lifespan is 10 billion years. Let's say the test is run every hour, twelve hours a day (at night time). This gives us a probability of the Sun exploding at one in 4.38×1013. Assuming this detector is otherwise reliable, when the detector reports a solar explosion, there are two possibilities:
# The sun '''has''' exploded (one in 4.38×1013) and the detector '''is''' telling the truth (35 in 36). This event has a total probability of about 1/(4.38×1013) × 35/36 or about one in 4.50×1013.
# The sun '''hasn't''' exploded (4.38×1013 − 1 in 4.38×1013) and the detector '''is not''' telling the truth (1 in 36). This event has a total probability of about (4.38×1013 − 1) / 4.38×1013 × 1/36 or about one in 36.

Clearly the sun exploding is not the most likely option.

===Presidential election predictions===
[[File:Nate Silver Tweet.png|.@JoeNBC: If you think it's a toss-up, let's bet. If Obama wins, you donate $1,000 to the American Red Cross. If Romney wins, I do. Deal?|right]]

This comic may be about the accuracy of presidential election predictions that used statistical models, such as Nate Silver's ''538'' and Professor Sam Wang's ''PEC''. The bet may refer to a well-publicized bet that Nate Silver tried to make with Joe Scarborough regarding the outcome of the election (see tweet on the right).

==Trivia==
* The Sun will never explode as a supernova, because it does not have enough mass.
*In the same blog comment as cited above<ref name="munroe-on-gelman"/>, Randall explains that he chose the "sun exploding" scenario as a more clearly absurd example than those usually used:
<blockquote>…I realized that in the common examples used to illustrate this sort of error, like the cancer screening/drug test false positive ones, the correct result is surprising or unintuitive. So I came up with the sun-explosion example, to illustrate a case where naïve application of that significance test can give a result that’s obviously nonsense.</blockquote>
*"Bayesian" statistics is named for Thomas Bayes, who studied conditional probability — the likelihood that one event is true when given information about some other related event. From {{w|Bayes Theorem|Wikipedia}}: "Bayesian interpretation expresses how a subjective degree of belief should rationally change to account for evidence".
* The "frequentist" says that 1/36 = 0.027. It's actually 0.02777…, which should round to 0.028.
* Using neutrino detectors to get an advance warning of a supernova is possible, and the {{w|Supernova Early Warning System}} does just this. The neutrinos arrive ahead of the photons, because they can escape from the core of the star before the supernova explosion reaches the mantle.

==Transcript==
:Did the sun just explode? (It's night, so we're not sure)

:[Two statisticians stand alongside an adorable little computer that is suspiciously similar to K-9 that speaks in Westminster typeface.]
:Frequentist Statistician: This neutrino detector measures whether the sun has gone nova.
:Bayesian Statistician: Then, it rolls two dice. If they both come up as six, it lies to us. Otherwise, it tells the truth.
:Frequentist Statistician: Let's try. [to the detector] Detector! Has the sun gone nova?
:Detector: ''roll'' YES.

:Frequentist Statistician:
:Frequentist Statistician: The probability of this result happening by chance is 1/36=0.027. Since p<0.05, I conclude that the sun has exploded.

:Bayesian Statistician:
:Bayesian Statistician: Bet you $50 it hasn't.

==References==
<references/>

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Multiple Cueballs]]
[[Category:Math]]
[[Category:Statistics]]
[[Category:Physics]]

Talk:1693: Oxidation

2016-06-14T12:55:43Z

108.162.219.80: added comment to Worm reference

The white balance is off in this comic. [[User:Mikemk|Mikemk]] ([[User talk:Mikemk|talk]]) 04:39, 13 June 2016 (UTC)
:Where? I checked it in gimp and the white balance is fine. In fact, the .png file for this comic uses the greyscale colour mode.[[Special:Contributions/141.101.98.130|141.101.98.130]] 09:57, 13 June 2016 (UTC)
:Reference to [http://www.explainxkcd.com/wiki/index.php/1014:_Car_Problems 1014: Car Problems] [[Special:Contributions/141.101.98.132|141.101.98.132]] 18:47, 13 June 2016 (UTC)
Maybe Randall drew this one on paper, which had already started oxidizing before it was scanned. ;D
[[Special:Contributions/108.162.216.91|108.162.216.91]] 08:36, 13 June 2016 (UTC)

I thought the arthropods mentioned were meant to be a reference to pubic lice (crabs). [[Special:Contributions/141.101.104.42|141.101.104.42]] 06:11, 13 June 2016 (UTC)

Okay, who else had immediately thought of Skitter? [[Special:Contributions/172.68.11.43|172.68.11.43]] 09:52, 13 June 2016 (UTC)
\ I can't say that I did, but I like this reference. [[Special:Contributions/108.162.219.80|108.162.219.80]] 12:55, 14 June 2016 (UTC)

There's no reason to think the Title Text is from Megan to Pony tail. It could just as easily be the other way around. [[Special:Contributions/173.245.54.47|173.245.54.47]] 12:30, 13 June 2016 (UTC)

Could this be a prequel to [http://www.explainxkcd.com/wiki/index.php/1014:_Car_Problems 1014: Car Problems]? [[User:Luc|Luc]] ([[User talk:Luc|talk]]) 15:33, 13 June 2016 (UTC)

Possibly inspired by What If #97? Randall talks about oxidation and mentions car rusting vs. car combustion. [[User:Meareaperson|Meareaperson]] ([[User talk:Meareaperson|talk]]) 18:05, 13 June 2016 (UTC)

Possibly the title text is a reference to the theory, that higher concentration of oxygen (this comic being about oxidation, which obviously requires oxygen) in the air would result in larger insects? [http://www.livescience.com/1083-oxygen-giant-bugs.html] [http://blogs.discovermagazine.com/notrocketscience/2012/06/04/giant-insects-disappeared-thanks-to-falling-oxygen-levels-and-agile-birds/] [http://news.nationalgeographic.com/news/2011/08/110808-ancient-insects-bugs-giants-oxygen-animals-science/] [[Special:Contributions/172.68.11.49|172.68.11.49]] 11:14, 14 June 2016 (UTC)

Talk:1680: Black Hole

2016-05-13T07:50:49Z

108.162.219.80:

IF the explanation of "Milkshake" being a coded message is correct, then I like how Melis plays with it. I always thought the more sexual way, Milkshake meaning shaking her milk bags. Sure, that brings boys to the yard.... [[Special:Contributions/141.101.104.151|141.101.104.151]]

It's not clear what exactly in the comic is a reference to the Big Lebowski movie. This needs clarification. [[User:Todor|Todor]] ([[User talk:Todor|talk]]) 06:48, 13 May 2016 (UTC)

In the Big Lebowski, The Dude's reasoning for wanting the rug replaced was that "It really tied the room together" [[Special:Contributions/108.162.219.80|108.162.219.80]] 07:50, 13 May 2016 (UTC)

Talk:1680: Black Hole

2016-05-13T07:49:43Z

108.162.219.80:

1659: Tire Swing

2016-03-23T13:32:02Z

108.162.219.80: /* Explanation */

{{comic
| number = 1659
| date = March 23, 2016
| title = Tire Swing
| image = tire_swing.png
| titletext = If we find one of those tire dumps, the next time he tries to get his truck back we can just retreat and let him have it.
}}

==Explanation==
When the two girls discuss the problem of properly disposing of old tires, the reader is led to infer that the girls have made their tire swing from one such old tire, taken from a dump.

However, the girls have actually taken this tire from someone's vehicle, and "that guy" was "real mad" that they did so.

==Transcript==
{{incomplete transcript}}

{{comic discussion}}

[[Category:Comics featuring Megan]]
[[Category:Comics featuring Hair Bun Girl]]