Campfire Habitable Zone

Explanation:
This comic plays on the concept of the astronomic "habitable zone" applied at the scale of people sitting around a campfire.
The habitable zone of a star is the range of distances in which a planet might support liquid water, and hence life in the only form that we currently know of (as an allusion to the "not too hot, not too cold, but just right " of the related children's story , the habitable zone is also commonly known as the "Goldilocks zone"). If the planet is too close to the star, then the amount of stellar radiation would be too great, causing the water to boil; too far from the star, and the planet doesn't have enough radiation, causing the water to freeze (although for life to actually exist, the planet itself must also have the right mass in order to maintain a life-compatible atmosphere and meet other such requirements). For our Sun, the habitable zone is estimated to range from about 0.38 to 10 astronomical units, where 1 astronomical unit is the distance from the Sun to the Earth.
Marshmallow toasting is a popular camping activity in which people place a marshmallow (a soft, sugary blob made of gelatin and covered in corn starch) on a stick and over/near a fire. As the marshmallow cooks, the inside becomes gooey while the outside becomes crispy (perhaps slightly charred and maybe even burned, depending on the toaster's preference), making it tastier via caramelization and the Maillard reaction .
In the context of the campfire, a similar "habitable zone" is posited by Randall to exist: a zone which is close enough to the fire such that the person can comfortably toast marshmallows, presumably on a stick of reasonable length (the ones in the comic seem to be about 1.5 times an arm's normal reach), yet far enough such that the person is not uncomfortably hot or even burned by either direct contact with the flames or by exposure to the radiant heat of the fire.
To demonstrate this hypothesis (with the habitable zones marked in green), Cueball is shown sitting outside the right habitable zone on the side of the fire. Even though he is able to toast his marshmallows on the fire due to his being close to it, he will have and is having part of his body scorched, as he is too close (fires can get really hot ). Megan, also on the right, is well outside the habitable zone on the side away from the fire. Although not burned, the marshmallow on the stick she is waving will presumably not toast due to its being too far from the campfire. Ponytail, on the other hand, has found and is enjoying the medium between the plights of both Cueball and Megan by sitting entirely within her (the left) habitable zone, thereby both being close enough to the fire to be able to toast her marshmallows while also staying far enough away such that she will not be burned.
The title text introduces the concept of tidal locking , in which one astronomical body synchronizes its rotation with its orbit around another such that one side always faces the other body (e.g. the case of Earth's moon, which always presents the same face to the Earth). The joke here is that if a marshmallow became tidally locked to the fire, then one side would become more and more cooked, perhaps burnt, while the other side never became toasted at all. This also may allude to the instance in which a marshmallow has begun melting more than you realized and dripped down so far that it no longer responds to your rotation of the roasting stick (the solution to which is to cut your losses and pull the marshmallow out immediately, before it drops into the fire pit).
[A campfire is in the middle of the panel in a white area with two areas shaded green to the left and right of the fire. There are also two white areas outside of these green areas. Ponytail is sitting normally on the ground to the left of the fire, with her body fully inside the left green area. She is facing the fire and is holding a stick in both hands. The stick has a marshmallow on the tip and she is holding it over the top of the flames of the fire. Cueball is sitting to the right near the fire, only half inside the green are. He is sitting sideways leaning away from the fire, holding one hand to his head, while his other hand seems to be ready to support him as he is leaning further away from the fire. The arm closest to the fire and his head seems to be very hot as three small smoke-like lines rises from Cueball. Megan is crouching to the right of Cueball, far from the fire outside the right green area. She is supporting herself on one knee and one foot. She is also holding a stick in both hands with a marshmallow on it. She is holding the stick inside the green area to the right of Cueball far from the fire. Four small lines above and below indicates that she is waving the stick up and down. The camp fire is built up of several logs on top of each other, with big flames above it, with smaller flames hanging loose in the air above the main flames. A small dead tree is to the far left and small rocks/stones lie along the ground all the way from left to right interspersed with grass tufts. Below the scene there is a label from which two curved arrows point to the two green areas.] Label: Habitable zone
[Caption below panel:] Astronomers define the Campfire Habitable Zone as the region where you're far enough not to be burned but close enough to roast marshmallows.


Asterisk Corrections

Explanation:
In text messages, asterisks are commonly used to denote a correction of some error in an earlier text. Asterisk corrections typically specify the corrected words, but do not explicitly mark the words that should be replaced. The words that should be replaced are simply the words in the message that make sense to be replaced by the correction, often the ones that are the closest by spelling or meaning to the correction.
In this comic, the messenger ( Randall ) corrects four such inaccuracies. The message, if the corrections were to be taken in order, might read "I'm gonna eat 3 AM on the couch at pizza." The typical reader should be sharp enough to know that it should read "I'm gonna eat a pizza on the couch at 3 AM.", replacing the ones that are closest by function in the sentence. Randall finds this remarkable.
Taken one at a time, it appears the reader would have the following sentences in their head:
I'm gonna ride a horse on the beach at dawn (original sentence - sounds adventurous and sporty) I'm gonna eat a horse on the beach at dawn (replacing the action - a figure of speech?) I'm gonna eat a horse on the beach at 3AM (replacing the time - occultish?) I'm gonna eat a horse on the couch at 3AM (replacing the location - lazily occultish, or worse?) I'm gonna eat a pizza on the couch at 3AM (replacing the food - not too odd, but very slobbish)
Human brains can process these corrections automatically because the syntax of most English sentences are as follows:
Subject — Verb — Object — Manner — Place — Time
Other languages have different word orders but generally have the same six categories.
The messenger's original sentence can be parsed as follows:
I (subject) — am gonna ride (verb) — a horse (object) — (no manner) — on the beach (place) — at dawn (time) .
Notice that the four corrections fall into four different categories in this structure, so there is only one sensible replacement:
"Couch" and "pizza" are both nouns so they could theoretically be subjects, but asterisk corrections must replace an existing part of the sentence satisfactorily, so the "'m" part of the verb prevents these third-person nouns from being parsed as the subject. Theoretically one could also swap "couch" and "pizza" around, giving "eat a couch on the pizza", but this makes much less practical sense than "eat a pizza on the couch". That said, in xkcd's fictional universe there is nothing to stop the character from eating a couch on a pizza.
In the title text, Randall says that he likes to make it as difficult as possible for his text recipient to guess where his correction should be, and uses the following sentence and correction:
"I'd love to meet up, maybe in a few days? Next week is looking pretty empty." *witchcraft
The trick here is trying to figure out which word(s) should be replaced by "witchcraft". Broadly speaking, "witchcraft" could serve as an activity, but no words for activities exist in the original sentence, leaving the reader to guess at the intent. Possible solutions suggested in the comments are:
"I'd love to witchcraft , maybe in a few days? Next week is looking pretty empty." "I'd love to meet up, witchcraft in a few days? Next week is looking pretty empty." "I'd love to meet up, maybe witchcraft a few days? Next week is looking pretty empty." (These three examples verbed "witchcraft" to mean "perform witchcraft".) "I'd love to meet up, maybe in witchcraft days? Next week is looking pretty empty." "I'd love to meet up, maybe in a few days? Witchcraft week is looking pretty empty." ( Witchcraft week is an event in Bargota, Spain.  It usually occurs in July, the month in which this comic strip was released, although this year's event in particular was canceled due to COVID-19 -- which would indeed make it pretty empty.) "I'd love to meet up, maybe in a few days? Next witchcraft is looking pretty empty."
Of course, none of these solutions would be evident as correct to the recipient of the message, until Randall sends further corrections.
One absurdity in the main comic panel is that, after all four corrections has been parsed, the meaning of the resulting sentence has no connection with the original sentence whatsoever. However, asterisk corrections are generally used to correct typing mistakes, not to completely change the meaning of the original message. This raises suspicion as to why the messenger wrote the original sentence in the first place. Perhaps Randall does want to make the comic as difficult for his readers to parse as possible while making the point that asterisk corrections are usually quite intuitive to understand.
[A screenshot of a text messaging app.] Other user: Do you have any weekend plans? User of this device: I'm gonna ride a horse on the beach at dawn *Eat *3AM *Couch *Pizza
[Caption below the panel:] I like how we can do corrections in text chat by appending words with asterisks and our brains just figure out where they go.


Faraday Tour

Explanation:
This comic is another in a series of comics related to the COVID-19 pandemic .
Hairy , addressing an unseen camera (possibly the reader's POV) welcomes viewers to a livestream broadcast - that he calls/brands as a 'Livecast' - walking through "the world's largest Faraday cage ." A Faraday cage blocks electromagnetic transmission into and out of the cage area. Attempting to broadcast a walk through such a cage with any medium that uses radio waves would (theoretically, at least) cause the transmitter's signal to drop out completely, resulting in the loading wheel shown in panels three and four. Faraday cages do not necessarily have to be dark inside, as this one appears to be (they typically block longer wavelengths than those of visible light, which consists of electromagnetic waves). However, the darkness visually aligns with the concept of communications blackout , which is what Hairy's viewers experience while Hairy is in the cage.  The darkness could be taken as a metaphor for depending so heavily on electronic connectivity for one's view of the world that anything not directly connected is conceived as unobservable. (Alternatively, the light switch could be inside the cage.)
The Faraday cage that Hairy is visiting may also be an anechoic chamber for testing radio equipment, which would be completely lined with radiation-absorbent material , not just an open-air cage, to ensure that the measurements inside are of the highest quality.  There's no particular reason that it would have to have the lights off for his tour (in fact, it would be better to have the lights on so that he could see the features inside), [ citation needed ] but some anechoic chambers have been used for sensory deprivation experiments , in which participants are shut inside in total darkness and quiet.
"Smash that like (or subscribe, etc.) button" is a typical command given by YouTubers to watchers, asking to publicly "like" the video or subscribe to their channel if they enjoyed it, ultimately to boost the creator's popularity. Developers want lots of views, likes, and subscribes because YouTube pays artists (e.g. $1 per 1000 views).
The title text refers to COVID-19 pandemic of 2020. The joke is that, as they don't get cell service in the cage, the owners would be unaware of global events. This implies for comedic effect that the owners and workers solely live inside the Faraday cage, continuing the theme of treating connectivity as the only way to acquire information.  They would still be able to receive news if they ever step outside to welcome visitors, or have print media delivered, but their choice to unconventionally isolate themselves might reflect their general attitudes to the world outside and it is also implied that Hairy is one of the rare few outsiders they have pre-agreed to allow to visit, or one of the few people who would think to ask for and plan a tour during a pandemic.
Randall has referenced Faraday cages for comedic effect in the past. See 1142: Coverage .
[Close-up on Hairy] Hairy: Hey there superfans, welcome to the livecast!
[Hairy walks toward an opening in a large building] Hairy: Got a real treat for you today: a tour of the world's largest Faraday cage! Hairy: C'mon, let's check it-
[Two panels of a "loading" spinner on a black background]
[Hairy exits the building] Hairy: -was so cool! Wow!! Hairy: Thanks for coming along, and don't forget to smash that like button!


Pods vs Bubbles

Explanation:
This comic is another in a series of comics related to the COVID-19 pandemic .
During the 2020 COVID-19 pandemic , various degrees of household self-isolation were often asked of people, depending on location, once it became understood that there was a virus spreading through contact/proximity vectors.
As the initial surge of cases appeared to decline, in places where such drastic restrictions had been implemented and seemingly had prevented ever higher infection rates, many regions decreased the strictness of these measures. For instance, permitting any two households (neither having signs of symptoms) to meet with each other and only each other , or allowing one person in a multi-occupancy residence to invite just one other person to reassociate with. Further relaxation of rules may have occurred since, with the caveat that even one case of COVID-19 discovered in such a co-isolating group of people should be considered a risk factor to every other member (however the local jurisdiction deals with that).
A common term for the larger social unit, not to overlap with any other expanded social unit, is a 'bubble', perhaps to imply that you can only have membership of one bounded bubble at a time (unlike an Euler diagram ). The term ‘build your bubble’ was coined by Dr Ingham (University of Otago, New Zealand) as a way of encouraging people with disabilities to create safe ‘bubbles’ with care givers during lockdown.  Another common term is 'pod', representing the closed nature of a pod. There is probably as much variation across the world about what podding or bubbling practically means as there is between any two instances of those podded vs. those bubbled. Some sports leagues have resumed play in these structures, with the media using the bubble terminology , both in the United States and across the wider world , as players and commentators alike resume some degree even of international competition (so long as they follow the 'bubble' rules ).
Despite the semantic inconsequentialities of the difference, here Cueball clearly expresses a personal preference that he would probably not like being kept in an enforced social situation with someone who uses the other term.
Randall realizes that, despite his tendencies towards strong opinions on semantics, this particular point is one he would have been highly unlikely to say a year ago, and probably would not even have understood what it meant, because he could not have foreseen the COVID-19 pandemic and its widespread impact.
Cueball was shown using a literal bubble (a hamster ball ) in 2331: Hamster Ball 2 , but evidently got tired of being rolled around by the neighborhood kids.
The title text refers to travel restrictions. Many countries have placed limitations on its citizens' travel, particularly in and out of that country. Canada has mandated 14-day self-isolation on anyone who has returned from out-of-country, and has strictly limited any attempts to leave the country, with the United States being specifically noted as a high-risk tourism destination. Randall jokes that such measures are only 99% meant as COVID-19 precautions, with the remaining 1% being due to the authorities sharing Randall's semantic opinions.

[Cueball is walking to the right with Megan.  He has his index finger raised dramatically.] Cueball: I refuse to bubble with anyone who calls it a "pod" and not a "bubble".
[Caption below the panel]: This is probably my opinion that would have sounded the most incoherent to me a year ago.


Cosmologist Genres

Explanation:
A cosmologist is someone who studies the universe; cosmology is a branch of astronomy. When describing the composition of stars in astronomical terms, metals are all the elements heavier than helium . This definition of metal is significantly broader than the one used outside astronomy . Likewise, this chart of musical genres describes everything "heavier" than pop as metal. The standard conception of elemental metals is a subset of the astronomical conception of metals; likewise, here the musical genre metal is presented as a subset of the genres cosmologists consider metal.
Randall may have decided to portray pop music in a similar way to the elements helium and hydrogen as a reference to the " pop test ", the test for hydrogen as a product of a chemical reaction.
Cosmologists also study the history and future of the universe, and the title text refers to the Big Bang . At roughly 10 -32 seconds after the Big Bang, the inflationary epoch ended, causing a large number of quarks, anti-quarks , and gluons to come into existence. In inflationary cosmology , this point is considered to be the end of the Big Bang. Randall jokingly refers to it as "post-" because nearly the entire history of the universe is after this instant. This is a reference to types of music with "post-" in their names, e.g. post-rock , post-punk , post-metal .


Scientist Tech Help

Explanation:
In this comic, Randall pokes fun at stereotypes of scientists that "tech people" hold.
In the first panel Randall, presents an idealized view of the tasks of tech people. A group of scientists have run their experiments and compiled their data, but find that the data is simply too complicated for humans, even advanced scientists such as themselves; the tech people resolve in heroic statements to decipher the data with their most advanced algorithms. Large portions of machine learning and data science hinge around finding a pattern (either regression or classification) in a given data set, but the more common, real-world problem is in data cleaning and preparation. For the most part, the rest can be done with preexisting implementations. These types of tasks are those that tech people both expect to perform, and hope to expand upon.
The second panel presents a different reality. The scientists are fully confident they can interpret the data on their own, provided they can access it, because the methods of recording their data are incredibly sub-par. Apparently wasps had infested the lab, and the scientists had to take photos of their equipment through the window. This created a much more fundamental problem of data format than normal (image vs spreadsheet, as opposed to something more normal like pixel-wise vs vertex-based segmentation).  The joke is that the scientists' questions for their tech specialists are very mundane in nature; it presents not a chance to test and prove their machine learning systems, but a simple and tedious process of untangling digital paperwork. This is true in real life — experts' expertise is usually deep, but not broad, and helping them with issues outside their comfort zone is rarely glamorous.
Polaroid is a brand of instant camera , though "Polaroid" is often used to refer to instant cameras in general. Excel is referring to Microsoft Excel , a spreadsheet management program.
The title text refers to WebPlotDigitizer , a tool which may be used on visual displays of data such as graphs and charts in order to extract the underlying data. This tool would have the potential to solve the problem which the scientists have by extracting data from the images taken of the equipment. Randall acknowledges the usefulness of the tool, but also expresses some dislike that the tool was invented at all — someone must have had the original data to draw the graph, thus if they had made the data available then he wouldn't have to reverse engineer the plot. Other possibilities are that he simply feels that the tool is too powerful and leaving him less work to do, or that tools so trite and seemingly unnecessary prove so useful in the end.
2116: .NORM Normal File Format deals with nested file formats.
What tech people think scientists need help with: [Cueball, Ponytail, and Megan are facing a second Cueball and Hairbun. Ponytail is gesturing with her hand out. The second Cueball has his finger raised.] Ponytail: Please–our data, it's too complex! Can your magical machine minds unearth the patterns that lie within? Cueball 2: We shall marshal our finest algorithms!
What scientists actually need: [The two Cueballs, Ponytail, Megan, and Hairbun are in the same position as before. The second Cueball no longer has his finger raised.] Ponytail: For a few weeks in June, the lab was infested by wasps, so we had to take pictures of the equipment through the window. Ponytail: How do you get graphs from a Polaroid photo into Excel?


Exposure Notification

Explanation:
This comic is another in a series of comics related to the COVID-19 pandemic .
During the coronavirus pandemic, many apps were developed to implement digital contact tracing , using proximity detection or location tracking to notify people who had been potentially exposed to COVID-19. People who know they are infected are encouraged to isolate, and it takes time to test and find out if somebody is infected; so most notifications are retrospective, telling the user about past potential exposures.
In this comic, a different type of app has been developed. Instead of notifying someone if they have been exposed to someone with COVID-19, the app produces notifications if they have been exposed to someone who has not tested positive. (Perhaps it also notifies the user if they have been exposed to a person who has tested positive, but if this is the case, it hasn't happened to the user in question yet.) This is much less useful because most people one would typically encounter would either not be infected, or not be aware of their infection, so almost every interaction will generate a notification, annoying the user.  Also, being exposed to someone who has not tested positive is not good news, because it is still possible that the person might have COVID-19; it is simply less bad than being exposed to someone who has tested positive, but still worse than not being exposed to anyone.
Socially and psychologically, modest amounts of people being close to each other normally is a positive behavior.  For a typical person, it could be considered a sad sign of our times if you needed an app to tell you whether you did right in social interactions and compliment you. (For socially awkward people , on the other hand, this could be a welcome development.)
In the title text, Randall decides to give in to users requests, and add a mode giving the bad news that you have been exposed to COVID-19.  Calling this dark mode is a play on dark referring to less desirable, as well as dark mode, a common user interface option. Dark mode is a common feature in apps which allows users the options to have a user interface that gives off less light. Alternatively, it may just be that the developer is completely misunderstanding the user's actual needs. This would be consistent with creating an app that alerts the way this one did in the first place.
Randall has published similar "useless useful apps" in 937: TornadoGuard (a tornado-alert app that has lots of great features, except it doesn't actually alert the user about tornadoes) and 2236: Is it Christmas? (a web page that correctly identifies most days as "not Christmas", but then fails to identify Christmas Day as Christmas, for a >99% "accuracy").
A week after this comic was posted, a user of the Canadian COVID tracing app posted an article about a similar issue: notifications from non exposure .
[Cueball standing, holding out his chiming smartphone to review alerts it has received.] Alert 1:43 PM Good news: You recently had close contact with someone who has not tested positive for COVID. Alert 1:38 PM Good news: You recently had close contact with someone who has not tested positive for COVID. Alert 1:36 PM Good news: You recently had close contact with someone who has not tested positive for COVID. Alert 1:31 PM Good news: You recently had close contact with someone who has not tested positive for COVID.
[Caption below the panel:] No one likes my new COVID exposure notification app.


Mathematical Symbol Fight

Explanation:
This comic imagines which mathematical symbols would be good in a fight if they were made corporeal in two (or three) dimensions.
Generally, objects with longer reach and pointier ends wound up on the right ("more useful") side of the scale, and symbols with less reach and more curves wound towards the left ("less useful") side. A straight line is farthest to the "more dangerous" side; however, the straight line does not appear to be any thicker or thinner, or pointier, than any of the other lines that would make it more "useful" (It should be noted that this chart seems to fall afoul of what Eliezer Yudkowsky (who also wrote HPMoR) calls the intent to kill : that humans tend to define "winning a fight" and "useful" as causing some form of bodily harm on their opponent despite survival and purely defensive strategies being an equally valid goals.).
Below the chart, with the symbols listed in order of usefulness, eight characters wield eight of the symbols. See the table below for the meaning of each symbol.
The comic invokes surreal humour by suggesting that mathematical symbols could be handled as physical objects in the real world. Another component of the humor is the implication that it is useful to prepare to use mathematical symbols in a fight, even though mathematicians, who use mathematical symbols, usually do not conduct their debates violently (though some stories suggest that Hippasus was killed by his fellow Pythagoreans for his proof that irrational numbers exist), and even if they did, they wouldn't use large reproductions of their symbols as weapons.
The title text refers to a Treble clef , which is not a mathematical symbol but rather a musical symbol . The note of concern in the text suggests musical symbols may be viewed in such fights as exotic or especially dangerous. See also the last entry in the table below.
[A chart is shown with 30 different symbols arranged above a line with arrows in both ends and with 17 ticks between the arrow heads. The symbols are mostly in two rows, but the first two symbols from the left do not have another symbol above them, and towards the right there are a segment with three rows of symbols. Above the symbols there is a heading and a subheading. And beneath those there is a long arrow pointing right with a label above it.] Mathematical Symbols By how useful they would be in a fight More useful ℝ     ∅ > ∝ π + Ψ ~ ⇒ ⋅ Γ √ ∮ ∫ ⇀ θ ∞ ∪ ∈ ∀ ∂ ≠ # Δ ζ ℵ ρ → ⊥ ––
[Below the double arrow line are eight characters that fight each other in groups of two by  using some of the symbols shown above them as weapons. They have chosen symbols that are almost above them in the chart.] [Megan is awkwardly handling a giant "ℝ" holding it up against White Hat who is holding a "θ" (or "∅"?) with both hands, as a shield.] [Cueball is holding an "∈" in both hands, with its "tines" pointed towards Blondie, who is swatting at him with a "#".] [Ponytail is leaping at Danish, swinging a " ρ " like an axe, while Danish is leaning back and thrusting a "→" back at her.] [Black Hat is swinging a long "√" like a polearm at Hairy, who is holding a long "⎯" defensively.]


26-Second Pulse

Explanation:
In this comic strip, Science Girl is presenting her project on geology to her class mates, and is explaining some of the non-earthquake signals that seismometers detect.  She describes a mysterious signal that repeats with a 26-second period .
Scientists have exploited this signal to correct for clock drift in historic seismic records.
Science Girl initially provides a plausible explanation (some kind of natural wave pattern on the coastline of the Gulf of Guinea , which is in fact the most common theory about this signal).
However, she quickly takes a turn for the dramatic when she claims that it might be a giant, murdered by seismologists, whose heart still beats.  This is a reference to Edgar Allan Poe's short story The Tell-Tale Heart , in which the main character murders a man and hides his corpse beneath the floorboards, and then hears (or believes he hears) his victim's heart continuing to beat; the noise eventually drives him to confess his guilt to visiting police officers.  (The narrator of The Tell-Tale Heart never uses that phrase in the story; he calls it a hideous heart.) "The Tell-Tale Heart" was previously referenced in 740: The Tell-Tale Beat .
Normal human hearts beat much more rapidly than once every 26 seconds, but large animals and hibernating animals may have much slower heart rates (which would include a giant at the bottom of the ocean [ citation needed ] ).
The title text gives an alternate explanation for the seismic activity: volcanic activity , but Science Girl continues to believe in the giant story. In the last panel she references the common science meme that further research is needed, which has been mentioned several times in previous strips, including 2268: Further Research is Needed .
A seismometer is a device for measuring vibrations in the earth's crust, and one is likely in the collection of Cueball from 2060: Hygrometer .
[Science Girl is standing in the front of a whiteboard holding a pointer up towards the board. Ponytail, Hairy, and Megan are sitting at desks facing Science Girl.] Science Girl: When everything is still, seismometers pick up faint tremors we call seismic noise. Science Girl: Most of it is from ocean waves, cars, etc.  But there's also a mysterious 26-second pulse.
[Close up on Science Girl. She is holding a hand palm up towards the board behind her, showing a map with Africa in the center and some other continents at the edges of the view. A star is drawn within the country of Ghana, near the coastline.] Science Girl: We've triangulated the source to somewhere in the Gulf of Guinea. Science Girl: It comes and goes with the seasons, but it's been there since at least the 1980s.  It's so regular we use it to sync up seismometers.
[In a frame-less panel only Science Girl is shown, once again in profile. She has the board behind her and points the pointer towards the board.] Off-panel voice: What causes it? Science Girl: Not sure.  The most popular theory is that storm-driven waves set up some kind of resonance with the coast.
[Science Girl has leaned her stick on the board's tray.  She has raised her clenched fists.] Science Girl: Another theory is that long ago, seismologists murdered a giant and buried the body at sea. Science Girl: Now we are haunted by the beating of its telltale heart! Science Girl: Could be either. Science Girl: Further research is needed.


Wish on a Shooting Star

Explanation:
This comic was published at the annual peak of the Perseids meteor shower . It is a common practice to make a wish when one sees a shooting star, in hopes that the wish comes true. This comic consists of a Venn diagram showing what things are commonly wished for upon seeing a shooting star, and what things the shooting star may cause. Shooting stars, as they are actually meteors, can only cause changes to physical phenomena, such as radio noise or the appearance of the sky as they burn up in the upper atmosphere. The only thing that is shared between the potential wish side of the diagram and the shooting star caused side is revenge. This would occur when a shooting star actually hits the planet, becoming a meteorite. This is frequently highly destructive, given the high speed of falling meteors. As such, it would be possible for the meteorite to hit something that someone for some reason or another wished revenge upon. However, given the massive surface area of the planet, the likelihood that someone's revenge would be "granted" by a meteorite would be very low (although not quite as low as dunking a meteorite through a basket ). The title text makes fun of this by detailing several incidents where a meteorite landed and caused damage.
List of things that were damaged by meteorites (from title text):
If there is a "message" to this comic strip, it could be similar to those of 1024: Error Code and 2247: Weird Hill : that we shouldn't bother wishing for things that shooting stars can't give us, but should instead take time away from our temporal concerns and just relax and appreciate their beauty.  Or maybe the message is that, if you must wish on a shooting star, you should wish for revenge, because that's something that might come true.  Of course, as the title text makes clear, meteorites don't really land according to our designs and schedules, and if you're close enough to a shooting star to see it, and you wish for it to avenge you, and it is big enough to hurt someone, you're probably at risk yourself.
Meteorites were most recently mentioned in 2328: Space Basketball .  Randall has discussed strange and "impossible" wishes in 1086: Eyelash Wish Log .
[A Venn diagram is shown:]
[The left circle is labeled "Things people wish for" and contains:] Love Money Fame Health Power Luck Success
[The right circle is labeled "Things shooting stars can cause" and contains:] Radio noise Dust and ionized gas in the upper atmosphere Infrasound Cool lights in the sky
[The only item in the overlapping section is:] Revenge


COVID Risk Comfort Zone

Explanation:
This comic is another comic in a series of comics related to the COVID-19 pandemic .
One of the major vectors for transmission of SARS-CoV-2 is in sharing an enclosed space with someone who is infected, especially someone who is asymptomatic and not aware of being infected.  Wearing a face mask, as both "Inside Cueball" and "Outside Cueball" are, will dramatically reduce the rate of transmission, perhaps by a factor of 30 compared to the "baseline" of neither wearing a mask, but given the limited volume of air available, it is likely that sooner or later one of them will inhale enough air with enough virus-bearing droplets to risk catching the disease.  This knowledge leads Outside Cueball to refuse Inside Cueball's invitation to visit indoors, but (in a recurring theme of xkcd ) leaves him feeling uncertain as to how he should refuse the invitation.  The comic proceeds to depict a spectrum of options.
The first option is overly technical to the extreme, to the point where Outside Cueball is effectively giving Inside Cueball an in-depth lesson on common health advice during the 2020 COVID-19 pandemic. Being overly technical is a common trope among xkcd comics -- in particular, Outside Cueball's fervent insistence that he made a spreadsheet so he doesn't "overthink every minor decision" is disproved by (a) the fact that he made a spreadsheet (cf. 1445: Efficiency ) and (b) the events of 2330: Acceptable Risk . The second option that is presented is the most reasonable of the three, being an expression of reasonable concern, and a polite refusal to enter. The last option is simplified to the extreme, and successfully insults the owner of the building while still expressing a desire to avoid coming inside. The title text appears to be a continuation of the last panel. In it, someone, presumably Cueball, compares themselves to a vampire, because folklore has it that vampires cannot enter a building without permission. However, the speaker has no interest in coming inside, despite any invitations that they may have, whereas vampires usually want to come inside to drain the occupants' blood.  Some vampires will even take measures to trick an invitation out of a hesitant "host", which is something that would be unthinkable to Outside Cueball under the COVID circumstances.
As a fourth option compromise between the second and third choices, Cueball could just flatly refuse: "No," or "No, thank you."  We don't know the circumstances here (is Inside Cueball a friend of Outside Cueball, a shopkeeper, or just a passing acquaintance?), but clearly there's no urgent reason that Outside Cueball has to go inside, and so he doesn't owe Inside Cueball any explanation (nor any insults).
Other comics mentioning "COVID-19 risk" include 2330: Acceptable Risk and 2333: COVID Risk Chart (which might itself be the spreadsheet made or used by Outside Cueball).
Ways to say no when someone tells you to do something outside your COVID risk comfort zone:
[A comic with three panels is shown.]
[The first panel is large. There are 2 Cueballs each wearing masks. Inside Cueball appears to be in a doorway that leads into a building. Outside Cueball is showing Inside Cueball a phone.] Label: Too Indirect Inside Cueball: You have to come inside. Outside Cueball: Ok, but... I've been trying to follow the science, and they're really emphasizing the transmission risk in enclosed spaces. I know you're wearing a mask, and I feel so awkward making a scene over a tiny risk. But I'm trying to keep my overall risk acceptably low, which means having simple rules so I don't overthink every minor decision. See, if you look at this spreadsheet-
[Second panel, smaller. Only the Cueball outside is shown now.] Label: Direct Outside Cueball: I'm so sorry, but I'm avoiding shared indoor spaces unless it's an emergency.
[Third panel, even smaller. Only the Cueball outside is shown.] Label: Too Direct Outside Cueball: I'm not setting foot in your haunted plague box.


Dependency

Explanation:
Technology architecture is often illustrated by a stack diagram , in which higher levels of rectangles indicate components that are dependent on components in lower levels. This is analogous to a physical tower of blocks, in which higher blocks rest on lower blocks. The stack in this cartoon bears a striking resemblance to a physical block tower, suggesting the danger that the tower will lose its balance when a critical piece is removed, in this case a piece near the bottom, labeled as being maintained by a single semi-anonymous person located somewhere relatively unimportant doing it for their own unknown reasons without fame or acknowledgement. The concept of balance is not intended to be communicated by a stack diagram, making this a humorously absurd extension of a well-known diagram style.
ImageMagick , mentioned in the title text, is a popular, standalone utility released in 1990 that is used for performing transformations between various graphics file formats, and various other transformations.  While there are also numerous libraries and APIs for performing these tasks within larger programs, ImageMagick is so popular and easy to use that many programs use its API or just find it easier to shell out to ImageMagick to perform a necessary transformation. They therefore depend on ImageMagick, and would break if ImageMagick were to disappear.
Taking code re-usability and modularization to its logical extreme has been a long-time tenet for programmers; programming began as a slow task on very memory-constrained systems, utilizing punch cards and days of delay waiting to discover a bug, so that reuse made things possible that otherwise wouldn't be.  Once systems became small, fast, and able to hold a lot of data, the ability to provide higher and higher degrees of automation made reusable libraries a huge engine behind the development of technology.  By outsourcing what would seem like basic functions, such as string manipulation, to other libraries, developers waste less time reinventing the wheel, so the philosophy goes (or as Beret Guy's business practices literally: 2140: Reinvent the Wheel ), and thus many tiny packages, many of which contained only one function, became popular dependencies. This was especially true in Unix and Linux, where an entire program is commonly used for one small task, and programs exist to tie others together into powerful shell scripts.
Node.js (a platform for JavaScript) and Python are two modern ecosystems providing huge stashes of centralized libraries where developers of the world can come together to stand on the shoulders of all the small useful libraries they make for each other, to make new ones that are more and more powerful, and also more and more prone to sudden new unexpected bugs somewhere in the dependency chain.  JavaScript was designed to be an easy to use front end scripting language, not a basic and core backend language as users of node.js's NPM package manager have made it be.  While in theory, such a system may sound good for developers who would need to write and maintain fewer lines of code, systems which are highly optimized are also highly susceptible to rapid changes. For example, the famous left-pad incident in the NPM package manager left many major and minor web services which depended on it unable to build. A disgruntled developer unpublishing 11 lines of code was able to break everybody's build, because everyone was using it.
In 2014, the Heartbleed bug revealed a significant portion of the internet was vulnerable to attack due to a bug in OpenSSL, a free and open-source library facilitating secure communication. One headline at the time demonstrated this comic in real life: "The Internet is Being Protected by Two Guys Named Steve" . The aforementioned Steves were overworked, underfunded, and largely unknown volunteers whose efforts nevertheless underpinned the security of major websites throughout the world. Randall provided a concise, helpful explanation of the bug in 1354: Heartbleed Explanation .
The current model of libraries and open-source development (topics which Randall has addressed extensively in the past) relies heavily on the free and continued dedication of unpaid hobbyists. Though some major projects such as Linux may be able to garner enough attention to build an organization, many smaller projects, which are in turn reused by larger projects, may only be maintained by one person, either the founder or another who has taken the torch. Maintaining libraries requires both extensive knowledge of the library itself as well as any use cases and the broader community around it, which usually is suited for maintainers who have spent years at the task, and thus cannot be easily replaced. Thus, there are many abandoned projects on the internet as people move on to greener pastures. Far from the days of backwards compatibility, that's usually not a problem, unless a project happens to be far up the dependency chain, as illustrated, in which case there may be a crisis down the road for both the developers and the users down the chain.
[A tower of blocks is shown. The upper half consists of many tiny blocks balanced on top of one another to form smaller towers, labeled:] All modern digital infrastructure
[The blocks rest on larger blocks lower down in the image, finally on a single large block. This is balanced on top of a set of blocks on the left, and on the right, a single tiny block placed on its side. This one is labeled:] A project some random person in Nebraska has been thanklessly maintaining since 2003


Boat Puzzle

Explanation:
This comic is a twist on an old riddle . In the original riddle, a person has to cross a river in a boat that can only hold them and one other object. They have a wolf, a goat, and a cabbage that they need to bring across with them, similar to the first panel. If the wolf is left alone with the goat, however, the wolf will eat the goat; and if the goat and cabbage are alone, the goat will eat the cabbage. (The problem can be solved in seven trips.)
However, the comic quickly devolves into surrealism in the later panels as new characters show up, bringing deviations of the original "cabbage", "goat", and "wolf" that add extra layers of complexity to the riddle. White Hat brings extra wolves and cabbages. Black Hat , in his traditional classhole style, brings cabbage moths which will infest unsupervised cabbages with destructive larvae, and boat-destroying termites . How he intends to bring them across the river (or even if he wants to) is unknown, but it brings to mind the parable of The Scorpion and the Frog . Beret Guy arrives with a wolf who can operate a boat, who could perhaps serve as a second pilot to expedite the crossing, so long as he is not asked to ferry a goat, and also a goat who eats wolves, possibly in addition to the cabbages. This is unusual, as one would expect from Beret Guy's associates.
The last panel is a reference to the Trolley Problem , a moral test that asks the participant whether they would passively let people in the way of an uncontrollable trolley die or actively divert the trolley to kill a single person standing on a branch of the tracks. The comic gives a twist here too: according to the title text, the characters must choose between stopping the trolley full of wolves with a cushion of cabbages (in which Black Hat's cabbage moths have laid eggs, which he implicitly argues are morally equivalent to "innocent children") or letting it crash into the river (at which point the wolf who can operate a boat will steal the boat to rescue the wolves from the trolley, which will delay the other characters from crossing the river).
The River Crossing puzzle was also mentioned in 1134: Logic Boat and referenced in 589: Designated Drivers .
The Trolley Problem was also mentioned in 1455: Trolley Problem and referenced in 1938: Meltdown and Spectre .
Unlike typical Logic Boat problems the presence of multiple humans makes finding a solution almost trivial, however trying to determine the solution with the least number of trips could still make the somewhat challenging.  Because the set of constraints are both ambiguous and incomplete, it requires the reader to make assumptions that, in turn, will lead to different solutions.
The following assumptions can be made based on the setup of the problem or are necessary to avoid an unsolvable puzzle.
The trolley problem creates two versions of the puzzle, one where the cabbages are destroyed, the other where they are not and a wolf rescue takes place.  The ethical issues associated with the trolley problem are independent from the logic of how to cross the river.
With four humans involved, the first trip across can bring an extra human who then can guard the cargo as it is brought across in arbitrary order with care being taken not to have predator and prey alone together at the end.  The termites must be last cargo ferried across as they will destroy the boat.
The cabbages are destroyed. The second to last trip brings across the last human and the last trip brings across the termites.
A pack of wolves is now on the near bank.  The last human is brought across in the third to last trip, followed by the last wolf and lastly the termites.
No information is provided about whether or not the humans all get along with each other and this is left as a possible exercise for the reader given all of the characters' varying personality traits.  However the sailing wolf would likely come in handy if certain humans (ex Black Hat, Beret Guy) cannot be left alone.  It is also probable that certain characters might not serve in the capacity as a cargo guard.
It is also unclear if humans can leave with their cargo once all the cargo has been brought across.  This could complicate matters if a far side "guard" leaves early.
[Cueball and Ponytail are standing on the bank of a river. There is a boat in the river. A goat and wolf are also on the riverbank, and Ponytail is holding a cabbage.] Ponytail: I need to cross the river. I have a wolf, a goat, and a cabbage. Cueball: Hmm.
[White Hat appears, accompanied by two wolves and pulling a wagon full of cabbages.] Cueball: OK, here's what- White Hat: Hi, I also need to cross. I have two wolves and 100 cabbages.
[Black Hat arrives, surrounded by a cloud of flying creatures and carrying a jar of bugs under his arm. Beret Guy follows with another wolf and goat on leashes.] Black Hat: I have 50 cabbage moths and 2,000 boat-destroying termites. Beret Guy: I have a wolf that can operate a boat, and a goat that eats wolves.
[The fourth panel is a zoomed-out shot, where everything but the sky appears black.]
[A trolley speeds in, leaving a trail of dust in its wake. A person is standing on the front, and many ears are barely visible above the seats.]
Cueball: Hang on, I need to make a spreadsheet. Trolley operator: Look out! Trolley operator: My wolf-filled trolley is out of control and can only be stopped by a cushion of cabbages!


Rabbit Introduction

Explanation:
Cueball is giving a presentation on the pygmy rabbit to a group of panelists, requesting a grant to introduce the species to the eastern United States. The head of the panel, Blondie , asks about typical reasons for introducing a species. If they were native to an area, but had been locally depopulated, re-introduction can help to restore the local ecosystem, but Cueball admits this is not the case.  Another reason animal populations may be introduced is to control a local pest. Cueball seems to have no idea what the impact on the local ecosystem would be. In fact, he makes quite clear that his reasoning is simply that the creatures are tiny and cute, and he wants to spread them. He also appears to be entirely perplexed that the panel doesn't feel the same way.
Blondie, very reasonably, immediately moves to deny the request. Not only would such a grant expend funds for no legitimate scientific or ecological purpose, but it would risk serious and unstudied impacts on the local ecosystem ( especially considering that this very thing has happened with rabbits before ). However, at this point, the other three panelists - White Hat , Megan and Hairy - have been swayed by Cueball's unconventional argument. All three of them are visibly entranced by the cuteness of the rabbits, and appear willing to fund the request purely based on affection for the animals.  This is sort of the opposite of the " charismatic megafauna " method of conservation - charismatic minifauna : the more mini, the more charismatic.
The title text mentions the effort to reintroduce the Columbia Basin pygmy rabbit into their native area of the Columbia River drainage basin . It refers to an "Interstate Bun Gap", suggesting a competition between states over which has the most and/or cutest rabbits.  That phrase is a reductio ad absurdum of other gaps in capabilities between states and nations, such as the bomber gap and missile gap (widely-publicized shortages - later revealed to be fictional - of the respective nuclear arsenals of the United States compared to the Soviet Union), perhaps similar to the satirical "mine shaft gap" from the 1964 film Dr. Strangelove .
This comic continues an xkcd tradition of dealing with the subjective cuteness of rabbits as a scientific discipline ( 1682: Bun ). Randall seems fascinated with the cuteness of lagomorphs, as it is a recurring subject .
[Cueball is standing in front of a screen and pointing at it with a stick. On the screen is a rabbit shown next to a smartphone, some keys on a key-chain, and two coins. The phone is larger than the rabbit.] Cueball: The US's smallest rabbit species is the pygmy rabbit from the Great Basin area. Cueball: We're seeking a grant to introduce them into the east.
[Blondie, White Hat, Megan and Hairy sit behind a long table. Blondie leans both her arms on the table. Hairy has one arm on the table. The other two have their arms down. Cueball replies to Blondie's question from off-panel.] Blondie: Are they native here? Cueball (off-panel): No. Blondie: Will they control some invasive pest? Cueball (off-panel): Dunno! Blondie: Then...Why would you do this?
[In a frameless panel Cueball is seen in front of the screen, which is seen from the side. He points to something on the screen with the pointer, while looking over his shoulder.] Cueball: I don't understand. Cueball: Did you see how small they are? Cueball: They're so round! Cueball: Those tiny ears!
[Back to the four people behind the desk. Blondie and White Hat are in the same positions but Megan has both her hands up into her hair, and Hairy has one arm on the table, and the other is held up high with a finger pointing up.] Blondie: I see. I'm afraid we'll be denying your grant. White Hat: Hang on. He is right about their ears... Megan: The little feet! Hairy: I vote we fund them!


Deer Turrets

Explanation:
Black Hat has built laser turrets that automatically shoot at nearby wireless devices. This could potentially be useful in a military context, but for reasons unforeseeable , he's gone and strapped them to local deer. Deer are well-defined by their tendency to move around (which Cueball attempted to exploit for ergonomic reasons in 1329: Standing ), typically in areas close to civilization, so attaching wireless-seeking laser robots to them effectively makes them organic killbots. As the last panel reveals, this can be circumvented by disabling wireless access on your devices (airplane mode), though Black Hat doesn't seem particularly concerned with letting people know this, and seems to brush these inventions off as simple mistakes.  At least one member of the press isn't convinced, sarcastically asking " is it really ?!"  It's not clear if the reporter is asking if it's really "another mistake" (i.e. expressing that this was Black Hat's plan all along), or if it's really "okay", but Black Hat chooses to interpret the question as meaning the latter, and declares that he thinks everything's fine -- after all, he's not the one getting shot by deer-mounted lasers.
The title, "Deer Turrets," may be a pun on "deterrents," as laser turrets would certainly deter people with wireless devices from approaching deer.
In the second panel Black Hat uses the common idiom "hindsight is 20/20 ". This may be a pun, as "hind" is a term for an adult female (doe) deer - as a counterpoint to the adult male (buck) deer being known as a "stag" - and a "sight" is a visual aligning device , often for weaponry. Whether or not the potential pun has any further caliber to its references, this might be the ultimate aim of this wording.
The auto-targeting laser turrets may be a reference to attempts by researchers at the University of Washington to create a laser-based battery charging device [1] . The device in question is mounted on a turret that locates and aims the beam at a photovoltaic cell attached to the battery. The same technology could theoretically be used with a higher-powered laser, but for the application described in the comic, the targeting mechanism would need to be altered to sense any electronic rather than the accompanying photovoltaic cell.
In the title text, Black Hat claims that his great grandfather designed the RMS Titanic , the then-largest ocean-liner in the world which sank after striking an iceberg in 1912, and the LZ 129 Hindenburg , the then-largest airship in the world which caught fire and crashed in 1937. He claims that his ancestor did not retire from the design business after the loss of the Titanic , but instead learned from it and made the Hindenburg "iceberg-proof". This is an obvious and humorous lie for several reasons. First, the lead designers of the Olympic -class Titanic and the Hindenburg -class airship were two different people, Lord Pirrie and Dr. Ludwig Dürr respectively, and Black Hat is probably not one of Dürr's great-grandsons (Lord Pirrie had no children). Secondly, while no airship has been recorded to be destroyed by striking an iceberg, it's not because of any "iceberg-proofing" efforts by Black Hat's great-grandfather, or anyone else -- it's just due to the basic fact that airships fly in the air, where there are no icebergs. [ citation needed ] Were an airship to strike an iceberg, it would almost certainly be destroyed; in fact, the even deadlier accident on the airship USS Akron resulted from the airship simply striking the (unfrozen) ocean.
The possibility of mounting devices on wild deer was previously referenced in the title text of 1924: Solar Panels .
Black Hat has built a similar device to target users of Google Glass in 1251: Anti-Glass .
[Black Hat is at a podium, addressing a crowd] Black Hat: Was it a mistake to build turrets that can track nearby wireless devices and fire powerful lasers in their general direction? Black Hat: Sure. I realize that now.
[Face-front view of Black Hat] Black Hat: Was it a mistake to mount those turrets on neighborhood deer, release them, then lose interest in the project and move on? Black Hat: Yes. Hindsight is 20/20.
[Close-up, Black Hat holds up his index finger] Black Hat: But science is about learning from mistakes Black Hat: And not being afraid to make new ones.
[Side view again] Black Hat: Like inviting you here, but not warning you to put your phones in airplane mode. Black Hat: Another mistake. Black Hat: But that's okay. Off-Panel: Gallop gallop Audience member: Is it really?! Black Hat: I think it's fine. Deer: Pew! Pew!


Standard Model Changes

Explanation:
In this comic strip, Randall is proposing some changes to the Standard Model of particle physics. The currently accepted particle table has 17 slots: 12 fermions (first 3 columns of the table - six quarks [top two rows] and six leptons [bottom two rows]) and five bosons (last two columns of the table - four gauge bosons [left hand column] and one scalar boson [right hand column]).

This comic consists of a normal version of the particle table to which Randall has made substantial alternations and additions, which are drawn in red over the black and white table.
While the Standard Model's predictions are very well supported by experiments, the physics community has identified several flaws in it (e.g. it lacks any particles to convey gravity), and so lots of research is committed to searching for " Physics beyond the Standard Model ".  Some of Randall's changes are sort of intended to fill some of those gaps, but for the most part they are nonsensical (although not quite as much as the Turtle Sandwich Standard Model or Fixion ).
Randall's proposed changes to the quarks are relatively restrained -- he proposes only that the "strange" and "charm" names should be moved to bosons, while the strange quark should be renamed the "right quark" and the charm quark should be renamed the "left quark", so that all quarks will have "ordinary" directional names.
In reality, the original quark model proposed by Murray Gell-Mann included only three quarks, with the "strange" quark so named because the particles that contained them were strangely long-lived relative to their masses.  The "charm" quark was so named when it was proposed because it brought a "charming" symmetry to the weak interaction, which we now understand is because it completes the second generation of quarks, along with the strange quark.  When a third generation of quarks was proposed, they were called top and bottom by analogy to the up and down quarks (which are so named because of the isospin they carry), though the names 'truth' and 'beauty' were briefly in competition, and colliders working with B quarks are sometimes even now called " Beauty Factories ".
Randall likely applied "left" to "strange" and "right" to "charm" simply due to the placement of the particles in the table: In the American English vernacular, the phrase "left and right" is more common than "right and left", in the same way that "top and bottom" is more common than "bottom and top", and "up and down" is more common than "down and up". So he placed "left" above "right" to match the ordering of the other quark generations.
While Randall leaves two leptons, the electron and the muon, untouched, he has opted to discard the tau lepton entirely. Each of these three leptons has an associated neutrino; Randall has decided to discard all but the electron neutrino, as he has decided that three are too many neutrino types. He has also replaced the standard symbol for the neutrino, the Greek letter ν (nu), with a capital N, in order to avoid confusion between ν and v, the two letters appearing similar, though this might further be confused with nucleon (particle physicists commonly use N to denote "proton or neutron", and excited states of nucleons are given the symbol N, followed by the mass in parenthesis [1] ) or possibly even with the symbol for Nitrogen (the atomic nucleus with 7 protons and a similar number of neutrons, encountered more in radiology/chemistry as an N, 7 N, 14 N, N + , N 2 and other variations).
In place of one of the neutrinos, Randall has introduced a new elementary particle that supposedly explains the existence of dark matter. The nature of dark matter is one of the most famous mysteries in physics: galaxies seem to have much higher gravity than their detectable matter would account for, yet this mysterious form of matter does not seem to interact with other matter in any other detectable way. Neutrinos are known for rarely interacting with other matter, due to their lack of charge, which could justify Randall's decision, but even the little interaction that neutrinos have with the weak force rules them out as candidates for dark matter.  Hypothetical sterile neutrinos could be the source of dark matter, and also for the small but nonzero masses of the familiar neutrinos, but no such particles have yet been identified. Together with the arrow, the only one in the comic that points at the particle's box rather than the symbol, the triumphant exclamation "We found it!" probably means that the new "dark matter" entry in the table is the dark matter particle.
Randall proposes several new names for existing particles.  First, that the W and Z bosons should be renamed to the charm and strange bosons, respectively (taking the names from the quarks), and second, that the Higgs boson should be named the Vin Diesel boson, as he considers Peter Higgs 's name to be too boring to be given to a particle.  The Higgs boson is known in the popular press (to the chagrin of many physicists, including Higgs) as " The God Particle ", which is certainly a flashy name, but which itself was changed by the editors of the book of the same name from its authors' originally-intended title: The Goddamn Particle.
Randall inserts the graviton, a purely theoretical particle, noting that its inclusion is "probably fine". While the graviton has never been observed, it is occasionally included in diagrams of the standard model to show its hypothetical place, which likely convinced Randall to do the same. Here it is shown below the Higgs boson, implying to be a scalar boson, though it is theoretically a 2nd-order tensor boson (with a spin of 2) and is usually given its own column.
Randall also proposes that a false decoy "Magic" particle should be added to the Standard Model, to trip up promoters of quantum mysticism .  Presumably, anyone who invokes this particle to support their claims will expose themselves as a fraud, much as cartographers will print trap streets on their maps to catch plagiarism.
Finally, Randall adds "Cool bugs" as a fundamental particle, with an explanation of "Very small bugs are fundamental particles now".
The title text builds on the "Cool bugs" entry, joking about what spin bugs would have if they were a fundamental particle.
The title text references quantum spin number , a property of particles in physics that bears similarities to actual spinning. Although the cool bugs particle is put in the scalar boson group with spin 0, Randall states that it instead has spin 1/2, like a fermion. It is thus not clear whether cool bugs obey the Pauli exclusion principle or not. Unique among elemental particles, cool bugs are affected by wind, which can change their spin.
Changes highlighted in red .
[A chart of the Standard Model of particle physics with red marks all over the chart.] Changes I would make to the Standard Model
[In reading order:] u up, connected to the down quark below. c charm, connected to the strange quark below, in faded gray with a red l left written over it. Above is a red note with an arrow pointing to the :charm quark. The note reads, Consistent quark names (use "strange" and "charm" for bosons) t top, connected to the bottom quark below. g gluon H Higgs, in faded gray with a red V Vin Diesel writted over it. To the right is a red note with an arrow pointing to the Higgs boson, which reads, With all respect to Peter H, the Higgs boson needs a flashier name
d down, connected to the up quark above. s strange, connected to the charm quark above, in faded gray with a red r right written over it. b bottom, connected to the top quark above. γ photon G graviton, in red with a red border. To the right is a red note with an arrow pointing to the graviton, which reads, Let's just include it, it's probably fine
e electron, connected to the electron neutrino below. µ muon, connected in faded gray to the muon neutrino below, with red rounded corners cutting it off. τ tau, connected to the tau neutrino below, in faded gray with a red scribble over it. On the tau lepton is a red note which reads, No one needs tau leptons Z Z boson, with the Z symbol and the Z in the name in faded gray. The symbol has a red s written over it and the Z in the name is scribbled out in :red. The word strange is written in red between the symbol and the name. M magic, in red with a red border. To the right is a red note with an arrow pointing to the magic particle, which reads, Decoy particle for people making nonsense claims about "quantum" philosophy stuff
v e electron neutrino, with the e as a subscript of the v, connected to the electron above. The v is in faded gray and a red N with a circle around it is written on it. Below is a red note with an arrow pointing to the electron neutrino, which reads, Fix neutrino symbol so I stop mixing up ν and v v μ muon neutrino, with the µ as a subscript of the v, connected to the muon above, in faded gray with a red scribble over it. On the muon neutrino is a red note which reads, Too many neutrinos v τ tau neutrino, with the τ as a subscript of the v, connected to the tau lepton above, in faded gray. Written over it is a D dark matter in red with a red border. Below the tau neutrino is a red note with an arrow pointing to it, which reads, We found it! W W boson, with the W symbol and the W in the name in faded gray. The symbol has a red c written over it and the W in the name is scribbled out in red. The word charm is written in red between the symbol and the name. 🐞 cool bugs, in red with a red border. To the right is a red note with an arrow pointing to cool bugs, which reads, Very small bugs are fundamental particles now


Synonym Date

Explanation:
Ponytail asks Hairy about Megan , his date. Hairy mentions that she's a talented writer and seems cool, but when prompted by Ponytail, says Megan is into synonyms. Megan apparently enjoys unsettling Hairy with words. Ponytail thinks word games aren't too bad, and she would be right if it weren't for Megan's unsettling use of them.
In the next panel (labeled "Earlier..."), it's raining (or humid), and Hairy comes back in. Megan comments, "Ugh, it's so watery out. You must be clammy! Want to guzzle some tea?" replacing wet (or humid ), cold (or sweaty ), and drink with more suggestive, possibly-repulsive-sounding words. "Clammy" does technically refer to having damp skin, but it is usually used in the context of nervousness or illness, and "guzzle" suggests very rapid consumption, which is not a safe way of drinking hot tea, and is also considered rude when enjoying a meal with others, especially romantic interests. Continuing, she says, "Let me slough off this dress, and slither into something more comfortable," replacing take (or remove , or disrobe ) and slip . This last sentence of course strongly suggests snakes shedding their skin.  Serpentine movements are sometimes regarded as alluring and attractive , but people usually don't favorably compare their clothing to snakes' skin care. [ citation needed ]
She further elaborates on this in the title text, saying "We need some grub to munch -- I'll go slouch over to the kitchen." By using the word "grub," she presumably means the slang term for basic food like the type served in pubs (which is often greasy fast-food, served in a dirty -- one might even say grubby -- environment), though it may also invoke the image of white insect larvae, like pale lumps of flesh squirming in a dark hole, while "slouching" has connotations of laziness or suspicious activity, rather than romance.
Excessive use of uncommon words is a common trope in fiction, and also seen in real life. Usually, the speaker is trying to demonstrate their superior intelligence or knowledge. Megan, on the other hand, seeks to use a similar tactic to make listeners uncomfortable. The words she's using aren't especially complex or uncommon, and they're technically correct, but they've been selected to evoke disgust in the listener.
Strange synonyms were also the focus in 1322: Winter , and a similar concept was the joke in 919: Tween Bromance (although in that strip, Cueball was making Megan uncomfortable).  Megan has previously shown off her love of uncomfortable puns ("Vore of the Roses") in 2245: Edible Arrangements .
Randall has written many comic strips before about his (comical, fictional) hobbies , but this is the first time he's written about someone else's hobby.
[Ponytail and Hairy talking.] Ponytail: So, how is she? Hairy: Well...she's a talented writer. Seems very cool. Ponytail: ...but? Hairy: She's really into...synonyms.
Ponytail: I don't understand. Hairy: Her hobby is finding the most unsettling possible words for any sentence. Ponytail: Word games? That doesn't sound too bad. Hairy: Well...
[Caption above reads "Earlier..."] [Megan is wearing a dress and talking to Hairy, who is dripping wet.] Megan: Ugh, it's so watery out. Megan: You must be clammy! Want to guzzle some tea?
[Hairy is now less wet and holding a cup of warm tea.] Megan: Let me slough off this dress, Megan: and slither into something more comfortable.


Hurricane Hunters

Explanation:
The comic strip opens with Black Hat explaining to Cueball (who is presumed to be some government official) that flying into hurricanes, while risky, provides valuable scientific data. Although the eye itself is relatively calm, it is surrounded by the eyewall , a region of extremely intense thunderstorms.  Thus, the danger of flying through such storms must be carefully weighed against the scientific knowledge being gained.  In the real world, such missions are conducted by highly-trained pilots with specialized aircraft, such as the NOAA Hurricane Hunters and the US Air Force's 53rd Weather Reconnaissance Squadron (also nicknamed "Hurricane Hunters").
However, Cueball's comment in the third panel shows that Black Hat is not discussing the activity of hurricane hunting in general, but rather is attempting to justify his decision to fly a passenger jet through the eye of a hurricane.  Passenger airliners are not meant to fly into hurricanes, [ citation needed ] and can easily crash there.  It's not clear if Black Hat is (somehow) a jet pilot himself, has come into ownership of an airline and was merely directing a flight, or, probably most likely , simply hijacked the flight he happened to be on, but the commercial jet passengers were not expecting to "participate" in a hurricane hunting mission.  Black Hat replies that, instead of being upset, the passengers should be proud of their contributions to meteorology, but their contribution is probably negligible, as they were not actively collecting useful scientific data.
This comic is likely referencing both Hurricane Laura , which was active during the week prior to this comic strip's publication, and Microsoft Flight Simulator 2020 , which players have been utilising the software's ability to simulate real-time weather to fly into and  explore the (virtual) aforementioned hurricane. The simulator currently only has passenger aircraft available to pilot, echoing Black Hat's flying of a commercial jet into a hurricane. A similar situation where historical/well-documented experimental techniques are used in inappropriate situations occurs in 1594: Human Subjects , albeit by test subjects rather than “researchers”, if Black Hat can be called that.
In the title text, Black Hat says that their flight gathered data on the possibility of making loops in the eye of the hurricane by passenger airliners, but if it had actually done a loop, he probably would have said so.
The Boeing 707 was made to successfully execute a barrel roll and fly inverted during a 1955 test flight . If no flight envelope protections are active, barrel rolls are possible with any aircraft and any helicopter, because the aircraft and its fuel systems only experience mild and positive g loads, never negative ones. Likewise, the air flow stays the same as in level flight. Problematic is ending the barrel roll, as there is a possibility of exceeding the safe speed limits.
Another passenger jet that was barrel-rolled is the Concorde . Pilots Brian Walpole and Jean Franchi did on a test flight - not once, but several times.
Loops are a lot more problematic because of the speeds reached when ending the maneuver, and the speed needed to begin it. But like the barrel roll, a loop can be flown while only experiencing mild and positive g loads. In fact, Harold E. Thompson flew several loopings in a Sikorsky S-52 , a helicopter first flown in 1947. Prolonged inverted flights, though, cause negative g forces, an altered air flow, and cause havoc with the fuel systems, parts of which are gravity-driven. Aircraft that can fly inverted for longer than a few seconds are specifically designed, for example aerobatic aircraft and fighter jets.
It is possible that this is his justification of why the flight contributed to meteorology. However, passenger airliners' abilities to do loops has nothing to do with that field of science. Moreover, the same data could be gathered by flying the same airliner without passengers, or with willing ones.
[Black hat facing left] Black Hat: Yes, flying into the eye of a hurricane is dangerous.
[Cueball on left at a desk being addressed by Black Hat on the right] Black Hat: But it provides us with crucial data that helps us understand and predict these storms.
[Same as previous cell, with Black Hat raising his hand] Cueball: But your passengers had bought tickets to St. Louis. Black Hat: They should be proud of our contributions to meteorology!
Everything on Cueball's desk has gone missing in panel 3.


Stellar Evolution

Explanation:
This is a pun on the main sequence , the continuous and distinctive band of stars that appear on Hertzsprung–Russell diagrams . Stars on this band are known as main-sequence stars. These are the most numerous stars in the universe, and include the Earth's Sun. The main sequence forms a major part of a star's life cycle, with smaller stars spending more time on it, where they transform hydrogen to helium via nuclear fusion to generate energy and sustain themselves.
Miss Lenhart starts off apparently describing the main sequence. However, she veers off into the history of Maine , the most northeastern of the 48 contiguous US states. She mentions the separation of Maine from Massachusetts and its lobster fishing industry, similar to how, soon after the beginning of their lifespans, stars evolve from early stages (like T-Tauri stars) and go onto the main sequence, where they become stable and stay for a long time. She makes a play between "main" and the U.S. state of " Maine ", which are homophones . The allusion to stars might also be a reference to the representation of individual states as stars on the canton of the US flag.
The title text puns on either the state or the star slowly growing for a long time, before suddenly becoming "redder". In the case of the state, the population of Maine has been slowly but steadily growing over the last century, increasing from about 700,000 in 1900 to about 1,350,000 in 2020. [1] Similarly, stars with a mass of 0.6–10 M☉ slowly grow while they are on the main sequence, then increase in size and leave the main sequence in the subgiant phase, before suddenly becoming red giants.
In American politics, "red" most recently refers to the Republican party (NBC showed Republicans in blue and Democrats in red until 1996, and CNN until 1992). While in the past Maine has frequently voted for Democratic party candidates, Republican party candidates have increasingly won more campaigns or lose campaigns with larger minorities of the vote. For instance, Maine, which has used a district-based voting system, voted in its entirety for the Democratic party presidential candidates in the 1992, 1996, 2000, 2004, 2008, and 2012 presidential elections, but one of its districts voted for Republican candidate Donald Trump in 2016 and 2020. Meanwhile, a main sequence star transitions eventually into a red giant , also becoming "redder". Alternatively, the color change could refer to lobsters; when one is cooked, it turns from a bluish-green to a bright red-orange. "Red" is unfortunately also used in the derogatory terms "rednecks" for rural lower income folks (Maine is a predominantly rural, lower income state), and "redskins" for indigenous Native Americans (discussion of indigenous empowerment has been rising in Maine).
[Miss Lenhart stands in front of a chalkboard. On the board are squiggly lines of text and a series of growing circles] Miss Lenhart: After a star begins fusing hydrogen, it may reach a stable equilibrium in which it separates from Massachusetts and develops a thriving lobster industry. Miss Lenhart: This is known as the Maine Sequence.


University COVID Model

Explanation:
This comic is another in a series of comics related to the COVID-19 pandemic .
Cueball begins telling Megan an anecdote about how a college decided to reopen "based on a COVID model developed by two physicists." (The incident in question is likely a reference to this article and tweet about the University of Illinois, that went viral with similar wording the day before the comic was published). Presumably, the model predicted that the university could allow students to return to campus while still keeping cases of COVID-19 under control, perhaps using some combination of reduced classroom and residence hall density, and by implementing policies against large social gatherings.
Before he can get further, Megan interrupts him with "Uh oh," perhaps worried that an epidemiological model created by people who aren't epidemiologists could be ineffective. Alternately, she may be expressing concern specifically about physicists' epidemiological modelling. Cueball then confirms her fears by saying that the model underestimated how many parties the students would hold, and so the actual number of cases on campus has turned out to be greater than even their worst-case prediction. Megan facetiously wonders how a physicist could have failed to know how much college kids party, implying that physicists do not attend many parties. Cueball, representing Randall , a physics major, then retorts that he "was invited to multiple parties! And attended both of them!" implying first that he was invited to many parties over an undefined period of time at college, but then admitting it was only two.
In the title text, Randall, no longer in-character, admits to attending at least a third party, and possibly a few more that have been forgotten, and confirms this was over the entire course of his degree studies, likely 4-8 years or more. This demonstrates, as an introverted physics major who struggles with social interactions ,
he (and by implied extension most Physics majors) has little interest in attending parties.  As many other people go to college for the parties rather than the education [ citation needed ] , we can only imagine how severely his campus epidemiology model would underestimate the number of opportunities for the coronavirus to spread.
A nontrivial number of colleges followed this trajectory in 2020, such as the aforementioned University of Illinois at Urbana-Champaign .
A different comic with physicists modeling another field is 793: Physicists .
[Cueball and Megan are talking to each other.] Cueball: Apparently some university reopened based on a COVID model developed by two physicists. Megan: Uh oh.
[Cueball raises an arm slightly.] Cueball: But even their worst-case model underestimated the number of student parties and they had to shut down.
[Cueball holds up a finger.] Megan: Can't understand why someone with a physics degree would be bad at judging how often college students get invited to parties. Cueball: Excuse me, I was invited to multiple parties. Cueball: And attended both of them!


Constellation Monstrosity

Explanation:
Constellations in the night sky are formed by pattern-forming various asterisms and other stellar relationships in the night sky.
Being rather subjective, different cultures have inculcated differences in their interpretations, some subtle and others less so, for the exact same objective views of the night sky. Even where the same groupings are recognised, different cultures can 'see' different forms behind that group of stars. However, observers in the southern hemisphere will see entirely new constellations not visible to those in the northern one, and vice-versa, whilst observing those patterns fully visible to both (on the ecliptic ) as inverted and therefore may inspire vastly different conceptualised images or even connectivities.  The International Astronomical Union has demarcated the sky into 88 constellations , mostly those known to ancient Greece (catalogued by Ptolemy) plus southern constellations designated by astronomers during the European Renaissance.
Randall has taken one particular zodiac (or at least part of the hellenic one, closely tied to western astrology and still inspiring astronomical naming) and imagined further lines connecting stars to link up four separate constellations, to create a portmanteau constellation with a portmanteau name. As a matter of fact, this connection is half true, since Libra used to be the two claws of a much larger Scorpio, the larger constellation having been split in two when the twelve zodiac signs were set as they are now.
The four constellations used here are Scorpio (the scorpion), Libra (the scales), Virgo (the virgin/maiden) and Leo (the lion), sequentially spread across the sky in positions relating to a span of astrological dates running 'backwards' from late November through to late July. The name Randall gave this meta-constellation, however, uses a different order to combine as "Virg(o, l)ibra(, )scorp(io & )leo". Possibly "Scorlibirgoleo", or a similar mash-up with the same source order, did not roll together nicely enough for his liking.
In reality, any apparent proximity of stars on the celestial sphere does not guarantee an actual proximity in the depths of space, either within or between constellations. Knock-on effects from this renaming would not change actual scientific understanding, but it could have a knock-on effect upon star catalogues and databases if this object regrouping forces so many incidental name changes to the current referencing system, which is why the astronomers are upset (as indicated in the title text). Similarly, astrology's conceit based upon four separate 'characters' and life-paths, arising from birth-signs and planetary transits across four distinct areas of the sky, would lose 'precision' if forced to accept a single symbolic area in their stead. Astrologers would be very upset because their work (interpreted charitably) is related to understanding the influences of the stars on life on Earth; they might be concerned that " crossing the stars " could lead to " disaster ". It's not clear how Randall hoped to alter the practices of either group with his changes, but he was banned from the IAU for his efforts ( not the first time this has happened ).  Randall previously mentioned being banned from the IAU in 541: TED Talk , but the reason stated in that comic was "redefinition of the 'planet' to include the IAU presidents' mom", so presumably he was reinstated and then banned again.
This monstrosity is reminiscent of the infamous 2009 Dutch horror film known as The Human Centipede , in which three humans are bound together such that their digestive systems are connected in sequence.  In this image, the head of Virgo appears to be connected to the hindquarters of Leo, and likewise the mouthparts of Scorpio are fixed to the bottom of the "stand" of Libra.  Libra's stand appears to go under Virgo's dress; to form a complete "celestial centipede", it should attach to Virgo's hindquarters, but judging by the connection between stars, it probably (mercifully) connects to her foot.
[Within a frame, a long title is written in a short arc above the drawn elements] Virgibrascorpleo
[Upon a background of astrological imagery merged in accord, basic point-and-line astronomical/astrological representations of Scorpio, Libra, Virgo and Leo are illustrated.] [(Scorpio may be slightly rotated/translated for aesthetic reasons.)]
[Red lines have been added to link stars in adjacent constellations.] [ Beta Scorpii may be connected to Sigma Librae (once known as Gamma Scorpii)] [ ...also Pi Scorpii may be connected to Tau Librae ] [ Beta Librae may be connected to Mu Virginis ] [ Nu Virginis may be connected to Beta Leonis (better known as Denebola )]
[Caption below the frame] I got kicked out of the International Astronomical Union for adding extra lines between the constellations to create a monstrosity.


Polls vs the Street

Explanation:
This comic discusses getting data or opinions through a study (polls) or by getting them anecdotally (on the street). The phrase "voice on the street" is commonly used by news reporters who get opinions on issues by literally asking people walking by what they think, and has been previously mentioned (and derided) in 756: Public Opinion .
Many news organizations, and other data-driven institutions, conduct or commission polls to assess the opinions of the general public.  These polls generally rely on asking a randomly selected and anonymous set of people a set of consistent, prepared and deliberately crafted questions about their opinions, experiences, and intents. The results of these polls are traditionally held to reflect the views of the public as a whole, within certain margins for error. Many news shows also conduct "man-on-the-street" interviews (more formally known as vox populi , "voice of the people"), to provide a human face of "the public" and engage viewers more.  Many pollsters, pundits, and politicians worry that polling data may not accurately reflect the true trends in public opinion, as in the infamous " Dewey Defeats Truman " newspaper headline, and so White Hat is here extolling the virtues of interviewing "real people" to get at that ground truth.
White Hat suggests that, while polls suggest "candidate X" is more favored, the people on the street that White Hat interviews are more supportive of "candidate Y". He implies that his experiences reflect reality better than the polls. There are a number of reasons why polls may not be entirely representative.  The sampling method might not be genuinely random, some groups might be less likely than others to respond to a poll, and it's argued that some people express views that they consider to be more socially acceptable, even in anonymous polls, but vote differently in actual elections (examples include the " Bradley effect " and the " shy Tory factor "). Despite these concerns, there is little evidence that individual conversations do a better job at determining public opinion than polling. However, attempting to get a person from off the street to report for a news anchor instead would obviously exacerbate all of these problems immensely, rather than fixing anything.
This comic is very likely a reference to the 2020 United States presidential election , which occurred on November 3, 2020 (about 2 months from the time of the comic's publication), which Democrat Joe Biden won. Most polls showed Biden polling ahead of incumbent Donald Trump, but Trump and his supporters frequently argued that the polls are inaccurate, often arguing that they personally knew or talked to many Trump supporters, and few Biden supporters. At the same time, the fact that Trump won the 2016 election astonished many (including Randall) who had seldom met Trump supporters in their own lives and within their own social circles. This kind of anecdotal evidence is generally a poor basis for gauging public support, for multiple reasons. Politics in the US are frequently regional, so sampling in a single area is unlikely to be representative of the whole country, or even a whole state. It's not uncommon for gathering places (both physical and virtual) to attract people from one political group more than another, producing a skewed sample. If someone uses their own perception, rather than rigorous analysis, confirmation bias is likely to have a major impact (a person might pay more attention to supporters of their preferred candidate, and ignore political opponents).
This strip lampoons such thinking, as it quickly becomes clear that White Hat's methodology is heavily driven by selection bias. He's apparently talking only to the residents of his town, and extrapolating those results to the whole country. By that logic, he would conclude that everyone has visited his town, and most people live there.  It is true that he's getting "ground truth", but it's also true that he's only sampling a very small (and highly idiosyncratic) part of the whole population.
The punchline in the final panel is a joke about the phrase "on the street". Usually this phrase means "anywhere out in public where the interviewer can openly approach people" (often a sidewalk near the studio), but White Hat is presumably taking the phrase literally and interviewing people he meets on the roadway. In the US, roads are generally reserved for vehicles (cars, trucks, motorcycles and in most areas bicycles), and walking or standing in the roadway for long periods is dangerous and usually illegal. White Hat's sample population thus consists only of the people who can be found on the roadway outside of designated pedestrian zones, who are generally from the small fraction of the population who have no qualms about the risks of being struck by moving vehicles or causing accidents when drivers swerve to avoid them.
The title text is a joke about selection bias and tautology . People who don't feel like taking surveys wouldn't get as far as answering a survey question about survey questions.  However, it does touch on an issue raised by FiveThirtyEight after the election: that polls only measure people who are interested in answering polls, and that population may not be politically representative of the entire country .
White Hat: Polls are just numbers. White Hat: You have to talk to people on the street .
White Hat: Polls say most people support <Candidate X>. White Hat: But the people I talk to on the street support <Candidate Y>.
White Hat: Polls claim most people don't live in my town and have never been here. White Hat: But the people I meet on the street tell a very different story.
White Hat: According to polls , most people don't like playing in traffic. White Hat: So why do I never seem to meet these people on the street ?


Gravitational Wave Pulsars

Explanation:
Pulsars are rotating neutron stars, which have a very precise period of rotation. Pulsars are highly magnetized, causing a them to emit a beam of electromagnetic radiation that rotates across their sky. Radio astronomers can detect these beams if and when they point towards Earth, where they appear as pulses of radiation with highly stable periods. They use the pulsars' periodic beams to try to detect gravitational waves by tracking the rotation period of an ensemble of pulsars extremely precisely over long periods of time. Disturbances in the pulsars' rotation period will be measurable at Earth. A disturbance from a passing gravitational wave will have a particular signature across the ensemble of pulsars, and will be thus detected. The process is called "pulsar timing" , or just "timing" for short.
Ponytail presents this to Cueball as a joke - specifically, a joke about comedy. One of the most important aspects of comedy is revealing the punchline with correct timing. Ponytail sets Cueball up for a joke like, "Ask me what the secret of comedy is." / "What's the secret of--" / "Timing!" In this format, the punchline ("Timing!") deliberately comes too soon, which makes it funny because the timing is bad. Ponytail also replaces the secret to comedy with the secret to detecting gravitational waves with pulsars, to set up the joke about the word "timing".
The title text is a play on a well-known real estate saying that the three most important parts of a real estate deal are "location, location, location." In 3D Euclidean space , the three Cartesian coordinates {X, Y, Z} all refer to locations along the three axes.
[Single panel with Ponytail and Cueball standing facing each other] Ponytail: Ask me what the secret to detecting gravitational waves using pulsars is.
Cueball: What's the secret to detecting grav—
Ponytail: Timing!