Every Major's Terrible

Explanation:
Randall has written a song called Every Major's Terrible and this comic illustrates the song. In this song the term Major refers to the US version of an academic major. The point of the song is that it makes no sense to pick any major since they are all terrible!
The header notes that the song is written to the tune of the satirical Major-General's Song from Gilbert and Sullivan's 1879 comic opera The Pirates of Penzance . The song satirizes the idea of the "modern" educated British Army officer of the latter 19th century. Major general is a military rank in the United Kingdom and many other countries. (As of August 2018, the title text has been changed to a link to the said song ). The meter in the Major-General's Song is iambic octameter , which means that in each line there are eight iambs, where an iamb is two syllables in an unstressed-stressed pattern. Therefore, each line contains 16 syllables.
The panels show Randall's rewritten lyrics to the song. Below each of the three verses are described in detail (go to Verse 1 , Verse 2 or Verse 3 ). Each verse ends with "Just put me down as 'Undecided' - Every Major's Terrible", which gives the song its name — and "Major's Terrible" is similar enough to "Major General", the corresponding lyrics in the original version, to serve as a callback. The last line of the first verse in each song goes as follows:
The lyrics are commonly rewritten, the most famous rewrite likely being The Elements (song) by Tom Lehrer which is also mentioned below the main header. This song is also available on-line .
His last suggestion, " Supercalifragilisticexpialadocious ", from Mary Poppins , is another fast-paced patter-song with a somewhat similar tune, though it doesn't fit quite so well, and the match falls apart at the end of the fourth line, when the "Um-diddly"s start up — still, it's better than nothing.
There are at least two performances of this xkcd song online where the transcription is shown to make it easier to understand the text:
Regarding the title text: "Undeclared" is sometimes called "General Studies". Most U.S. universities will not let you get a degree in this, let alone an advanced degree such as a Ph.D. Also, it should probably be noted that this song refers to U.S.-like university systems, in other countries, one will study little to nothing outside your major, making it more-or-less impossible to be undecided as to major.
It should also be noted that the title text fits the cadence of the first line of the song, possibly teasing a fourth verse. As to what that consists of, only Randall knows.
Panel 1, Philosophy's just math sans rigor, sense, and practicality Cueball is posing as Rodin 's The Thinker , a common symbol for philosophy . The equation in the background (two plus light bulb equals sailboat) is nonsense, hence " math sans rigor, sense or practicality" ( sans meaning without).
Panel 2, And math's just physics unconstrained by precepts of reality. A cannon is firing. However, instead of going in the normal parabolic arc (a precept of reality and thus physics ), the cannonball splits and splits again, so that it looks like a bifurcation diagram from chaos theory . The dashed line indicates the cannonball's trajectory, which bifurcates twice, although the sum of the momentums of the four resulting (1/4 sized?) cannonballs is presumably mathematically identical to the original.
Panel 3, A business major's just a thing you get so you can graduate Business is the most common major, often seen as a practical choice applicable to a wide variety of careers, or, as the comic illustrates, preferred by those who just want an easy way to graduate. Cueball gets his diploma and runs away from the dean on the podium while shedding both his robe and his square academic cap (or Mortarboard).
Panel 4, And chemistry's for stamp collectors high on methylacetate. Stamp collecting refers to the famous quote by Ernest Rutherford , "All science is either physics or stamp collecting." Methyl acetate is a solvent that for instance can be used to remove stamps from their envelope (although water will do the same). The stamps in the background form the periodic table of the chemical elements. And since chemistry is not physics, according to the quote, chemists must be stamp collectors (as, the high on methylacetate, Ponytail wearing goggles and holding an Erlenmeyer flask ).
Panels 5 and 6, Why anyone who wants a job would study lit's a mystery , Unless their only other choice were something like art history. These lines, both sung by Cueball, refer to subjects where a majority of graduates will end up unemployed or eventually working in a field outside their majors. Topics such as Literature or Art History are often and historically said to be in this category — although from actual statistics , it is clear that there are far worse majors these days.
Panels 7 and 8, A BA in communications guarantees that you'll achieve , A little less than if you'd learned to underwater basket-weave Here Cueball first has a major in Communications and next he is seen underwater with a basket. Underwater basket weaving is a commonly used metaphor for any college major that is easy and/or worthless. "Communications" is a major chosen by people interested in news broadcasting or other media. Note that, if following the original music exactly, the line "A little less than if you'd learned to underwater basket-weave." will be repeated three times by the chorus after these panels.
Panel 9, I'd rather eat a Fowler's toad than major in biology, We see Cueball holding a frog out in front of him while taking his hand to his head (in disgust?). A Fowler's toad is a relatively common toad in the eastern US, and a stereotype of studying biology is a frog dissection , which is likely part of the reference, albeit oblique. Fowler's Toad emits a noxious secretion that irritates skin and thus probably also the mucous membranes in the mouth. It would thus be rather painful to eat, making it very bad for Cueball to major in biology since he would rather eat such a toad.
Panel 10, And social psych is worse than either psych or sociology. Social psychology is compared to sociology (study of humans in society) and psychology (study of human minds). Psychology is represented by a serial killer with a chainsaw, and sociology is represented by a zombie . These are to the left of Megan . To her right is a zombie serial killer with chainsaw. She is standing between them undecided as to take one, the other or both. They are all terrible options...
Panels 11 and 12, The thought of picking any one of these is too unbearable, Just put me down as "Undecided"—Every major's terrible. End of the first verse where Cueball tells his academic advisor that he is undecided as every major's terrible. He even throws away his study guide . Every verse ends with some variation of this couplet, and in the original tune, each of these couplets are repeated by the chorus afterwards. Unbearable and terrible rhyme for people who have the Mary-merry merger .
Panel 13, Now, if you can't prognosticate, that's OK in seismology, Prognosticate means "to predict". This refers to the inability of seismology to reliably predict catastrophic earthquakes , even after centuries of extensive research. The panel shows seismic waves from a seismograph . The seismograph chart has four traces and about halfway across one trace begins oscillating vigorously indicating an earthquake. Five months after this comic was published several seismologists in Italy were convicted of crimes that effectively stemmed from an inability to predict an earthquake. This does not go down well for the message of this panel... Their conviction was overturned on appeal in 2014.
Panel 14, But if your hindsight's weak as well, you'd best stick to theology. The bearded theologist represents Theology by stating the formal logic proposition shown in the illustration: "X ∴ ∃X". This says "I can describe this thing called X, therefore X exists". This is what Anselm’s ontological argument for God boils down to. Briefly, it asks you to imagine the best possible deity, which, by definition, would be God. A God which exists in both reality and theory would be greater than one who exists in merely the latter. Therefore, this proposition concludes that God exists. The fatal flaw of this argument is that it can be used to prove the existence of anything (e.g. a vacuum cleaner which exists in both reality and theory is greater than one which exists merely in theory). Just because a perfect God would exist does not mean he does. Thus it has been largely rejected. (See 1505: Ontological Argument .)
Panel 15, CS will make each day a quest to find a missing close-paren. "CS" is short for " Computer Science ." Most programming languages use parentheses as part of their syntax, and often have multiply-nested parenthetical expressions. This is especially true of Lisp . It is often difficult for a programmer to determine where the unbalanced parenthesis begins or ends when the code and parentheses are not properly formatted and indented. In the panel there is one more left "(" parenthesis (13) than right ")" or close-paren (12).
Panel 16, Virology will guarantee you'll never get a hug again. Virology is the study of infectious diseases . The green symbol above the central figure is the biohazard symbol , implying that people who study infectious diseases, and are therefore located near them at some points in time, will be shunned like the plague, because they're probably carrying it. Thus no hugs to Megan as three Cueballs and Ponytail lean back away from her.
Panel 17, I.T. prepares you for a life of fighting with PCs nonstop. "I.T." is short for " Information Technology ", a degree for people who maintain computer systems. If there is a need for an I.T. position (in which I.T. professionals are employed) there are computers which need fixing — hence the I.T. Professional is always fixing (or fighting) computers, which may or may not have been "broken" by users . In the panel Megan, wielding an axe, is in a real fight with a PC.
Panel 18, As Pratchett said, "Geography's just physics slowed with trees on top." This is a slightly amended quote from Discworld author Terry Pratchett , from his book " Feet of Clay ". The actual quote is " Geography is just physics slowed down, with a couple of trees stuck in it." But the meaning is the same, that physics also describes geography - a similar quote to the one about physics vs. stamp collections mentioned under panel 4.
Panel 19, Though physics seems to promise you a Richard Feynman-like career, Richard Feynman was a 20th-century Nobel -laureate physicist known for his great sense of humor, including being photographed for one of his books while holding a bongo drum . Here he is depicted with the drum and with both a blond woman and Megan looking admiringly upon him. Feynman made physics seem cool, and many a young fan might choose the subject in the hope of obtaining a Feynman-like career. This is, however, very unlikely for most people as is also shown in the next panel.
Panel 20, The wiki page for "Physics major" redirects to "Engineer." A redirect on Wikipedia is a page which immediately sends the visitor to a different page. This implies that the title of the first is either a synonym or a sub-topic of the second. Physics majors usually learn to code, and the standard joke is that they invariably get hired as computer programmers after graduation, but here in this comic they get hired as engineers . This relates back to the previous panel, as it is here shown that most of those that major in physics end up as engineers and not like Feynman.  The Wikipedia page physics major didn't actually exist when this comic was published. It was created the same day, but as a redirect to physics education . It is such a redirect page that is shown in the panel. In the subsequent days, there were dozens of instances of people changing it to redirect to engineer, usually reverted within minutes. The redirect page was fully protected and locked for editing. As with the underwater basket-weaving line in the first verse, after the soloist sings this, the line would be repeated three times by the chorus.
Panels 21 and 22, They say to study history or find yourself repeating it, But all that it prepares you for is forty years of teaching it. This uses a version of a quote by George Santayana (although often attributed to others as well), Those who cannot remember the past are condemned to repeat it as a reason to study history — only to be followed by an indication that by studying history as a major, you will only be prepared to become a history teacher, and you will then spend the rest of your life teaching history. The first panel shows a flow chart that will lead you to repeat your sad past if you cannot remember it, and only move on to happier times if you can. In the next panel we see a Hairbun as a history teacher, with glasses and her gray hair tied up in a bun, standing in front of a green blackboard with three important years for her current history class.
One connection between these years could be pivotal points in Jewish history concerning the formation of nationality: the Nurenberg Laws of 1935 removing citizenship from Jews in Germany, Israel's claims on Jerusalem, and the UN Security Council's condemnation of the treatment of Palestines by Israel.
A more lighthearted connection, more in line with the message of learning from history, is the collapse of three notable communications towers: the wooden radio tower in Langenberg in 1935 (by tornado), a TV mast at Emley Moor in 1969 (due to ice build-up), and the Warsaw radio mast in 1991 (due to construction errors). This demonstrates various attempts and failures to learn from engineering mistakes from the past, connecting this with the earlier mentioning of physicists becoming engineers, and perhaps not taking real-world practical considerations into account (such as storms or ice build-up).
Of course, in practice, with a narrow enough subject, there are likely to be many more examples fitting these three years. The two examples above were from general world history.
Panels 23 and 24, I recognize my four-year plan's at this point not repairable, But put me down as "Undecided"—Every major's terrible. End of the second verse where Cueball again talks to his academic advisor saying that he is undecided. In the last of the two panel he says almost the same as at the end of the first verse. In the first, however, he mentioned his "four-year plan" which is the list of all the courses a student plans to include in their degree program. If you change majors every semester, or do not decide on one until too late, this list gets really difficult to turn into any one degree. Again these lines would be repeated by the chorus afterwards.
Panel 25, Astronomers all cringe when they hear "supermoon" or "zodiac". Supermoon is a term invented by astrologers in the 1970s, with no significance in astronomy other than being the co-occurrence of orbital perigee and full-moon. But it comes up often in the press, linked to supernatural behavior. That also Randall dislikes seems realistic and he also "mocked" the term soon after in 1080: Visual Field and then finally confirmed what he thought about the term directly when he published 1394: Superm*n . This was the first comic referencing supermoon, here is a list of all such comics. The zodiac is the circular band in the sky containing the apparent path of the sun, moon and planets.  Most often when people talk about it, they're referring to astrology and horoscopes and other pseudo-scientific notions which often lead to conversations which are frustrating to astronomers, like the bearded one from the panel.
Panel 26, Agronomy's a no-go; I'm a huge agorophobiac. Agronomy is the science of farming, while agoraphobia is the fear of wide open spaces. Fields, where most farming happens, are wide open spaces. In the panel an anxious Cueball is standing near a fence on an open field with a tractor. Presumably he may be OK inside the tractor, but once he gets outside he becomes anxious.
Panel 27, I'm too ophiophobic to consider herpetology, Herpetology is the study of reptiles and amphibians , while ophiophobia is the fear of snakes (a reptile). The panel shows sweating Cueball holding his hands to his mouth while looking at a green snake asking for his love? It is possible that Cueball is afraid of the snake, who is harmless and just wants to be friends.
Panel 28, And I can't stomach any part of gastroenterology. As the pun suggests, gastroenterology is the study of the human digestive system and the image shows the human stomach . To not be able to stomach something means you can't stand or tolerate this thing.
Panel 29, While pre-med gives you twitchy-eyed obsession with your GPA, Pre-med (pre-medical) is a major chosen by students hoping to go on to medical school to study medicine and eventually become doctors . Medical school is extremely competitive and usually requires a very high undergraduate GPA for prospective students. Hence we see a pre-med student holding all his grades.
Panel 30, a poetry degree bespeaks bewildering naïveté. The text is in all lower-case, a different font and strangely laid out compared to the text in all the other panels. All-lower-case and "free" layout are both associated with 20th century " Modernist " poetry , especially the works of E. E. Cummings . Ponytail is actually reciting this line of the song.
Panels 31 and 32, TV's behind the rush into forensic criminology , (Or so claims meta-academic epidemiology). This refers to how forensic - criminology shows, specifically CSI: Miami (Crime Scene Investigation: Miami) as shown on the TV screen in both panels, often dramatize, exaggerate or otherwise confuse the science behind forensics; this gives people unrealistically glamorous views of the career, thus encouraging them to join it. Epidemiology is the study of causes and effects of events and trends. We see a pipe smoking epidemiologist standing with Ponytail and watching CSI - presumably making wild claims on cause and effect based only on what they see on TV. This is, again, the point where the chorus joins in three times, as in the previous two verses.
Panels 33 and 34, By dubbing econ "dismal science" adherents exaggerate; The "dismal"'s fine - it's "science" where they patently prevaricate. "Econ" is short for " economics ". Thomas Carlyle declared economics " the dismal science " in the Victorian era as a derogatory alternative name. Economists often claim that economics is a science like any other; however, as the predictive powers of all economic theories are exceedingly weak compared to those of any science, this is disputed by those outside the field at times. It is of course also disputed by this song, in which Cueball "clearly" (see below) states that economics should not call itself a science - that is the dismal science is not derogatory enough for him.
Panel 35, In terms of choices, I'd say only Sophie's was comparable. Panel 36, Just put me down as "Undecided"—Every major's terrible! End of the third verse, with yet another variant on the closing couplet. Choosing a major is compared to Sophie's Choice , which is any dilemma where choosing one cherished person or thing over the other will result in the death or destruction of the other, derived from the theme of the novel of the same name, which has also been turned into a romantic drama film . So Cueball tells the academic advisor that choosing any of the majors over any other is as horrible as to have to choose which cherished person should die to save the other. Although in his case, it is the other way around, since he thinks all choices suck. Again these lines would be repeated by the chorus.
[The entire comic is a 4 by 9 grid. Left-justified headings above the 36 panels:] Every Major's Terrible to the tune of Gilbert & Sullivan's Modern Major-General Song (Which you may know from Tom Lehrer's Elements . If not, just hum Supercalifragilisticexpialidocious .)
[To make it easier to read the lyrics, the lyrics text is double indented. If no one says the line it is just written after the description. Unless otherwise stated, the text is inside the frame of the panel above the drawing. If any other text is present it will be written after the lyrics.]
[Panel 1: Cueball sitting with his chin on fist on a square, gray rock. Next to him is a mathematical expression "2 + a picture of yellow glowing light bulb  = picture of Cueball in sailboat on a blue sea".] Philosophy's just math sans rigor, sense, and practicality Expression: 2+[lightbulb]=[sailboat]
[Panel 2: A black and brown cannon standing on a green hill fires and a dashed line indicates the cannonball's trajectory. The line splits in two twice ending up at 4 cannonballs.] And math's just physics unconstrained by precepts of reality.
[Panel 3: A student in robes and square academic cap receives a diploma from a dean on a brown podium, while Cueball, diploma in hand, runs away on the green lawn, arms in the air, shedding both robe and cap.] A business major's just a thing you get so you can graduate
[Panel 4: Ponytail wearing goggles and holding a flask with the periodic table in the background.  Three stars and circle lines around her head indicates that she is dizzy.] And chemistry's for stamp collectors high on methylacetate.
[Panel 5: Cueball holds up his hands questioningly, in a shrugging pose.] Cueball: Why anyone who wants a job would study lit's a mystery
[Panel 6: Cueball holding his chin.] Cueball: Unless their only other choice were something like art history.
[Panel 7: The text is above this panels frame, which is only about two third of the other frames. In the frame is a close-up of Cueball as a graduate wearing yellow embroidered robe and yellow tasseled mortarboard.] A BA in communications guarantees that you'll achieve
[Panel 8: The text is above this panels frame, which is only about two third of the other frames. In the frame is the same Cueball graduate, only now he is submerged in blue water. A wicker basket flows to the left, where air bubbles escape from Cueball. To the right are two black fish.] A little less than if you'd learned to underwater basket-weave
[Panel 9: Cueball holding a gray frog at arm's length.] Cueball: I'd rather eat a Fowler's toad than major in biology, Frog: Ribbit
[Panel 10: Megan indicating to the left a scruffy individual and an individual holding a chainsaw, and to the right a single scruffy individual holding a chainsaw.] Megan: And social psych is worse than either psych or sociology.
[Panel 11: Cueball stands in front of a brown desk holding a gray course catalog. Behind the desk sits a man with glasses and hair at the back of his head. He sits on his gray office chair. There is a stack of papers on the desk.] Cueball: The thought of picking any one of these is too unbearable.
[Panel 12: Same picture as panel 11, only now Cueball tosses the course catalog over his shoulder.] Cueball: Just put me down as "Undecided"—Every major's terrible.
[Panel 13: The text is above this panels frame, which is only about two third of the other frames. In the frame is a seismograph chart with four traces; about halfway across one trace begins oscillating vigorously.] Now, if you can't prognosticate, that's OK in seismology,
[Panel 14: A bearded man with white hair states a formula with his left arm lifted.] But if your hindsight's weak as well, you'd best stick to theology. Bearded man: X ∴ ∃X
[Panel 15: Two lines with gray parenthesis.] CS will make each day a quest to find a missing close-paren. (((()((((()( ))))())())())
[Panel 16: Megan with a green biohazard symbol floating above her head stands alone; to the left and right three Cueball-like guys and Ponytail shun her.] Virology will guarantee you'll never get a hug again.
[Panel 17: Megan running at a PC on a brown table at the left of the frame, with a brown and black axe raised over her head.] I.T. prepares you for a life of fighting with PCs nonstop.
[Panel 18: The frame is a little smaller than the other frames. Above the frame is the first part of the text. In the frame is an image of a bearded man with glasses who says the rest of the text. ] As Pratchett said, Pratchett: "Geography's just physics slowed with trees on top."
[Panel 19: A man with black hair plays on brown bongo drums while Blondie and Megan lean into the frame and look at him from left and right respectively.] Though physics seems to promise you a Richard Feynman-like career,
[Panel 20: The text is above this panels frame, which is only about two third of the other frames. In the frame is screenshot of a wiki redirect page. Below the title is the normal text for such a page. This is unreadable though, although it is possible to imagine it is possible to read the first line which would say: From Wikipedia, the free encyclopedia . But not the other line which would be Redirect page . Below this line is an arrow down to the page the redirect points to. This is written in blue underlined letters.] The wiki page for "Physics major" redirects to "Engineer." Wiki page: Physics major Engineer
[Panel 21: Flowchart: a gray-brown box with a sad face chains to a decision diamond reading simply "?"; the "yes" branch leads to a yellow happy-face box while the "no" branch loops back to the initial sad face.] They say to study history or find yourself repeating it, Flow chart: ? No Yes
[Panel 22: The text is above this panels frame, which is only about two third of the other frames. In the frame is Hairbun as a teacher with boxy spectacles and a bun in front of a green chalkboard with three years in white. She is holding a rod and using it to point at the board.] But all that it prepares you for is forty years of teaching it. Chalkboard: 1935 1969 1991
[Panel 23: Cueball at his adviser's desk again as in panel 12, but now without any catalog and holding his arms down.] Cueball: I recognize my four-year plan's at this point not repairable,
[Panel 24: Same as panel 23 except Cueball has raised a first and the adviser has his hand to his mouth.] Cueball: But put me down as "Undecided"—Every major's terrible.
[Panel 25: Image of a bald man with beard and glasses. He raised both hands one as a fist the other pointing up. There are lines out from his head to the left and lightning lines out from his head to the right.] Astronomers all cringe when they hear "supermoon" or "zodiac".
[Panel 26: Silhouette of Cueball, agitated, in an open field near a fence and a tractor.] Agronomy's a no-go; I'm a huge agorophobiac.
[Panel 27: Cueball looking aghast at a green snake on the ground, both hands at his mouth and sweat jumping from his head. The snake is "saying" a red heart with a black question mark next to it.] I'm too ophiophobic to consider herpetology, Snake: ♥ ?
[Panel 28: Anatomical image of a stomach in pink and red.] And I can't stomach any part of gastroenterology.
[Panel 29: A man with wild hair, glasses askew, clutching folders and papers (green, blue and white), and dropping several.] Man: While pre-med gives you twitchy-eyed obsession with your GPA,
[Panel 30: Ponytail reciting poetry; her poem is this panel's line, in a lighter, lower-case font.] Ponytail: a poetry degree bespeaks bewildering naïveté.
[Panel 31: The text is above this panels frame, which is only about two third of the other frames. The frame is a TV screen with the CSI: Miami logo, CSI in yellow.] TV's behind the rush into forensic criminology TV screen: CSI: Miami
[Panel 32: A balding man wearing glasses and holding a smoking pipe together with Ponytail holding a notebook watch a wall-mounted flat-screen TV on which the CSI: Miami logo from the previous panel is showing.] (Or so claims meta-academic epidemiology). TV screen: CSI: Miami
[Panel 33: Cueball is talking with his left arm raised, palm up.] Cueball: By dubbing econ "dismal science" adherents exaggerate;
[Panel 34: Close-up on Cueball with right arm up and one finger in the air.] Cueball: The "dismal"'s fine—it's "science" where they patently prevaricate.
[Panel 35: As panel 23 with Cueball at his adviser's desk once more though with both hands held out in front of him. The adviser is holding his hand to the side of his head.] Cueball:In terms of choices, I'd say only Sophie's was comparable.
[Panel 36: Same as panel 35 except that Cueball makes a final dramatic flair spreading both arms out.] Cueball:Just put me down as "Undecided"—Every major's terrible!


Ten Thousand

Explanation:
This strip argues that one shouldn't make fun of people for not knowing something that's considered common knowledge. The basic premise of the first panel is that, since people aren't born knowing anything , everyone has to learn everything for the first time, at some point. If everyone eventually learns a given fact, there are an average of 10,000 people, in the US alone, who learn the fact for the first time each day.
The approximate rate of 10,000 people per day hearing about something for the first time is estimated by the birth rate of 4,000,000 people per year divided by 365 days per year, assuming that the birth rate is constant and that indeed everyone learns or gets the fact (or that those in the US who don't are about equal in number to those in other countries who do). The target age of thirty years is irrelevant in this calculation; the 10,000 number is simply equal to the number of newborns per day, or equivalently, the number of people who reach a given age each day.  (The fact that not everyone lives to be that old, and some die younger, is not considered.)
The second panel points out that (certainly, for someone like Randall), teaching people an interesting fact for the first time is fun .  Mocking someone for their lack of knowledge makes them less likely to reveal that they don't know something, which means you don't get the opportunity to share in the experience as they discover it.  Taking this approach is much more socially effective and generally enjoyable than mocking them for being ignorant. When Cueball learns that Megan doesn't know about the "Diet Coke and Mentos thing", he refers to her as "one of the lucky 10,000" who's experiencing it for the first time that day.
Diet Coke is a popular brand of sugar-free soda. Mentos is a brand of chewable mints. Famously, if you drop Mentos into a bottle of Diet Coke, the soda will erupt quite aggressively , sending a fountain of soda 10 feet or more into the air.  This interaction is widely beloved because it's dramatic and unexpected, while being generally safe, simple, and inexpensive to do (though it does make quite a mess, and should only be done outdoors). This effect appears to only happen with this specific type of soda and this specific mint, and is believed to result from a very particular interaction between the ingredients in the two, the texture of the mints, and the carbonation in the soda.  This was explored, in some details, in a Mythbusters episode .
The Diet Coke and Mentos eruption has also been mentioned in a previous strip 346: Diet Coke+Mentos .
The title text provides another, perhaps more emphatic example of how explaining a fact to a person for the first time is much more entertaining than just expressing annoyance about that missing knowledge. Here is a good video about the Yellowstone supervolcano . Interestingly enough, both events includes some kind (although very different kind) [ citation needed ] of eruption.
Supervolcanos are again mentioned in 1159: Countdown and in 1611: Baking Soda and Vinegar .
This comic also appears in Randall Munroe's book How To , in the introduction of the book, albeit in a modified form.
[Caption above the panel:] I try not to make fun of people for admitting they don't know things. [Caption right below said caption:] Because for each thing "everyone knows" by the time they're adults, every day there are, on average, 10,000 people in the US hearing about it for the first time.
[A list of equations.] Fraction who have heard of it at birth = 0% Fraction who have heard of it by 30 ≈ 100% US birth rate ≈ 4,000,000/year Number hearing about it for the first time ≈ 10,000/day
[Caption above the next panel:] If I make fun of people, I train them not to tell me when they have those moments. And I miss out on the fun.
[Megan is standing. Cueball is walking, with his palm out.] Megan: "Diet Coke and Mentos thing"? What's that? Cueball: Oh man! Come on, we're going to the grocery store. Megan: Why? Cueball: You're one of today's lucky 10,000.


The Bacon

Explanation:
This comic plays off the English colloquialism "bring home the bacon", which generally means to work hard and bring money home to your family to put food on the table. If a man is out of work he may be stressed out about how to "bring home the bacon."
Some men would not be assuaged if their wife took over, but at first it seems that White Hat is happy that his wife, who works as a pharmacist, does bring home the bacon, and he tells this to Cueball .
Later, however, Cueball finds out, that what White Hat actually was saying was " Thebacon ", which is a common name for dihydrocodeinone enol acetate an opioid commonly marketed under names like Acedicon and Diacodin. As a pharmacist White Hat's wife has easy access to such drugs, and this may be the reason that he is so calm, because his wife supplies him with painkiller drugs. Opoids suppress emotional pain as well as physical pain.
Thebacon is compared to the better known drug Vicodin , another opioid sold as a painkiller, which can (and often has) become a drug of abuse.
The title text lists what Randall assumes to be the normal pronunciation for Thebacon. This hints at the second joke in this comic. If White Hat said "THEE buh kon" there is no way for Cueball to confuse that with "the bacon". Apparently Cueball was reading White Hat's word balloon rather than hearing him speak aloud.
According to Wikipedia , Randall seems to be mistaken in no fewer than three places (which seems to indicate that Randall has only passing knowledge of the drug and did not do extensive research beforehand):
[White Hat is holding out a hand towards Cueball while telling him about his job situation. The space between the and bacon is very small.] White Hat: I'm out of work, but I'm not stressed about it because my wife is a pharmacist and she brings home the bacon.
[Caption below the panel:] Only later did I learn that "Thebacon" is the common name for dihydrocodeine enol acetate, a synthetic opioid similar to Vicodin.


Kickstarter

Explanation:
Kickstarter is a platform for funding projects in which anyone can give money at any level of funding starting usually as low as $10. Funding at different levels gets you different perks, e.g. If the Kickstarter is for a book, a large donation makes you eligible for a signed copy.
In this comic, Black Hat is attempting to game the system by raising money to work on the perfect Kickstarter pitch. He appears to have gained no money, but has only started the scheme that day. The title text is an attempt to entice people to pledge a larger amount, by guaranteeing a more prestigious pledge level during the actual campaign. This is a scam for (even more) gullible people, as anyone can give any amount of money; there are no limits on pledge levels - or, at least, it may have been that way at the time of this comic's publication. Kickstarter does actually allow campaign hosts to designate a finite amount of higher-tier rewards, so if a wealthy person knew in advance that they would want to guarantee a specific reward from a pledge level, this VIP-list-first-dibs offer may have been desirable.
This has actually been done via an indiegogo campaign . There are a number of similarities to the comic (the black hat, $5,000 vs $500 goal), so Baron von Husk may have got the idea from xkcd.
[A kickstarter page with zero donations, a target of $5,000 (and no money raised), and 90 days to go.] [Black Hat has posted a video and a description of his project, the first lines of which are visible.] Time was, anyone with a webcam and an idea could raise boatloads of cash on Kickstarter. But with increased popularity comes tougher competition. Now, to get support, you need a really standout video or compelling write-up.
I have an idea for a Kickstarter campaign that could raise millions, but I need your help to craft the perfect pitch.
If I raise $5,000, I'll be able to devote the


Felidae

Explanation:
This comic shows a graph with three parts.
First, the names are sorted up by genera (plural of genus , a low-level taxonomic rank used in the biological classification of living and fossil organisms) from bottom to top of which animals would win in a fight. Secondly, the names within the genus are then sorted by coolness of name from left to right (the degree of "coolness" of the name is apparently determined in subjective manner by the author). Thirdly, in red you can see the direction that Apple has taken with nicknaming the versions of their OS X operating system. They started at v10.0 "Cheetah", and have moved through genera from there in no order that this chart can make out.
Please note that the second words in "Snow Leopard" and "Mountain Lion" are capitalized in the table because they are used as the proper names of the operating system versions. In their normal use, as species vernacular names , they are not capitalized and are written as "snow leopard" and "mountain lion".
Bobcats are a running XKCD joke, so their inclusion is to be expected. The genus Puma here only lists synonyms for the puma (see cougar ) instead of the actual genus . Of course, the three OS X versions named by three of these synonyms are not the same.
Since this comic was published, Apple has stopped naming versions of OS X after big cats, and now names them after Californian landmarks. OS X v10.8 "Mountain Lion" was followed by v10.9 "Mavericks", named after a surf spot , followed by v10.10 "Yosemite", named after a national park , and so on.
The title of the chart depicted on the comic ("OS X problem") is perhaps an allusion to the travelling salesman problem , as the directed arrows and graph nodes might appear as a possible path of the salesperson between the cities. The computational difficulty of the travelling salesman problem might echo with the difficulties that the author has with trying to figure out the underlying reason for naming the OS X versions in particular order. The chart thus looks like a parody on the scientific presentation.
In the title text, a Smilodon fatalis is a saber-tooth cat, a Dracorex hogwartsia is a dinosaur whose skull looks like that of a fairy tale dragon, and a Stygimoloch spinifer is one of the last dinosaurs before the K-T (Cretaceous-Paleogene) extinction about 66 million years ago. Notably, it's possible both Stygimoloch and Dracorex are in fact juvenile members of the genus Pachycepholosaurus who were wrongly identified as a separate species, meaning two of Randall's top four coolest extinct animal names would no longer be recognized. All of the animals mentioned in the title text are now extinct.
Well-known felines: [A graph organizing various feline species labeled with common names ordered by genera (in order of which would win in a fight) on the y axis, and coolness of name on the x axis.] Smilodon (extinct): "Saber-toothed cat (scientific name: Smilodon fatalis) Panthera: "Jaguar", "Leopard", "Snow Leopard", "Tiger", "Lion" Puma: "Cougar", "Puma", "Panther", "Mountain Lion" Other felidae: "Ocelot", "Cheetah" Felis & Lynx: "Housecat", "Bobcat", "Wildcat", "Lynx" [Some elements are further connected using an unbranched acyclic digraph. The elements are connected thus: "Cheetah" -> "Puma" -> "Jaguar" -> "Panther" -> "Tiger" -> "Leopard" -> "Snow Leopard" -> "Lion" -> "Mountain Lion".] The OS X Problem


Klout

Explanation:
Klout was a site that sought to measure your "influence" on social media networks. They sometimes gave away "perks" to the users with the highest Klout scores, as a means of advertising the products of their sponsors. Generally, the information provided by Klout was not held in high esteem. The type of person who took most interest in their score was typically not well-liked.
There are multiple ways that Klout measured your influence. An example of increasing influence is having been given a +K (a recommendation for a higher score) for knowledge about "Pitbull" (The Bud Light promoter and producer/rapper/musician, etc., not the type of dog). Another could be having an inspiring tweet that generated 2000 retweets. Klout supported many social networks, and ranked people based primarily on how much reaction they garner from the public. For example, if Selena Gomez tweeted that she simply loved a certain blog, she would probably get more people to visit that blog, and thus get a bigger Klout score, than if the mayor of Anchorage, Alaska tweeted that he liked that blog. Or xkcd publishing a comic about Klout would lead to an all time high in Google searches for it. However, their "about us" page did claim that a small, active group of followers is considered more influential than a large, passive group of followers.
The gist of the comic is that Cueball (here representing Randall ) does not feel that Klout agrees with his core values, probably as he prefers self-assurance to having an outside authority tell him of his importance to society. He uses this comic to give himself incentive to stay away from Klout. He is very clear that he is dead serious about anyone meeting him after he has (been proven to have) used Klout should punch him in the face. He even makes sure that he cannot later retract this statement, if he for instance becomes interested in Klout (something he would never wish for). Because his last statement is that people should ignore anything he says to retract this statement later.
Randall will now have a problem though because since he also posted the 706: Freedom comic earlier, he will never know if people that hit him does because they believe he has used Klout or just to exercise their free will.
In the title text, a "dead man's switch" is any mechanism which is designed to activate if the user does not take any action. This is generally used to create a failsafe in case the user is incapacitated . For example, many exercise treadmills include a tether meant to connect the runner to the machine's base station. If the runner gets too far from the base station, the tether pulls a pin and the machine stops immediately. This way, if the runner has fallen or is struggling to keep up, the machine does not exacerbate an already unsafe situation. Randall's "douchebag deadman switch" is a variation that would trigger if he ever became enough of an asshole to use Klout. This would lead to him being constantly punched in the face, so he doesn't dare become that type of person.
Shortly after this comic was posted, a Klout user was created claiming to be Randall. This was a fake, so if you ever meet Randall in real life, please don't punch him, unless you view making a webcomic about Klout counts as interacting with it.
Klout shut down on May 25, 2018, for reasons that were never officially stated, but are generally assumed to be related to the General Data Protection Regulation , which went into effect on that day.
[Randall has drawn himself as Cueball in a slim panel:] Randall: I'd like to ask a favor. Randall: If someday, in the future, we meet in person,
[Zoom out of Randall talking.] Randall: And if, as of that day, I've interacted with Klout in any way except to opt out, Randall: I want you to punch me in the face without warning.
[Zoom in on Randall's head.] Randall: This may sound like a joke, so let me be clear: Randall: I am dead serious . Randall: Ignore anything I say retracting this. Randall: Thank you.


Old-Timers

Explanation:
In this comic the man with the beard thinks he is Leet and tries to show this to his conversations partner by calling her noob (see also n00b ). He claims that he has been on the internet since the BBS days, and thus long before his conversation partner was even born.
A Bulletin Board System , or BBS, is an online service based on microcomputers running appropriate software. They were the precursors to modern day online forums.
However, he is up against Science Girl who tells him he is wrong. She explains that her parents took samples of their sperm and egg and sequenced the DNA . The resulting genome was then e-mailed to the Venter Institute where they synthesized the genome and used this to create the egg and sperm that became Science Girl.
The J. Craig Venter Institute (JCVI) is a non-profit genomics research institute founded by J. Craig Venter , Ph.D. in October 2006. Although what Science Girl is describing may be possible this comic must take place in the future as this has not yet been used to create human beings.
Her point though is, that the man is wrong when he says that he has been on the internet. When you are "on-line" you are really just looking on the screen where the results found "on" the internet is displayed. So he has been looking at the internet. The girl's genome (which is basically the closest you can come to the data a computer would need to create you) has been sent on-line in an e-mail. So in her words, she has actually been there.
Objectively, the Science Girl is just as bad as her adult conversational partner; simply being the most significant advancement in test tube babies in over two decades doesn't prove anything about your personal knowledge or experience. Subjectively , however, her reputation alone is more than enough to stun and thus "defeat" anyone who actually understands her special heritage, as well as of course her pun and correction regarding being and looking on the internet. It is also worth noting that it was technically her parents' sex cells, not her, which traversed the internet.
The title text is another common retort from "old timers" that they have been doing X since before the younger person was born. In this case, Science Girl accepts that the old timer was "on the Internet" before she was born, but so was she... At least in the form of her genetic information.
[A man with black hair and a neck beard types away at his computer screen.] Man (typing): Whatever, noob. I've been on the internet since the BBS days. Screen (reply from the noob): Wrong. type type
[The noob turns out to be Science Girl, with two hair buns, who kneels on her chair, typing at a laptop on a table in this frame-less panel.] Science Girl (typing): Before I was born, a lab took egg and sperm samples from my parents and sequenced the DNA. type type
[The man sits at his desk, reading his screen.] Screen (Science Girls writing): They emailed the genome to the Venter Institute, where they synthesized the genome and implanted it into sperm and eggs which became me.
[Science Girl still typing on the laptop.] Science Girl (typing): So, no. Science Girl (typing): You've looked at the internet. Science Girl (typing): I've been there. type type


Bel-Air

Explanation:
This comic is a take on the 90s TV series Fresh Prince of Bel-Air and its much parodied and repeated theme song. Consequently, the song coming out of Cueball 's TV right now is a take on that song. The joke is that Will Smith has somehow gone from being a successful rap star to an ambitious politician. Doggerel is a derogatory term for verse considered of little literary value or a comic verse of irregular measure, or in this case, rap music. Obviously, the song is updated with a reference to Adele , who was, of course, not performing during the series' run, seeing as she was two years old at its start.
In the last panel, Cueball is annoyed about this stupid show and he switches to another channel or turns the TV off. The timing of the "click" indicates that he became annoyed when the song turned into a political advertisement and/or he did not want to hear "some Adele for ya" be rhymed with the name of the city Philadelphia .
The title text refers to Mr. Smith Goes to Washington , a 1939 Academy Award-winning movie about an idealistic young man who is chosen to be a Senator and soon finds himself battling corrupted politicians, perhaps as Will Smith might be in this comic. The two characters/character and actor is a coincidence that Randall plays on. Aaron Sorkin is the writer behind the comedy drama The American President and the creator of political television drama The West Wing . Pat Toomey is a current U.S. Senator of Pennsylvania (which includes Philadelphia), who was first elected in 2010.
The theme song of Fresh Prince of Bel-Air was also referenced in 464: RBA .
[Cueball sits on an easy chair in front of a TV.] TV: Well, my posh Bel Air life took a turn for the worse.
TV: It's a story best related in a doggerel verse.
TV: So kick back, relax, lemme put on some Adele for ya,
[Cueball raises the remote and points at the screen.] TV: While I tell you why I'm running for mayor of Phila- CLICK


Crowdsourcing

Explanation:
Crowdsourcing is the practice of obtaining needed services, ideas, or content by soliciting contributions from a large group of people, and especially from an online community, rather than from traditional employees or suppliers. In the new Internet economy, it is not uncommon for companies to rely on crowdsourced designs or ideas, to contract the marketing to another firm, or to interact with customers through social networks established by other companies.
Cueball , however, is describing a business strategy which manages to do all three by "crowdsourcing" the process of getting a company and a prospective employee together. Cueball describes it as helping people with ideas find funding, similar to Kickstarter or Indiegogo, but rather than setting up a system to facilitate the process, he plans to use already-existing social networks (such as Facebook and Twitter).  Effectively, by relying on outside support for all steps of the business plan, his company does nothing; however, because the parts of his strategy are all feasible separately, and because he describes them with a barrage of trendy buzzwords, his audience is impressed and fails to notice the company's essential pointlessness.
In the title text Cueball claims that "we don't sell a product, we sell the marketplace," a phrase that typically describes a company whose business model is to facilitate the business of other companies, and would be a plausible reason for a company to not make products. However, this is revealed to be yet more empty buzzwords when Cueball clarifies that they don't actually do any work and instead play video games ("shooters" refer to shooter games, a genre of video game).
[Cueball is standing in front of a flowchart on a wall, indicating with a pointer. A man and two women are looking on with interest. One woman holds a briefcase.] Cueball: We crowdsource the design process, allowing those with the best designs to connect— Cueball: via already-in-place social networking infrastructure— Cueball: with interested manufacturers, distributors, and marketers. [Caption below the panel:] Nobody caught on that our business plan didn't involve us in any way— it was just a description of other people making and selling products.


EST

Explanation:
This comic pokes fun of attempts to "fix" the calendar by making it simpler or more rational, which inevitably result in a system just as complicated. This is an example of the paradox in complexity theory that if you attempt to simplify a system of problems by creating a new system of evaluation for the problems you often have instead made the problem more complex than it was originally.
Randall advertises his idea for a "Universal Calendar for a Universal Planet". He combines calendar definitions with time zone definitions. The abbreviation EST in this comic stands for Earth Standard Time (hence the title), but it is in itself a joke on the American Eastern Standard Time . In the rest of the explanation, EST refers to the comic's Earth Standard Time.
Because there are approximately 365.2422 days in a solar year , various calendars use different means to keep the calendar year in sync with the solar year and the seasons. The Julian Calendar, for example, has leap days every four years, giving it an average year length of 365.25 days. The most widely used system is the Gregorian calendar , which also has leap days every four years, but skips leap days in years divisible by 100 unless the year is also divisible by 400, the latter additions come from Earth's axial precession . This gives it an average year length of 365.2425 days, which is very close to the length of a solar year (see detailed explanation in this video: Earth's motion around the Sun, not as simple as I thought ). Other calendars have been proposed, some of which do not count leap days and special "festival days" as a day of the week, in order to make every date fall on the same day of the week every year.
Many of the claimed benefits for the calendar are highly dubious:
The features of the calendar get increasingly bizarre as the description proceeds:
[Caption above the frame:] xkcd presents Earth Standard Time (EST) A universal calendar for a universal planet EST is... Simple • Clearly defined • Unambiguous Free of historical baggage • Compatible with old units Precisely synced with the solar cycle • Free of leap years Intermittently amenable to date math
[Inside the frame a list of the details concerning EST is shown:] Units Second: 1 S.I. second Minute: 60 seconds Hour: 60 minutes Day: 1444 minutes (24 hours 4 minutes) Month: 30 days Year: 12 months
Rules For 4 hours after every full moon, run clocks backward. The non-prime-numbered minutes of the first full non-reversed hour after a solstice or equinox happen twice.
[In two columns the "Epoch" is put into a contrasting juxtaposition to "Time Zones":] Epoch 00:00:00 EST, January 1st, 1970 = 00:00:00 GMT, January 1st, 1970 (Julian Calendar) Time Zones The two EST time zones are EST and EST (United Kingdom) . These are the same except that the UK second is 0.9144 standard seconds.
[A few further statements:] Daylight saving: Countries may enter DST, but no time may pass there. Narnian Time: Synchronized✔ Year Zero: EST does have a year 0 . (However, there is no 1958.)


Budget News

Explanation:
This comic is a use of homonym of the word "hawk" in the phrase " Deficit hawk ". Wikipedia has a great definition: "Deficit hawk is an American political slang term for people who place great emphasis on keeping the federal budget under control. Deficit hawks believe the best way to reduce the deficit, pay off national debt, and balance the budget is by a combination of increasing taxes and cutting government spending."
And obviously, a hawk is a type of bird of prey.  In this case, the prey is politicians. This event may have been contrived, as a certain Black Hat is visible in the audience.
In the title text, there is a reference to the sugar glider , which is a small gliding possum originating from the marsupial infraclass or subclass. They are generally considered to be cute and harmless, as well as being relatively obscure, indicating a politician who is humorous and good-natured enough to make such a comparison, as well as nerdy enough to know what a sugar glider is.
[The front page of a newspaper with the name of the paper in large gray letters at the top, and several unreadable sections left of, right of, and below the main front page news. A large heading is written to the left of a photo on the right. In the photo a man with black hair who has been standing behind a lectern with a microphone delivering a speech is falling towards the left and holding out one hand in that direction while blocking his face with the other hand against an attack from a large black bird. Below the podium with the lectern is the top of the crowd in the front row. Five Cueball-like guys (two cut off at the edges), a person with black hair and Black Hat to the right can be seen. Below the headline and below the picture are black lines indicating the main text in the article.] Title: The Daily News Headline: Deficit Hawk Attacked by Regular One


Kill Hitler

Explanation:
After Black Hat announces his completion of a time machine which will only ever work once, Cueball gives a common suggestion for what to do when you have a time machine: killing Adolf Hitler , the Austrian-born dictator who famously led the Nazi Party to a hostile takeover of the German government, which eventually led to World War II where the Nazis conducted a military invasion of several other European countries and a genocidal campaign known as the Holocaust . Even though Black Hat has other (and probably better) ideas about how to use his time machine, he relents to Cueball's pleas and goes off to kill Hitler, comically using the casual phrase "BRB" which is an abbreviation for "be right back". He soon returns, commenting that he found Hitler in a very noisy bunker in the year 1945.
In the real world, Hitler and his wife Eva Braun committed suicide on April 30, 1945, in Hitler's personal office in the Führerbunker . Berlin was the last major stronghold of Nazi Germany at that point, and was under heavy military assault by the Soviet Union, making it fairly obvious to the Nazis that they wouldn't control the city for much longer. Germany surrendered to the Allied forces almost immediately after Hitler's death, bringing an end to the European side of the War (the Pacific side, mostly fought between the United States and the Nazi-allied Empire of Japan, would linger on for a few more months until Japan was driven to surrender by two nuclear attacks ). The fact that Black Hat killed Hitler in the Führerbunker in 1945 means that the War and the Holocaust had already resulted in the deaths of millions, and history would not be significantly changed by murdering Hitler at that point. Also, Black Hat's comment that "1945 was loud!" suggests that Berlin was already under attack when he emerged in the Führerbunker, implying that the killing took place around the time Hitler would have taken his own life anyway, possibly just a few moments before.
Cueball's intent was clearly for Black Hat to travel back to a time before Hitler's rise to power, in the hopes that killing him back then would prevent both the War and the Holocaust; he's therefore horrified by the realization that Black Hat had used his sole opportunity for time travel and probably made little difference at all. This is typical Black Hat behavior, going out of his way just to troll people like Cueball and cause horrible things to happen, in this case deliberately not changing any history or avoiding any of the atrocities carried out by Nazi Germany. That might be for the best, however, since killing Hitler early might cause more problems than it would solve .
Sure enough, there are some conspiracy theories claiming that Hitler had no intention of taking his own life and was actually shot dead by someone else, most of them relying on some kind of "evidence" that Hitler and Braun weren't alone in the room when they died. If this comic was meant to be taken as a serious theory on Hitler's death, it would suggest that Black Hat was directly responsible, but because he used a time machine to reach Hitler's office, historians would have no knowledge that he was ever there and therefore could only conclude that Hitler and Braun killed themselves instead. Also, if the Novikov self-consistency principle is true, it means that Hitler's suicide was interrupted by Black Hat in the first place, and Black Hat was merely going back in time to do the thing he already did.
The title text refers to the time travel theme from the Superman movie in which Jor-El states, "It is forbidden for you to interfere with human history." Here it is suggested that Black Hat needs to know some history before going back in time to interfere with it, perhaps so that he would do the right thing and kill Hitler before the Holocaust and World War II.
[Black Hat and Cueball stand in front of a double door, which bears the label 'TIME door'. Black Hat has his hands on his hips.] Black Hat: I finished my time machine, but it's one-use-only. Cueball: You gotta kill Hitler.
[Close-up of Black Hat, one hand palm upward.] Black Hat: Why are you so obsessed with this Hitler guy? We have all of time we could explore!
[Close-up of Cueball with both hands palm upward.] Cueball: He's evil incarnate! He murdered millions and sparked global war! Everyone agrees—if you get a time machine, you kill Hitler.
[Black Hat enters the now open Time door as the other man looks on..] Black Hat: Fine, fine, I get it! Calm down. BRB, killing Hitler.
[Black Hat returns, shutting the door with one hand. Cueball has outstretched arms.] Black Hat: There. Done. Are you happy? Cueball: Thank you. Black Hat: He was in some kind of bunker. 1945 was loud! Cueball: NO!


Front Door

Explanation:
This comic is showing in graphical form three different actions/feelings as Randall is approaching his front door at night. His "Fear That There's Something Behind Me" rises, so then his "Forward Speed" rises to get to his door faster. And then when he gets in the door and finds that in fact, there is nothing behind him, his "Embarrassment" rises. The y-axis of the chart is not labeled, so it is presumed to indicate amount, as in how embarrassed Randall is.
The interesting fact revealed is that Randall gets more concerned that someone is behind him when he walks up the steps to this door, and not while walking in the yard where there might be more hiding places. The worst fear is just before he walks up the steps to lock himself in. This is probably because now that he is almost home and safe, he now has to fumble with the key concentrating on getting the key in the lock, thus not being able to pay attention to what's coming up behind him.
This is of course an irrational thought, but it seems to happen to many people, and has certainly been used for suspense in many movies, whether it is "Did I hear a noise upstairs?" or "Is that an axe murderer hiding in that hedge?" or "There might be a velociraptor lurking nearby". (However in all of these cases getting inside would probably not help you anyway just adding to the funny part of how the fear drops once inside. See 87: Velociraptors for why getting inside probably also would not help against them.)
The title text attempts to alleviate the problem of the following embarrassment by introducing potential threat that could affect anybody. Since Randall mentioned that he will randomly release a wolf into a front yard sometime in the next thirty years, there will always be a fear that a wolf has been released onto your front yard. In that case, the fear one feels will be justified and not embarrassing, as it is possible that there is indeed a wolf released by Randall into their front yard. However, even assuming that Randall can find and release a wolf onto someone's front yard, the chance of this happening to you is minuscule.
[A graph with three colored lines. There is no scale on the Y-axis but the X-axis represents geographic location and has four labels. From the Y-axis to around the midpoint is "Yard", with an arrow from the word yard pointing left, at a point beyond the midpoint there is a tick labeled "Steps", at a point after that is another tick labeled "Door", and all points afterward are "Inside" with an arrow pointing right from the word inside, there are no tick for the first and last label. The three lines are all labeled with a small lines going from the label to the lines. The blue line begins to slowly increase from the start, with a slight dip further into the yard, and a steep increase right before the steps, maxing on the steps, and declining steeply at the door, bottoming out once inside. The gray line is at a steady medium height until it gets to the steps, at which point it shoots upwards, and then slowly declines once inside. The red line stays at 0 until just before the steps, where it begins to trend upwards, spikes at the door, and begins to slowly decline once inside. Above the curves to the left there is a black frame with the title of the graph:] Walking Back to My Front Door at Night: X-axis labels: Yard Steps Door Inside Blue line: Fear That There's Something Behind Me Gray line: Forward Speed Red line: Embarrassment


Shoes

Explanation:
Cueball is a knight that has saved a kingdom. It seems that he is being rewarded by a god, since his reward is inside a box that is floating in a beam of heavenly light. Inside the box is a pair of shoes with five toes - and with these magic shoes, he can outrun Death .
This comic refers to a new type of running shoes which have very little actual support with individual areas for each toe (they are supposed to make you feel like you are running barefoot). Specifically, the shoes Cueball takes out of the box look like Vibram FiveFingers .
The joke in the comic is that the shoes are so strange/creepy, that Cueball is not even sure he would want to live forever if he would have to wear these shoes at all times. Immortality is not worth it.
The title text is a play on the common phrase "x is the best thing since sliced bread". The way that Randall uses the phrase in the title text humorously implies that these shoes would be almost as good to wear on your feet as two slices of bread.
Earlier in 977: Map Projections , it was stated that those who preferred the Dymaxion projection would wear shoes with toes. And later in 1735: Fashion Police and Grammar Police it was a different type of shoes that were deemed non-fashionable with the Crocs .
[Cueball, holding a sword, looks up to a disembodied voice coming from above, and a box hovers in the air before him.] Voice: For saving my kingdom, I offer you a gift of great power.
[Cueball's sword is now propped up against the right edge of the panel. The box opens, a glow emanating from within.] Voice: These magic shoes enable the wearer to outrun death itself. Cueball: Thank you. I...
[A close-up on Cueball as he examines the shoes. They have five toes.] Cueball: Whoa, wait. They have those creepy individual toes.
[Cueball puts the shoes back in the still-hovering box. The sword cannot be seen.] Voice: But they make you immortal. Cueball: ...I have to think about this.


Laundry

Explanation:
This comic is all about college laundry habits and how as time goes by, you end up just throwing clothes on the floor and then wearing them again.
In the first week, the student undertakes a proper laundry routine. However, due to increasing laziness, by the second week they have abandoned folding their clothes, and by the third week no longer bother hanging them in the closet. By the second month dirty clothes are no longer stored in a laundry hamper and are just dumped on the floor, and by the end of the semester clothes are not washed at all.
The title text seems to indicate that the student has a brainwave, some time later, to wash their clothes in the dishwasher along with the dishes. Presumably as a timesaver. The experiment was brief because dishwashers aren't actually any good at washing clothes [ citation needed ] as they wouldn't move the clothes about.
College Laundry Habits
[Panel labeled "First Week". 5 ovals arranged in a rough circle, with a clockwise path connecting them: "Dresser & Closet", "On Body", "Hamper", "Washer & Dryer", "Folding Area" (and back to the first). The area outside the ovals is labeled "Floor."]
[Panel labeled "Second Week". The path has been modified so that it does not go through "Folding Area" - only through the other 4 ovals.]
[Panel labeled "Third Week". The path has been modified so that it does not go through "Dresser & Closet". Only "On Body", "Hamper", and "Washer & Dryer" remain.]
[Panel labeled "Second Month". The path no longer passes through "Hamper" - only "On Body" and "Washer & Dryer".]
[Panel labeled "End of Semester". The path no longer goes to "Washer & Dryer", instead just looping back around from "On Body" to "On Body" again after passing through the "Floor."]


Pressures

Explanation:
This comic is a reference to revolutionary physicist Albert Einstein , who got his first big ideas about physics while he was working as a Swiss patent clerk. Hence, Randall jokes that there is pressure on other Swiss patent clerks to come up with genius ideas while they are working there. The Zen Pencil comic "Albert Einstein: Life is a mystery" gives some background about Einstein's choice to work at the Swiss patent office. The fact that he was turned down by several universities was beneficial to the science of physics, as the duties as a patent clerk were not challenging to him, paid enough, and allowed him to work on his theories without any pressures .
The title text refers to quantum gravity , a highly anticipated theory that would unify quantum mechanics with the current model of gravity, general relativity. Such a theory would be very useful to understanding how space behaves at high energies and high densities, such as black holes and the very early universe. The joke is that instead of a patent clerk making this theory, as everyone is supposedly expecting, it's instead made by someone wearing "patent" leather shoes and working on a movie called "Clerks" II, thereby suggesting that anytime something called a "patent" crosses with anything called a "clerk", radical breakthroughs in physics result. Clerks II is the second movie in the Clerks series by Kevin Smith, widely regarded as not nearly as good as the first — which could be said about most sequels, but you get the point.
[Ponytail walks up to Megan examining documents] Ponytail: So... what've you been up to? Megan: Handling patent applications. Ponytail: Yeah, but... besides that? Megan: That's about it. Ponytail: You're not, like, thinking about any cool stuff? Just curious.
For the last hundred years, Swiss patent clerks have been under some weird pressures.


Swiftkey

Explanation:
Cueball has installed SwiftKey on his smartphone and brags about this to Megan . SwiftKey is a product that is installable on iOS / Android -based phones and tablets.
Cueball explains that if you type space bar on the keyboard it auto-completes the word you are currently typing founded on its best guess, and then if you continue to press space it will add new words using this guessing process based on the previous word(s) and what it believes is the most likely words you would use in a sentence containing the previous word(s).
Megan asks what happens if you begin a new message by just using space to automatically create a text. Cueball's best guess it begins with the word SwiftKey has found to be the typical starting word and then continues as normal from that.
Megan then realizes that in this way it builds up his "typical" sentence and she tries this over the next eight small frames: I am so sorry- that's never happened before.
"I'm so sorry– that's never happened before." is a typical excuse for a mishap, usually when one fails to produce an erection when it is needed . Such a phrase being quoted by an algorithm implies that such mishaps are common, and therefore "I'm so sorry– that's never happened before." is a lie. Also, Swiftkey might be saying "I'm so sorry– that's never happened before." because the software doesn't know what to do.
SwiftKey has noticed their inclusion in xkcd and have created a blog post for other users to comment with their default phrase when they hit the "central prediction key". The results are pretty funny (the site now redirects to a website asking to download the keyboard, an archived version can be found here ). In addition, Reddit users have a similar model creating /r/subredditsimulator , which is populated by bots generating submissions and comments based on the language of their subreddits.
In the title text, a Markov chain refers to a system that transitions between a countable number of states, based only on the current state and none of the previous ones that led up to it. SwiftKey follows this property since it provides outputs based only on the most recently entered word or words, not the whole sentence.
"Massachusetts Institute of America" is a nonexistent organization. The name appears to have formed by combining " Massachusetts Institute of Technology " and either "[Field] Institute of America" (e.g. Mining) or "United States of America". This illustrates the memoryless property of a Markov chain; after generating "Massachusetts Institute of", SwiftKey may have attempted to predict the next word using only the last "of" or "Institute of". Since it was not considering the word "Massachusetts" at all, the word "America" was viewed as the most likely follow-up.
[Cueball showing his phone to Megan.] Cueball: Have you tried SwiftKey? It's got the first decent language model I've seen. It learns from your SMS/Email archives what words you use together most often.
[Cueball and Megan in a frameless panel, with Megan now holding Cueball's phone.] Cueball: Spacebar inserts its best guess. So if I type "The Empi" and hit space three times, it types "The Empire Strikes Back". Megan: What if you mash space in a blank message?
[Zoomed in on Megan looking at Cueball's phone, with Cueball now off-frame to the left.] Cueball: I guess it fills in your most likely first word, then the word that usually follows it... Megan: So it builds up your "typical" sentence. Cool! Let's see yours! Cueball: Uh—
[Eight small frames arranged in panel space, 2 frames wide by 4 frames high, showing each word added by Swiftkey as Megan hits space each time:] SwiftKey: I SwiftKey: Am SwiftKey: So SwiftKey: Sorry— SwiftKey: That's SwiftKey: Never SwiftKey: Happened SwiftKey: Before.


Alphabet

Explanation:
This comic is mainly a joke on the traditional pick-up line that goes: "Baby, if I could rearrange the alphabet, I'd put 'U' and 'I' together", i.e. "you and I", or "the letter U and the letter I".
However, in typical xkcd fashion, rather than continuing with that tired pickup line, addressed at Blondie at the bar, Cueball jumps at his hypothetical chance to rearrange the alphabet and fix the English orthography .
An orthography is a standardized system for using a particular writing system (script) to write a particular language, including rules of spelling. The English orthography happens to be one of the deepest (that is, most irregular) ones around, since almost every sound can be spelled in several ways, and most spellings and all letters can be pronounced in more than one way, and often in many different ways.
So faced with this opportunity, the hooking up could wait. Restructuring the alphabet and creating a sensibly regular English spelling is the chance of a lifetime, and would make history, making Cueball immortal in the sense of living on forever in memory, as the alphabet-fixer.
In the title text Cueball muses on the possibilities. Does he get to remove letters entirely or just rearrange them (like putting U and I together)? Then he mentions "the 'k/c' situation" specifically because that "situation is ridiculous". This is about the use of the letter 'c'. It doesn't have a unique sound, and most often makes a 'k'-sound or an 's'-sound . Combined with an 'h' it usually makes the 'ch'-sound in chair , but also they often sound like 'k' ( character ), and in not too few cases they even make the 'sh'-sound (like champagne , see more examples here ). So a reasonable change Cueball might make is to replace 'c' by 'k' or 's', and keep 'c' only followed by 'h' (or even giving 'c' the current sound of 'ch' as in chair or giving the role of 'ch' as in chair to 'kh', spelling 'khair') .
He finishes off by stating that they can make out any other time, because fixing the alphabet now would bring him immortality.
Orthography was again the subject in 1562: I in Team . A non-standard version of this pickup joke was previously referenced in 279: Pickup Lines .
[Cueball stands behind Blondie who has turned her head towards him while sitting at a bar stool at a bar desk. She holds on to a wine glass standing on the desk. Two regular glasses are standing on the desk in front of her.] Cueball: Baby, if I could rearrange the alphabet, I'd forget about you in a heartbeat . Cueball: I'm not gonna waste my one chance to help the mess that is English orthography.


Words for Small Sets

Explanation:
The noun "couple" can mean "exactly two items of the same kind," or it can be used interchangeably with words like "few" or "several", which in this context mean "comparatively small but definitely greater than one". But some people insist that "couple" can only mean two, by analogy with the specific use of the word "couple" to refer to exactly one pair of people who are in a romantic relationship.
This comic also alludes to similar arguments about the relative meaning of phrases like "few" and "several" (some people will argue that "several" should mean more than "few", while others will argue the opposite or that it doesn't matter), making this comic troll bait . Randall is attempting to "troll" (intentionally provoke) the people who claim "couple" must mean exactly two by taking the other side of the argument.
The title text similarly alludes to the argument. Randall says "Try asking a couple of friends [...] unless all three of them agree," which jokingly refers to the same group of people first by the vague term "couple," which can include three, and then specifies the exact number, resulting in a jarring effect as if a "couple" meant exactly three. The title text also mentions the sentence spacing issue as an example of another topic known to ignite energetic arguments among pedantic types without ever leading to consensus. Sentence spacing is later seen in 1285: Third Way . The sentence spacing arguments are about whether one or two space characters must be used after the period character at the end of the sentence.
The title text also points out an unusual situation where troll baiting may not work: namely, intending to spark an argument is most effective if there is a disagreement on the matter. If all of the inquired friends have the same opinion on the matter (be it the definition of 'couple' or the number of spaces after a period), then an argument may not spark, and the trolling attempt may fail. Randall also takes a side in the title text, saying "a couple of friends" and then later "all three of them".
[Heading above table:] Just to clear things up: [A chart with four rows and two columns is shown.] A few Anywhere from 2 to 5
A handful Anywhere from 2 to 5
Several Anywhere from 2 to 5
A couple 2 (but sometimes up to 5)


Exoplanets

Explanation:
An exoplanet is a planet outside of our solar system, orbiting a different sun. 786 planets were known in mid-2012: 778 exoplanets and the rest in our Solar System.
Since then, astronomers have found thousands more. In the comic, our Solar System 's eight planets are depicted in the small rectangle above the central text. From this we find that the largest dots (red) and second largest dots (dark brown) indicate planets larger than Jupiter, light brown is roughly Jupiter or Saturn -sized, blue is roughly Uranus or Neptune -sized, and the tiny dots are small terrestrial planets (like Earth ).
We only have a few ways of finding exoplanets . Astronomers initially used doppler spectroscopy , which detects minute changes in a star's movement towards or away from us to infer the presence of large gas giants or brown dwarfs . Currently the most successful method is to notice when a star seems to briefly get dimmer on a repeating cycle. This may indicate that a body of matter has passed between that star and us, blocking some of the light. The Kepler space telescope was designed for this purpose, and has made the vast majority of exoplanet discoveries.
Most of Kepler's discoveries are between the sizes of Earth and Neptune, but it's sensitive enough to detect planets smaller than Mercury (if the orbital plane is aligned with us). Kepler is only able to observe relatively close stars in a narrow field of view . The great number of nearby planets implies there should be billions of planets in our galaxy, assuming our local arm is not uniquely abundant.
The title text refers to this by saying that to show them all, each dot on the chart should hold another chart with the same amount of dots; each of these dots should then also have a similar chart, and then do this one more time for a three level deep chart. This chart would have space for 786^4 planets (786*786*786*786 = 382 billions). Our Milky Way contains about 100-400 billion stars. But if the chart were only two levels deep there would "only" be room for 786^3 = 0.5 billion planets.
This comic's design is similar to the Ishihara Color Test , a series of circular pictures made of colored dots, used to detect red-green color blindness. However, Randall's picture probably does not contain a hidden number like it did in 1213: Combination Vision Test .
Two different xkcd comics have the title "Exoplanets". The first was 786: Exoplanets , and this one was drawn at a time when 786 exoplanets had been found. Probably not a coincidence when it comes to Randall . This is the first time Randall released a comic with the exact same name as a previous comic. Since then he has done so a few times . When this comic was released it caused problems on xkcd as the title of the image files were the same for the two comics. This was resolved by renaming the original image adding the year 2010, the year when it was released, two years before this one was released.
See also Category:Exoplanets and this list of lists of exoplanets .
[An large diagram of dots, mostly of varying shades of brown and greenish yellow, with a number of smaller blue dots, tiny green dots and some larger red dots. At the top of the circle are five lines of text in very different font size.] All 786 known planets (as of June 2012) to scale (Some planet sizes estimated based on mass.)
[Below this text is a small section of 8 planets which are framed in a light gray frame with lighter gray background . It is situated right below the above text with only a few planets in between the text and the frame. These planets include two large yellow, two smaller blue two small green and two tiny green planets. A line goes between this frame to another frame with the first word in the text below, that is in a similar frame. The rest of the text follows to the right and then below this first word covering the central part of the circle from just around the center of the circle and a bit below.] This  is our solar system. The rest of these orbit other stars and were only discovered recently. Most of them are huge because those are the kind we learned to detect first, but now we're finding that small ones are actually more common. We know nothing about what's on any of them. With better telescopes, that could change. This is an exciting time.


Seventies

Explanation:
This is a take on the common insult "<year> called and they want their <item> back", used when one is wearing something out of fashion (used before in 875: 2009 Called ). In this case, the comment is literally true: someone in the '70s called, but did not leave a message. Instead, the caller is puzzled because answering machines and especially voicemail were rare or nonexistent in the 1970s, and his telephone has a rotary dial , rather than a touch tone , so he can't "press" 1.
The caller is wearing flared ("bell bottom") trousers, which are frequently associated with 1970s fashion. The caller is somehow using time travel to directly dial a number in the present.
Originally telephones had rotary dials instead of buttons, hence the origin of the terms "dial tone" and "to dial a number". Touch tone phones were introduced in the 1960s, but weren't standard in many places until the 1980s. Rotary dial telephones used pulse dialing to transmit numbers and push-button telephones use DTMF (although phones from the '80s and '90s could often use both). Modern voicemail systems regularly don't support pulse dialing, so even selecting "1" on the rotary dial would not choose "1" in the voicemail menu system.
The title text plays off the fact that the telephone had not yet been invented in the 17th century: in fact, all of the component technologies, including the materials used for the casing, were unknown at that point, and therefore the telephone is assumed to be supernatural in origin ("demonic... ſorcery"). Randall uses the character "ſ", the long s , which was used in written English to take the place of the modern lowercase "s" in the beginning and middle of words. It was phased out around the beginning of the 19th century.
Cueball: Nice jacket. Hey– Cueball: The seventies called. Out-of-panel: Oh? What'd they want?
[Cueball looks at his smartphone, holding it in his hand.] Cueball: I don't know. They didn't leave a message. Out-of-panel: Weird.
1974: [A person in bell bottoms, who has no jacket, looks at a rotary phone receiver.] Voicemail service: If you'd like to leave a message, press "1".


Weekend

Explanation:
This comic was posted right after the weekend , on a Monday, so it was on time to emphasize that we all hate Mondays .
In the first image, there is a reference to the Loverboy song " Working for the Weekend "; both the song and the panel refer to how most working and middle-class people are constantly focused on merely surviving until Saturday with enough energy to relax properly.
Cueball then goes on to state the fact that any calendar used is just a social consensus and since nature doesn't know the day of the week he simply suggest making this Monday into a Saturday. Actually, why not make all days into Saturday, to have eternal weekends?
When you actually stop and think about the speech, the argument turns into utter nonsense. Simply renaming every day on the Gregorian Calendar to "Saturday" doesn't actually do anything, and "the first Saturday of the week" would carry the exact same stigma as "Monday". Furthermore, if Cueball is proposing to abolish the work week entirely, the economy would collapse within days. This fact may explain why the last panel is drawn in negative, with the background black. It gives a very ominous feeling to the last remark.
No confirmation has yet been found that any of these words are references to something from former US President James Garfield or to Garfield the cartoon cat who are the two speech writers mentioned in the title text. However, Garfield the cartoon cat has often bemoaned the existence of Monday (ironically, because he is a cat and not subject to the common human work schedule). And hence the title text suggest that this speech was written by Garfield the cat, and that this would be a better speech than any delivered by James Garfield.
[Cueball stands behind a lectern on a podium before a very large crowd.] Cueball: We all hate Mondays. We're all working for the weekend. Cueball: But our chains exist only in our minds.
[Zoom in on Cueball from the lectern upwards, seen from an angle. He raises one hand in explanation. His text goes above the frame and is written in the top part of this panel which is frame-less.] Cueball: Calendars are just social consensus. Cueball: Nature doesn't know the day of the week.
[Closer zoom on Cueball who looks straight out of the panel, the top of the lectern is just visible.] Cueball: My friends— Cueball: We can make today Saturday.
[Extreme close-up, the lectern now below the panel, and negative colors with Cueball and the text in white on a black background.] Cueball: We can make it Saturday forever .


Moon Landing

Explanation:
The comment to which Cueball is referring is a tweet by Neil deGrasse Tyson , an American astrophysicist and science communicator. He has appeared on many different shows, ranging from The Discovery Channel to The Big Bang Theory.
There are a number of conspiracy theories claiming that the moon landing was a hoax. Tyson offers a pretty compelling argument against them, but Megan presents an even more convincing refutation, snarkily implying that NASA really hasn't done anything spectacular since 1969.
And Cueball responds with a pun on the word "burn". Burn can mean a particularly effective insult, or it can mean the consumption of fuel for propulsion. In this case, the "burn" was so effective it pushed the spaceship out of orbit (which usually takes a very large amount of burning, depending on the gravity of the planet or moon).
In the title text Randall mentions many successful NASA unmanned missions:
The final sentence of the title text notes that all manned missions since the Moon landings have taken place in low-earth orbit, which is barely far off of the Earth's surface. If the Earth were scaled to the size of a regulation basketball, approximately 24 cm (9¼ inches) in diameter, those manned missions would have all taken place within 1.25 cm (½ inch) of the ball's surface. At this scale the Moon would be at a distance of 7.7 m (25.3 ft). Unmanned missions, such as those named above or the Voyager and Mariner probes of the 1960s and 1970s, have traveled much further.
A basketball-sized Earth was the main focus of 1515: Basketball Earth .
[Cueball is sitting at a table with a laptop open. His hands are on the keys.] Cueball: Hah- Neil DeGrasse Tyson has a great reply to people who doubt astronauts went to the moon. Voice off-screen: Oh? Cueball: "Atop 3,000 tons of rocket fuel, where else do you think they were headed?"
[The voice off screen turns out to be Megan. She is depicted, and now Cueball is off-screen.] Megan: Cute. But it overlooks an even simpler argument. Cueball: Which is?
[Both Megan and Cueball are now visible. Cueball has turned his chair around to face her.] Megan: If NASA were willing to fake great accomplishments, they'd have a second one by now. Cueball: Ouch. Megan: ...Too mean? Cueball: That burn was so harsh I think you deorbited.
As of this comic, Tyson is the "Frederick P. Rose Director" (a special honorary title) of the Hayden Planetarium


Warning

Explanation:
This parody of a road sign essentially reminds drivers of the reality of the situation they are now in and thereby implicitly refers to the dangers inherent to it. Because the ability to travel in a box on wheels at  high speeds was not selected for in the evolution of human, if anything happens to said box on wheels, such as crashing into a wall, the humans inside may be badly injured, if not killed. Had they evolved something like exoskeletons, for example, this may not have been the case. This reminder would presumably prompt drivers to drive more carefully or perhaps slow down.
Humans did not evolve to have the ability to withstand such forces because their ancestors commonly never traveled any faster than about 20 km/h (top human speed on foot), although some individuals may have moved faster than that by falling out of a tree or off a cliff. Fast vehicles, on the other hand, have only appeared in the last couple of hundred years, and it would take many more tens or hundreds of thousands of years before these new selection pressures made any noticeable difference to human physiology, if any.
The road sign is far too lengthy and philosophical to be used in practice but is conceivable as an advertisement for safe driving.
The phrase "next 5 miles" is common to road signs, particularly those on US highways in rural areas. This is to indicate that the conditions on the sign will continue for the next five miles along that road.
The title text refers to the fact that the sign doesn't really know how many more miles the driver may travel, and that it may be more than five. Since the average American drives over 13,000 miles per year , this is indeed very likely.
[An American Diamond warning sign with the following message on it:] You're in a box on wheels hurtling along several times faster than evolution could possibly have prepared you to go Next 5 miles


Groundhog Day

Explanation:
Groundhog Day is a philosophical comedy film from 1993. The main character Phil, portrayed by Bill Murray , finds himself in a time loop , which forces him to relive the same day (February 2) over and over again. This date is the titular Groundhog Day , which is celebrated in Punxsutawney , Pennsylvania, where the film is set. The folklore ritual consists in removing a groundhog from its burrow. If the sun is shining and the groundhog can see its own shadow, the winter is assumed to continue for six more weeks.
During the course of the film, Phil makes more and more drastic attempts to end the time loop, but not even suicide can prevent his waking up every morning on February 2 with the clock radio on his nightstand invariably playing I Got You Babe by Sonny & Cher . Eventually, his character improves and he finds himself increasingly attached to his coworker Rita (portrayed by Andie MacDowell ). The pair gets closer, and, in the end, they sleep together. This breaks the time loop, and Murray's character can finally wake up on February 3. However, whether they had sex before this final scene is disputed, as Phil is still wearing the same clothes as the night before and, when Phil starts kissing her in the morning, Rita comments that he wasn’t so affectionate the previous night. It is therefore left in doubt if they did anything more than literally sleep in the same bed. Randall was apparently not aware of this and apologized for it.
The comic assumes that the loop was indeed not broken, and that Phil and Rita simply had sex night after night for all eternity. It is then stated that not even forever is forever . This can be explained with the mathematical set theory developed by Georg Cantor . Cantor distinguished between transfinite numbers , which are larger than all finite numbers, yet not infinite , and the concept of Absolute Infinity , which he equaled with God . It was a common concern in Cantor's time to preserve the consistency between mathematics and Christian belief. Cantor's philosophical conception of infinity would allow the comic's scenario to eventually reach the transfinite date of February 3.
The last panel references the chronology of the history of the world of Archbishop James Ussher . Ussher deduced the age of the world from the timeline of the Old Testament and calculated the date of Creation to have been nightfall preceding 23 October, 4004 BC. The comic observes that October 23 is exactly 264 days after February 3, which corresponds to the average length of pregnancy. This calculation draws on Ussher's own methodology, which was basically to add the lifespans of the Old Testament genealogy. Although the universe is much older than 6000 years, chronologies like Ussher's can sometimes be found in the arguments of Young Earth Creationism . The comic might therefore be seen as a sideswipe to these theories by introducing Groundhog Day as a possible creation myth. The creation myths of many cultures claim that Earth was born by some sort primordial mother . Here, this role would be assumed by Rita.
The title text refers to the cosmic microwave background radiation , which is often called the lingering sound of the Big Bang and regarded as a strong proof for it. If the universe were indeed the offspring of the film's protagonists, we might hear the faint echo of Murray's radio clock lingering in the cosmic background.
Groundhog Day really didn't end that way. When Bill Murray finally slept with Rita, it didn't break the loop. [Phil Connors and Rita gettin' busy under the covers of his bed.] They just kept having sex, night after night, [Bed containing Phil and Rita repeats.] February 2nd after February 2nd... [Calendar page repeats.] ..forever But nothing is forever. Not even forever And the day after that sexual infinity [Calendar page shows Feb 3. ] was February 3rd. 264 days later (the length of a pregnancy) was October 23rd — [An enormous explosion in space.] Bishop Ussher's date for the birth of our world.
The comic mentions Bill Murray by his own name, and not by his character's ( Phil ), whereas Andie MacDowell is mentioned as Rita . This could be subconsciously done, since Murray is mostly remembered for his role in this film, although he has had many other successful ones. Alternatively, the other way round, Bill Murray is famous enough from his various other works to be recognized as an actor, while Andie MacDowell is less known to a broad audience.


Home Organization

Explanation:
This comic is a take on the typical "how to" which details "how to" organize your home. In many cases, finding the best organization can be difficult and/or can take a long time. To skip this problem, Cueball "Just Gives Up" and puts all his items and furniture into a box labeled  "Misc" for miscellaneous, with the exception of his laptop, cable modem and router.
The title text is a take on the popular website Lifehacker which includes all sorts of posts on how to "hack" your life and improve it. Life hacking appears to be a common theme in xkcd, such as in 2024: Light Hacks .
[One big plain room with a person sitting on the floor with a laptop on one side, a modem and wireless router on the other, and a big box full of the usual accoutrements of living in the middle, with "MISC" written on the side.]
Home Organization Tip: Just Give Up.


Knights

Explanation:
This comic is comparing the opening moves of the game of chess to the opening moves of the Battle of Agincourt , which was fought between the English and the French in the Hundred Years War . In the battle, just like in the comic, the English used their longbowmen effectively, neutralizing the French knights and infantry. The two pieces that are moved out of the white side of the board are both the pieces known as the Knights. White moves first in chess, and in the actual battle, the French knights on horseback attacked first; the English being the black pieces may also be a reference to Edward the Black Prince , who was a prominent figure in an earlier stage of the Hundred Years War. As you can see, all the pawns (foot soldiers) on the right side of the chess board have bows.
The title text uses algebraic chess notation . Nf3 means a knight has moved to square f3. Nc3 means a knight has moved to square c3. N means knight because the king piece has the K abbreviation covered. What comes after the typical chess move is what can only be read as a hail of arrows. 0-1 at the end means that "Black Wins". This implies that White resigned, as he is not in checkmate (for non-timed chess games, the only ways to win are by checkmating your opponent or by accepting their resignation).
The word " gambit " means "an opening in chess, in which a minor piece or a pawn is sacrificed to gain an advantage". The usual gambit of sacrificing a pawn is subverted to be a sacrifice of a high-value piece, as an analogy of what happened at Agincourt.
[A chessboard, The black pawns have all gained longbows and have specifically taken down the white knights as they move forward, without any black pieces needing to move from their opening positions. Caption below the panel:] The Agincourt gambit.
In the title text, Nf3 was accidentally written as Ne3. At the beginning of a chess game, neither knight can move to e3. The proper move (and the move actually made, in the picture) is Nf3. This was later corrected.