Self-Description

Explanation:
This comic is self-referential , because every graph is dependent on the whole comic. If you were to change anything in the comic, you would change the ink distribution, and would therefore have to update all three graphs. This would result in further changes that would have to be considered.
In the first panel's pie chart , "this image" refers to the entire comic image, the one that can be downloaded from xkcd (and the entire comic as displayed here above). This is a little confusing as it would be easy to misunderstand this meaning, and believe that the first panel only refers to itself. The title text though makes it clear that it is the entire comic that is called image here. The image size is 740x180 or 133200 pixels. Out of those, 14228 pixels are black (gray pixels are accounted based on their brightness). The ratio of black pixels to the size of the image is 0.1068, so the pie chart segment describing black part should be about 38.5 degrees wide, which is indeed true for the pie chart in the image.
In the second panel the amount of black used in each panel is displayed in a bar chart . This actually makes this panel the one that uses most black. The first panel (including the border) has 4944 black pixels, the second 6180 and the third 3103. The first bar is about 70 pixels high, the second about 87 and the third about 43, which roughly checks out. It is hard to measure the exact height of the bars as the axis and bars themselves are not straight.
The third panel features a scatter plot labeled "Location of black ink in this image." It is the first quadrant of a cartesian plane with the zeroes marked. The graph is the whole comic scaled proportionally to fit the axes, so the last panel also has to contain an image of itself having an image of itself ad infinitum thus displaying the Droste effect , a type of visual recursion .
The title text refers to the comic's own self-reference, but it is also self-referencing because of the character count in it. It would be difficult to write this sentence, as just one more character would not be solved by writing 243, as "three" has two more characters than "two", and "four" has only one more character...
"The graph of panel dependencies is complete and bidirectional, and every node has a loop." This means that if we draw a dot corresponding to each panel, and then we draw arrows connecting the dots to indicate dependencies, the resulting graph is complete (meaning that all the points are connected to one another) and bidirectional (meaning that if point A has an arrow to point B, then point B also has an arrow to point A). "Every node has a loop" means that each point also has an arrow connecting to itself.
This is an observation of the interdependent relationship between description and creation that pertains to all things perceived by humans, including the concept of "Self".
Self-reference was used very early for instance in 33: Self-reference , but never so famously as here. See other self-references here .
[A pie chart which is mainly white with a black slice of about 30 degree towards the bottom left. The two sections are labeled with a line going from the label to the sections. The line going into the black section turns white in in this last part.] Fraction of this image which is white Fraction of this image which is black
[A bar graph labeled with a label over the Y-axis. There are three black bars with a label below each bar. Bar 1 is of medium height, bar 2 highest and bar 3 the lowest.] Amount of black ink by panel: 1 2 3
[A scatter-plot with a label over the Y-axis. In the bottom left corner of the graph, the two axis has a tick just away from the origo, and these are labeled with zeros. The graph shows the whole comic scaled proportionally to fit the axes. The scale is too small to actually read any of the text in this representation, which would of course be the same as that noted here for the two previous panel and for this panel here below:] Location of black ink in this image: 0 0


FIRST Design

Explanation:
Two members of a team are designing a robot for the 2010 FIRST Robotics Competition , in which teams design robots to push soccer balls into their team's goals. The final design for this team's robot is a trailer with a matchbox on a telescoping pole and the actual robot, a mobile platform with an umbrella on top and pusher in front.
This is an underhanded design, exploiting the presence of a heat-activated sprinkler system at the venue and lack of water resistance in the opposing team's equipment.
When the event starts, the robot moves off and deploys its umbrella. The trailer extends its arm, causing a lit match to set off the sprinkler, which causes the opposing robots to short out and malfunction. This allows the umbrella-protected robot to score goals without opposition.
This may also be referencing how FIRST is famous for its bending of the rules, as loopholes are not only not against the rules, they are encouraged. This would be shown best by how Team 67 designed a robot that utilized a loophole, which allowed them to control a robot using an Xbox Kinect during the time where the robot is supposed to be autonomous. (This loophole has been removed in the rules for more recent competitions.) Note, however, that this would be simply illegal based of the 2010 FRC Breakaway rules , as rule S01 under section 7.3.1 Safety prevents dangerous robots from competing and R02 points E and F under section 8.3.1 Safety & Damage Prevention prevent "Flammable gases" and "Any devices intended to produce flames or pyrotechnics.". This rule could be bypassed if the sprinkler could also be triggered by smoke, which is the case in at least some venues, in which case a few capacitors in a circuit designed to destroy them could trigger the sprinkler system.
In addition, this comic may be a reference to the water game meme in FRC, where most students really want a game to involve water, even though this is unlikely to ever happen due to the safety concerns about using electronics near water.
The title text is an excuse presented by the umbrella robot team, presumably because they won but are facing disqualification. This excuse seems weak because none of the venues have a rooftop pool. [ citation needed ] The comment "the pool on the roof must've sprung a leak" is a quote from the 1995 movie "Hackers".
Team Member 1 (out of panel): Wow, this is a much better design. Team Member 2 (out of panel): Let's build it. [A blueprint depicting a robot design for the FIRST competition. It consists of a standard mobile platform, with a pusher blade at the front. Additional parts include an umbrella on top and a trailer unit consisting a telescoping pole with a matchbox and match on top.]
Referee (out of panel): Go! CLICK [A FIRST competition field, with teams at opposite ends. Various robots appear on the field, and the team whose design appears above activates their robot.]
[The robot's trailer unit detaches as the telescoping pole begins to extend, and the mobile platform with umbrella rolls forward.] VRRR CLICK
[Telescoping pole extends further.] VRRRR
[Telescoping pole extends further.] VRRRR
[Telescoping pole extends further, approaching a sprinkler head fixture.] VRRR
[Telescoping pole stops extending, placing the matchbox and match very near the sprinkler head fixture.]
[The mobile platform stops moving.]
[The umbrella deploys, extending beyond the dimensions of the mobile platform.] FWOOMP
[The match box and match are lit beneath the sprinkler head.] FWOOSH
[The heat from the match triggers the sprinkler's valve, and water sprays out of the sprinkler into the room below.] PSSSSHH
[Water pours from the sprinkler onto the competition field, causing the electrical components of the opposing team's robotics platform to short and malfunction. The opposing team appears distressed and confused.] FZZZT BWooooooo!!!
[The initial robot, still protected by its umbrella, pushes along the balls toward the goal zone without any difficulty.]


Semicontrolled Demolition

Explanation:
The World Trade Center towers were destroyed in the September 11, 2001 attacks ( 9/11 in American date notation). The planned attack was for two planes to collide with the north and south towers simultaneously, but what ended up happening was that plane 1 hit the north tower at 8:46 am , and the second plane hit the south tower a little less than 20 minutes later . In the ensuing investigation many people raised questions that didn't seem to get a satisfactory answer for several months, if not years. Many people, who called themselves 9/11 Truthers , began to claim that the whole thing was a government conspiracy, in what has come to be known as the "controlled demolition plot" (referenced by the title of this comic), which alleges that the towers were brought down not by the fires caused by the planes but by demolition charges intentionally placed there by the government.
Cueball proposes a compromise to make both those who believe in the conspiracy and those who don't happy. Since there is only a government related video of a plane flying into the north tower — done by a man who was with FDNY fire fighters — that was a government conspiracy. But it just so happened that the government decided to demolish the north tower on the same day that terrorists decided to demolish the south tower.
The title text is a restatement of the Golden Mean fallacy : that the truth can be found in a compromise between two opposite positions. In this comic, one of the positions is a fanciful conspiracy theory and the other is a sober fact-based conclusion.  The error of this fallacy is apparent here, as it can lead  to even more ridiculous conclusions. In this case, the compromise theory would make no one happy because both sides would have to concede claims which they have already dismissed as bogus, as well as accept an incredibly unlikely coincidence.
On January 6, 2016, The Onion , a satirical news site, reported that the government has confirmed Cueball's theory by releasing an article titled, Government Admits It Was Only Behind Destruction Of North Tower.
This is one of the compromises Cueball (or Randall) has proposed, most of which will also be unlikely to be accepted...
[Cueball is holding up a pointer to a screen with an image of the World Trade Center towers mid-disaster.] Cueball: Based on my analysis, I believe the government faked the plane crash and demolished the WTC north tower with explosives. Cueball: The south tower, in a simultaneous but unrelated plot, was brought down by actual terrorists.
[Caption below the panel:] The 9/11 truthers responded poorly to my compromise theory.


MicroSD

Explanation:
microSD is one format of the Secure Digital memory card format, used in digital cameras, cell phones, and other devices. It is very small, only 15×11×1 mm, but can hold large amounts of data. The US dime in contrast has a diameter of 17.91 mm. When this comic was published in January 2010 the maximum capacity for microSD cards was 16GB. The current maximum capacity is 1TB (as of January 2021).
The main character in the comic (on the right) thinks about all the ideas that could be expressed by the data in the microSD card, or in a library. He feels not just reverent and intimidated, but sexually aroused by the thought. As he begins to touch it, his friend is disgusted by what might happen if he uses the card as some kind of sex toy, and does not want to help him locate the card if it gets "lost" inside a body cavity.
The title text seems to be the main character thinking about how much data the card holds, in terms of floppy disks and the iTunes music library, and feeling aroused by these thoughts.
Randalls claims in the title text do check out. A high-density floppy disk with a FAT format holds about 1.4 MB of data, and has dimensions of 90×94×3 mm, for a volume of about 2.5 cm³. A refrigerator carton is the large cardboard box that fridges are delivered in. A typical refrigerator carton may be 1800×700×700 mm, a volume of about 0.9 m³. So a fridge carton could hold about thirty-five thousand 90 mm floppies, or roughly 50GB. This is comparable to the storage on a single microSD card. A soda can (500 ml = 500 cm³) could hold three thousand microSD cards or store 50TB of data (3000TB today). However, the iTunes store claims to hold thirty-five million songs (as of Summer 2016), and allowing for about 2MB per song gives 70 TB of music. The claim that a soda can could hold the iTunes library seems to be unreasonable, but it was reasonable at the time.
Related to this topic is this xkcd What If blog entry .
[Cueball and a friend approach a table.] Cueball: Hey, what's up? Friend: Shhhhh. Cueball: Hrm? Friend: There's a microSD card on your table.
[A 16GB microSD card sits next to an assortment of coins for size reference.] Cueball (out of panel): So? Friend (out of panel): I dunno, high storage densities freak me out. A whole aisle of library shelves on something smaller than a dime.
[The two people stand near the table, the friend peering at the coins and card on the table.] Friend: Libraries are unnerving enough-millions of ideas surrounding you, towering over you. These cards fill me with that same reverence, that same intimidation.
[Cueball stands alone.] Friend (out of panel): ...that same faint arousal. Maybe I'll just touch it. Cueball: If you lose that card I'm NOT helping you find it.


Dirty Harry

Explanation:
The comic references Dirty Harry and Rain Man , two classic American films, from very different genres.
Dirty Harry is an action thriller about a police officer named "Dirty" Harry Callahan, who's notorious for being aggressive with criminals and quick to resort to lethal force. His weapon of choice is a .44 magnum revolver (which holds six rounds of ammunition). The comic references one of the most famous scenes in the film, in which Harry has a criminal at gunpoint, following a fire-fight. As the criminal considers reaching for his own gun, Harry claims to have lost track of how many bullets he's fired, meaning that there may or may not be one round left in his gun, and coldly tells his opponent "you must ask yourself one question: do I feel lucky?". The implication being Harry will definitely fire if the man reaches for his gun, and his life will depend on whether there are any bullets left.
Rain Man is a comedy-drama about the relationship between two brothers. One of the brothers, Raymond (AKA "Rain Man"), is autistic and has an eidetic memory . Several times in the film he encounters a number of objects that would be difficult for most people to count (such as toothpicks spilled from a box) and immediately knows how many there are.
The comic portrays a mash-up between the two films, in which Dirty Harry faces Rain Man, instead of a less numerically gifted adversary. Rain Man accurately tracks every bullet fired, and knows that Harry's gun is now empty (with the implication that he can safely grab the gun and kill Harry).
The title text implies that Randall tends to obsess about tracking quantities, even while watching action films, and thus gets 'distracted' keeping track of how many rounds each person fires. He jokes that energy guns shown in science fiction are intended to counter this tendency, because they're not limited to a specific number of shots.
[Detective "Dirty" Harry Callahan stands near a wall, pointing a revolver at another figure, presumably a suspect, reclined on the ground. A shotgun is on the ground next to the reclined figure.] Harry Callahan: I know what you're thinking--"Did he fire six shots or only five?" In all this excitement, I- Suspect: Six. Definitely six. Harry Callahan: Shit.
Dirty Harry Meets Rain Man


Children's Fantasy

Explanation:
Children's fantasy stories such as The Chronicles of Narnia and The Phantom Tollbooth involve a kid who is magically transported out of their time to some fantastic realm, goes through trials and becomes a hero, and then is returned to their own mundane world at about the same time they left with no one else realizing or believing what happened to them. The growth of the protagonist often involves learning self-confidence.
The comic illustrates this type of story and considers what the rest of the child's life would really be like as they reach adulthood. If they tell their friends, spouse, and family what happened to them, no one will believe them and these loved ones will think them a bit crazy. If they don't tell anyone, they are pretending that the episode never happened. Either way, it seems this would not be an enjoyable experience to live with for their entire adult life.
The title text continues the thought by pointing out the impossibility of contributing anything to the scientific world after visiting a magical world, as the child would know many scientific baselines, and, indeed, most regularly practiced scientific theory to be false, but would be unable to say anything or convince anyone of what they knew.
[Kid is sitting on the ground with his chin in his hand.] Kid: I'm such a loser- POP [Princess sticks her head through a portal.] Princess: Come quickly, young one! Kid: Holy crap, a portal! Princess: My kingdom needs you!
[He falls through.] Kid: AAAAAA
[We see him on horseback, helmeted wielding a sword. There's a castle on the horizon and two moons in the sky. There are a few other riders as well.]
[Kid, with helmet and sword, stands before King, Princess, and another warrior. Princess is holding out a ring.] King: You've saved our kingdom and found your self-confidence. Now it's time to return home. Goodbye, young hero! Princess: Take this ring to remember us!
[Kid stands alone, holding the ring.] Kid: Well, I guess I spend the rest of my life pretending that didn't happen or knowing that everyone I love suspects I'm crazy. Kid: This'll be a fun 70 years.


Retro Virus

Explanation:
This comic uses the word "retro" as a reference to retro style and "virus" as a reference to computer viruses . This portmanteau is also a double entendre for a retrovirus , which is a type of biological virus.
Cueball finds himself needing to clean a virus off his Windows machine. Unfortunately, the registry editor (regedit), a key tool in manipulating Windows, is affected. A coworker comes over and mentions that it has been a while since he has worried about cleaning viruses in the Win32 API .
Cueball responds that Windows XP operating system is still the most popular (which it was in 2010, and remained until mid-2012), but is drowned out by another coworker ( Ponytail ) who exclaims that it is as if they are back in 2003. Back then, Windows XP machines were the standard in many places, and were far more often targeted by viruses than other systems, e.g. Linux , Mac OS X , etc.
In the final panel, Cueball's coworkers continue to make fun of him by referencing things that were important back in 2003 like Howard Dean , Friendster or Kazaa . Such things have since fallen largely out of prominence.
The title text is a reference to the year of Linux on the desktop , which is an expectation that in an upcoming year, Linux will make a large breakthrough and be widely adopted by businesses and personal users. The expectation has been around since about 2000, however, and has not exactly happened (although non-desktop devices running Android , a Linux-based OS, are now very common). If it were to happen, the large market share enjoyed by Windows OSes would fade away.
[Cueball is using a computer.] Cueball: Argh, this is frustrating. Friend (off-panel): What?
Cueball: This Windows box has a virus and I can't get RegEdit to- Friend (off-panel): Haha, cleaning viruses? Man, what a blast from the past!
Friend: Check it out! Dude's cleaning Win32 viruses! Remember that? Ponytail (off-panel): It's like we're back in 2003! Cueball (small): Hey, XP's still the most-
Friend: Did you get the virus from Kazaa? Ponytail (with laptop): Guess what I just read on Howard Dean's Friendster!? Cueball (head in hands): Guys...


Spirit

Explanation:
Anthropomorphism (or personification) is attribution of distinctly human characteristics to animals or non-living things. We make parallels between ourselves and objects, to the point where some people even jocularly worry about hurting the feelings of, say, an automobile. We call ships "she." We see human faces in objects like the arrangement of lights on the front of a car.
The Spirit Mars rover , like many high-functioning robots in real life and fiction, shares many physical similarities with a human being or animal. It has a head, eyes, neck, body, legs, feet, arms, and a hand. And it strikingly resembles robots from fiction, such as Johnny 5 from Short Circuit , or WALL-E from the film with the same name.
Thus, this comic explores what the Spirit rover's life would be like if it had a human personality. The rover lasted 5¼ active years on the Martian surface, far exceeding its expected mission duration of 90 Martian days. A sentient  robot might assume that after its initially planned 90 Martian day mission was over, it would get to return home.  This assumes, of course, that the rover never understood that the mission was a one-way trip, and that the expectation was that it would simply fail after ninety days. When no one comes to return it home, Spirit , possibly in a pun on its name, keeps its hopes alive while continuously analyzing rock after rock for years.
It would be cruelty of the absolute worst kind to abandon a human on an uninhabited planet with no intention of ever bringing them home, [ citation needed ] so it feels horrifying when we anthropomorphize the rover. One is rather heartened that the Spirit rover is, in fact, just a programmed machine. Furthermore, even if it were sentient, Spirit has little reason to think of earth as its home, as it had always been designed for Mars, and would have little purpose on earth.  Additionally, a sentient machine might be expected to understand the limitations on its own lifespan, and so would expect to survive only three months.  From that perspective, surviving for years would seem like a victory, rather than cruelty. One alternative version of the strip (see below) makes a similar point.
It is worth pointing out that Opportunity , the rover's twin, has been even more wildly successful and was only shut down in February 2019 ( 2111: Opportunity Rover ). More than five years after this comic, when Opportunity had passed a Marathon distance, Randall celebrated this rover with the comic 1504: Opportunity .
The title text has an apparent miscount: January 26, 2010, is more like sol (Martian day) 2156 by JPL's mission status site, not 2274.
The final contact with Spirit was on sol 2210 (March 22, 2010).
Alternative versions
The strip had a strong emotional impact on the fans of the rover, who created a number of alternative versions and endings for it.
In a blog post Randall mentioned this upbeat rewrite of the comic. Several others were made , including a silent one.
Many alternative endings were also proposed:
[The Spirit rover is on the surface of Mars.] Day 1 of 90 Spirit (thinking): 89 days to go!
Day 88 of 90 Spirit (thinking): Two days until I go home!
Day 91 of 90 Spirit (thinking): ?
Day 103 of 90 Spirit (thinking): Maybe I didn't do a good enough job.
Day 127 of 90 Spirit (thinking): Maybe if I do a good enough job, they'll let me come home.
Day 857 of 90 Spirit (thinking): I thought I analyzed that rock really well. Spirit (thinking): It's okay, I'll do the next one better.
Day 1293 of 90 Spirit (thinking): Sandstorm. Power dying. Spirit (thinking): But a good rover would keep going. A good rover like they wanted.
Day 1944 of 90 Spirit (thinking): Oh no. whirrrr Spirit (thinking): I'm stuck. whirrrr
Spirit (thinking): Did I do a good job? Spirit (thinking): Do I get to come home? Spirit (thinking): Guys?
[ Spirit rests in the middle of a vast Martian landscape.]


Strip Games

Explanation:
The frequency of strip versions of various games is measured by means of Google search results. Strip versions of popular games are a common activity at parties, especially when alcohol is involved. The obligation to remove pieces of clothing is supposed to add an extra zest to the game. A very widespread variant is Strip Poker , followed by strip versions of regular party games like Truth or Dare or Spin the Bottle .
However, the comic also suggests playing other games in a way that involves stripping. In reality, playing such games as "Strip Tennis " or "Strip Agricola " is rather unusual. The Chris Van Allsburg picture book Jumanji and the Robin Williams movie adaptation Jumanji are about a magical board game that manifests dangerous creatures and traps from the jungle and lost civilization therein; a theoretical Strip Jumanji would probably not remain very titillating during the chaos (evidently, therefore, "strip Jumanji" refers to the real-life board game based on the movie ).
The last column features games of which strip versions are (according to Google) nonexistent. While the other columns named sports or board games where a strip variant would be at least conceivable, the last one includes the zero-player Game of Life and the Iterated Prisoner's Dilemma , which is a theoretical example in game theory . It is therefore left to the reader to imagine how a strip version of these pseudo-games would appear.
"Global Thermonuclear War" in the title text is a reference to the film " WarGames ", where a young hacker accesses a US military supercomputer and starts a nuclear war simulation, believing it to be only a computer game.  The film ends by showing the computer that nuclear war is "a strange game" in which "the only winning move is not to play", and proposes "a nice game of chess".
Strip global thermonuclear war is a patently absurd idea; while it is a common trope for people to engage in one last moment of intimate pleasure before certain doom, foreplay (including strip games of any type) is a time-consuming practice, and time is something you don't have much of considering that the bomb could drop on your place of residence at any moment. Besides all that, the act of betting on which city is going to go up next in a nuclear inferno tends not to be an effective aphrodisiac for most people. [ citation needed ] But at least you wouldn't be wearing your radioactive clothes!
Frequency of Strip Versions of Various Games
n = google hits for "strip <game name>" / google hits for "<game name>" (at the time of this writing)
Frequent (n > 1%) -Poker -Spin the Bottle -Beer Pong -Never Have I Ever -Truth or Dare
Rare (1% >= n > 0.01%) -Chess -Blackjack -Tennis -Settlers of Catan -Pictionary
Extremely Rare (0.01% >= n > 0) -Cricket -Magic: the Gathering -Stickball -Agricola -Jumanji
Nonexistent (n = 0) -Poohsticks -Podracing -Iterated Prisoner's Dilemma -Chess by Mail -Conway's Game of Life


Tensile vs. Shear Strength

Explanation:
Tensile strength represents how hard you can pull on something without it breaking. Shear strength represents how hard you can try to cut it without it breaking. Many materials have great tensile strength but low shear strength (such as dental floss — try to break it by just pulling on two ends), including whatever this space elevator is made of. The material clearly has extremely high tensile strength because it can hold the elevator in place, with one end on the ground and one in space, but it can be cut with a simple pair of pruning shears. This also highlights the fact that "shear strength" and "shears" are etymologically related .
A space elevator is a proposed construction that would make space travel easier. It consists of a long string attached to the Earth (near equator) on one end and a counterweight (beyond the geostationary orbit ) on the other end, kept taut and in one place by the gravity and centrifugal forces. This would make it possible to carry spacecraft into the orbit by simple mechanical means, as opposed to requiring the use of rockets as is the case nowadays, saving a lot of energy and resources.
The phrase "a modern Babel" refers to the biblical story of the Tower of Babel (later referenced in 2421: Tower of Babel ), in which humans endeavor to build a tower reaching heaven. Their arrogance angers God and prompts him to sabotage the project. A space elevator can be seen as a modern equivalent of a tower to heaven. [ citation needed ] Additionally, the expression "a modern Babel" may be used figuratively to describe huge projects (especially buildings or human-made structures) that fail because they are too ambitious.
The title text makes the point that even before Black Hat cut the space elevator's cable in two, it was ruined by the holes in it for the banner. The holes would reduce the surface area of the cross section of the pole, reducing its ability to keep the elevator attached to the ground. The flag and holes would also potentially make it impossible for the elevator to travel up the pole, making the entire elevator useless.
[A space elevator occupies the height of the frame, consisting of a base, a cable extending out into space, and an elevator unit with standard elevator features such as sliding doors and up/down buttons. A banner flutters in the breeze attached to the cable going up above the elevator. There is text on the banner. Text appear in four lines split across the elevator cable itself, the rhyming portions of the text is on the right side of the cable. Five individuals stand at the base of the elevator. To the left are Megan, a Cueball-like guy with his arms raised, and Ponytail, who is holding a bottle of champagne/sparkling wine which is bubbling out down the neck of the bottle. To the right is Black Hat, who cuts the cable with a pruning shear like it was part of the ceremony as a ribbon cutting. Finally further right is Cueball who sees what Black Hat is doing. He is very alarmed holding a hand to his mouth while holding the other out towards Black Hat.]
Banner: Space Elevator Banner: Grand opening
After countless engineers spend trillions over fifty years, a modern babel disappears because some fuck brought pruning shears.
Pruning shears: Snip Cueball: !!


You Hang Up First

Explanation:
Telephone conversations end when someone hangs up. There's a traditional cliche of young romantic partners, both of whom are so besotted that they can't bear to hang up on the other. As a result, the end of the call devolves into a cycle where each one teasingly insists that the other one hang up first.  It's a sweet, if somewhat mawkish display of how infatuated they are with each other.
As xkcd often does, this comic takes the cliche to its logical extreme with Cueball and Megan , by turning it into an argument resulting in their breakup. What's normally a cutesy game between lovers becomes a battle of wills, leading them to break up because neither is willing to back down.  And then, even after they break up, both are still unwilling to back down, with Megan insisting that Cueball "move on and find somebody else first."
[Cueball is sitting on a bed, on the phone.] Cueball: You hang up first.
[Megan is lying on a bed, on the phone.] Megan: No, you hang up first.
Cueball: No, you hang up first.
Megan: No, you fucking hang up first!
Cueball: You hang up first, or we're OVER!
Megan: Then I guess we're fucking OVER!
Cueball: FINE!
Megan: ...
Cueball: ...
Megan: You move on and find somebody else first.


Trimester

Explanation:
Some pregnancies are different than others, but a universal truth except in cases of Cesarean section is that a baby will always exit a woman's body through the vagina. Cueball is wearing a white lab coat and holding a clipboard, looking like a doctor, telling Megan that until the second trimester, the baby may decide instead to exit through any opening, including the mouth, anus, nose, navel, etc. This does not normally happen in real life. [ citation needed ] The caption reveals the truth, that Cueball simply bought the lab coat, he is not a doctor, and is either pranking Megan, or is impersonating a physician for some other reason.
The expectation that a person in a white coat is a medical expert, or at least a scientist, can be seen in the studies of the placebo effect: people who receive a "sugar pill" from a person who has the authority implied by wearing a lab coat will experience a greater placebo effect than those who receive identical pills from a person in mufti . This leads to more doctors wearing a white coat while working, and due to that a reinforcement of the expectation of white coats belonging to doctors. In some medical schools students receive a white coat as part of their graduation and qualification ceremony.
The title text implies also that in addition to faking being a doctor, he has also faked being a Nobel laureate, on the logic that people will not choose to verify this claim.
[Cueball is wearing a lab coat, and talking to Megan, who is sitting on a desk. He also has a clipboard.] Cueball: Well, until the second trimester, the baby hasn't decided which opening it will exit through. Megan: What? Cueball: We'll hope for one of the lower ones, so it won't be fighting gravity. [Caption below the panel:] Did you know you can just BUY lab coats?


Complexion

Explanation:
Cueball suffers from acne . Like many others afflicted with the same condition, he uses skin care products designed to treat acne. Unlike most other people, he does his own controlled trial by using them on only one half of his face and measuring the effects; the blemishes on the treated half of his face are noticeably diminished, while the untreated half remains the same, allowing him to isolate the effects of the cream versus the effects of time.
He convinces his friends to try the same experiment with different treatments so they can find out which works the best. In order to properly randomize the trials, he flips a coin. However, because half of his face is "scarred" (with acne blemishes), he's flipping a coin, and appears to be threatening someone with acid, he's mistaken for the Batman villain Two-Face . (Two-Face flips a coin to decide whether his victims will live or die, and was badly burned by acid on exactly one half of his face.) Cueball is subsequently punched by Batman; the title-text implies this has happened before.
Salicylic acid and benzoyl peroxide are both chemicals known for their skin care effects (salicylic acid in particular is also used to treat psoriasis ).
I get frustrated trying to judge whether acne creams are having any effect. In the spirit of a controlled trial, I used one on just half my face for a few weeks. [A graph shows pimples vs. time, with two lines: one remains one steady, and one is declining.]
It was cool seeing the effects so clearly, so I got some friends to try different treatments in an impromptu study. [Cueball looks in a mirror, sees a half-pimpled face, and applies a treatment.]
[Cueball is talking to Ponytail and Megan, each with some pimples also.] Cueball: Okay, you try the salicylic acid first. Ponytail: Wait, we should randomize the trials. Got a coin?
Cueball: Okay, call it. Heads, she gets the- (Off-panel): YOU!
[Batman runs into frame and punches Cueball. The coin goes flying.]


Science Valentine

Explanation:
Cueball is taking a scientific approach to creating a valentine card. Based on the first chart, the recipient is his fiancée since he noted major events (first meeting and engaged, thus they are not married yet, or it should have been noted on the graph). The labels of a heart and smiley represent Cueball's feelings for her and happiness accordingly. This implies that Cueball had love and feelings for someone else before he first met the love he is breaking up with. While they were dating, the feelings and happiness levels were very unstable, as is expected for any new relationship. That later dropped to current levels, probably due to Cueball's lack of love towards her.
In the second panel, there are variables r 0 , r 1 , r 2 , each value at 0.20, -0.61, -0.83 accordingly. Given their names and values between -1 and 1, these are probably correlation coefficients . If they are based on the data in the graph in the preceding frame, they could compare how well one of the variables correlates with time passed since the relationship. For example, if they are based on the heart line, they could measure the correlation between heart (Cueball's feelings for his fiancée) and time, being a weak positive correlation for the first period (0.20), a moderate negative correlation for the second period (-0.61), and a strong negative correlation for the third period (-0.83). Alternatively, they could be comparing the correlation for the accumulated periods, 0.20 for the first, -0.61 for the first and second, -0.83 for all three. Either way, it looks like there becomes a strong negative association between times passed and Cueball's love. The same reasoning would apply if the values are based on the smiley (Cueball's happiness) line.
The text in the space between 2nd and 3rd panels show that Randall Munroe is against scientific misconduct . It also shows that Cueball's rigorous approach makes him realize that the happiness he derives from the relationship is declining, which presents him with a choice. Will he be a true scientist by accepting data that he doesn't like, or will he be romantic and just make a cute card?
The last panel is a parody of a broken(torn) heart, a common symbol used to represent people falling out of love. The line could be interpreted as a graph of the amount of love between the two or a literal tearing of the heart in two.
He decides that he is a scientist and so presents his significant other with a breakup valentine even though he originally intended it as a confirmation of their love.
The comic may be intended as a cautionary tale to new scientists; while the graph in the leftmost panel shows an apparent correlation between Cueball's love and his happiness, and it shows his happiness is lower than it might be expected to be without his partner, it fails to show that the falling love effects falling happiness-- it may be the case that falling happiness effects falling love, or that both happiness and love are affected by an unidentified factor.  For example, temporary external crises may be weighing on Cueball's relationship as well as his happiness.
The title text seems to be him trying to console himself that he did the right thing. You should not use science to prove that your theory is right, but to find out which theory is the right one!
I wanted to make you a science valentine with charts and graphs of my feelings for you. [A graph shows romance and happiness. Romance cuts off, indicating a breakup before the meeting of Cueball and his current significant other, and happiness dips accordingly. A line indicates where the couple first met; romance is jagged thereafter, initially upwards but later down. Happiness climbs slightly more steadily and then dips again. More lines indicate a period of dating and then one of engagement.] and the happiness you've brought me.
But the more I analyzed [Cueball works at a computer.] r 0 = 0.20 r 1 = -0.61 r 2 = -0.83 the harder it became to defend my hypothesis.
In science, you can't publish results you know are wrong and you can't withhold them because they're not the ones you wanted.
So I was left with a question: do I make graphs because they're cute and funny, [Cueball sits, looking at a sheet of paper.] or am I a scientist?
Enclosed are my results. I hope you can find somebody else [A jagged, declining graph is superimposed over a red heart.] to be your valentine.


Snow Tracking

Explanation:
This comic is a guide to recognizing various animals by their footprints. However, the comic typically detours into strange, ridiculous or pop-culture-referencing footprints. In order:
BACKYARD SNOW TRACKING GUIDE
[Each panel contains an overhead view of tracks through the snow, with a caption indicating the apparent source.]
[Standard paw prints through the snow.] CAT
[Large split-toe tracks and smaller rodent tracks.] MOOSE AND SQUIRREL
[Cat prints, but with more space between the pairs of prints.] LONGCAT
[Two similar careening tire tracks.] MOUSE RIDING BICYCLE
[Longer tracks, with a large melted ring surrounding a point in the middle of the frame.] RABBIT STOPPING TO USE HAIR DRYER
[No visible tracks.] LEGOLAS
[Single deep holes with cratering.] BOBCAT ON POGO STICK
[Round prints that suddenly turn to the right halfway into frame.] KNIGHT
[Human footprints up to a square melting pattern, turning into animal prints.] KID WITH TRANSMOGRIFIER
[Human footprints up to a rectangular melted area, which are then doubled to another rectangular area, which are then doubled again up to another rectangular area, which are then doubled.] KID WITH DUPLICATOR
[Right curve on a road, with tire tracks careening out of frame.] Out of Frame Garden Owner: MY VEGETABLE GARDEN! PRIUS
[A series of spiraling and outwardly traveling lines extend from a point in the middle of the frame.] HIGGS BOSON


Honor Societies

Explanation:
Cueball has apparently been invited to join an honor society , but he considers the reason he should join to be a circular argument: because honorable people are in honor societies and people who are in honor societies are supposedly honorable. He objects that this is a tautology : a claim that something is true because it is true (and thus a meaningless claim). From this, he concludes that he might as well be in a "tautology club" and then starts one. Thus Randall mocks honor society clubs for being pointless.
In the final panel where Cueball has formed the club, Ponytail asks a new member (a Cueball-like guy) how he found out about them and he tells about their Facebook page. The reference to Facebook mocks Facebook groups whose names refer to a number of members they hope to attract (such as I Bet I Can Find 1,000,000 People Who Dislike Romanian Dog Abusers ), usually ostensibly to raise awareness for some issue but perhaps in fact just for the ego-stroking pleasure of amassing a large number of followers. Tautology Club employs this tactic only for the sake of creating yet another tautology.
Cueball is listing the rules of the club from a podium. The phrase "The first rule of _______ Club" is a reference to the 1999 movie Fight Club (see also 922: Fight Club ), which contains the famous line "The first rule of Fight Club is 'You do not talk about Fight Club,'" a reference to the club's intended secrecy. This phrase has been appropriated for myriad other varieties and parodies, such as the one mentioned in the comic.
The short guy with glasses could be Jason Fox from the FoxTrot comic (see the first two frames of 824: Guest Week: Bill Amend (FoxTrot) .) Although it takes a little imagination to see, the hair, the height, the glasses, and the geek factor fits. Three of the other characters from the audience look like regular characters but with slightly different hairstyles than usual. There is a buzz cut version of Hairy , a curly-haired version of Hairbun with a ponytail ( Science Girl ), and Megan is drawn with an uncharacteristically white stripe in her hair.
The answer to the title text would also be a tautology: he gets to be the president because he is the president.
Tautologies were mentioned again in 1310: Goldbach Conjectures .  Tautology Club was mentioned in 1602: Linguistics Club .
[Cueball sits at a desk, while someone off-screen answers his question.] Cueball: Wait. I should join this honor society to show colleges I'm honorable, and I'm honorable because I'm in an honor society? Off-screen voice: Basically, yes.
[Close up of Cueball.] Cueball: Sounds like I could save time by joining the Tautology Club directly. Off-screen voice: That's not a real club. Cueball: Then I'm starting it.
[Inserted in a frame crossing the top of the third panel's frame is a caption. Cueball is standing on a podium in the right part of the panel speaking. From left to right we find Ponytail, a Cueball-like guy, a short guy with glasses, a buzz cut version of Hairy, Science Girl, and to the right of Cueball, a woman that looks like Megan although with an uncharacteristically white stripe in her hair.] Caption: Tautology Club: Ponytail: So how'd you learn about us? Cueball-like guy: From your Facebook group, "If 1,000,000 People Join This Group, It Will Have 1,000,000 People In It." Cueball: Listen up! The first rule of Tautology Club is the first rule of Tautology Club.


Principle of Explosion

Explanation:
Cueball's friend (who also looks like Cueball) explains the principle of explosion , a classical theorem of logic, which shows that if within a system of logic you can use the axioms and rules of deduction to derive (prove) a contradiction, it then becomes possible to derive any statement at all within that system (whether it’s actually true or not). In particular, if you start by assuming a self-contradictory statement, you can derive anything.
Cueball then proceeds to misinterpret (perhaps intentionally) that you can derive any fact about the physical world. His formula of propositional logic in the third panel reads " P and not P ", where ∧ is the formal logic symbol for "and" and ¬ is the symbol for "not". P stands for a proposition. As " P and not P " is shorthand for " P is both true and false", this forms a contradiction from which the principle of explosion can begin. Humorously and to his friend's bewilderment he then successfully manages to 'derive' the phone number for his friend's mom.
An example from math : If you assume that √2 is a rational number, you can 'prove' things that are obviously false, such as the fact that some numbers must be both even and odd. Consequently, you can draw the conclusion that √2 must be an irrational number (provided such a thing exists at all! - luckily, it does and obeys the same calculation rules as for rational numbers; this is how proof by contradiction works.)
This can be seen in a Truth Table :
P ¬P P ∧ ¬P P ∧ ¬P ⇒ Q T F F T F T F T
The formula P ∧ ¬P ⇒ Q is true in every possible interpretation. No matter what propositions are substituted for P and Q the implication is true. So if a single example of a contradiction were found, then every proposition would be true, (and simultaneously false).
After deriving the phone number Cueball instantly calls his friend's mom, who turns out to be Mrs. Lenhart . She asks Cueball out, without any preamble, to his friend's vexation. It does not get better when it is obvious that she wishes to drink "cheap" boxed wine with him, and Cueball is free tonight! There is definitely a hint of Mrs. Robinson over Mrs. Lenhart here.
In the title text we hear more of Cueball's (one-sided) conversation with Mrs. Lenhart. She asks him to pick up waffle cones, a variety of ice cream cone . And when he sounds bewildered by this she explains that it is for drinking the wine. This is probably not a very good idea, since waffles are typically not water proof and would also dissolve into the wine. But it could also be considered kinky; something Mrs. Lenhart's son would not like to hear about. The rest of the title text is just more of the main comic's derivation joke, since Cueball will use a second to derive her son's credit card number, so he can buy the cones at his expense.
In reality, Cueball really could start with the principle of explosion and "prove" a statement such as "Mrs. Lenhart's phone number is 867-5309 ", but the same could be said of any conceivable phone number, most of which don't actually belong to Mrs. Lenhart, and because his axiom system is inconsistent, he has no way of knowing which is correct. Likewise for his friend's credit card number. Much like The Library of Babel , an axiom system which can prove any statement might as well prove nothing. Perhaps Cueball already knows these phone and credit card numbers, and is just talking about the principle of explosion to mess with his friend.
[Cueball's Cueball-like friend is talking to him.] Friend: If you assume contradictory axioms, you can derive anything. It's called the principle of explosion. Cueball: Anything? Lemme try.
[Cueball is writing on a piece of paper on a desk.]
[Cueball is holding up a piece of paper to his friend, while holding a phone.] Cueball: Hey, you're right! I started with P∧ ¬ P and derived your mom's phone number! Friend: That's not how that works.
[The friend is looking at the piece of paper, while Cueball is talking to someone on a phone. The desk from before can be seen to the right.] Cueball: Mrs. Lenhart? Friend: Wait, this is her number! How— Cueball: Hi, I'm a friend of— Why, yes, I am free tonight! Friend: Mom! Cueball: No, box wine sounds lovely!


Devotion to Duty

Explanation:
In this comic, we see a man talking on a phone. We are unsure of his aims (terrorism, robbery, etc.) but he has taken hostages and cut all links to the outside world, in order to control the situation and prevent the police from observing the interior of the building (as popularly depicted in film and television). Initially, the villains seem to have everything under their control, but then the hostage-taker explains on the phone that someone has entered the building, climbed the air vents to bypass their cordon, effortlessly killing other hostage-takers (who are likely hardened killers with weaponry) on his way to the server room and then ignored the hostages, preferring instead to reconnect the servers to the outside world. The hostage-taker is evidently puzzled by this and explains it to the person on the other end of the phone, who immediately recognizes the reason: the man that entered the building is a sysadmin (short for system administrator ), and he is concerned that his servers are losing uptime (time spent running or connected to the internet). This evidently concerns the man on the phone, who knows that a good sysadmin is an unstoppable force once started!
This comic is a reference to one of two things (or both): the Hollywood depiction of heroes able to perform superhuman feats in tricky situations (such as John McClane in Die Hard , which the first two panels are a deliberate reference to), or the duty that people impose upon themselves to go above and beyond the call of duty to ensure that they carry out their work (in this case a dutiful sysadmin, concerned for those trying to use his server).
The title text is a simple joke about the fact that the sysadmin will crawl through broken glass and defeat criminals/terrorists (forces of darkness) just so a cat blog (where owners write about their cats) can stay up. This creates a humorous contrast between the seriousness with which large websites treat issues like uptime and business continuity and the often mundane and banal uses people actually have for them.
A sysadmin is also mentioned in the title text of 309: Shopping Teams and in 1305: Undocumented Feature .
[Bearded criminal is holding a pistol and talking on a mobile phone.] Criminal: We took the hostages, secured the building and cut the communication lines like you said. Phone: Excellent.
[Still talking on the phone, waving gun around in the air animatedly.] Criminal: But then this guy climbed up the ventilation ducts and walked across broken glass, killing anyone we sent to stop him.
Phone: And he rescued the hostages?
[Criminal looking confused and defeated, shoulders hunched and pistol hanging limply at his side.] Criminal: No, he ignored them. He just reconnected the cables we cut, muttering something about "uptime". Phone: Shit, we're dealing with a sysadmin .
This comic was made into a shirt in the xkcd store, which includes a new illustration on the back.


Freedom

Explanation:
Cueball on the left, here most likely representing Randall as given in the title text, comments on the absence of physical enforcement for social norms . He tells his friend that he is  sometimes shocked to realize how many options he has. Cueball then goes through a list of possible things he could do that only his conscience and learned social norms (and his cerebrum) prevent him from doing, including stripping naked, taking a plane to Fiji or just punching his conversation partner for no reason at all, with all the "interesting" ensuing events that would result, potentially life changing (he could go to prison for instance).
Cueball continues, explaining that he does understand the mental rules and also the reason, but also that at least once in his life he should exercise that "freedom", hence the title. This is enough to convince his friend who promptly exercises his option to punch Cueball in the face, perfectly in keeping with Cueball's beliefs of how everyone should do so at least once.
On the ground, Cueball remarks that he should have expected this reaction. That he didn't was the beauty of it all, his friend states, because only when the "freedom" is used to do something completely unexpected could the person doing so denounce his mental ruleset.
The title text is a restatement of the first line of the comment, but reversed to show that Randall is terrified about his realization that the same freedoms apply to other people. This is justified by the comic, as some of these people could engage in actions detrimental to others, as Cueball's friend demonstrates; combined with the fact that there are many other people, [ citation needed ] that makes for a lot of unpredictable possible situations.
[Cueball is talking to his Cueball like friend.] Cueball: Sometimes I'm shocked to realize how many options I have. Friend: Oh?
[The text is written above a half height frame with a zoom in on Cueball who shakes his fist.] Cueball: Like, at any moment in any conversation, I could just punch the person I was talking to, and all these potentially life-changing events would unfold.
[Zoom further out than the first panel with Cueball holding his arms out and his friends taking his hand to his chin.] Cueball: It's only my mental rules that stop me from punching you, or stripping naked, or getting on a plane to Fiji. Sure, rules have reasons. But shouldn't you exercise that freedom at least once before you die? Friend: Hmm.
[In very big black letters written vertically between the two panels:] WHAM
[Cueball is knocked to the ground, dazed (three stars over his head) and bruised while his friend is looking down at him with his fist raised.] Cueball: Okay, I should have seen that coming. Friend: But you couldn't! That's the beauty!
"Your right to swing your arms ends just where the other man's nose begins."


Joshing

Explanation:
"I'd tell you, but then I'd have to kill you" is a flippant response to a question that's been around at least since the movie Top Gun , and has entered regular use in the English speaking world, even among people who don't know its origin.
The Cueball uses the line here, but the joke is that he actually is planning to kill the other one, and if he answered the question he'd have to kill him even sooner.
According to the title text, he'd go from #49 on his hit list (which apparently includes an approximation of the entire world population) to #31.
The title 'Joshing' refers to the colloquial American verb 'to josh', meaning to joke with.
Cueball: So, is the new project going forward? Friend: I could tell you, but then I'd have to kill you!
[The men laugh cautiously.]
[The men resume conversation.] Friend: I mean, kill you even sooner.


Sex Dice

Explanation:
Sex dice consist of two dice, one listing various actions, and one listing various body parts ( sometimes a third specifying a manner in which the action should be done). Roll the dice, do the specified action to the specified body part, repeat as necessary.
Because most games require the same dice, in many peoples' game collections, the dice get mixed around between games. Unfortunately it seems Cueball and Megan have accidentally exchanged one of their sex dice (the one that contains actions) with a normal six-sided die; as a result, the people playing a role-playing game in the last panel find themselves doing unusual actions.
Given the situation, it's likely the player who fondled the guard was supposed to roll 2 or 3 six-sided dice to determine the damage of his attack. The sex die came up as "fondle," while the other dice added up to six; hence, he fondled the guard for 6 damage.
The title text is another possible situation that might arise: "rolling for initiative " in role-playing games is how the players determine who attacks in what order during combat. Here, the player rolled the sex die as part of his initiative roll, and therefore "took initiative" in an entirely different way.
Typically the missing sex dice will show different actions like these: Blow, bite, nip, lick, pat or suck (from a set that did not include fondle). The other dice with places on the body like breasts might also have these options: Ass, thigh, ear, navel or lips. Other dice may show positions to use, like doggy style, or places in the house on which to perform these, as in the kitchen. It is a little difficult to imagine any of the actions mentioned above resulting in the response in the title text: Wow, do you ever take it. Maybe there are other types of dice, but they are not easily found with a Google search...
[Cueball and Megan kneel on a bed, Cueball, on the foot of the bed, is shaking a cup of dice. Behind Megan is a pillow and the bed poles.] Cueball: All right, baby. Get ready for... Shake shake shake roll
[There is no frame around the next drawing of the two dice that have been rolled. The first is a regular five (seen almost from the top, but the sides with one and three can be seen). The second die has text written on it:] Breasts
[Cueball and Megan are bent over the dice lying on the bed staring at them. Beat panel.]
[Cueball leans back on one hand while taking the other to his chin while Megan sits straighter.] Cueball: I really need to organize the game cupboard. Megan: Wait, so where's the other sex die?
[A Cueball-like guy lies on his stomach, and another Cueball-like guy sits to the left. Hairbun is sitting and Ponytail also lying on her stomach, hands beneath her chin. They are sitting/lying down around a game board. On the board is what appears to be two dice.] Guy lying: I... fondle the castle guard? That doesn't seem right. Hairbun: It did 6 damage, though.


I Am

Explanation:
In the Book of Exodus in the Hebrew Bible , God announces his presence to Moses by way of a burning bush . The quotation in this comic is a combination of Exodus 3:14 - "I am that I am", and Exodus 3:16 - "I am the God of your father, the God of Abraham, the God of Isaac and the God of Jacob."
The punchline comes when God introduces his "counterpart, R2-D2 ", implying that the "god" in this case is not actually the God of the Jews as expected, but rather C-3PO , a droid from the Star Wars universe; theoretically, in the mind of the reader, God's voice might humorously go from booming and sepulchral in the first frame, to snooty and British in the second frame.  It could be a reference to a plot point from Return of the Jedi , in which the Ewoks believe C-3PO is a god .  (In the movie, C-3PO states that it's against his programming to "impersonate a deity ", but he does so anyway; whether it's actually a violation of his programming is debatable .)
The joke is that "I AM", the name of God in the Bible, is represented in Hebrew by the Tetragrammaton , YHWH. This abbreviation coincidentally [ citation needed ] follows the 4-character naming convention of Star Wars droid characters such as C-3PO and R2-D2 and, like the latter, contains identical characters in the 2nd and 4th positions. (In English translations of the text, this is the part rendered as "LORD" in capitals.)
In the title text, "LO-M" refers to the LOM , a model of protocol droid in the Star Wars universe similar to the 3PO model; "L-O-M" sounds like " Elohim ", a Hebrew word for "God". Bocce refers to a language that Owen Lars wanted his protocol droid to be able to speak; C-3PO claimed that it was "like a second language to me" .
[The Burning Bush of Exodus fame speaks to Moses, who is shielding himself with his arm, as if a great gust of wind is overtaking him.] Bush: I AM THAT I AM, THE LORD YOUR GOD AND THE GOD OF YOUR FATHERS, OF ABRAHAM, OF ISAAC, AND OF JACOB. [A droid comes into frame, Moses looks down at it.] Bush: AND THIS IS MY COUNTERPART, R2-D2. BLEEP BLOOP


Collatz Conjecture

Explanation:
The Collatz conjecture is a longstanding unsolved problem in mathematics. It states that repeating the sequence of operations described in the comic will eventually lead to the number 1. The description in the comic starts out accurate, then veers into the joke.
The comic illustrates the sequence with a graph in which an arrow connects each number to its successor. For example, the number 22 is even, so the next number in the sequence is 22 ÷ 2 = 11, and there is an arrow from 22 to 11. On the other hand, 11 is odd, so the next number is 3 × 11 + 1 = 34, and there is an arrow from 11 to 34.
According to the caption, Cueball is obsessively writing out the graph by hand, and is so preoccupied with the task that he has stopped socializing with his friends. He will be busy for a very long time, because the Collatz conjecture has been confirmed for all starting values up to 5 × 10 18 .
The Strong Collatz Conjecture in the title text is a humorous extension of the Collatz Conjecture. Some other mathematical conjectures and axioms also have normal and Strong variants, where the Strong variant gives a more general rule. This practice is further parodied in 1310: Goldbach Conjectures .
[Cueball sits in a chair at a desk, papers piled on top, writing furiously. Depicted above are apparently the writing, a series of nodes in various Collatz sequences (starting with 7, 21, 24, 29, 106, 176 and 256), all eventually leading back to 1.] The Collatz Conjecture states that if you pick a number, and if it's even divide it by two and if it's odd multiply it by three and add one, and you repeat this procedure long enough, eventually your friends will stop calling to see if you want to hang out.


Seismograph

Explanation:
A polygraph (popularly referred to as a lie detector) measures and records several physiological indices such as blood pressure, pulse, respiration, and skin conductivity while the subject is asked and answers a series of questions. The belief underpinning the use of the polygraph is that deceptive answers will produce physiological responses that can be differentiated from those associated with non-deceptive answers. Polygraphs are generally considered to be pseudoscientific and are not admissible as evidence. (They've been described as worse than coin toss to determine whether as individual is a trained double agent, for instance. The reasoning is that while the coin toss is [also] randomly incorrect about half the time, at least you can't train to beat the coin toss every time). However, they can be an effective prop to convince suspects that interrogators will know if they lie.
A seismograph is a machine which measures and records the ground's motion during e.g. an earthquake. Older seismographs held a pen against a slowly turning roll of paper, and ground motions were amplified and recorded as spikes in the pen line.
The lie detector works by measuring physiological signals which could presumably be visualized by drawing a line on paper like a seismograph. It is assumed that when someone is lying, their physiological signatures will be sharper and more stressed. In the comic, the character on the right is hooked up to the lie detector, and apparently must answer "No" to the question of the earthquake. As long as there is no earthquake, then the subject will be telling the truth, and the polygraph signal will be more stable. But if there is really an earthquake happening, then the subject is lying, and so the polygraph will show sharper signals. This mimics the effect of an actual seismograph. It is not clear why the two characters seem to be upset with each other. It is perhaps because the scene mimics a polygraph test where the subject is trying to hide something. Or, more likely, they are simply panicked.
The title text considers the idea of using a seismograph as a lie detector. If the subject has a nervous twitch, presumably they will twitch in some way when they are telling a lie. This would require them to twitch hard enough to vibrate the ground around them, a vibration that can be picked up on a nearby seismograph.
[Cueball is standing over another man, who is strapped into a chair with wires attached to his head and arms. The wires lead to a large lie detector on a stand next to him, which has jagged lines drawn across it.] Cueball: IS THERE AN EARTHQUAKE HAPPENING?! Sitting man: No! Lie detector: scritch scritch
[Caption below the panel:] Pro tip: In a pinch, a lie detector can double as a seismograph.


Single Ladies

Explanation:
The character in armor is Sauron , the main villain in The Lord of the Rings trilogy. In the backstory of the The Silmarillion , he takes control of Middle-earth by giving several Rings of Power as "gifts" to the great kings of  men after teaching the craft to dwarves and elves. However, he also forged a master ring, the One Ring , to control the Rings of Power and ultimately rule over the kings. However, the elves were not deceived by his plan and took off their rings. Enraged, Sauron started War of the Elves and Sauron . After losing that war Sauron started a religion in Númenor . After using his influence to convince Númenóreans to attack Aman , the island is destroyed by Eru . Then Sauron started War against the Last Alliance . Sauron is eventually defeated in said war by Isildur who cuts off his ring finger. The books tell the story of a small group of adventurers who rediscover the lost Ring and attempt to destroy it, as Sauron's army gathers its forces to attempt to reclaim the Ring for their master.
Gil-galad is a high Elven-king, and Galadriel is an Elf of royal blood who serves as a matriarch of sorts to the remnants of the Elven race. Lindon is a location on the westernmost side of the continent, serving as the final transition point for Elves passing on to the Undying lands. Sauron refers to an actual event in the first panel, when he tried to gain control of Lindon through deceit; Galadriel and Gil-galad saw through his disguise and cast him out.
In the second panel Sauron is talking about Eru Ilúvatar , the creator in Tolkien's Middle-earth legendarium. While Eru created elves and men it was Aulë who created Dwarves, Eru gave them life. Orcs were Elves twisted by Morgoth so Sauron, being his principal lieutenant, would be a natural leader to orcs by the time he created the One Ring.
The song playing in the background is "All the Single Ladies" by Beyoncé, which includes the line "If you liked it then you should have put a ring on it," referring to wedding rings . This is shown as being what inspired Sauron to devise his plan to control others through the gift of rings.
The title text refers to an often-suggested fan theory that the One Ring is actually meant to be symbolic of marriage. This theory is incorrect. The Nazgûl , also known as ringwraiths, are the former nine human kings who were bound by the rings, now a band of nine servants to Sauron who constantly seek out the Ring for him.
[Beret Guy is talking to Sauron; Sauron is wearing his trademark helmet, but his head is downcast. Music plays in the background.] Music: All the single ladies, All the single ladies Beret Guy: Hey Sauron, why so glum? Sauron: Gil-galad saw through me and threw me out of Lindon. Galadriel as well. I'll never rule anyone at this rate.
Music: All the single ladies, All the single ladies Sauron: Eru created such beautiful creatures - Elves and men and dwarves - and all I've got are these stupid orcs.
Music: 'Cause if you liked it then you should have put a ring on it Sauron: I mean, I-
[Sauron is suddenly quiet.] Music: If you liked it then you should have put a ring on it


GeoIP

Explanation:
GeoIP is a service that converts IP addresses to their respective location on the Earth. This is done by looking up the IP address in a database maintained by various internet service providers. Advertisers often take advantage of the Jones effect by creating localized ads which misleadingly appear to be specific to your location, but are often simply stock photographs with the name of the nearest town superimposed on top.
The comic satirizes this phenomenon. The International Space Station (ISS) has a high speed data downlink, but no direct connection to the internet. But here, Cueball trolls the advertisers from on board the ISS, by inserting his actual location on low Earth orbit into the database under that IP address. He proudly presents his result to Ponytail where the advertisements claim that there are "local girls" in low Earth orbit; a distance of roughly 420 kilometers above the Earth surface, and thus at least that far away from all other girls in the world if they are not on the space station (or a nearby spacecraft, such as one bringing supplies to the space station).
The title text shows GeoIP has become so accurate that it can now pinpoint the user's location to his Mom's basement. In United States, an adult living with his parents is considered shameful for that person, since it means that the adult does not have a job and cannot support himself. The ads are typically of the form -- "Meet hot young singles in <user's location>" where the <user's location> part is filled in from GeoIP. In this case, the GeoIP is so accurate that it not just identifies that user is in his parents' house, but it also pinpoints the location that he's hiding in the basement, perhaps because he does not want to be seen by people visiting his parents. Thus GeoIP is unknowingly shaming the user by reminding him that he is in his mom's basement, and hence the "Screw you" response. However, this would also prove the false nature of these advertisements, as the user is unlikely to have not noticed any hot young singles currently sharing his mom's basement. [ citation needed ]
[External view of a the International Space Station (ISS) orbiting the blue Earth below, shown with white clouds as stripes below and black sky above. Dialog, written in white on the black sky, comes from within the ISS.] Cueball (inside the ISS): Yes! Ponytail (inside the ISS): What? Cueball (inside the ISS): I got our downlink into a GeoIP database.
[Internal view of the satellite, Cueball and Ponytail are floating weightlessly around, Cueball is at a laptop style computer mounted to the wall. They are in a white room, with black around, but due to being weightless in space, the room is turned on edge as to not give any semblance of a given up/down direction.] Ponytail: Why? Cueball: To mess with advertisers. Check it out.
[A zoom in on the computer screen is shown, it shows an ad on a pink background. The ad has a heading and then shows two photos of long haired girls in sexy poses each with captions below and a labeled button at the bottom. The location (as messed up by Cueball) is written in gray, the rest of the text is in black, to indicate that this part of the text has been inserted in the ad based on the location.] Meet local girls in Low Earth Orbit tonight! Tanya, 18 Amber, 19 Chat live


Porn For Women

Explanation:
Porn for Women is a popular illustrated humor book that features exactly what the comic says.
There is an opinion that women especially dislike blunt porn that objectifies the people involved in the intercourse. The authors of the book follows this line, presenting no sex but several images of extremely attractive men performing household chores. Megan objects to this, stating that her porn contains sex.
Galactica is the ship from the show Battlestar Galactica . Megan likely has a romantic attraction to some of the characters on the show, possibly involving "shipping" fanfiction .
[Megan sits at a desk, typing on a computer with a fairly large flat-panel display.] Megan: To the authors of Porn for Women : Your book features pictures of hot, clothed guys cooking, doing laundry and vacuuming.
[Megan continues typing.] Megan: The idea seems to be that my deepest fantasies, like the rest of my life, likely revolve around housework.
[Megan continues typing.] Megan: So I wanted to write in to clarify: in my porn,
[Megan leans forward in her chair.] Megan: People fuck .


Numbers

Explanation:
This comic use the popular search engine Google to show how many hits (or web pages) are returned as relevant based on a given search replacing <X> by different numbers.
Bottles of beer The top one is of the old drinking song 99 Bottles of Beer on the Wall . In this song, the singers begin with 99 bottles and with each repeat of the verse, decrease the bottles of beer by one. The graph shows a slowdown at 66 bottles of beer, something highlighted. A spike occurs at 49 bottles of beer, which seems to be a popular variant (possibly due to 49 bottles taking about half the time that 99 would).
Boy/girlfriends On the second row, the left graph represents how many girlfriends or boyfriends someone has had. They seem pretty similar, though the logarithmic chart may be working on that. There is a clear peak at four girlfriends.
School grade In the middle of second row is a curve for how old (in grade) Internet users seem to be. Going purely by grade, the average is at 7th grade. However, using the notation of Freshman (9)/Sophomore (10)/Junior (11)/Senior (12), there's a notable resurgence.
Penis length The graph on the far right of the second row describes Internet users talking about the lengths of penises that they have. 5-6 inches (~13-15 cm) is generally considered average, but it doesn't appear that way on the Internet. There is a general trend (also shown by the line), but the maximum, 9 inches (23 cm), peaks way above the trend line - indicating that guys think they can pull this one off, although 12 inches (30 cm) peaks way above the trend line as well. Probably because 12 inches equals a foot.
Cup size The third row contains four graphs. The far left is the breast size of the Internet user. (This presumably refers to female users, since male breasts are not typically measured in cup size.)  The actual breast size is generally considered a bell curve around a B or C cup, yet the hits on Google describe almost an exact opposite trend. Taken with the above male penis length and this describes a trend where either the "average" person posting information seems to embellish or the majority stay quiet. Typically those with small breast will complain, and those with large breast will complain or brag. Those that are content with a C cup do not need to do either.
I have never had a boyfriend The second graph on row three is number of hits per (mostly) female Internet users talking about how old they are without having a boyfriend. There's a spike at 18. The comic was written in 2010; as of 2014 the spike does not exist. Google behaves very strangely in this case, as it shows two very different numbers for each search.
Glasses of water a day Third from the left in row three is the number of glasses drunk per day. Many "health authorities" claim that  8 glasses of water a day should be the most healthy. This common misconception is not supported by scientific research. This is the subject of 1708: Dehydration and is also mentioned 1853: Once Per Day . In both these six glasses of water is mentioned first rather than eight. (New research...)
Number of lights On the far right is a description of the number of lights. The spike at four is due to a famous scene from Star Trek: The Next Generation , episode Chain of Command Part II where Captain Picard answers that there are four lights, despite pressure to answer that there are five. This is itself a reference to George Orwell's novel Nineteen Eighty-Four , where Winston Smith is tortured until he "learns" to be unsure of the number of fingers being held up by his torturer, despite him only holding up four.
Number of problems Bottom left is a reference to the popular Jay-Z rap song 99 Problems . It is the only reason that 100 problems only ends up second by more than a factor of 100.
IQ Bottom right describes the IQ of the Internet goer compared to the average. By the definition of the test the average is 100 with a standard deviation of 15. However, the comic implies that the average claimed IQ closes in on 133 more than 2 standard deviations above the real average! This high average are thanks mainly to the million who has given their IQ as 147. There are four other peaks that are also labeled, and these peaks are the only other above 100,000 hits, but neither of these have much more than 200,000 hits. Apart from these five there are only 5 more with more than 50,000 hits. Note the log scale of the y.axis! Many studies have shown that people today would score a higher average than 100 if they took the earlier test - an effect know as the Flynn effect . However, new tests from today should still average out to 100, as an IQ of 100 is defined as the average of any given IQ test. The five labels: Why is 147 so popular? The maximum break in snooker is 147, but it is unlikely that this is known by enough to make a difference here. There is also a frequently repeated factoid that Albert Einstein scored an IQ of 147 but there's no real record or consensus of this. The 100 (the average) peaks out is obvious. 110 - ten more also makes sense. In general there are almost always more hits at every 5 and 10, than the two values before or after. 133 is a third of the way to 200, and also it will take you clear of the Mensa requirement for membership of 132 on the Stanford–Binet Intelligence Scales . Why 142 is popular is also difficult to say. Of course 42 is a special number for fans of The Hitchhiker's Guide to the Galaxy , so 142 for an IQ score could be helped to peak for this reason. Although then it is no longer 42... (But an IQ of 42 would be really bad!) The scale of the graphs x-axis is completely off. This can easily be seen from the labeled points. Whereas 100 and 110 is close to the mark, the point labeled 133 is much closer to 140 than 130 (at about 138) and the 147 point lies clearly past 150 (at around 152). It is, however, for sure the scale that is off as there are the correct number of points between all five labeled points. There is a clear point on the y-axis at 80, but then there seems to be a gap up to the next point, and there are also only 16 points between this first point and the point labeled 100. It thus seems that while there are in fact about 20,000 who claim as low an IQ as 80, then there are not enough who claims a score of 81-83 for them to be shown in this graph. The graph begins at around 80-90 hits because of the log scale so there could be some hits, but way less than the lowest point on the graph which lies close to 1000 hits. From an IQ of 84 and up to 168 there are a point for each IQ for a total of 86 points (with the point at 80).
Title text The title text refers to the searches. It concludes that the average (male) internet user has a 9-inch penis and an IQ of 147. Humorously it continues to state that this is better than the reverse - having a 147-inch penis (over 12 feet or 3.7 m) and an IQ of 9 (only 2 % of the population have below 70).
Google Result for Various Phrases: {Each panel is a scatterplot of the described X against the number of Google hits, with trend lines. The scales vary.}
<X> Bottles of Beer on the Wall [There are peaks at 1, 49, 73, and 99. A dip in the middle is marked "They lose steam at 66." After 99 is a steep dropoff. The largest peak is around 100,000 hits.]
I've Had <X> Boy/Girlfriends [Both lines descend at roughly the same rate from 1 to 10, although the boyfriend graph is smoother; the girlfriend graph has a small peak at 4 and a small dip at 6. The peaks are between 100,000 and 1,000,000 hits.]
I'm in <X>st/nd/rd/th Grade [The curve is a bell peaking at 7th grade and about 500,000 hits. A second line labeled "Including Junior, Senior, etc." follows the bell curve until the peak, then dips only slightly for 10th grade and resumes climbing.]
I Have a/an <X>-Inch Penis [The line ascends shallowly from 100,000 hits for 3 inches to a peak of 180,000 for 9 inches, then descends steeply to 20,000 for 13 inches.]
I'm a/an <X>-Cup [A has a few hundred thousand hits; the graph dips to a few thousand for C, peaks again around 100,000 for E, and then tails off.]
I'm <X> and Have Never Had a Boyfriend [The graph is mostly a simple bell, starting and ending around 300,000 hits for 13 or 21, but there is a sharp peak of 700,000 at 18 (well above the trend line).]
Drink <X> Glasses of Water a Day [There are barely any hits below 4 or above 12; between the two it rises steeply to about 1,000 hits, with a steep, narrow peak of 10,000 at 8.]
There Are <X> Lights [The graph descends smoothly from several hundred thousand hits for 1 to about 10,000 for 10, except for a peak of about 1,000,000 for 4.]
I Got <X> Problems [The plot is extremely jagged, with the largest peak of 10,000,000 hits at 99, another of 10,000 at 96, and 100 and 88.]
My IQ Is <X> [A smooth curve starts and ends at a few thousand hits for around 85 and around 170, with the peak at several tens of thousands for 140, but there are several prominent outliers: 100, 110, 133, and 142 are all around 100,000 hits, and 147 is around 1,000,000.]


Time Machine

Explanation:
Rob is about to discover time traveling , but a future version of him comes back in time and hits him with a baseball bat before he can actually build this time machine.
A common theme in time travel fiction is going back into the past to fix some mistake or stop some tragedy before it happens (see for instance The Terminator movies). In this comic, it is implied that Rob's time traveling turned out to cause a tragedy of some kind, so in order to stop it, Future-Rob must go back in time to stop himself from time traveling in the first place. The last panel supports this by suggesting that at least once a month somebody discovers time travel, but inevitably ends up going back in time to prevent themselves from doing so.
This is a plot point from the 2004 time-travel drama film Primer : one character intends to travel back in time to prevent them from discovering time travel in this way, and another character has already traveled back in time, drugged his earlier self, and taken over the operation to discover time travel before the narrative of the film begins. Primer has a notoriously complicated plot that Randall already has made a jocular attempt at explaining in 657: Movie Narrative Charts . Some more thorough attempts to explain it can be found here and here .  Doubtless, this has also been spoofed in countless other comedic settings.
The blood on the bat suggests that future Rob actually killed past Rob. This is of course a paradox like the grandfather paradox - but there are theories about how it would still be possible - see the link. The obvious paradox is that when Rob dies the future Rob never existed. But also the time travel Future Rob undertakes uses a technique that is now never invented. This was the reason for future Rob's travel.
The title text states that this is why we never see any time travelers since they would have stopped their own past selves from time traveling. After getting rid of their past selves they would then assume their place in the timeline, hence why a friend would suddenly look older: they have aged, just in another timeline before returning to the past.
[Rob is working at a workbench. Future-Rob appears out of nowhere with a baseball bat.] Future-Rob: Hi, Rob. Rob: Whoa, you're me!
[Future-Rob holding the baseball bat, standing next to Rob.] Future-Rob: You're about to have an idea for a time machine. Rob: I am?
[In a frameless panel, Future-Rob hits Rob over the head with the baseball bat.] WHAM
[Megan approaches Future-Rob working at the workbench, with Rob nowhere to be seen. The bloody baseball bat is stashed behind it.] Megan: Hey, Rob. What's up? Future-Rob: Nothing.
[Caption below the last panel:] This happens somewhere roughly once a month.
This comic's title is very similar to 1203: Time Machines .


Furtive

Explanation:
The person in the comic is Inspector Gadget from the animated series of the same name . Gadget was a cyborg detective that had access to a wide variety of gadgets which he would activate with the words "Go go gadget [insert item here]." The gadgets would usually spawn from his hat, such as his trademark personal helicopter ("go go gadget copter!"). One of the running gags of the series was that Gadget was completely clueless during his missions, and unbeknownst to him, relied heavily on the assistance of his niece Penny, her computer book, and her dog, Brain.
In this strip, Inspector Gadget (wearing his trademark hat and trench coat) looks around furtively and apparently moves away from the listener (or the camera pans out to reveal the empty environment) before saying the words "Go go gadget two lesbians doing it."  The fantasy of lesbians having sex is a common turn-on for straight men. The command, given in the last panel of the comic, also serves to identify the person speaking. Identification along with the punchline is a common comedy trope.
In the title text, Gadget requests further gadgets: A video camera, to record the action, and a cup. The cup is probably a reference to the well-known, scatological pornographic video 2 Girls, 1 Cup , which was prominent at the time the comic was created.
[Inspector Gadget in a trench coat and hat stands mid-frame.]
[Gadget turns his head, looking to his right.]
[Gadget stands alone in a wide expanse.]
[Gadget finally speaks.] Gadget: Go go gadget two lesbians doing it.


The Flake Equation

Explanation:
This strip parodies the Drake equation , which is an method for estimating of the number of detectable extraterrestrial civilizations in our galaxy.  The Drake equation starts with the best estimate for the number of stars in our galaxy, then multiplies it by successive probabilities (such as the number of stars with planets, the number of planets which can support life, etc), to ultimately calculate how many civilizations exist. While such a calculation necessarily uses speculative numbers, it gives a good sense of how many civilizations could potentially exist.
The Flake equation presented in this strip provides an estimate about how many false or fake stories about aliens are likely to exist. It does so in similar manner as the Drake equation, by starting with the entire population, estimating how many people are likely to believe that they've had an alien encounter, and then calculating how likely those stories are to become public. Just like in the Drake equation, exact numbers are unknown, but can be estimated, and the equation in the comic shows Randall's guesses about these values. See an explanations of values below.
"Flake" is American slang for a person who is casually dishonest or unreliable, implying that such a person would be likely to imagine an alien encounter. Note that, while the Flake equation includes people who imagine encounters "because they're crazy or want to feel special", it doesn't attempt to include outright lies or deliberate hoaxes.
The final results tells us that there should be about 100,000 stories about aliens that have reliable explanations. (The numbers given in the equation gives 126,000 stories). The data is obviously highly speculative, and as with the Drake Equation, you can plug in your own numbers, but if you keep your guesses realistic, you will most likely get a very large number. This convinces the reader that the fact that there are many stories about aliens does not necessarily mean that many people actually met aliens.
The title text refers to Fermi's Lack-of-a-Paradox.  The Fermi paradox refers to the contradiction between high numbers of calculated civilizations and the total lack of verified alien contact with earth. This is related to the Drake Equation, many estimates calculate that there should be large numbers of civilization in the galaxy, and they should have existed for long periods of time, suggesting that humanity should have been contacted by them, or at least seen some clear evidence of their existence. There are multiple explanations for this paradox, but it remains a question of scientific debate.  The Lack-of-a-Paradox in this strip, however, is that the math suggests that there should be huge numbers of claimed alien sightings, and that's exactly what we observe.
Another comic parodying this equation is 384: The Drake Equation . The credibility of paranormal reports in general is revisited in 1235: Settled , which posits that if such phenomena were real they should have been unambiguously captured on camera by now.

The Flake Equation: P = W P × (C R + M I ) × T K × F 0 × F 1 × D T × A U ≈ 100,000 Where: W P = World Population (7,000,000,000) C R = Fraction of people who imagine an alien encounter because they're crazy or want to feel special (1/10,000) M I = Fraction of people who misinterpret a physical or physiological experience as an alien sighting (1/10,000) T K = Probability that they'll tell someone (1/10) F 0 = Average number of people they tell (10) F 1 = Average number of people each friend tells this "firsthand" account (10) D T = Probability that any details not fitting the narrative will be revised or forgotten in retelling (9/10) A U = Fraction of people with the means and motivation to share the story with a wider audience (blogs, forums, reporters) (1/100) Even with conservative guesses for the values of the variables, this suggests there must be a huge number of credible-sounding alien sightings out there, available to anyone who wants to believe!


Brain Worms

Explanation:
Another comic in the My Hobby series. Cueball is tricking Megan by pretending to read from a book about a parasitic brain worm, describing the apparent symptoms caused by an infection. The dreams described sound very specific, which leads Megan to believe that since she has been having these types of dream, she must be infected. The comic text asserts that these types of dream are fairly common however, and this knowledge can be leveraged to trick people who aren't aware of this.
Dream contents are likely to be affected by many factors, however because people share common thoughts, feelings and experiences in waking life, it is unsurprising that our dreams share common features. In the case of the comic, cars are a ubiquitous feature of life for most people, and for many driving or being a passenger in a car is a regular experience. It is therefore to be expected that cars are likely to feature in dreams. What is less logical, but still common is there being something strange about the situation. The car may be huge, tiny, backwards, upside-down, flying, underwater, non-descript, etc. The examples given in the comic are typical of the 'unusual factor' reported in dreams.
Some people believe (to varying degrees) that dreams may be interpreted as a representation of a persons thoughts, emotions, or their subconscious. One of the more generally accepted interpretations of dreams involving driving or riding in a car, is that it expresses how you feel about your control over your own life. A dream about not fitting or not being comfortable in a car might be interpretted as the dreamer feeling out-of-place or uncomfortable in their own life, while dreams about losing control of a car might indicate the dreamer feels their life is out of control.
Megan of course does not have an infection from these fictional brain worms. Cueball is taking a "shot in the dark", with the success of his trick relying on Megan recognising these dream types as ones she has experienced. He may be playing on fears possibly carried by many people that these types of dreams hold a deeper significance which they can't identify. In the comic, Megan appears not to realize that he is pulling a prank on her and begins to get scared.
The title text continues the joke with another common dream, this time about teeth falling out. One commonly-accepted meaning of teeth falling out is a loss of confidence or power in one's life.
Common dreams are also discussed in 1943: Universal Dreams .
[Megan sits at a computer desk, and Cueball stands near her holding a book.] Cueball: Weird-this parasitic worm infects the brain, damaging the areas responsible for spatial reasoning in dreams. Signs of infection include dreams about not fitting in your car comfortably, driving from the backseat, or veering all over the road. Megan (thinking): Oh God.
My Hobby: Taking advantage of the fact that some specific dreams are weirdly common, but not everyone who has them realizes this.


Recipes

Explanation:
A genetic algorithm starts with a set of candidates and evaluates them. The best candidates are combined and randomly mutated to form the candidates for the next generation. After being allowed to proceed for an extended period, a genetic algorithm can often produce remarkable results. If the initial candidates are randomly-generated (as appears to be the case here), the initial generations are usually horrible.
In the comic, the computer science (CS) department is the host of a dinner party. They choose to create a genetic algorithm to generate their recipes. Based on the remarks of the second diner, this is probably not the first generation, and the results are still horrible. Vermouth is a type of fortified wine , usually served alone or in cocktails. It seems unlikely that cheerios would complement the flavor of it. Quail eggs are a delicacy in many countries, as opposed to whipped cream , which is usually served on desserts. It was topped off with MSG, or Monosodium Glutamate , which is a non-essential amino acid used to enhance the flavor of savory foods. The last person has skittles , a brand of candy with a hard outer shell and a inside composed of corn syrup and hydrogenated palm kernel oil . Deep-frying is usually done to savory starches and meats, not sweet confectionaries. The host of the party is so enamored of the promise of the genetic algorithm that he fails to take into account that it will be several years before the recipes become remotely good.
The title text could make reference to the fact that genetic algorithms will sometimes return results which are highly abnormal and vastly deviate from what we would think to be "selected for," but nonetheless can be quite successful, albeit unorthodox. Braising is a cooking practice involving both searing on an open pan and boiling in a pot with liquid; newts are small lizard-resembling amphibians that are not commonly eaten in America, and Doritos are a cheese-covered tortilla chip. None of these are elements that a sane chef would use together when preparing dinner, but the title text concedes that it did taste good despite the abnormality. It also showcases that the algorithm has stumbled upon a recipe that engages in wordplay with the movie and common phrase "Dazed and Confused".
[Three people sit along a table with dishes and drinks in front of them. Cueball is walking in, a plate with food on it in one hand, a laptop in the other.]
[Blondie looks down at her bowl. She has a cup with what appears to be a lump of coal in it.] Blondie: I've got... Cheerios with a shot of vermouth. [Cueball 1 has a plate with some kind of cubic food on it. He has a cup of what appears to be two lovebirds in it.] Cueball 1: At least it's better than the quail eggs in whipped cream and MSG from last time. [Cueball 2 has a plate with a several lumps of some form of white stuff on it. They have a cup of what appears to be some kind of superfluid flowing out of it.] Cueball 2: Are these Skittles deep-fried ?
Cueball 3: C'mon, guys, be patient. In a few hundred more meals, the genetic algorithm should catch up to existing recipes and start to optimize. We've decided to drop the CS department from our weekly dinner party hosting rotation.


Flatland

Explanation:
This comic is a reference to the satirical novel Flatland: A Romance of Many Dimensions , in which a society of flat shapes live in a 2D world. Half the book is a direct satire of Victorian society, and the other half explores the experience of discovering a new dimension, where a sphere introduces a square (named A. Square) to 3D . Cueball appears to have taken the place of this sphere, and the comic takes place after the square knows the third dimension exists.
Humans will never fully be able to fully grasp the concept of a fourth spatial dimension (at least not in the foreseeable future), but there are ways of squashing or slicing four dimensions to create partial visualizations of 4D space. Miegakure is a yet-to-be-released 4D game that uses cross-sections of 4D space. Cueball attempted to play a pre-release version of it, but after having his "mind blown", he gained more sympathy for A. Square, who'd had similar trouble understanding 3D. A. Square accepts his apology.
The joke here is that Cueball was being silly and drew lines on A. Square to make him look like SpongeBob , which did not make the square happy. Cueball apologizes again.
The title text is a third apology for when Cueball crawled down into the second dimension. Being a stick figure, he is composed of a circle and straight lines. In Flatland, circles are priests (Flatland's highest social level), and all women are lines; thus, to a watcher in Flatland, Cueball would look very much like a priest above many connected women, which may look like a lesbian orgy.
[Cueball talks to a square on the ground.] Cueball: Hey, A. Square. How's Flatland? A. Square: Still flat. What's up? Cueball: I just spent an hour playing a demo of this 4D game called Miegakure.
[In a frameless panel, a character in Miegakure jumps around the 4D landscape.] Caption above the panel: Trying to jump from block to block in four dimensions hurt my brain.
[Cueball continues talking to A. Square on the ground.] Cueball: So I apologize for giving you a hard time when you were slow to understand 3D space. I sympathize now. A. Square: It's okay.
[Zoom in on Cueball's head] Cueball: Also, I apologize for drawing arms, legs, and eyes on you to make you look like SpongeBob. That was out of line. A. Square: Yes, it was.