Sandwich

Explanation:
On both Windows and UNIX computer systems, users can be assigned all kinds of rights, for example rights to access certain directories and files, or to execute certain commands.  The sudo command (pronounced "sue due" or "pseudo") lets certain (authorized) UNIX users override these policies by executing the command (everything after the word "sudo" on the command line) as the root user. Root (sometimes called the superuser) has complete system powers, exempt from all access controls; it is similar to a Windows administrator, however even the powers of a Windows administrator is limited - the system32 folder, for example, cannot be deleted because it is a critical part of the operating system, while there is no such restriction on UNIX - if a root user feels like (or accidentally) deletes a vital file, they are free to do so. As a result, common advice is to not use sudo unless the command in question absolutely requires it - indeed, most commands do not require such privileges.
One very common activity for UNIX administrators is to install or configure software using the UNIX make command, e.g. % make install .  Often this command requires administrative permissions in order to complete successfully, which in practice means the " make this " command will fail unless it is typed as " sudo make this " instead. However as mentioned before since most commands work just fine without sudo, along with general discouragement from using it willy-nilly, it is fairly common for people who use or administer UNIX systems to attempt a straight up % make install and have it fail. They then need to repeat the command with "sudo," whereupon the computer responds obediently, and everything works smoothly.
Cueball is demanding a sandwich from his friend. Not being properly asked, the friend denies the request. Cueball then (ab)uses the sudo command on the friend, who then has no choice but to go and make the sandwich, and now does so without complaint, because Cueball has all the rights. For anyone versed in installing system software with the make command, this exchange is intensely reminiscent of the analogous onscreen experience.
Simon Says is a children's game in which a leader gives various commands that must be followed if and only if ( iff ) the leader prefixes the command with "Simon says." The title text compares the way the computer will run some commands if they are preceded with "sudo" to the way Simon Says players are supposed to follow orders if (and only if) they are preceded with "Simon says."
Alternatively, the title text might merely be referring to the similarity between Cueball ordering his friend around with "sudo" to the Simon Says game leader ordering other players around. Wikipedia suggests  that the "Simon" in the name of the game may be the powerful lord Simon de Montfort, or a corruption of Cicero, both of whom were influential politicians of their day.
[Cueball is sitting on a couch, talking to a Cueball-like friend.] Cueball: Make me a sandwich. Friend: What? Make it yourself. Cueball: Sudo make me a sandwich. Friend: Okay.


Grownups

Explanation:
Randall is again playing with the child/grownup mental setup. During childhood, adults ("grownups") make most of the decisions and put constraints on what their children do. As children age and eventually become grownups, there are some things that they do not do anymore, as they see them as childish.
Megan has taken these thoughts seriously, and realizes that with her newfound freedom as a grownup, she gets to define what her adulthood means. Free from constraints, she goes ahead and creates a ball pit in her apartment of colored plastic balls. Cueball admires this spirit and enters the ball pit. It is difficult to decipher Randall's true intent behind this somewhat cryptic comic, but it seems from the heart that the two are engaging in sexual activity in the pit.
The trend with adults participating in children's activities is continued in 219: Blanket Fort , and with adults who feel like children while doing adult things as in 616: Lease , which references this comic in the title text.
The title text reveals that Randall also would like to make his own ball pit, but he finds it expensive to buy and also hard to keep clean . Both of these are true - see links. Most public ball pits can easily become very dirty, as many children and toddlers play in them.
[Cueball is talking to Megan who is behind a waist-high screen across a doorway with colorful playpen balls behind her.] Cueball: Hey, I was wondering if you had plans for-- holy crap, what happened to your apartment? Megan: I filled it with playpen balls! Cueball: I... what? Why?
[Megan is seen from the front through the door with the colored balls behind her.] Megan: Because we're grown-ups now, and it's our turn to decide what that means.
[Cueball is seen from the side standing next to the open door. Megan cannot be seen, except her hands on the screen, but some of the coloured balls can be seen through the door. A beat panel.]
[Same view but both have entered into the apartment, removing the screen so coloured balls have been spilling out into the corridor. A big pink  love heart drifts out the door.]


Mario

Explanation:
One-upmanship is the act of surpassing another person. In this case, one female character is one-upping her friend's claim of being taken on a mountain hike with a claim that she was proposed to.
Mario is the major figure in the Super Mario series. In the games, completing specific conditions causes a "1-up" (but the marks are chevrons («»), used in some languages like Russian instead of quotation marks) to appear on screen, referring to an additional life. The comic relies on the homonym of the action of one-upmanship and the event of one-ups in Mario.
In the title text, Randall implies that this is a pretty bad joke.
Megan: For our anniversary, my boyfriend took me hiking in the mountains. Ponytail: My boyfriend proposed to me. Ponytail: They should call you Mario, 'cause you just got <<1 up'd.>>


Hamster Ball

Explanation:
The comic starts with a genie , who, having been freed from a magical lamp, grants the owner three wishes; this isn't unusual, since the idea of a genie who does this is a very common trope in the fantasy genre.
Cueball asks for a human-sized hamster ball , and when he gets it, he starts to roll around in it, obviously entertained.
The genie then asks what he would like for his other two wishes , to which, having already being granted his heart's desire, he states that he wouldn't need the other wishes for anything.
The title text refers to the activity of Zorbing . Later, Randall found out where to get one and went on a hamster ball heist , and hamster balls have been a recurring theme on xkcd since this comic, and 14 years later it received a direct sequel 2331: Hamster Ball 2 .
This comic is referenced in 1975: Right Click , where one of the things the ADVENT.EXE wishing well allows you to wish for is a human-sized hamster ball. Doing so redirects you to this page.
Genies (or magic lamps) are mentioned in at least four other comics:
In the first two, Randall manages to use the concept to make penis-related jokes. In the fourth, the issue of number of wishes is discussed, from the perspective of wanting more than three wishes. The issue of wishing for more wishes is also the subject of 1086: Eyelash Wish Log , so it is not always enough with one or even three wishes!
[Cueball stands by a genie, whose lower body becomes smoke and trails down to an old-fashioned lamp.] Genie: You have awakened me from the lamp. You may have three wishes. What does your heart desire? Cueball: I'd like a human-sized hamster ball.
[A hamster ball appears; Cueball is inside it, arms outstretched.] Cueball: Sweet!
[Cueball steps to left; the ball rolls that way.]
[He does the same thing to his right.]
[Cueball comes to rest in the centre of the panel.]
Genie: And your other wishes? Cueball: Why would I need other wishes?


Cryptography

Explanation:
This comic refers to the study of cryptography . We can note the presence of the International Association for Cryptologic Research (IACR) logo in the lectern ( podium? ), an association that organizes the most important conferences in the cryptology field.
Randall , drawn as Cueball behind the lectern at the podium, is describing a proposed crypto system in which a computer program turns a very large number, called the " key ," and a message into an encrypted form that can only be read by using the same key, based on the model of a Feistel cipher . Part of any Feistel cipher is the "round function," which determines how the key is applied to the original message; this is applied multiple times with a variety of tricks and techniques to ensure that the process can eventually be reversed. One common component of round functions is the S-box , a simple table that converts input bytes into output bytes, preferably in a way that doesn't correspond to any mathematical rules.
Here, the S-box would be implemented by doing the following (with the computer operation actually shown in the diagrams indicated in parentheses):
This would be run on each round of the cipher to further scramble the message for the next round. As the caption implies, the steps are based on a line from the Missy Elliott song Work It : "I put my thing down, flip it and reverse it." As with any encryption system, there must be a way to decrypt the cipher text. In Missy Elliott's song, the phrase "I put my thing down, flip it and reverse it" is repeatedly played backward, sounding like gibberish. In the same way, steps to a Feistel cipher-based algorithm are executed in reverse to obtain the original plain text from a cipher text.
The keyspace for a cryptographic algorithm is the number of possible keys the algorithm can possibly accept. For example, AES-256 has a keyspace of 2 256 (roughly 1.1579209e+77) possible keys, simply because the algorithm specifies that each key is 256 bits wide. The title text is referring to "searching a keyspace," which is to say, simply trying every key until you find one that works. (For reference, a computer would require roughly the energy of a billion billion supernovas to even count to 2 256 , let alone actually try each one.) The precise wording, "If you got a big keyspace, let me search it" is, of course, another reference to the same song: "If you got a big **** let me search ya" (The word "penis" is censored by the trumpeting of an elephant).
This was the first comic where Randall was banned from conferences. Since then, he has been banned from multiple conferences for similar pranks; especially in 541: TED Talk , there is a whole list of conferences from which he has been banned. This has sometimes resulted in him being invited to those conferences - see more here on this PyCon response to Randall claiming he was banned from their conference.
[Randall Munroe (drawn as Cueball) stands behind a lectern on a podium in front of a large conference audience (consisting of Cueball heads), with a poster hanging beside him.] Randall: My cryptosystem is like any Feistel cipher, except in the S-Boxes we simply take the bitstring down, flip it, and reverse it.
[The poster reads:] Decryption 01101010 >> 00110101 [inverter symbol] 11001010 [crossed arrows] 01010011
[Caption below the crowd:] I've been barred from speaking at any major cryptography conferences ever since it became clear that all my algorithms were just thinly disguised Missy Elliott songs.


Beliefs

Explanation:
This comic is a reference to Young Earth creationism , which includes the belief that the Earth has only existed for about 6,000 years. Young Earth creationism is mainly based on literal interpretations of the Bible , which is pseudoscience . The professor is originally not bothered by the fact that someone believes in Young Earth creationism and simply tells the child to look at the scientific evidence . However, she then hears that the person is actually a United States senator , who would presumably influence national policy according to his creationist beliefs. This, she acknowledges, is an actual problem.
The comment on the fossils refers to an argument by some Young Earth creationists about the discovery of fossilized sea creatures at high altitudes . While mainstream science sees this as evidence of geological processes taking far longer than six thousand years, these creationists say that sea life reached these locations during a worldwide flood that covered even the tops of mountains.
The story of this flood, colloquially called Noah's Ark , is found in the Biblical Book of Genesis ; chapters six through nine . Though it is not stated in the Bible story, many sea creatures are presumed by those who make this claim to have died at high altitudes when the waters lowered. This is a theory held by some Young Earth creationists for the fossils.
The last panel is a reference to the fact that a number of people vote based on their perception that the person they're voting for shares their religious views, and then that person goes on to make legislative or educational (if they were voted to a board of education) decisions based on said beliefs.  There have been several instances in the U.S. of state boards of education trying to or succeeding at including young-earth or other creationist theories in the state's science curriculum. See for instance Theistic evolution .
The title text makes a further, more playful jab, claiming that scientists not only have the upper hand in reasoning but also in sexiness. This subverts the once-commonly held idea that smarts and attractiveness are not always contained in the same "package," the stereotypical scientist being boring and dull. It also adds a tinge of irony, as no competent reasoner would make an argument from sexiness .
[A girl with long black hair and a professor who looks like Megan stand together. The girl points to Cueball in the distance.] Girl: Professor, that man claims the earth is 6,000 years old! Professor: So? Just use your head and don't concern yourself overmuch with what other people think.
[Cueball is gone and the girl is no longer pointing but just talking to the professor.] Girl: But he says the fossils in the mountains were put there in a flood! Professor: Well, evidence suggests that they were not. Girl: But he--
[A mountain landscape with blue sky to the left with white clouds, gray clod cover to the right and gray mountains below. The most prominent peak is just right of the middle, but there are 14 small and large peaks all in all.] Professor (off-panel): A million people can call the mountains a fiction, yet it need not trouble you as you stand atop them.
[The girl throws her hands in the air while the professor just looks at her.] Girl: But he believes the silliest things! Professor: So?
[The girl has her arms down again and looks on the talking professor.] Professor: The universe doesn't care what you believe . Professor: The wonderful thing about science is that it doesn't ask for your faith, it just asks for your eyes.
[The girl and professor talks.] Girl: But he's a US senator! Professor: Ah, then yes, we do have a bit of a situation.


Search History

Explanation:
The comic references the AOL search data leak , where users had potentially identifying and embarrassing search histories published. Randall , drawn as Cueball , thus publishes his own potentially embarrassing searches in solidarity with the AOL users.
All of his searches relate to his fear of dinosaurs, mainly velociraptors , as a consequence of the Jurassic Park movie he saw when younger. The search " Utahraptor " may be a reference to Dinosaur Comics, which xkcd has parodied in 145: Parody Week: Dinosaur Comics . Alternatively, "Utahraptor" may be referenced because the raptors portrayed in Jurassic Park were much more like utahraptors than velociraptors in terms of size.
The title text refers to a document posted on a humor site: link (part 1) link (part 2) , link (part 3 ).
[In a slim panel at the top of the comic Randall (drawn as Cueball) stands to the left and his speech is written in the rest of the panel to his right.] Randall: In solidarity with the many AOL users whose often embarrassing web searches were released to the public, I offer a sample of my own search history:
[The long panel beneath the first panel shows a screenshot of Google's front page. The Google logo is partly cut through the top third of the logo. It is in the typical Google color code. Beneath the logo are six links for where to search, one of them is black, because it is chosen, the others blue. One has a red super script indicating there are news there. Below is the search bar. To the right of this, there are three lines with links, for what type of search preferences etc.] G o o g l e Web Images Video New! News Maps more>>

Advanced search Preferences Language Tools
[Below the search bar is a box with a thin line around, which comes up when Randall presses the bar, it has the following 20 entries that Google suggests for autocompletion:] velociraptors site:imdb.com "jurassic park" raptors dromaeosaurids utahraptor "home depot" deadbolts security home improvement surviving a raptor attack robert bakker paleontologist robert bakker "possible raptor sympathizer" site:en.wikipedia.org surviving a raptor attack learning from mistakes in jurassic park big-game rifles tire irons treating raptor wounds do raptors fear fire how to make a molotov cocktail do raptors fear death can raptors pick locks how to tell if my neighbors are raptors


Commented

Explanation:
When Cueball asks Black Hat for a favor, he seems to be making a rude gesture , by lifting a finger towards Cueball. However, the word he says, Commented! , does not seem to fit with the shorter four letter word usually combined with such a gesture.
Cueball also fails to understand this, but as it turns out, as the panels move around Black Hat and zooms in on his fingers, he is not making this rude gesture, but is instead actually lifting two fingers toward Cueball , forming a double slash and thereby ignoring both him and his question for a favor, by commenting him out programming style, even to the point where Black Hat sees the commenting out slashes, Cueball, and anything he says in the color for ignored parts of the program (or real world in this case).
In certain programming languages (including but not limited to C (since C99), C++, C#, Java, Javascript, PHP, and Scala), inserting a double slash ( // ) in a line marks everything after the double slash in the line as a " comment ," i.e. something for humans to read that generally helps them understand the code better, rather than something for the computer to execute. Since all comment lines are ignored when a program is run or compiled, it is possible to simply put a double slash in front of any line of code to skip that line. This is known as "commenting out" the line. For example:
An Integrated Development Environment (IDE for short) is an application that programmers use to write, compile, execute, and debug code. Many IDEs color-code text to make reading the code easier. In IDEs like Eclipse and Microsoft Visual Studio, a line that is commented out will be colored green; however, the color may vary depending on which IDE you use, and can usually also be customized. The title text refers to this variation among IDEs' color schemes.
[Cueball calls out to and Black Hat while they are some distance apart as seen from the side. Black Hat is holding an arm out towards Cueball making a gesture and speaking one word.] Cueball: Hey, can you do me a favor? Black Hat: Commented!
[The same setting seen from behind Black Hat with Cueball drawn much smaller in the background.] Cueball: Huh?
[Black Hat's hand is shown in close up. He is holding his first and second fingers parallel and at an angle towards the "small" Cueball to the left of the hand. The two fingers, as well as Cueball and his next line, are green.] Cueball: Wait, what does that gesture even mean?


Filler Art

Explanation:
There are times in which the owner of a webcomic can not make a comic on time for the next scheduled update (for example, needing to attend to a family emergency). Some deal with these situations by creating a "buffer" of comics (that is, making several comics ahead of time) in anticipation for these events. However, if the buffer runs out (or if there was no buffer in the first place), the owner might have to resort to uploading whatever is available (e.g. concept art, random sketches, a draft of the planned comic, etc.). Many webcomic owners prefer to upload filler art so that their more fickle fans can see that they have not abandoned the comic.
Here, Randall parodies this situation with two separate punchlines. First, he tells us that he has to go to the doctor to get his thighs rotated, which is medically unnecessary (as a "thigh rotation" is physically impossible, and is likely a play on tire rotation ). Second, he refers to "new character art" for his comic. The punchline here is that, since the characters are drawn in a stick figure style, there are no distinguishable features between the man here and most other males in the comic series. In addition, the fact that this stick figure should not have taken more than 10 seconds to draw makes the notion that Randall has been "working on" it ridiculous.
The title text refers to Megatokyo , a popular webcomic widely known for its use of filler art. Creator Fred Gallagher , who goes by his online moniker Piro, frequently makes use of what have come to be called " Dead Piro Days ", in which he posts character art, or concept art often based in the comic's world or characters, generally of draft or unfinished quality. By his own admission, these days of filler art are sometimes the result of nothing more than his feeling too under the weather, or tired, or emotionally depressed to put in the necessary amount of work to finish a proper update. While Gallagher has been raked over the coals for this by the broader webcomics community, longtime fans of Megatokyo tend to be highly tolerant and have been described as " some of the most patient and forgiving " readers, often viewing these lapses as endearing rather than inconvenient.
Randall 's mention of letting up on Megatokyo refers to 142: Parody Week: Megatokyo , in which Megatokyo and Gallagher were also teased.
[Cueball stands in the middle of a single panel. The text above reads:] Sorry guys no comic today. I've gotta go to the doctor to get my thighs rotated. But here's some new character art I'm working on!


Six Months

Explanation:
Cueball is addressing his ex-partner, telling her that six months after their split-up, he still has dreams of their being together. In the moment after waking up, he is sometimes unable to tell reality and dream apart. However, the third panel reveals the punchline: His confusion results from the likeness between his ex and her mother, next to whom he apparently wakes up every morning. It becomes clear that he has left the girl six months ago in order to live with her mother instead. The comic lampshades at the state of emotional confusion after a break-up that is prominently featured in many films and books.
The title text furthers the joke, saying the confusion of why he left her is gone once the older woman does "that thing with her tongue," possibly referring to fellatio.
[Cueball is standing.] Cueball: It's been six months and I still have those dreams where you're pressed tight against me, where you look into my eyes and give me that grin and it's like you've forgotten everything.
Cueball: And something in the back of my head says it's wrong, it's not like this anymore, but I push it down.  In the morning, I tell myself I can't control my dreams, but there's a part of me that doesn't want them to stop.
Cueball: And honestly, waking up would be a lot easier if your mom didn't look so much like you. Cueball: There's always that moment of confusion.


Boombox

Explanation:
We see Cueball declare his love for Megan in an oft-used setting, paying homage to similar events in classic literature, notably the "balcony scene" from William Shakespeare's play Romeo and Juliet ( act 2, scene 2 ), and a similar situation in Edmond Rostand 's Cyrano de Bergerac ( act 3, scenes 6-7 ). In the former, Romeo, attempting to woo Juliet, stands beneath her balcony to profess his love for her. In the latter, an inarticulate cadet, Christian, professes his love for Roxane by arranging to use the words of a fellow soldier, Cyrano, who secretly also loves Roxane.
The 1989 movie " Say Anything... " contains a modern interpretation of this declaration of love, where John Cusack plays Peter Gabriel's " In Your Eyes " on a boombox outside the house of the girl he likes.
Parodying this iconic scene ( video ), Cueball is holding up a boombox (a self-contained semiportable stereo system, typically with cassette tape or CD player, and complete with integrated speakers) that is playing music while Cueball declares his love for Megan. She first is startled, embarrassed, then eventually confused by the 1990 hit single Ice Ice Baby ( video ) by Vanilla Ice playing on the boombox. Cueball then admits he is "not very good at this," attempting to recreate the classic romantic scene, but utterly failing to play music suitable for such an event.
The title text mentions that Cueball is actually playing " Under Pressure " ( video ), the 1981 hit song by Queen and David Bowie , but Megan has confused it with "Ice Ice Baby," which samples the bassline from "Under Pressure." It also may be that Cueball is having trouble holding the boombox, hence Cueball being 'under pressure.'
These two songs are again referenced together in 1561: Water Phase Diagram , and "Ice Ice Baby" is also lampooned in 210: 90's Flowchart . It is possible that this is the same couple as mentioned in 112: Baring My Heart , as the creator of that Venn diagram reveals to their romantic partner that their feelings towards their paramour are comparable to their feelings for Vanilla Ice.
This was the first time that the name " Megan " was used in xkcd. The next comic to use it was the much more depressing 215: Letting Go .
[Megan is looking out a second story window at Cueball holding a boombox over his head. Musical Notes are coming out of it.] Cueball: Megan! Megan: Oh my god, I can't believe this is happening. Cueball: I love you! Megan: Okay, that's great. Wait a second. Is... is that... Ice Ice Baby? What the hell? Cueball: I'm not very good at this.


Penny Arcade Parody

Explanation:
Penny Arcade is a webcomic , primarily about video games and the culture surrounding them. It is written by Jerry Holkins and illustrated by Mike Krahulik , though they are better known as their comic alter-egos: Tycho Brahe and Jonathan "Gabe" Gabriel.
This strip begins as a parody of the Penny Arcade strip, which makes fun of Sony for providing a lack-luster selection of PS3 games available on the console's launch date. However, it quickly turns into the narrator's fantasy of what might happen if Tycho discovered his spoof.
The enormous wall of text in the second and third panels may be a reference to the Penny Arcade strip "I Hope You Like Text."
The cardboard tube references one of Gabe's alternate characters, Cardboard Tube Samurai .
[The first panel uses the art style of Penny Arcade.] Gabe: What? Sony has plenty of launch titles lined up that aren't lame sequels. Tycho: Name one. And furthermore, they... I... uh...
[The art style is dropped. The next two panels are just text.] I can't do this. I can't parody Penny Arcade. I've got nothing on those guys. They're a class act, they know their audience, they know exactly what they're doing. Gabe experiments with his art, always bold and fresh without trying to perform. Tycho's writing continues to astound day after day. I can just see him, reading my uncultured swill masquerading as his florid prose.
[The panel is bottomless, and the text escapes the panel.] But he's not angry, no. He's sitting at his desk smiling that condescending half-smile, the corner of his mouth belying the self-assurance of a writer who never misplaces a word. His firm hands rest easily on the keyboard, his right thumb caressing the space bar gently, as I enter the room. He knows I'm there without turning around, and I'm too nervous to speak. But I don't have to; he understands, I can see it in the way his eyes play over me, reading my fears and doubts in a glance and washing them away with a knowing smile. Then he's on his feet, he's in front of me, and I don't feel the electric jolt I expected as our hands meet. It's just warm, warm and right: As I sink into his eyes I feel a hand on my shoulder, and I see Tycho smile at someone behind me. Gabe is standing there, grinning that mischievous grin, and twirling his beloved cardboard tube between his fingers.
The night has just begun.


Accident

Explanation:
After someone plays a game enough, various instincts develop. One might be ready to push the right button when a right arrow comes up on screen. One might learn the tricky sequences of moves needed for a situation in the game, and find oneself doing them in another game in a similar situation. Or, as in this case, one might get used to pushing a giant ball around trying to collect smaller objects, and try doing so with your car when the game's theme song starts playing.
In the game Katamari Damacy , the player has to grow a large ball of clutter by rolling the ball over smaller objects in the playfield, which become attached to the ball, growing the clutter ball larger and larger. As the clutter ball gets larger, bigger things in the environment will begin sticking to the clutter ball instead of acting as obstacles, giving the player more clutter to grab. How big the player can get this clutter ball, or "katamari," determines how well the player does in the game, as is also mentioned in 83: Katamari .
When Katamari Damacy's theme song comes on in the third panel, Cueball begins acting out the game's premise, and drives his car into a mailbox - which "looked smaller" than his car - trying to get it to attach. This doesn't work so well outside of the game. [ citation needed ]
The title text implies that music used in the game Guitar Hero is equally hazardous when driving. Anyone who's become accustomed to rocking out on a fake guitar to a particular song could find themselves involuntarily playing the air guitar when said song comes on the radio unexpectedly. Randall is pointing out that Guitar Hero-induced spontaneous air guitar performances are not safe activities while driving. Alternatively, one may try to hit all incoming objects in an attempt to mimic hitting strings of notes as they move down the fretboard, which would be immediately more disastrous. Another possibility is that the hazard is pressing several buttons repeatedly to mimic Guitar Hero, which would not only distract from driving, but also cause chaos in the car.
The theme song from Katamari Damacy is also mentioned in 851: Na .
[Cueball driving in a car while listening to some music.] Music: ♫ ♩ ♬ [Another panel of Cueball listening to music while driving. Cueball's head is turned to the right.] Music: ♬ ♪ ♩ [A third panel. Cueball's head is turned to the left.] Music: ♫ NAAAA NA NA NANA NANA NA NA KATAMARI DAMACY ♪ ♩ [Cueball and Megan talking.] Megan: And that's when you veered into the mailbox? Cueball: It looked smaller then me. It was just instinct.


Angular Momentum

Explanation:
A moving object (like the Earth) has momentum. Momentum is the mass (size) of the object multiplied by the velocity (speed) of the moving object. So the Earth has a very high momentum because the Earth has a large mass (size) and is moving at a high velocity (speed) around the Sun. However, the momentum referenced in this comic is the angular momentum of the Earth spinning on its axis, which creates the days and nights. A moving object has to keep moving at the same velocity for its momentum to stay the same. The momentum of a moving object can increase, decrease, or stop via the force of another object. Force is the transfer of momentum from one object to another.
Megan attempts to slow down the Earth's angular momentum, and spins counter-clockwise to force her momentum onto the Earth, so that she can have more time with the one she loves.
The Earth has a massively high momentum, and the momentum that she produces is minuscule relative to the Earth's. And the few nanoseconds gained by spinning, while being with Cueball, is effectively offset by the seconds spent spinning.
Slowing down the rate of time in the universe directly slows down the velocity of life, so there would be no change in the total duration of life. And as the text implies, this isn't even possible: While not being able to reverse time, enjoy your night time. Sunrise always comes too early.
Her attempt of surmounting the seemingly impossible is grand; culturally, we value this kind of high romanticism.
Later in 442: xkcd Loves the Discovery Channel , the same kind of spinning Megan is used in the first frame to tell that xkcd loves momentum.
Technical notes: Angular momentum depends on the axis used for measuring angular momentum .
Apparently, the time Megan is stopping is “ less than 1/20th of the time light takes to cross the diameter of a hydrogen atom ”
A considerably larger (but still minuscule) effect could be achieved by Megan (and/or Cueball and/or the bed) moving even a few meters closer to the equator . This would also have the advantage of not interfering with any other activities Megan and Cueball might want to undertake in their time together.
[Cueball sits sideways on a bed under an open window in the corner of a room. He is looking at Megan, who is spinning fast, indicated with two large circles indicating where her arms that are spread far out rotate, as well as two smaller circles around her knees and feet. The bed sheets are clearly messed up, as if someone has used it for activities other than sleeping. It is night and dark gray outside the window, and inside the room everything is also gray but lighter. Behind the spoken text, the background is white, but fades to the darker gray at the edges. There is also different gray shading in different parts of the room.] Cueball: What are you doing? Megan: Spinning counterclockwise Megan: Each turn robs the planet of angular momentum Megan: Slowing its spin the tiniest bit Megan: Lengthening the night, pushing back the dawn Megan: Giving me a little more time here Megan: With you


Donald Knuth

Explanation:
Donald Knuth is a computer science Professor Emeritus at Stanford University who is famous for writing The Art of Computer Programming and developing the T e X computerized typesetting system.
In computer science, an array is a structure that stores multiple values in a fixed order, and the elements are accessed by their index number.  In Fortran , for instance, one writes array(1) to access the first element in the array. Most "modern" (read: descended from C ) languages use 0 as the index for the first element in the array, but it is possible (if one is careful about it) to ignore the 0th element and use 1 as the first index. In some programming languages, such as Pascal or Ada , it is possible to select an arbitrary range of indices for each array type, so the first index might not only be 0 or 1, but also −42 or 100000. Cueball is complaining that Black Hat was not consistent in his choice of where to start his arrays. This is a valid complaint, as a lack of such consistency can make coding errors both more likely and more difficult to detect.
Black Hat cites Donald Knuth to support his rebuttal, but the quote he uses does not seem relevant. Presumably, Black Hat had illegally entered the professor's house in order to question him on indices. Donald Knuth's words were not an intellectual response to the question, but rather an alarmed response to the presence of an intruder. It is not clear if Black Hat is aware of this.
The title text suggests that Black Hat finds Knuth's books intimidating, due to perhaps their size or complexity, to the extent that he considers breaking into Knuth's house (a risky, difficult crime) to be the better option in finding his answer. Even for Donald Knuth's books, this is very exaggerated and illogical behavior. [ citation needed ]
[Black Hat and Cueball are sitting back to back at two separate desks, typing. Black Hat has turned toward Cueball to respond to him.] Cueball: Man, you're being inconsistent with your array indices. Some are from one, some from zero. Black Hat: Different tasks call for different conventions. To quote Stanford algorithms expert Donald Knuth, "Who are you? How did you get in my house?"
[Black Hat and Cueball are sitting back to back at two separate desks, typing. Cueball has turned toward Black Hat, confused.] Cueball: Wait, what? Black Hat: Well, that's what he said when I asked him about it.
Later, the topic of breaking into a software expert's house through the skylight became topic of 225: Open Source again.


Playing Devil's Advocate to Win

Explanation:
Global warming is the rise of the average temperature of the Earth's atmosphere and oceans since the late 19th century and its projected continuation. More than 97% of scientists are sure that it's caused by an increase in greenhouse gases caused by humanity's industrialization and activities such as the burning of fossil fuels and deforestation. Losses of human food security and habitat; melting of glaciers leading to a rise in sea temperatures; and more frequent heat waves, droughts, and species extinctions are just some of the many likely effects of global warming.
Yet, despite the unequivocal nature of climate change , it's a hot-button political topic in the United States, with many conservatives denying its existence, arguing that it has natural causes, or claiming that global warming could be a good thing. Liberals counter by saying that conservatives are claiming these things because they're in bed with the oil companies, and by denying the existence of global warming, they're saved from having to do anything about it. It's such a controversial topic in the U.S. that, in this comic, Cueball says he's decided to keep his mouth shut about the whole thing. He has withdrawn from the debate because it doesn't matter if he wins the debate or not — science doesn't care about who got the last word. If humanity reaches the tipping point and one day can't do anything to stop global warming, Cueball will find it interesting to watch exactly what happens. And if it turns out that the scientists are wrong, he won't feel embarrassed that he's been making a big deal about it this whole time.
In the title text, he touches on the political side of global warming, saying that there are many well-meaning conservatives out here who honestly believe that global warming doesn't happen, and that liberals only bring it up to have a moral issue to attack conservatives with.
This was the first direct reference to global warming in xkcd, but since then, climate change, with an emphasis on global warming, has become a recurring theme in xkcd. Seems Randall would no longer like to be on this ride, especially with the comic 1732: Earth Temperature Timeline released almost 10 years after this one.
[Cueball is standing under a large amount of text said in one go.] Cueball: Yes, from the evidence it looks pretty likely to me that we're causing global warming on a horrific scale. But with science you don't need to argue. It doesn't matter who wins the debate — it's about reality. By just waiting a little longer, we'll get to see who was right. It feels unethical but I find myself wanting to keep quiet about the science just to know for sure. As terrible as it sounds, the state of the world isn't really my responsibility. I'm just thrilled to get to watch. If the scientists are right — and if we keep people from understanding just a little longer — we'll enjoy quite a ride. And pragmatically, on the outside chance that they're all wrong, I get saved the embarrassment of having spoken up.


Turn Signals

Explanation:
Turn signals are designed to flash between 60 and 120 times per minute. Most turn signals are driven by an electromechanical device. Due to manufacturing tolerances, battery state of charge, ambient temperature, and various other factors, two different turn signals rarely flash at the same rate, even among cars of the same make and model. Having two cars with turn signals flashing at the same rate would be a rare event.
Cueball notices this event, and expresses his excitement to the driver of the other car, despite being stopped at an intersection. The other driver is confused by this. Turn signal frequency is something that most people don't take notice of. [ citation needed ] Cueball, however, takes it as an opportunity to strike up a conversation and make a new friend.
The beat frequency is the rate at which two frequencies transition from being in phase with each other to being out of phase and then to being in phase again. In other words, two turn signals that begin by flashing together will transition to flashing opposite each other and then back to flashing together, and the rate at which this process cycles is the beat frequency. Because the beat frequency is simply the difference between the two turn signal frequencies, two turn signals whose frequencies are closer together will take longer to pass through the in-phase/out-of-phase cycle, and two signals whose frequencies are identical would take an infinite time (i.e., their relative phase never changes). The beating of turn signals is an easy phenomenon to observe when one is stopped at a traffic light with nothing to do but watch the flashing turn signals, and it is the lack of beating that Cueball noticed and excitedly reported.
The title text refers to the fact that this is probably not a good strategy for making friends, and it could suggest that the character Cueball may be Randall .
[Two cars are seen sitting at a red light. One person is seen walking from his car up to the driver of the car in front of him. The turn signals of both cars seem to be blinking at the same time.] Person in Street: Hey, our turn signals are in sync! Person in Car: What the hell?
Person in Street: Usually they're at least a little off. But I've been watching like 30 seconds and haven't seen any beat frequency! Person in Car: Who are you?
Person in Street: You know, from the beat frequency you can tell the difference in timing of the two signals. Person in Car: ... Person in Street: But ours are the same! Person in Car: ... Person in Street: So, wanna hang out later?


Misusing Slang

Explanation:
Randall expresses excitement for the time in the future where he can intentionally misuse modern-day slang in order to make nearby teenagers feel uncomfortable. He illustrates this by using the word "pwned," the past tense of "pwn" (from "own," as in to defeat completely): "The noob was pwned by the pro."
Many teenagers believe their parents to be not "with the times," but Randall suggests that parents actually do know what the words mean, but are acting otherwise in order to mess with their heads for their personal amusement. The title text reinforces this, as every generation has had some form of slang that they used, and it could be possible that this practice has been continued for a good while. It also suggests that the parents of teenagers may be "pwning" their children by intentionally misusing these modern-day slang.
The best part of getting older is gonna be intentionally misusing slang around teenagers just to watch them squirm. Cueball: Oh man, that song is so pwned! Teenager: twitch


Nihilism

Explanation:
It is argued by some that atheism leads to nihilism . One rebuttal would be to reject the premise that there is no purpose outside of fulfilling divine intention, but Randall instead rejects the premise that nihilism ought to be burdensome. As a result, Beret Guy resolves that, if everything is ultimately meaningless, then it would be more fun to spend one's meaningless existence having fun rather than constantly moping. The presence of squirrels may relate to Beret Guy's head's resemblance to an acorn.
As reinforced by the title text, the complete lack of angst on Beret Guy's part is off-putting to other nihilists.
[Beret Guy and Cueball approach a tree while talking.] Cueball: There is no God. Our existence is without purpose. Beret Guy: Oh, definitely. Beret Guy: We are adrift in an uncaring void indifferent to all our mortal toil. Cueball: Exactly! In the end, nothing we do matters. [Beret Guy climbs the tree.] Beret Guy: Totally. Cueball: We just... Why are you climbing that tree? [Beret Guy is now completely submerged in the tree.] Beret Guy: Because the future is an adventure! Come on! Cueball: But-- Beret Guy: Hey! I found squirrels !


Reverse Euphemisms

Explanation:
Euphemisms are figures of speech used in place of more offensive terms. In this comic, Cueball uses swear words in the place of benign terms, inverting the typical usage of euphemisms. To "drop the kids off at the pool" is a euphemism meaning to "go take a shit." In this case, however, Cueball actually has to drop kids off at the pool but instead uses "go take a shit." Cueball is using the euphemism in reverse , hence the title.
In the title text, the figure is waiting for a situation in which he has to see a man concerning a horse, as this relates to another euphemism meaning to urinate. It can be assumed that, when telling someone about seeing the man about the horse, he would say "...then I had to go take a piss."
This is not to be confused with the opposite of a euphemism called a dysphemism .
My Hobby: Reverse Euphemisms [Two people talking.] Cueball: Oh, hey, school just let out and it's YMCA night, so I've gotta go take a shit. Friend: What? Cueball: I mean I actually have to drop the kids off at the pool.


Words that End in GRY

Explanation:
This is a reference to a famous joke (see the first of the meta versions under the wiki link), mistold in the above comic.
The original, correct telling of the joke is:
Think of words ending in "-gry". "Angry" and "Hungry" are two of them. There are only three words in the English language. What is the third word? Hint: The word is something that everyone uses every day. If you have listened carefully, I have already told you what it is.
Phrased this way, the answer is "language" because "There are only three words in (the phrase) 'the English language' ."
Cueball tells this joke (unfortunately by mis-phrasing the original riddle). When Cueball attempts to say the answer is "language" and act smugly about it, Black Hat is unimpressed and cuts off Cueball's forearm, explaining that communicating badly is not the same as cleverness. Black Hat's point is that the riddle's "cleverness" depends on misleadingly implying that "three words" refers to words ending in "-gry," rather than the phrase "the English language." Black Hat does not seem to agree that this riddle is clever.
In the title text, Randall clarifies that his point about bad communication applies to the riddle in general. [1] However, a secondary interpretation is that Black Hat is angry that Cueball botched the joke. The joke is supposed to go, "There are only three words in 'the English language,'" while only implying that you meant "words that end in '-gry.'" By instead saying, "There are three words in the English language that end in '-gry,'" Cueball has ruined any chance of Black Hat determining the correct answer; now, "three words" can't refer to the correct answer "the English language" because Cueball has accidentally used a longer phrase instead. Thus, Cueball has communicated badly both intentionally and unintentionally.
In any case, no matter how annoying Cueball's smugness, Black Hat responding by cutting off Cueball's forearm is a comical overreaction [ citation needed ] (while his calm demeanor in doing so is a comical underreaction to the overreaction). Additionally, his calmly-made point about the riddle is likely not to be understood by Cueball, who can only focus on his debilitating injury. Black Hat has, ironically, failed to communicate his point about proper communication, although given Black Hat's personality he likely doesn't care, and may even have intended the irony.
As Black Hat mentioned in the comic, if you count obscure and archaic words, there are additional English words that end with "-gry." Some are listed here .
The title text refers to postmodernism , a philosophy and corresponding art movement. Postmodern music is often minimalist , as exemplified by the weird sounds of Philip Glass and Steve Reich , and postmodern visual art saw trends such as lowbrow and installation art gain attention. Apart from a rejection of modernism, however, it is difficult to outline postmodernism to justify the strange works of art. Deconstruction is another important concept, but it is difficult to describe the process. In short, postmodernists make art that no one understands and may act smugly about it, but they do not adequately explain what their art means, or it doesn't really mean anything. In other words, there is nothing to understand. Thus, Black Hat's statement, that such practice is not "cleverness," applies to them as well.
[Black Hat and Cueball are standing next to each other.] Cueball: There are three words in the English language that end in "gry". "Angry" and "Hungry" are two. What's the third?
Black Hat: I don't think there is one, unless you count really obscure words. Cueball: Ha! It's "language"! I said there are three words in "the English--" Hey! GRAB [Black Hat grabs Cueball's hand, with a knife in hand.]
Cueball: What th--AAAAAAAAAA SLICE [Black Hat slices off Cueball's hand with the knife.]
[Cueball is bleeding profusely.] Black Hat: Ok, listen carefully. Cueball: AAAAAAAAAAAAAAAAA
Black Hat: Communicating badly and then acting smug when you're misunderstood is not cleverness. Cueball: AAAAAAAAAAAAAAAAAAA
Black Hat: I hope we've learned something today. Cueball: AAAAAAAAAAAAAAAAA
Around the time this comic was posted, Randall also posted Blue Eyes : The Hardest Logic Puzzle in the World. He apparently took his own advice to heart as he explicitly states he has gone over the wording of the puzzle several times before publishing it to make it as unambiguous as possible.


Turn Back

Explanation:
Calvin and Hobbes was a daily comic drawn by Bill Watterson , published between 1985 to 1995. It followed the adventures of a young boy named Calvin and his tiger, Hobbes. The frequent themes of spontaneity, beauty, and adventure that characterize many of Calvin's conversations with his friend Hobbes can also be seen in this exchange between Cueball and Megan as they explore a landscape reminiscent of Calvin's daydreams of intergalactic adventure. The cluelessness and simultaneous wonder that Cueball and Megan feel at their surrounding landscape mirror Calvin's inexperience and curiosity that he exhibits in Watterson's comic.
The title text, while unclear if it were actually true or not, reflects Mr. Watterson's reclusive nature. He has never licensed his characters for any use outside of reprints, and he stays out of the public spotlight. Thus, it is very probable that it was true at the time of this comic. The title text also serves to point out the connection between Watterson's work and this comic.
However, in more recent years, Watterson has come out of his shell a bit. He collaborated with Stephan Pastis, creator of "Pearls before Swine," to do a story arc where a second grader was a better artist than an actual cartoonist. Stephan Pastis later wrote of the experience: "I began to wonder if [Bill Watterson] even had electricity, then I remembered we were using e-mail to communicate."
Cueball: Should we keep going? Megan: I don't know. Cueball: We can turn back if you want. Megan: Look--
Megan: Did it ever occur to you that maybe I don't have a plan any more than you? Maybe just having this conversation means we're lost.
[Wide shot of the characters in a Calvin and Hobbes-esque alien landscape.]
Cueball: Kind of scary. Megan: It's terrifying. Cueball: This place is beautiful. Megan: Yeah.


String Theory

Explanation:
String theory is a theory in theoretical physics for explaining how the universe works. It is a theory trying to explain everything belonging to our universe; specifically, it aims to unite general relativity and quantum field theories .
When a new theory is thought up, the theorists will usually supply some predictions, measurable by experimental physicists. String theory's predictions, however, are few and extremely difficult to test; though its inception was over forty years ago, string theory has yet to be experimentally tested.
Randall is unimpressed with string theorists (for another instance of this, see the punchline to 397: Unscientific ). String theory has not provided any useful new knowledge to engineering science as quantum physics has, and lacks the imagination-stirring philosophical implications that the general population associates with other fields — for example, quantum scientists have proven predictions like tunneling , used by modern electronic devices, and relativity is relevant to modern systems like GPS navigation. String theory either hasn't reached that stage yet or cannot.
In the title text, Randall points out that string theory is so technically difficult that at essentially every level (except, presumably, the very top), this explanation is as good as it gets.
[Heading above panel:] String theory summarized:
[Two Cueballs are talking.] Cueball: I just had an awesome idea. Suppose all matter and energy is made of tiny, vibrating "strings". Friend: Okay. What would that imply? Cueball: I dunno.


Skateboarding is Not a Crime

Explanation:
The skateboarding subculture has taken up the phrase "skateboarding is not a crime" in protest of how many cities have banned skateboarding in certain areas, such as parks. Randall apparently really does not like these stickers and states that when he becomes president, any and all displays of stickers bearing the phrase (like the one on the locker in the comic) will be considered a felony, though skateboarding itself will still be legal.
The title text also shows another protest phrase, "Arrest me, I'm a skateboarder," that Randall hates even more than "skateboarding is not a crime."
[A set of lockers, that are dark pink, blue, yellow, dark pink then blue. The middle one has a white sticker stuck to it proclaiming "Skateboarding is not a crime."] When I'm president, skateboarding will still be legal, but display of those stupid stickers will be a felony.


Movie Seating

Explanation:
At the time of writing in most movie theaters in the US, seats were not reserved . [1] That is, tickets are sold by screening without seat assignment, and therefore an entering patron can take any vacant seat. Therefore, a group of incoming patrons may walk in a column and take a section of consecutive seats in a row, each person taking one next to the person in front of them. The order of these people is thus determined by the order in which they walk into the theater, which is in most cases random.
Cueball is upset at the way he and his friends have sat down at the movie theater. Part of the problem is that two people who are apparently in a relationship do not sit together. He therefore tries to use a social graph to calculate the best way for him and his seven friends to sit in a row, while taking into account all of the social connections among them. In mathematics , this type of problem is called combinatorial optimisation . The most popular example, the traveling salesman problem , is referenced in the title text, as well as in comics 287 and 399 .
The title text shows that another part of the problem is that Cueball's friends, who could have helped him calculate a solution, are each sitting three seats away from him, and so he cannot ask them for help.
Two hypothetical solutions for the specific problem proposed in the comic are displayed:

At the movies, I get frustrated when we file into our row haphazardly, ignoring the computationally difficulty problem of seating people together for maximum enjoyment. [Map of relationships between 8 people.] [Legend:] Single line: friends. Double line: in a relationship. Arrow: one-way crush. Dashed line: acquaintances [The eight friends sit in a row in a dark cinema. Cueball and one other are between two lovers.] Cueball: Guys! This is not socially optimal!


That's What SHE Said

Explanation:
" That's what she said! " is a phrase used in the US in response to an unintended sexual innuendo, similar to the UK phrase "said the actress to the bishop." An example usage might look like the following:
A: (while putting together some furniture) I think this is too big. B: That's what she said!
In this example, the innuendo is that A was referring to a furniture component (say, a bolt too large to fit into the hole that was drilled in the factory), but the phrase might also refer to a human penis. While popular for a while, the phrase is considered puerile and cliché nowadays, so it isn't often used except in mockery.
In this case, no sexual innuendo is intended; instead, the phrase is used to maximize the ambiguity of the statement. Ambiguity is when a statement could mean more than one thing. In English, it is often created as a result of pronouns like "he" and "they," which might potentially refer to many different things in context. Here, "that's what she said!" could mean several things, because "that" and "she" could refer to multiple parts of the sentence:
Another explanation would be that the intense grammatical ambiguity of the situation allows for any type of interpretation of the situation... even a more "perverted" interpretation. Taken more literally, the "she" in "that's what she said!" could be a hypothetical woman who is known for saying crazy things, thus the grammatically ambiguous statement reminds the speaker of this  hypothetical woman.
The title text turns this back around, saying that there is actually a sexual innuendo in the statement: apparently the girl in question said this during sex. Since all of these possibilities are highly unusual things to say during sex, the observation in the second sentence is accurate.
One of Randall's many hobbies .
My Hobby: Using "that's what she said" only in the most grammatically ambiguous situations. Friend: He doubts she could've done what they claimed she did. Cueball: That's what she said!


Automatic Doors

Explanation:
Cueball has an uneasy suspiction that the automatic doors may have feelings, possibly due to their apparent sentience. This assigning of human characteristics to non-human things such as the doors is called anthropomorphism . Cueball extends the premise that the doors have feelings to those feelings being hurt by his not entering the opened doors. This is analogous to the social faux pas of ignoring someone who has waved to you, or purposefully failing to acknowledge someone who is trying to get your attention.
The anthropomorphized doors are much like those in the starship Heart of Gold in Douglas Adams' Hitchhiker's Guide to the Galaxy . In the story, the characters find a brochure describing the ship, which states that "All the doors in this spaceship have a cheerful and sunny disposition. It is their pleasure to open for you, and their satisfaction to close again with the knowledge of a job well done." Such doors would not be given the "satisfaction" of the "knowledge of a job well done" if the figure passes close enough to trigger the doors, but does not actually go through them.
In the title text, it is revealed that Cueball has made the acquaintance of a number of automatic doors and possibly hung out with them only because he doesn't want to hurt their feelings. His being embarrassed about hurting the feelings of any automatic doors who happen to read the comic and thus find out that what they thought was a genuine friendship was only Cueball trying not to hurt their feelings, in fact should more likely be embarrassment over making friends with mechanical doors who he believes have feeling that can be hurt in the first place. [ citation needed ]
When I walk past an automatic door and it opens for me, I worry that if I don't go in I'll hurt its feelings. [Automatic door whirrs open.] whirrrr Cueball: Oh, um, I'm sorry, I was just... um... I guess I can hang out for a bit.


Before Sunrise

Explanation:
This is another example of Randall's propensity towards "your mom" jokes. The second panel contains an eloquent prosaic description of an idyllic sunrise over an unfamiliar landscape analogizing the uncertainty and excitement of the life that lies ahead. This is designed to put the reader off-guard for the "your mom" stinger in the third panel.
Cueball wants to settle down on his own, but every time when he tries, he still ends up at the reader's Mom's place (as is customary in such jokes).
In photography, the term Golden Hour is used to describe the hour after sunrise (and also the hour before sunset), due to the good lighting conditions at those times. In the title text, you could initially believe that Cueball is using these early morning trips to capture beautiful photographs of the scenery, until it turns out that in fact the photos were of the reader's Mom (and likely risque in nature).
Cueball: Every morning for a week now I've gone out driving before sunrise. I wanted to get lost in the dark, park my car, listen to music, and sip from a warm drink as dawn broke around me, gradually revealing a landscape I'd never before seen. A chain of unique beginnings forcing wonder into the seeds of each day. Cueball: But I guess I need more willpower, because each sunrise just found me at your mom's apartment again.


Alice and Bob

Explanation:
Any good cryptography presentation will include at least one story about Alice and Bob . They are the canonical "protagonists" of the crypto world, frequently used in illustrations to demonstrate how a cryptographic system works. (The names were mostly chosen to abbreviate to A and B, as well as being of different genders so that they can be distinguished by pronouns alone.)
Here, Randall casts the story in a different light. Instead of Alice and Bob being perfectly innocent people who just want to communicate in private, Bob is actually having an affair with Alice, and his former partner, upset, cracked the encryption to see what the message contained. Nevertheless, the "gossipy cryptographic protocol specs" all took Alice's side (since the goal of any good crypto system is, of course, to succeed in this struggle).
The rest of the comic makes a few other allusions to cryptography:
Finally, in a twist ending, the girlfriend is revealed to be none other than Eve, the eave sdropper, who is also ubiquitous in Alice and Bob stories. Hell hath no fury, indeed.
The title text continues the theme of Randall getting barred from speaking at conferences due to his unusual take on certain topics.
To further spice things up, there are many other characters in the Alice/Bob canon, including Mallory, the mal icious attacker, who wants to actually alter the message with nefarious intent; Craig, the cr acker, who doesn't particularly care about the message but does care about the passwords used; Plod, a law enforcement officer attempting to access keys or data; and Chuck, a third party in the communication who secretly has a villainous intent.
[Eve stands in the frame, talking to the reader.] Eve: I'm sure you've heard all about this sordid affair in those gossipy cryptographic protocol specs with those busybodies Schneier and Rivest, always taking Alice's side, always labeling me the attacker. Eve: Yes, it's true. I broke Bob's private key and extracted the text of her messages. But does anyone realize how much it hurt ? Eve: He said it was nothing, but everything from the public-key authenticated signatures on the files to the lipstick heart smeared on the disk screamed "Alice." Eve: I didn't want to believe. Of course on some level I realized it was a known-plaintext attack. But I couldn't admit it until I saw it for myself. [Eve places her hands on her hips.] Eve: So before you so quickly label me a third party to the communication, just remember: I loved him first. We had something and she tore it away. She's the attacker, not me. Not Eve.


Not Really Into Pokemon

Explanation:
Pokémon is a popular franchise that includes 5 children's animated television shows, a collectible card game , and a whole series of video games. The premise is that a young "trainer" goes out to explore the world and catch Pokémon: fanciful wild creatures that come in many varieties, ranging from armoured dinosaurs that have drills for horns to robotic bugs that change their type depending on the items they are holding . When the trainer comes across wild Pokémon or other trainers, they use their Pokémon to fight each other.
In this comic, Randall claims that "I'm not really into Pokémon" can serve as an all-purpose phrase of condescending dismissal. The implied insult to the thing being dismissed can include:
The example in the comic is Black Hat dismissing Ubuntu , an open-source computer operating system. Ubuntu may have been particularly chosen as specifically suitable for the "Pokémon dismissal" for reasons such as:
The title text refers to the complications that new software releases can have on computers, especially if either the release is an alpha or beta release, or if the computer is rather old. Randall specifically mentions Ubuntu 6.10 and Firefox 2.0 , both of which were officially released around two weeks after this comic was posted, so the versions causing problems were certainly pre-release editions. While Randall does not detail any specific issues, the title text may paint a picture of two computer programs fighting each other inside the computer and making a mess in the process, as if they were Pokémon.
Other comics which advocate using catch-all phrases as standard responses for any comment:
I have found the perfect phrase for condescendingly dismissing anything: Cueball: Have you seen the new Ubuntu release? Black Hat: Nah, I'm not really into Pokémon.


e to the pi times i

Explanation:
The comic largely references Euler's identity . This identity states that e iπ + 1 = 0. Therefore, e iπ = −1.
The humor from this comic is because of the seemingly arbitrary relationship between e, π, and the identity of i (the square root of −1). e is the mathematical identity of which the derivative of e x with respect to x is still e x , while π is the relationship between the circumference of a circle divided by its diameter. Taking these two values and applying them to the value of i in such a manner makes it seem counter-intuitive  that it would yield −1 from basic analysis. The above linked Wikipedia page goes into good detail of how to derive this identity, as does this YouTube video .
The title text refers to how Euler's identity is called upon in complex form (separating real and imaginary numbers): e ix = cos(x) + i sin(x).
[Two Cueballs are standing at a board with writing on. One Cueball is pointing at the board.] Cueball: Numbers of the form n√-1 are "imaginary," but can still be used in equations. Friend: Okay. Cueball: And e^(π√-1)=-1. Friend: Now you're just fucking with me.


Canada

Explanation:
Canada is the country north of the USA . [ citation needed ] During political seasons, partisan voters often threaten to move away if their side loses. For Americans, this often comes to claims of moving to Canada .
The punchline references the tagline "If you die in the game, you die in real life" from the 2006 horror movie Stay Alive (released a few months before this comic), where people die in real life soon after their characters are killed in a certain video game. The idea was also present in The Matrix : "If you're killed in the Matrix, you die here?" There is also a Yahoo Answers thread about this question.
Taken literally, it is obviously true, as Canada is, arguably, part of reality [ citation needed ] . It really is "all real" as the title text says.
[Two men stand talking to each other.] Cueball: If we lose this election, I'm moving to Canada. Friend: You say that every year. Cueball: I mean it this time.
Friend: Well, becoming a citizen takes work. Meanwhile, you have no money, half an art degree, and it's the start of winter. You'll freeze to death in the streets. Cueball: Whatever.
[Friend raises his hands.] Friend: No, don't you get it? If you die in Canada, you die in REAL LIFE!


Interblag

Explanation:
The comic parodies the habit of word coining on the internet, as well as the enthusiasm for modern sounding terms in the IT world in general. Common examples include the shortening of "weblog" to " blog ," while the entirety of blogs is referred to as the " blogosphere ." The internet itself is sometimes called "The Tubes," a term derived from Senator Ted Stevens 's infamous statement " Series of Tubes ." The suffixes "-net" and "-web" are often used to denote a certain interconnection of information on the internet, as well as to make products and brands sound fit for the 21st century.
The matrix shown in the comic spoofs the internet jargon by combining common prefixes and suffixes to new and impressive but meaningless words. The culmination of nonsense is, as indicated in the transcript, the term "blagoblag." This is also a sideswipe at comic 148 , where "blag" was introduced as a substitute for the usage of "blog." The official weblog of the xkcd webcomic is called "blag." The prefix "blago-," meanwhile, was used again in comic 239: Blagofaire .
Terms I have used or heard used to make fun of the internet: [Below: A matrix whose entries may contain crosses to indicate that a term has been used. The rows (prefixes) are labelled WORLD WIDE, INTER-, BLOGO-, BLAGO-, and WEB-; the columns are labelled NET, WEB, SPHERE, TUBES, and BLAG. In the interests of properly propagating the term "blagoblag," the full list of used terms follows:] World Wide Web Internet Interweb Intersphere Intertubes Interblag Blogosphere Blagonet Blagosphere Blagoblag Webnet Webweb [Cueball and Megan stand facing each other; Cueball raises his hands in the air while Megan is nonplussed.] Cueball: I heard about it on the interblag!


Nash

Explanation:
The first panel references a scene in the movie A Beautiful Mind in which Dr. John Forbes Nash, Jr. comes up with his famous concept of Nash equilibrium when he realizes that they get suboptimal results if all the guys go after the same hot girl. The second panel deconstructs the idea as Dr. Nash point out that staying away from the hot girl does not actually constitute a stable Nash equilibrium. The third panel has physicist Dr. Richard Feynman render their entire discussion a moot point by getting all the girls while the mathematicians ponder optimal strategies.
In fact, the situation in the comic is a great example of what a Nash equilibrium is not . The only reason that one player (pun intended) wouldn't try to go for the hot girl is if they were afraid that someone else would go for the hot girl as well. However, in a Nash equilibrium, each player assumes that the other players won't change their strategy, and concludes from this assumption that their own strategy shouldn't change either. If all of them have the strategy of flirting with the hot girl's friends, and all of them are assuming (incorrectly) that the others won't change their strategies, then they all would change their strategies simultaneously, breaking the equilibrium.
Feynman shared the Nobel Prize in Physics in 1965 for his important work in quantum electrodynamics . Feynman wrote popular books and gave public lectures. These presented his work in advanced theoretical physics to the general public, a practice that was not very common at that time. One of his more famous books, Surely You're Joking, Mr. Feynman! gives many personal anecdotes from his lifetime, and it contains a passage giving advice on the best way to pick up a girl in a bar.
The aforementioned public books and lectures brought him great attention in the media, and his exceptional results in physics coupled with this have led to his getting an almost cult-like following among scientists. He's also (largely due to his book) known as something of a womanizer, thus why he would take several women home at once.
The title text explains that Randall wonders whether this "collective crush" (crush as in love affair) will fade away one day, but he doubts it. Great respect for Feynman continues to this day, even though he died about a quarter-century ago.
[Cueball and Dr. Nash (the Cueball-like guy to the right) stand talking to each other. Cueball is looking left and pointing off-panel.] Cueball: Hey, Dr. Nash, I think those gals over there are eyeing us. This is like your Nash Equilibrium, right? One of them is hot, but we should each flirt with one of her less-desirable friends. Otherwise we risk coming on too strong to the hot one and just driving the group off.
[Cueball is now looking at Dr. Nash.] Dr. Nash: Well, that's not really the sort of situation I wrote about. Once we're with the ugly ones, there's no incentive for one of us not to try to switch to the hot one. It's not a stable equilibrium.
[Cueball again looks left while Dr. Nash shakes his fist.] Cueball: Crap, forget it. Looks like all three are leaving with one guy. Dr. Nash: Dammit, Feynman!


Snacktime Rules

Explanation:
The comic shows Randall's mother telling Randall that he can have a snack in his room before bed only when his age is "one less than a multiple of three." This means that the child starts getting snacks in his room before bed when he turns 2 years old, then stops getting them when he turns 3. Then he starts again when he turns 5 but stops when he turns 6. This cycle repeats every 3 years, so the kid has the privilege to get snacks in his room before bed when his age is 2, 5, 8, 11, etc. (every 3 years).
It's difficult to defend this policy with a reasonable argument. The first impression is that the mother just made up the rule for some obscure, unknown reason. However, the title text explains that Randall's mother actually enforced this rule on him, and his mother claims that, at the time, there was a valid reason for it (though the reason is not explained in the comic). The caption says that Randall has figured out that his nerdiness as an adult comes (at least in part) from his mother's strange rules.
Note that there is some debate about whether the privilege spoken of is to have snacks, to have snacks in his room, to have snacks before bed, or to have snacks in his room before bed.
My dad was always the one who taught me about science, but looking back, I'm starting to realize how much my nerdiness was influenced by my mom.
[A woman and a child talk.] Child: Mom, can I have a snack in my room before bed? Mom: No, dear. You know you only get that privilege when your age is one less than a multiple of three.


Matrix Transform

Explanation:
A rotational matrix transformation (i.e. the big brackets with "cos" and "sin" in them) is used in computer graphics to rotate an image. In general, to rotate a point [a1, a2] in a 2D space by z° clockwise, you can multiply it by the rotation matrix [[cos z°, sin z°], [-sin z°, cos z°]]. In this case, the left side of the equation is rotating [a1, a2] by 90°. Simplifying the trigonometry, the 90° clockwise rotation matrix is [[0, 1], [-1, 0]], so multiplying this by [a1, a2], you should get [a2, -a1].
The joke is that the author performed the rotation transformation on the image of the vector rather than just the vector itself.
Rotational matrix transformations are a special case of the general linear matrix transform, which can do other things to images, including the other two affine transformations of scaling them or translating (moving) them.  On a pedantic note, normally mathematics uses counterclockwise as a default, although computer graphics frequently use a clockwise default, so this may be an intentional reference.
So the title text may be referring to the professors going home (translation) and shrinking (scaling) from the joke; it may also refer to them going home and seeing a shrink (counselor) in despair of their student understanding.
[A square matrix next to a vertical two-by-one matrix, equated to a horizontal matrix that looks like the two-by-one matrix turned 90 degrees.] [Square matrix: cos90°    sin90° -sin90°   cos90°] [Two by one matrix:] [a₁ a₂] [An equal sign] [The same two by one matrix, but rotated by 90 degrees clockwise:] [a₁ a₂]


Wikifriends

Explanation:
The comic's title refers to Wikis , which are collaboratively edited websites (such as this one). The first such site was WikiWikiWeb , but Wikipedia (an online encyclopedia) has become the most well-known example, and may have been specifically what Randall had in mind while drawing this comic, as other comics also reference Wikipedia.
The influence of social environment is called peer pressure , often with a negative connotation. The term "Wikifriends" is coined in the comic as a label for people who adjust their views in order to incorporate into a group. That is to say that, in the same way a Wiki page can be edited by people other than the original author, a "Wikifriend" allows their opinions to be "edited" by someone else. As an example, the comic shows a discussion about a movie in which one contributor changes his opinion entirely when he hears what his friend thinks.
The title text suggests that Randall also sees himself as being frequently influenced by others.
WikiFriends: [Two people are talking to each other.] Cueball: I really liked that movie. Friend: I hated that movie. Cueball: Me too.


Console Lines

Explanation:
This comic relates to video game consoles . At the time this comic was published, there were three major competing products: the Playstation 3 by Sony , the Xbox 360 by Microsoft , and the Wii by Nintendo . When a game console gets released, fans are often seen queuing outside the stores or camping on the pavement in order to be among the first to get their hands on a console. The comic shows such a console camp and points out the differences between the fan communities. While the fans waiting in line for a Sony or Microsoft product are very rude, the Nintendo fans are apologetic and try to comfort (that is to say, console ) those who arrived too late to obtain a package. The cliché that Nintendo fans are nicer and more polite may be attributed to the fact that the Wii is targeted at children and families, while the PS3 and the Xbox are targeted at the more "serious gamer" crowd.
The title text primarily expresses Randall 's distance from the console wars (he has never owned a game console before), but also indicating an inclination towards the Nintendo Wii.
Fans turning away latecomers to all-night game console campouts: [Two different lines presumably leading to a video game store are shown. In the line labeled Sony/Microsoft:] Cueball: The line is full, asshole! Get off! [And in the one labeled Nintendo:] Cueball: I'm so sorry, all the consoles are spoken for. Cueball: Do... Do you want a hug?


The Familiar

Explanation:
Cueball's friend asks him to go with him to view the sunrise over the ocean. Cueball refuses by giving a list of excuses, including the statement that "rationalizing the familiar is easy." This statement is amusing, because Cueball acknowledges the fact that he is making excuses and seems to refuse going out on the basis that rationalizing going to see the sunrise would require much more effort. This criticizes some people's tendency of not trying new things or going out with friends, even though one would likely get more fulfillment by doing these things. It may well be implied that the friend doing the inviting has left to view the sunrise, leaving Cueball behind since he wasn't willing to engage in an activity.
The computer with the egg-shaped profile looks like an iMac G3, sold from 1998 until 2003. It seems that rationalizing the familiar has made Cueball resistant to upgrading his computer long beyond its obsolescence date.
The title text indicates Randall's frustration with this mentality and his hope that when he wants to make plans with someone, they are just as eager.
[A guy is standing behind his friend who sits at a computer. Both look like Cueball.] Guy: Let's go see sunrise over the ocean. [The friend turns and replies:] Friend: That's a long drive, it's cold, I'm tired, and rationalizing the familiar is easy. [The guy leaves, and in the next two frames, the friend remains at his computer alone.]


Reload

Explanation:
This comic refers to the common method for reloading your ammunition in arcade game type shooters, also known as "rail shooters." The player is typically given a Light gun , and the player characters typically have unlimited magazines of ammunition; to load a new magazine, the player would aim his light gun away from the screen and pull the trigger.
The title text tells you to watch out for the guy from comic 53: Hobby , which shows a man who randomly pops up to the police when they are performing a drug raid. This refers to the random figures that pop out at many games; if they are not a valid target and you shoot them, you will lose points.
[Four soldiers are preparing to enter a battlefield; their leader addresses them.] Leader: Okay men, we're going in. Stay low, keep behind cover, and if you run out of ammunition, shoot outside the battlefield to reload.


Exercise

Explanation:
Role-playing games (RPGs) are a pastime commonly associated with geeks in which players assume the role of a fictional character in a fantasy world. In many RPGs, character evolution and advancement is represented by "leveling up." Through winning battles and, less frequently, completing tasks or missions, characters are awarded experience points (XP), which can be spent on increasing their ratings in attributes (such as strength or speed) or skills (such as bow-hunting or computer hacking). The number of XP awarded is generally proportional to the difficulty of the task completed.
Cueball is doing chin-ups , a strength-training exercise that targets the latissimus dorsi and biceps. Repeating this exercise over time will improve his ability to do more chin-ups in one go - in other words, he will become stronger. In doing so, he is effectively leveling up his STR (strength) attribute in real life. While doing his chin-ups, he comments that he will soon switch to running - an aerobic exercise that improves endurance - in order to build up his CON (constitution) attribute. Cueball is treating his gym session like an RPG, and observes that, as a self-confessed geek, he would not be as interested in exercising without that link.
The title text implies that since Randall has lost his patience and ability to play RPG games, likely due to the connection to exercise.
Like many geeks, I got a lot more interested in exercise once I made the connection to leveling up. [Cueball is doing pull-ups on a bar in a doorframe.] Cueball: One more point to STR, then I'll run to work on CON.


IPoD

Explanation:
IP is one of the main protocols of the Internet. It is used to route data packets from one computer to another, using other computers or even complete networks in between if needed. It is designed to use the fastest (not necessarily the shortest) route to the target, automatically using another route if a connection or a transmitting host fails.
Every participant of the network has to have a so-called IP address . The data is divided into packets , each consisting of a header and the payload. The header tells the transmitting parties where the packet comes from and where it should go (together with some other details). The payload is the data to be transmitted.
IP packets can be carried by a variety of transport networks. Such methods are often referred to as "IP over X" (or "IPoX" for short). Examples include IP over DVB , IP over ATM , and the humorous IP over Avian Carriers .
Black Hat (and other statisticians) is using demographics as IP packets to send data. In order to adjust the death rate to encode the header, Black Hat plans to travel to New Jersey and go on a killing spree with a crossbow, instead of merely hacking the census bureau's computers. Such antics could only be used to increase the death rate; decreasing it would require saving lives instead, as mentioned in the title text. Also as mentioned, birth rates would be trickier to manipulate, as doing so would require encouraging or discouraging women to have children and would require an approximately nine-month delay, which is a great deal more difficult than taking a crossbow to a heavily populated area.
Crossbows were also mentioned in 564: Crossbows . Black Hat is also seen using his crossbow in 929: Speculation .
[Black Hat sits at a computer. Cueball stands behind him.] Black Hat: You see, statisticians communicate using IPoD -- IP over Demographics. For example, the header of the next packet I send will be encoded into the New Jersey death rate. Cueball: So you're going to hack the census bureau and change the number of reported deaths? Black Hat: Guess again. Black Hat: Hey, have you seen my crossbow?


Lojban

Explanation:
Lojban is a constructed language designed to be logical, unambiguous, and culturally neutral — similar to the better known artificial language Esperanto . The authors originally designed it as an experiment, but a few people have picked it up and tried to learn it. However, anyone actually willing to learn Lojban is someone Black Hat would rather avoid. Alternately, only people who speak Lojban, who compose an admittedly tiny proportion of the general population, could benefit from the logic of the language, making the benefits of Lojban mostly pointless to most people.
Clicking on the original comic brings you to a Lojban translation of the comic . The Lojban version literally translates to something like:
Cueball: Hypothetically, you becoming an expert in Lojban implies things you say would completely be an unambiguous meaning and logical. Black Hat: Agreed, but would be talking to the people subgroup that is an expert in Lojban.
If reading pedantically, a few mistakes can be identified:
The title text is also written in Lojban. It translates roughly as: "That was a joke. Really. Wanna be friends with me?" Since Lojban aims to be completely unambiguous, idiomatic structures like sarcasm and humor have associated particles - when a joke is made, it must be explicitly marked as such or else it's incorrect. Most languages rely on intonation expressing this, but Lojban does not, leading to the strange practice here of specifically pointing out that a joke was made.
A more literal translation gives: "Humorously that false. Please is-it-true-that you friend me?"
[Cueball and Black Hat are having a conversation.] [English version:] Cueball: If you learned to speak Lojban, your communication would be completely unambiguous and logical. Black Hat: Yeah, but it would all be with the kind of people who learn Lojban.
[Lojban version:] Cueball: da'i ganai do crebi'o la lojban gi le se cusku be do cu mulno pavysmu je logji Black Hat: .i .ie ku'i cusku fi le prenu klesi poi certu la lojban


Working for Google

Explanation:
Many look up to Google as the ultimate workplace in the IT industry. Therefore, they have lots of applicants but can afford to be very selective, and only the best and brightest succeed.
In the first panel, the guy at the computer asks his friend (both look like Cueball ) what he thinks about working at Google HQ ( Head Quarters ). His friend starts out by dismissing Google as a "corporate idea factory," but from the rest of his speech, we can infer that these are not his true feelings. He is exhibiting the attitude known as " sour grapes ," where you criticize something that is out of your reach, or that has been denied from you.
In the last panel, it is revealed that the friend has been trying very hard to get a job at Google, even resorting to bribing the interview panel by baking them a cake "shaped like the Internet."  This misguided action is a sign of how much he wanted a position.
Since the Internet does not have a defined shape, it is difficult to visualize exactly what he baked. The comment was maybe foreshadowing 195: Map of the Internet that came out a week later. It would, though, be a more interesting cake if it looked like the map in 256: Online Communities , but that came out 20 weeks later. Another possibility is that the comment is a reference to this video , in which the black box shown is supposedly the Internet. If this is the case, then the cake would have been shaped like the box in the video.
The title text says that if you work for Google for 256 (2 8 ) days, you get to learn how to levitate. This displays some of the mystique with which Google is commonly viewed. The joke here is that 256 is the largest value a single byte can hold, as has been demonstrated with the 256 Bug . However, Astro Teller, the director of Google X labs, a Google division that researches "moonshot" projects, has mentioned in an interview that they contemplated starting a levitation project.
[A guy sits at a computer and addresses his friend standing behind.] Guy: Have you read about Google HQ? It sounds like an incredible place to work.
[The friend throws his hands in the air as he delivers this speech:] Friend: Man, I ain't going to be chained down in no corporate idea factory! They think just 'cause they've got a nice building and laid back culture, I'm gonna want to come in all day long and work on fascinating problems with the smartest people in the world.
[Close up of the guy staring at his friend.]
[Back to the original setting.] Guy: So, what, they turned you down? Friend: I don't understand it! I even baked them a cake shaped like the Internet!


The Perfect Sound

Explanation:
This comic relates to the song " Mickey ", performed in 1982 by one-hit-wonder Toni Basil . The lyrics, as well as the instrumentation of the song, were in fact rather simple, being a perfect example of bubblegum pop in the early 1980s.
In the comic, however, the song is introduced as a musical masterpiece. Cueball points out the opening sequence to his friend and states that it should be considered art. When the chorus sets in and the song unfolds its lyrical brilliancy, his friend has no other comment to make except that there must be something wrong with Cueball.
Cueball's actions might be seen as a critical approach towards over-interpreting music. The comic's title, as well as the stereo setup depicted, could perhaps also denote a sidesweep on audiophiles .
The title text parodies a line from the song and links it with the incomprehension of Cueball's friend.
[Cueball and his friend are listening to music on a stereo.] Cueball: I'm telling you, listen right here to the sets of rising notes following the opening section. Friend: Uh huh. [Cueball indicates stereo.] Cueball: And then right here, the transition into the chorus. This is music. This is art ! [Cueball dances along with the music.] Stereo: Oh Mickey, you so fine, you so fine you blow my mind, hey Mickey! *clap* *clap* Hey Mickey! Friend: There's something wrong with you.


Penises

Explanation:
The comic takes aim at what is considered by some to be the apparent societal obsession with the male sexual organ ("phallocentrism"), especially in regards to size. In general, depictions of an erect penis (also called phallus ) represent male potency.
While present in every human civilization, the symbol of the penis is also prominently featured in modern mass media. Many films and television series make use of penis-related jokes. A very common trope is the male obsession with the idea that a larger penis is considered more desirable, and a smaller penis less manly or satisfying to women.
Megan criticizes this obsession by pointing out that most penises are about the same size, and normal variations in size are not worth getting worked up about.
The title text refers to the excessive advertisement for potency pills and penis enlargement in spam emails . The symbol of the phallus can be regarded by some as omnipresent in modern Western society (but not necessarily in other cultures) [ citation needed ] , with presumably every public toilet sporting at least one badly drawn depiction of a penis.
PENISES: Megan: They are about this big. [Holds her hands close together, about half a foot apart.] Now can we PLEASE , as a culture, move on?


Map of the Internet

Explanation:
On the map, all allocated IPv4 address blocks (as of 2006) are shown using a fractal mapping. (The Hilbert curve is used: the pattern is demonstrated at the bottom of the image.) In February 2011, the final remaining IPv4 blocks were allocated to the Regional Internet registries , and so today there would no longer be any green spaces outside of Class E addresses (above 240 through 255, excluding the Broadcast address of 255.255.255.255).
In the early 1990s, corporations and governments could register an entire class A segment (one 256th of the total space), but later it was divided into smaller parts because of a lack of space.
This leads to the title text, which mentions IPv6 . This protocol has so many addresses that only a swarm of nanobots could exhaust them. The default desktop picture in Windows XP is a green landscape, and the joke is that since barely any of the addresses are allocated yet, the IPv6 map would just be a green landscape.
Later, Randall actually drew some "real" maps of the Internet, or at least its online Communities (see 256: Online Communities and 802: Online Communities 2 ).
Map of the Internet The IPv4 Space, 2006 This chart shows the IP address space on a plane using a fractal mapping which preserves grouping--any consecutive string of IPs will translate to a single, compact, contiguous region on the map. Each of the 256 numbered blocks represents one  8 subnet (containing all IPs that start with that number).  The upper left section shows the blocks sold directly to corporations and goverments in the 1990's before the RIRs took over allocation. Diagram showing IP ownership: 0: Local 1-2: Unallocated 3: General Electric 4: BB&N INC 5: Unallocated 6: Army AISC 7: Unallocated 8: BB&N INC 9: IBM 10: VPNs 11: DoD Intel 12: Bell Labs 13: Xerox 14: Public data nets 15: HP 16: DEC 17: Apple 18: MIT 19: Ford 20: CSC 21: DDN-RYN 22: DISA 23: Unallocated 24: Cable TV 25: UK MoD 26: DISA 27: Unallocated 28: DSI 29-30: DISA 31: Unallocated 32: NORSK 33: DLA 34: Halliburton 35: Merit 36-37: Unallocated 38: PSI 39: Unallocated 40: Eli Lily 41: ARINIC 42: Unallocated 43: Japan INET 44: HAM Radio 45: INTEROP 46: BB&N INC 47: Bell North 48: Prudential 49-50: Unallocated 51: UK Social Security 52: duPont 55: Boeing 56: USPS 57: SITA 58-61: Asia-Pacific 62: Europe 63-76: USA & Canada (contains: UUNET, Google, Digg, Slashdot, Ebay, Craigslist, XKCD, Flickr) 77-79: Europe (unused) 80-91: Europe 92-95: Unallocated 96-99: North America 100-120: Unallocated 121-125: Asia-Pacific 126: Japan 127: Loopback 128-132: Various Registrars 133: Japan 134-172: Various Registrars 173-189: Unallocated 188: Various 189-190: Latin America & Caribbean 191-192: Various (contains Private (RFC 1918)) 193-195: Europe 196: Africa 197: Unallocated 198: US & Various 199: North America 200-201: Latin America & Carribbean 202-203: Asia-Pacific 204-209: North America (contains Suicide Girls, BoingBoing) 210-211: Asia-Pacific 212-213: Europe 214-215: U.S. Department of Defense 216: North America (Contains Myspace, SomethingAwful) 217: Europe 218-222: Asia-Pacific 223: Unallocated 224-239: Multicast 240-255: Unallocated


Command Line Fu

Explanation:
The Linux command line allows a user to make their computer do nearly anything. The only hitch is that the interface is entirely text-based, and reading through user manuals to find the commands that you need can take a very long time.
In this comic, Cueball recounts how he used a command line hack to solve a problem with his monitors turning off during a movie. However, in the time that he spends trying to solve the issue, the woman he had brought home had already left, and his need for a movie to watch was gone.
The title text is the supposed moral to this story: if your user interface takes as long to operate as a command line, you may very well be denying your users the chance to get laid.
Software that jiggles the mouse actually exists, as well as instructions for linux scripting (although installing the necessary libraries might take a while).
[Two men talking.] Cueball: Last night I was watching videos with this girl and my monitors kept turning off - even though I had disabled power save. Friend: Odd. Cueball: However! I wrote a command to jiggle the mouse pointer every couple minutes to keep it from going idle. Friend: Not the first hack I'd try, but see? Linux has problems, but it gives you the tools to deal with them - and save your date! Cueball: Actually, I was half an hour into the pointer scripting documentation when she got dressed and left.


Ninja Turtles

Explanation:
The Teenage Mutant Ninja Turtles , or Ninja Turtles, are a pop-cultural phenomenon especially prominent in the late 1980s and 1990s. The four turtles are named for four artists of the European Renaissance: Leonardo da Vinci , Michelangelo di Lodovico Buonarroti Simoni , Donato di Niccolò di Betto Bardi , and Raffaello Sanzio da Urbino . Due to the popularity of the Ninja Turtles in a variety of media, some of the names are now better known through their Ninja Turtle connection than their original artist forebears. The pie charts provide an approximation of this effect - Leonardo da Vinci remains one of the most notable artists of the period, and thus "Leonardo" is depicted as more notable for the artist. Donatello is the most obscure of the four as an artist, and consequently the majority of the current notoriety of "Donatello" is as a Ninja Turtle.
The title text alludes to a similar phenomenon, as two villain characters from the same Ninja Turtles show called "Bebop" and "Rocksteady" are now better known as the characters than for the musical genres they are named for. Similarly, the William Tell Overture became so closely tied to the character of the Lone Ranger in media for the previous generation that, to many, the William Tell Overture is in effect "The Lone Ranger Theme."
[Four pie graphs, each colored green and brown.] Leonardo [Almost one-half green.] Michelangelo [More than one-half green.] Donatello [Five-sixths green.] Raphael [Roughly half-and-half.] [A legend] Notoriety as a [Brown.] Renaissance artist [Green.] Ninja turtle