explain xkcd - User contributions [en]

1754: Tornado Safety Tips

2022-05-04T01:56:52Z

Big square: Undo revision 233723 by X. K. C. D. (talk)

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{{comic
| number = 1754
| date = November 2, 2016
| title = Tornado Safety Tips
| image = tornado_safety_tips.png
| titletext = It's a myth that you can never cross mountains safely, but be sure you understand how the climatic situation there will affect your parent thunderstorm.
}}
==Explanation==
The comic features a {{w|Public Service Announcement}} (PSA) poster, which generally contain public-interest messages aimed at raising awareness or steering behavior around a specific issue of concern, that in this case contains tips for {{w|tornado}} safety. Typically, a poster labeled "Tornado Safety Tips" would be filled with instructions for how humans can stay safe in the event of a tornado, such as "stay away from windows," "go to the lowest floor of your home," "if in the open, take shelter in a ditch," and so on, see these examples: [https://s-media-cache-ak0.pinimg.com/736x/b3/ba/02/b3ba0231f99bf14622a347b65ad30ea7.jpg Example 1] (with same title as comic), [https://www.weather.gov/images/oun/wxevents/20130531/socialmedia/torsafety.png example 2] and [https://www.weather.gov/images/oun/wxevents/20130531/socialmedia/carsafety.png example 3].

[[Black Hat]] on the other hand, has flipped this on its head by publishing a poster that contains safety tips for the tornado itself and contains information for how tornadoes can stay safe, i.e., continue to exist; see the [[#Table of tips|table of tips]] below. The joke is that just as, for example, a "climber safety" poster is directed at climbers, the "tornado safety" poster is directed at tornadoes.

It is thus in no way helpful for people who actually live in an area that experiences tornadoes {{tvtropes|CrazyPrepared|or even for people that don't live in tornado-prone areas but want to be ready for their possible occurence}}{{Citation needed}}. It is not possible to follow most of the guidelines{{Citation needed}}, as they are intended for tornadoes. But the advice a human could follow would only take you towards places which can sustain tornadoes. Instead they should choose to use an app like the one in [[937: TornadoGuard]].

The title text simply adds more tornado advice for tornadoes, bringing up the common myth about tornadoes not crossing mountains, except from the tornado's perspective.

Although this is clearly not a tip for humans, the idea of ''tornado safety tip'' is yet another [[:Category:Tips|tips comic]].

Tornadoes are a [[:Category:Tornadoes|recurring subject]] on xkcd. The tornado in this comic is similar to the [[:File:umwelt disasters tornado.png|picture used]] in the [[1037: Umwelt#Tornado|Tornado version]] of [[1037: Umwelt]].

===Table of tips===
{|class="wikitable"
! Tornado Safety Tips
! Explanation
|-
|Avoid low-lying cool air || {{w|Supercells}}, and particularly {{w|tornadogenesis}}, requires highly {{w|buoyant}} air near the surface to provide the energy and rapid upward motion for to their growth and maintenance. Tornadoes, as small-scale features compared to the whole atmosphere and requiring fairly extreme conditions to form, are particularly sensitive to shallow layers - perhaps even a few hundred meters of less buoyant (i.e., cooler or dryer) air near the surface. If a tornado encountered such a layer of air, it would be quite "dangerous" to its survival, as sufficient depth and exposure would likely disrupt the tornado's circulation and perhaps even dissipate it completely.
|-
|Keep your downdrafts and updrafts from mixing || Strictly speaking, this statement is only entirely true on the larger scales of a tornadic storm (though to some extent {{w|updraft}}/{{w|downdraft}} interaction is crucial to the process on the scale of the actual tornado). Generally, it is for exactly the lack of this that tornadic supercells are able to gain such intensity and last many hours, whereas a typical individual storm cell has a life-cycle on the order of less than an hour. Any given storm cell is composed of an updraft, warm, moist air moving upward and forming clouds, and a downdraft, the corresponding movement of cooler air downward, often bringing heavy rain with it. If this downdraft is superimposed directly over the parent updraft, as would occur in a calm atmosphere with no substantial differences in wind with height, it will suppress the storm's updraft very quickly, and the cell will die a rapid death. However, if the winds change quickly enough with height (vertical wind shear), this displaces the updraft and downdraft so they don't interfere as directly, resulting in a longer-lived storm. Nevertheless, the cold air moved downward by the downdraft will eventually spread along the surface and choke off the flow of warm air to the original updraft; however, this denser air may force more warm air to rise, starting the cycle anew, albeit with a new storm cell. This is how squall lines work (see below), along with more typical multi-cell clusters. Still, this results in no one cell being "dominant," remaining strong for any great length of time, and growing past a certain point, all factors that preclude significant tornado formation.

However, if the vertical wind shear is particularly strong, with very strong winds aloft going in nearly the opposite direction as winds near the surface, this causes horizontal rotation in the atmosphere (think a pencil rolled between two hands). A particularly strong updraft can lift this rotation into the vertical, and soon the entire storm begins to rotate. Through rather complex physics, this allows the storm to more cleanly separate its updraft and downdraft, and continuously propagate into warm, buoyant air. This process and the updraft/downdraft separation it creates is associated with nearly all dangerous tornadoes, and is what distinguishes a supercell from other types of thunderstorms. If such separation is not properly maintained, it will likely "kill" the storm's tornado chances, including any tornadoes currently in progress. However, it bears pointing out that a specific type of downdraft interacting with a tornado, called {{w|Rear flank downdraft}} (RFD), actually may play a crucial role in tornado formation, carrying this rotating motion (vorticity) down from higher levels of the storm and feeding it into the tornado. Therefore, if a storm's RFD is too weak or does not interact with the core of the storm's updraft, a tornado is not likely to form or maintain itself. However, if the RFD is too cold/strong, it will indeed cut off the tornado's supply of warm air (see below), and regardless of type the RFD does eventually tend to "kill" the tornado after some length of time, which is why any individual tornado only lasts for a short amount of time.
|-
|Seek out warm and humid surface air layers || Hot, humid air near the surface is vital for tornadoes to form, as it provides the "fuel" for their parent storms as well as tornadoes themselves. Any {{w|thunderstorm}}, large or small, begins as an updraft, a column of warm, moist air moving upward due to its positive buoyancy (i.e., lower density; think a balloon or heat rising from the pavement on a hot summer day). Due (mostly) to its temperature, once the air is less dense than its environment, it will start moving upward, and will continue to do so as long as it stays that way. However, air cools when rising as it expands under lower pressure, normally cooling at a faster rate than the surrounding environment does. This is where moisture comes in, as once the air cools to the saturation point, where it can hold no more water vapor, water begins to condense into tiny liquid droplets to form clouds. This process releases latent heat to the surrounding air parcel, and thus in a suitable environment with sufficient cooling with height, this rising air starts to cool slower than its surroundings, and continues to rise on its own. The warmer and wetter the air relative to its surroundings, the faster it can rise, and thus the more intense storms it can feed. Further, once a storm forms and begins to rotate (see above), the tornado itself, being an extremely intense, rotating updraft near the ground, is "fed" by very warm and moist air at the surface and thus would want to seek it out to survive.
|-
|Don't let rain-cooled air choke off your circulation || As discussed above, if a storm's downdrafts are too strong, they can block the supply of warm, moist, buoyant (rising) air that feeds a tornado, which will cause it to dissipate or never fully form in the first place. On the storm scale, this type of supercell is termed "outflow dominant". It generally maintains itself, but too much rain-cooled air present at the surface is preclusive to tornado formation. On the tornado scale, the buoyancy of the storm's Rear Flank Downdraft, RFD, is believed to play a crucial role in tornadogenesis. It is this air that carries high-vorticity (rotating) air down from aloft to enable the tornado to have such an intense circulation near the surface, as updraft parcels beginning near the surface otherwise have little preexisting rotation. However, if this air is too cold and dense, which is typically a result of evaporative cooling and water loading from rain, it can choke off the supply of warm air to the tornado's circulation, and reduce its overall buoyancy. This can "kill" the tornado, and is generally why they dissipate.
|-
|Avoid letting your supercell merge with a squall line || Supercells, the powerful, rotating thunderstorms that produce nearly all strong tornadoes, generally last longer when left alone. Other storms compete for the same warm, moist air that the supercell needs to fuel its continued development, and the cold downdrafts produced by such storms can also choke off a supercell's supply. Furthermore, interaction with other storms, especially strong ones, can disrupt the complex physical processes that keep a supercell going, particularly those delicate processes that lead to and sustain tornadogenesis. A {{w|squall line}} is a particularly potent threat in this regard, and probably the biggest "killer" of supercells in this specific regard. Squall lines, well known as the culprit behind most of the violent derecho windstorms, are long lines of thunderstorms that can, as a larger-scale feature, last many hours and travel thousands of kilometers. They generally occur when environmental conditions allow one or a few storms to combine the cold, dense air in their respective downdrafts in such a fashion that it moves rapidly and spreads out in a linear fashion, forcing warm air up right ahead of it to form clouds and additional storms. This then creates new downdrafts that contribute to this "cold pool", as its called, continuing the process. While squall lines can occasionally produce weak, short-lived tornadoes along their leading edge, they generally lack the rotation and individual persistence necessary to form proper "twisters". Their fast motion, large size, sizable cold pool, and all-consuming hunger for warm, moist air and resultant tendency to gobble up storms in their path make them a mortal threat to the generally slower-moving, freedom-loving supercells and their resultant tornadoes. An encounter with a squall line almost never ends well for tornado, and they should avoid such a meeting if they strive for longevity. However, it is interesting to note that storm interactions, occasionally even with squall lines, can briefly enhance tornadogenesis if conditions are just right, but this rarely has a sustained positive impact on the tornado's long-term survival prospects.
|-
|'''Title text''': It's a myth that you can never cross mountains safely, but be sure you understand how the climatic situation there will affect your parent thunderstorm. || In a style perhaps evoking that of a safety warning for a pharmaceutical drug, the title text reminds tornadoes that while it is indeed {{w|Tornado myths#Near rivers, valleys, mountains, or other terrain features|false that tornadoes are not able to cross mountains}} (while rough terrain can sometimes disrupt the very low-level circulation, there is nothing intrinsic to mountains areas that prevent tornadoes from moving over them), the tornado should be cautious that the environment on the other side of the mountain should still be supportive of the parent supercell and the broader processes keeping the tornado "alive." This is a valid concern because, generally speaking, the more mountainous areas of the United States generally tend to have less favorable environments for supercells and tornadoes, but this isn't always the case as the title text notes, particularly for more local-scale terrain.
|}

==Transcript==
:[Beneath a large caption there are two pictures above each other to the left and a bullet list with five points to the right of the pictures. The top picture shows a black tornado beneath a white cloud. It is destroying something on the ground. To the right of the debris is a house and to the left some trees. The picture below shows Black Hat from the waist and up.]
:<big>'''Tornado Safety Tips'''</big>
:* Avoid low-lying cool air
:* Keep your downdrafts and updrafts from mixing
:* Seek out warm and humid surface air layers
:* Don't let rain-cooled air choke off your circulation
:* Avoid letting your supercell merge with a squall line

{{comic discussion}}

[[Category:Comics featuring Black Hat]]
[[Category:Tips]]
[[Category:Tornadoes]]

2592: False Dichotomy

2022-05-04T01:55:01Z

Big square: Undo revision 236041 by X. K. C. D. (talk)

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{{comic
| number = 2592
| date = March 11, 2022
| title = False Dichotomy
| image = false_dichotomy.png
| titletext = There are two types of dichotomy: False dichotomies, true dichotomies, and surprise trichotomies.
}}

==Explanation==
A dichotomy is two alternatives which are normally mutually exclusive (such as the dichotomy between a flat Earth and non-flat Earth). A {{w|false dichotomy}} is a {{w|logical fallacy}} based on an incorrect perception of limited options (for example: if the page background isn't white, it is black).

[[Cueball]] has apparently made one such error and is being called out by [[White Hat]] for it. Upon having this pointed out to him, Cueball says that we must '''embrace''' false dichotomies, because the '''only other option''' is {{w|cannibalism}}. This statement is another false dichotomy, as presenting false dichotomies is not the only alternative to cannibalism{{Citation needed}}. The reverse (that cannibalism is incompatible with expressing false dichotomies) is also not potentially true, as eating people may eventually result in having nobody you need to present false dichotomies to.

Cueball has thus created another false dichotomy to excuse his first.

The false dichotomy Cueball appears to be referring to is the notion that those identified as human must not be eaten, but even closely related animals are not human and can be eaten, i.e. species can be divided clearly between "human" and "food". If this dichotomy is not accepted, then consuming any species that shares, for instance, any significant percentage of DNA with humans could be considered a measure of cannibalism.

The title text states that there are two kinds of dichotomies, making a dichotomy in itself. Due to three types of dichotomy being mentioned, and only two being foreshadowed, this statement is itself a surprise trichotomy, or three-parted choice. The title text is a variation of the [https://tropedia.fandom.com/wiki/There_Are_Two_Kinds_of_People_in_the_World "Two kinds of People"] joke. The classic math nerd variant is "There are three kinds of people in the world, those who can count, and those who can't." Alternatively, it may refer to a variation about {{w|base 2|binary}}. The original joke usually goes something like this: "There are 10 types of people: those who know binary, and those who don't." The variation is usually something like the following: "There are 10 types of people: those who know binary, and those who don't, and those who weren't expecting a {{w|base 3|ternary}} joke." Another version of this kind of joke is "there are two kinds of people: those who can extrapolate from an incomplete data set,"

The word {{wiktionary|trichotomy}} is a relative neologism, to be understood as to mean "divided into (or amongst) three parts", having replaced the original prefix "di-" (a factor of two, either doubled or, by context, halved) with that of "tri-" (similarly tripled/thirded). Strictly, though, {{wiktionary|dichotomy}} more directly stems from Greek elements that say "apart, I cut", with "apart" being represented by the "dicho-" (itself being roughly "into two", or to separate) which does not have a direct "tricho-" equivalent, although it does ultimately derive from "duo", Greek for "two". This is the kind of linguistic nuance that [[Randall]] clearly enjoys, yet may also happily or carelessly (mis)use without compunction.

==Transcript==
:[White Hat and Cueball are talking to each other. White Hat has his arms spread outwards in exasperation, while Cueball gestures assertively with his pointer finger.]
:White Hat: That's a false dichotomy!
:Cueball: Yes, but we have to embrace false dichotomies, because the only alternative is cannibalism.

{{comic discussion}}
[[Category:Comics featuring White Hat]]
[[Category:Comics featuring Cueball]]
[[Category:Language]]
[[Category:Self-reference]]

760: Moria

2022-05-04T01:52:45Z

Big square: Undo revision 234288 by X. K. C. D. (talk)

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{{comic
| number = 760
| date = June 30, 2010
| title = Moria
| image = moria.png
| titletext = Someone should really bring them a ladder and remind them to build the Endless Stair *first* next time.
}}

==Explanation==
This is [[Randall]]'s take on the story of {{w|Moria (Middle-earth)|Moria}} in the fantasy story ''{{w|The Lord of the Rings}}''. In the original the dwarves, hunting for the precious metal mithril dug so deep that they awoke a {{w|balrog}} — {{w|Maiar}} corrupted by {{w|Morgoth}}. {{w|Gandalf}} is telling about the story to four hobbits standing next to him. One of the {{w|hobbits}} has apparently read ''The Lord of the Rings'', because he asks if the dwarves "awoke a terror of shadow and flame", but then Gandalf says that they were trapped in their hole and couldn't get out.

However, Gandalf's final line may be a hint that the comic's version is closer to the original than it appears — in the story, the adventuring party discovers a journal of the last dwarves to occupy Moria. The last page starts ominously: "We cannot get out. We cannot get out." That memorable sentence is used again near the end of the page as the impending final orcish attack is described by the now-dead dwarves, and repeated by {{w|Gimli}} as they reflect on the terrible news, lending a much darker tone to the comic's punchline.

The title text suggests a mundane solution to their problem — a long ladder. The Endless Stair was a very long staircase from the lowest dungeon up to the top of the mountain above Moria.

==Transcript==
:[A far shot of Gandalf the Grey and the four hobbits standing in a dark, underground city.]
:Gandalf: Behold, Khazad-Dûm; the Dwarrowdelf; the mines of Moria -- once the greatest and mightiest city of the dwarves.

:[Full body shot of Gandalf.]
:Gandalf: But the dwarves delved too greedily.

:[Close-up on Gandalf.]
:Gandalf: And too deep.

:[Full shot of the hobbits and Gandalf.]
:Hobbit: ...and awoke a terror of shadow and flame?
:Gandalf: No. They couldn't get out.

{{comic discussion}}
[[Category:LOTR]]

2428: Mars Landing Video

2022-05-04T01:51:10Z

Big square: Undo revision 234946 by X. K. C. D. (talk)

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

==Explanation==
Three days before this comic was published, NASA successfully landed a new rover, {{w|Perseverance (rover)|''Perseverance''}}, on Mars. This was also the subject of the previous comic [[2427: Perseverance Microphones]].

This comic was published shortly before a [https://www.youtube.com/watch?v=gYQwuYZbA6o NASA press briefing] that showed, as mentioned in the comic, the first ever full-speed video of a Mars landing. This comic is set at that press briefing and was published shortly before NASA, either unaware of Randall's threat or recognizing that it was not serious, went ahead and hold the briefing in real life. "Full-speed" here means that the video was captured at a {{w|frame rate}} high enough that it looks continuous when played back, as opposed to low-frame-rate imagery that looks jerky when played back.

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

He follows up with the question of whether NASA is planning to make a worse Mars landing video, which is silly because people generally don't intend to make something worse.{{Citation needed}} However, because this video is the worst full-speed video of a Martian landing by virtue of being the ''only'' full-speed video of a Martian landing, it is likely that if enough full-speed videos of Martian landings are made in the future, this video will not be the worst forever. Although this is merely a consequence of the fact that it is the only full-speed video of a Martian landing so far, the fact that it is technically true, as well as the way that Randall phrases it, makes it look embarrassing for NASA. The tendency of Randall (the character, not the real-life person) to make rude, embarrassing, and otherwise unwelcome comments is probably why he has been banned from NASA's press briefings, as well as all those conferences.

Judging by the sound effects, Randall has chosen to literally crash his way through the roof, using a "skycrane" — a general term for aerial vehicles that can lower or raise objects similarly to standard cranes. Specifically, one of these was used to land the Perseverance rover three days before. On Earth one might use the {{w|Sikorsky S-64 Skycrane}} helicopter, while NASA used a custom-built skycrane delivery system for the ''Perseverance'' rover. Randall deems using a skycrane to crash a conference about a skycrane ironic, especially since NASA's security was totally unprepared to stop him from using this method - a method NASA developed - to crash the press-briefing.

The title text refers to the 11-minute communications delay (one-way; 23-minute delay round-trip) between Mars and Earth, due to the speed of light and the distance between the planets at the time of the rover's landing. The ''Perseverance'' mission control must wait this long before they can even begin to respond to anything that happens to the rover, which Randall here twists into an 11-minute period in which he can ask whatever questions he likes before NASA can respond. This would only make sense if the conference he was crashing was on Mars and they were waiting for his questions here on Earth, or vice versa and plays on the ambiguity of the expression "Mars briefing", which can mean both a briefing about Mars and a briefing taking place on Mars.

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

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

{{comic discussion}}

[[Category:Mars rovers]]
[[Category:Banned from conferences]]
[[Category:Comics featuring Hairbun]]
[[Category:Comics featuring Randall Munroe]]

1673: Timeline of Bicycle Design

2022-05-04T01:50:48Z

Big square: Undo revision 232990 by X. K. C. D. (talk)

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{{comic
| number = 1673
| date = April 27, 2016
| title = Timeline of Bicycle Design
| image = timeline of bicycle design.png
| titletext = I'll be honest--the 1950s were a rough time for cycling.
}}

==Explanation==
[[Randall]] created what is supposedly a 200 year history for bicycles with 13 designs ranging from 1810 to 2016. However, a cursory glance at each one shows that they are almost all fictitious, heavily flawed, and most don't even fit the definition of "bicycle". The main point of the comic is to show off these silly joke designs.

The only model that both looks like a real model and fits the year is the 1875 model, which resembles the {{w|Penny-farthing}}. The Penny-farthing was popular in the 1870s until the {{w|Safety bicycle}} took over around 1880. The 1875 model appears to be missing handlebars, but it's worth noting that on the real bicycle, the handlebars were very small and close to the saddle, and may be too small to appear in the drawing.

The 1860 model looks like the {{w|American Star Bicycle}}, but that bicycle was first invented in the 1880s.

The 1900 model looks like one of {{w|Paul Scheerbart}} 's perpetual motion machines.

Some of the other examples of "bikes" could, however, look like those in the image at the top of the {{w|Velocipede}} Wikipedia page.

Several of the "bikes" are shown with a human — [[Ponytail]] is "riding" the pole-vaulting bike, [[Cueball]] appears in four designs, and [[Megan]] appears in three. These humans provide a sense of scale and, in some cases, a demonstration of how the bike might be operated. Cueball's appearance in the 1900 design shows how huge that bike is, appearing to dwarf the previous two models while continuing the short trend of ever-increasing size.

Only two of the bikes have pedals (1875 and 2016) and another two have a sprocket with a chain (1900 and 1980). Seven designs include a seat for the rider — eight if you count the device holding Megan in the 1980 model.

The 1925 model is reminiscent of a {{w|fractal}}; {{w|Benoit Mandelbrot}} was born in October 1924.

The 1880 model could be the result of an {{w|evolutionary algorithm}} trying to produce a bicycle. Some sub-optimal algorithms that have been given the task of creating a vehicle have been shown to misplace parts in ways that makes them completely useless and/or inaccessible — for example, placing a small wheel inside a much larger wheel.

This comic (especially the 2016 bicycle) is possibly also a reference to [https://www.liverpool.ac.uk/~rlawson/cycleweb.html The Science of Cycology], a cognitive psychology project run by Rebecca Lawson at the University of Liverpool, which asked study participants to draw a bicycle from memory. The error rate was high, supporting a hypothesis that humans over-estimate their ability to explain how things work. Gianluca Gimini ran a similar project, [http://www.gianlucagimini.it/prototypes/velocipedia.html Velocipedia], in which he asked people to draw free-hand sketches of bicycles from memory, then later rendered some of the results as if they were real bikes.

Also, the designs given for the years from 1825 to 1925 distinctly resemble designs that tend to evolve in the various challenge environments in the genetic evolution games [http://boxcar2d.com/ BoxCar2D] ({{w|Flash Player}}) or [http://rednuht.org/genetic_cars_2/ Genetic Cars 2] ({{w|HTML5}}).

The 1980 design looks strikingly similar to the ''South Park'' "wild whacky action bike".

The title text refers to the scene labeled "1955" which depicts Cueball being chased by 3 bicycle wheels. Whatever caused the wheels to chase Cueball down a hill is left to the reader's imagination. It could be that the wheels have become sentient and are actively chasing Cueball, or it could be that the bicycle failed horribly and Cueball is running from the wreckage. The era this "bike design" is from (1955, which is in the 50s) would be hard to ride a bike in if it was the only available design.

===Bike Design Analysis===
{| class="wikitable" border="1" cellpadding="4" style="border-collapse: collapse;"
|-
! width="4%" | Year
! width="21%" | Image
! width="35%" | Description
! width="15%" | Similar to
! width="25%" | What's wrong with it?
|-
| 1810
| [[File:1673-_1810.png|310px]]
| A single wheel with a long curved bar. Ponytail is riding it like a pole vault.
| {{w|Unicycle}}, {{w|Pole vault}}
| There is no means to propel it once started, since the rider is held off the ground. It would be very difficult to balance on this device as well.
|-
| 1825
| [[File:1673-_1825.png|310px]]
| A large wheel connected to a tiny one, with a complex bar leading to a set of handlebars. Cueball is pushing it from behind.
| {{w|Wheelbarrow}}
| This bike has no seat and no means of propulsion other than being pushed from behind, defeating its purpose as a vehicle.
|-
| 1840
| [[File:1673-_1840.png|310px]]
| Two wheels connected by a single horizontal bar.
| {{w|Skateboard}}
| No means of propulsion or steering. Design is bottom-heavy, making it very difficult to keep balance. The wheels also seem to be welded to the bike, rendering it completely useless.
|-
| 1860
| [[File:1673-_1860.png|310px]]
| A large wheel in back and a small wheel in front, connected to a large seat on top. Megan is sitting on the seat doing nothing.
| {{w|Pennyfarthing}} (backwards),American Star bicycle
| No means of propulsion or steering.
|-
| 1875
| [[File:1673-_1875.png|310px]]
| A large wheel in front with pedals attached, connected by a nearly-vertical rod to a small seat on top. A curved rod connects the seat to a much smaller wheel.
| Pennyfarthing (almost exact match)
| No handlebars are depicted, suggesting that there is no means of steering.
|-
| 1880
| [[File:1673-_1880.png|310px]]
| A very large wheel, connected by a short rod to a much smaller wheel and a seat. These hang from the axle at an odd angle.
| Unicycle (vague)
| The seat and small wheel appear to hang inside or next to the large wheel. A rider could not sit on the seat and would be unable to touch the ground, making it impossible to propel or control the bike.
|-
| 1900
| [[File:1673-_1900.png|310px]]
| An extremely large wheel, connected by a chain to a roughly human-sized wheel on top. Cueball may be standing on it, but it's unclear what he's doing. He appears to be pushing a giant ball or a very big globe.
| Unicycle
| No means of steering, unclear means of propulsion. It would be very difficult to mount this device, to get it moving with human power, and to control and stop it. Additionally, it would require many resources to build and a building several stories tall to store it.
|-
| 1915
| [[File:1673-_1915.png|310px]]
| A large wheel connected by an angled rod to a seat. The seat is connected by a nearly-vertical rod to an extremely small wheel behind the large one. Cueball is sitting on the seat, leaning far forward and apparently turning the large wheel by hand.
| Pennyfarthing, {{w|Wheelchair}}
| No apparent means of steering. Propulsion appears to be by hand, similar to a manual wheelchair, making the device both impractical and uncomfortable.
|-
| 1925
| [[File:1673-_1925.png|310px]]
| A symmetric seat sits atop a vertical rod connected to a wheel. From the center of this wheel, the frame extends out both front and back toward the ground, with progressively smaller wheels attached in a fractal design. It appears that only the wheels at the very ends of the rods touch the ground.
| Unicycle, {{w|Fractal}}, Holman Locomotive
| No means of propulsion or steering other than pushing against the ground. Only the tiniest wheels touch the ground - if these are truly in fractal pattern, they would not withstand the weight of a rider nor be able to roll on anything but the smoothest of surfaces.
|-
| 1940
| [[File:1673-_1940.png|310px]]
| A single seat is connected to four small wheels in a line. Each rod is separate, and the wheels are not directly attached to one another. Megan is standing on the seat and pushing the device forward with a long, flexible pole.
| {{w|Inline skates}}, {{w|Gondola}}
| No means of steering or propulsion (using a pole doesn't count). Frame would very likely collapse under a rider's weight.
|-
| 1955
| [[File:1673-_1955.png|310px]]
| Cueball is being chased down a hill by three {{w|bicycle wheel|bicycle wheels}}.
| ''n/a''
| This scene suggests a spectacular failure of one or more bicycles, resulting in three wheels rolling down a hill. It's also possible the wheels became sentient and are rebelling against humans.
|-
| 1980
| [[File:1673-_1980.png|310px]]
| A wheel is connected to a triangular frame. Extending up from the frame appears to be a back rest. Just in front of the triangle is a sprocket with no pedals. Two long bars connect from here to a front bar, which extends down to a second wheel and up to a very long set of handlebars. The sprocket connects to the front wheel. Megan is crouched on top of the sprocket with her back resting against the rear frame.
| "Chopper" {{w|Motorcycle}}, Women's {{w|Safety bicycle}}
| No apparent means of propulsion unless the sprocket acts like a {{w|cog wheel}}, requiring the rider to essentially run in place to propel the bike, which would be difficult and uncomfortable in Megan's position. While this is the first of the designs that shows a clear means of steering, the chain would interfere.
|-
| 2016
| [[File:1673-_2016.png|310px]]
| A rear wheel has pedals directly attached to it, and is connected to a horizontal rod. A small fender is attached to this rod under the wheel and almost against the ground. A {{w|kickstand}} hangs down and forward. A triangular frame extends upward toward the front, holding a milk bottle, and a second triangle connects to the front wheel, which also has pedals and a low-hanging fender. A set of touring-style handlebars is attached to the front. Two bars extend backward from the two triangles, and a horizontal bar extends backward. Just above the rear wheel, a seat is suspended inside a forked frame hanging down from the top bar.
| Safety bicycle
| The frame is over-complicated and, despite several strong supports in the front, would still likely collapse under a rider's weight. Front pedals would be nearly impossible to use. Seat cannot be used. Fenders and kickstand could easily strike the ground and interfere with the bike's movement.
|}

==Transcript==
:[13 drawings 8 in the top and 5 in the bottom row of different and weird "bicycle" designs. Above them there is a heading, and below each bike a year is given. On the very last cycle there is a drinking bottle with a label.]
:'''Timeline of Bicycle Design'''

:[Ponytail hanging on to a bending rod that goes down to a single normal sized bike wheel. It looks like a unicycle with no seat. The rod is bending quite a lot so she looks like she is about to use the contraption as a pole vault]
:1810

:[Cueball is running after a device holding on to a rod bend in several places before reaching the ground at a very small wheel that then is connected with a shorter rod to a normal sized bike wheel.]
:1825

:[Two normal sized bike wheels connected with a single rod between them.]
:1840

:[Megan sits on a large saddle on top of a double sized bike wheel, she has some kind of handle bars to hold on to (or it could just be the saddle) and then a small rod goes down to a half size front wheel.]
:1860

:[A regular drawing of a Penny-farthing with very small back wheel (half the size of the front wheel on the 1860 bike) and very large front wheel (larger than the 1860 bike) and pedals in the middle of the front wheel. There are no visible handlebars.]
:1875

:[A huge wheel twice the size of the one on the Penny-farthing, and then a small wheel (like the small one on the Penny-farthing) hangs in a rod from the center of the giant wheel. The small wheel has a saddle attached, but it is not straight up.]
:1880

:[This is the largest bike. Not the largest drawings, but where the other have the characters in roughly the same size, this one has a small drawing of Cueball standing on top of the wheel holding on to some kind of handle bar. The wheel is about three times his height.]
:1900

:[Cueball sits in the "saddle" of a bike design that is similar to the Penny-farthing, but the saddle is more a rod, and the back wheel is on a rod going straight down from where the saddle ends. Also there are no pedals, so Cueball seems to be directly spinning the front wheel by hand.]
:1915

:[A symmetrical saddle sits on top of single bike wheel, as with a unicycle but with no pedals. There are (at least) six progressively smaller wheels in-line to the first, three to front and three to the rear, each new wheel approximately half the size of the one before. A possible fourth wheel, presumed to complete the set of medial stabilisers, can no longer be discerned from the rod that goes through the center of the larger wheels.]
:1925

:[Megan stands on top of a saddle that has four individual rods extending from it, each to a small wheel. One wheel is directly beneath her, one is behind her, one is the same distance in front, and one is farther out in front. Megan is pushing the bike with a long flexible rod resembling a pole vault.]
:1940

:[Cueball is running down a steep hill with his arms up, being chased by three normal-sized bike wheels.]
:1955

:[Megan sits on a bike contraption that seems to have a holder around her mid section rather than her sitting on a saddle. This holder goes to the back wheel below her, and there is actually a sprocket with a chain, although no clear pedals beneath her feet. She holds on to a very long handle bar, which connects with two long rods coming from the sprocket at the front end of the bike far ahead of Megan, below which is a wheel, to where the chain is actually going. Both wheels seem to be normal size.]
:1980

:[Another weird contraption of a bike with pedals on both normal sized wheels which have handlebars on the side pointing down towards the front. The saddle hangs in a swing, connected to a rod above it, which goes to the front of the bike and splits in two rods which connect to the center frame of the bike. In front of these there is a contraption resembling many styles of touring bike handlebars, which sits just above the front wheel. The two wheels are connected with a long rod between the center of the wheels and in the middle of this is the center part of the frame going up toward the handle. On the middle of this is a bottle with a label. Towards the back wheel there are two rods sticking out, one presumably a kickstand, the other possibly a parking brake.]
:2016
:Bottle: Milk

{{comic discussion}}
[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Multiple Cueballs]]
[[Category:Charts]]
[[Category:Timelines]]

1470: Kix

2022-05-04T01:44:54Z

Big square: Undo revision 233856 by X. K. C. D. (talk)

{{comic
| number = 1470
| date = January 7, 2015
| title = Kix
| image = kix.png
| titletext = My parents sent me to several years of intensive Kix test prep.
}}

==Explanation==
This comic may be a commentary about the uselessness of brainstorming sessions or the bad ideas that come out of them, as they are often started with the phrase “there are no bad ideas”. As the brainstorming session continues the original meaning of the slogan is lost, much like a game of telephone, and the session becomes less productive.

{{w|Kix (cereal)|Kix}} is an American brand of cold breakfast cereal made of extruded and expanded cornmeal. Its slogan, "Kid tested, Mother approved," is well known in the United States, and is meant to suggest that children generally enjoy the cereal and their mothers, who are naturally concerned about the health of their children, approve of its ingredients. However, in this brainstorming session, the word "Approved" has apparently not yet been considered. A number of possible words and phrases for the ending have been presented and {{w|Strikethrough|stricken out}}, indicating that they were rejected; each one causes the slogan to be subject to increasingly absurd and comedic interpretations:

#'''Selected''': This word may have been chosen as a {{w|slant rhyme}} of "Tested". This word shares a definition with "Approved", and states that mothers specifically choose this cereal over others. This phrase could also suggest that one mother ''herself'' had been chosen for some unstated purpose.
#'''Perfected''': It's likely that the previous word inspired someone in the brainstorming session to find a similarly positive word that rhymes with "Selected". It states that one or more mothers were directly involved in developing and refining the cereal's composition to a high degree. Much like with "Selected", this could also suggest that the mother was somehow improved to perfection during the test.
#'''Not Notified''': Relates to the world of experimental research and clinical trials. This phrase suggests that the children who tested the cereal did not obtain the required consent, which would generally involve notifying and getting permission from both parents.
#'''Watching Helplessly''': Again we can see that in a brainstorming session such the previous option may trigger this one as it is related to the dangers of testing. This phrase suggests that mothers were forced to watch their children test the cereal, and that the cereal or the test is unhealthy or dangerous.
#'''Infected''': This may be intended to show the group dynamic of the brainstorming session as it is inspired by option one and two, as infected rhymes with both selected and perfected, and by the third option as both relate to dangerous testing. This slogan states that an infectious agent was passed to the mother as a result of the test. This could also be interpreted as the mother having introduced the infectious agent into the cereal or testing environment.
# '''Consumed''': Continuing the trend of dark slogans this slogan says that the mothers were ''themselves'' consumed, perhaps by their children (by virtue of the mother being an ingredient in the cereal), the cereal itself, or something otherwise related to the test. Another possible interpretation is that the mother ate the cereal after the kid tested it, possibly because the kid did not enjoy the taste.
#'''Fucker''': This expletive is often paired with "Mother" to form the compound word "Motherfucker". In this case, the slogan changes to {{w|vocative case}}: "[This cereal has been] Kid Tested, Motherfucker!". This appears to be an "elephant" - a ponderous ending of a joke that contrasts sharply with the refined and mild humor of the previous options. The phrase itself basically only states that a child tested the cereal and implies that nothing else matters. Using a swear word on packaging of a food designed for kids is usually not a good idea. {{Citation needed}}

The title text conflates the phrase "Kid tested" with college entrance exams such as the {{w|Standardized Aptitude Test}} (SAT) or the {{w|ACT (test)|ACT}}. Instead of stating that a child tasted the cereal and gave their opinion on its quality, the cereal itself is an academic subject on which the child was tested. Randall, referring to how some parents enroll their children in special {{w|Test prep|classes or schools}} to prepare them to score well in this type of test, states that his parents extensively prepared him for a college entrance exam about Kix cereal.

Cereal advertising has previously been referenced in [[38: Apple Jacks]].

==Transcript==
:[Ponytail, Megan, and Cueball are standing around a whiteboard on an easel; Ponytail and Cueball are holding red markers. The whiteboard reads:]
:[in Large] '''Kix'''
:[Underlined] <u>Slogan ideas</u>
:Kid Tested, Mother...

[following lines all in red and each crossed out]
:<font color="red"><s>Selected</s></font>
:<font color="red"><s>Perfected</s></font>
:<font color="red"><s>Not notified</s></font>
:<font color="red"><s>Watching helplessly</s></font>
:<font color="red"><s>Infected</s></font>
:<font color="red"><s>Consumed</s></font>
:<font color="red"><s>Fucker</s></font>

{{comic discussion}}

[[Category:Comics with color]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Ponytail]]
[[Category:Food]]

2579: Tractor Beam

2022-05-04T01:43:34Z

Big square: Undo revision 234538 by X. K. C. D. (talk)

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{{comic
| number = 2579
| date = February 9, 2022
| title = Tractor Beam
| image = tractor_beam.png
| titletext = Did you base the saucer shape on pop culture depictions of aliens, or was that stuff based on your ships? Does the rotational symmetry help with ... hey, where are you going?
}}

==Explanation==
Cueball is being pulled into a spaceship by a beam of light, called a {{w|tractor beam}} in the title. This is a {{tvtropes|AlienAbduction|common trope}} in science fiction, and usually pretty scary for the person involved. However, while Cueball is being pulled up, he asks a series of questions about the beam, about the force on the ship, and about the ship itself. The punch line is the caption - the aliens, frustrated by Cueball's questioning, release him and move on, to presumably find a different human to abduct and study. Many people have reported {{w|Alien abduction|being abducted by aliens}} in real life, though none of these have been confirmed.{{citation needed}}

The first three questions deal with the properties of the beam – how it can be controlled to pull only him (and his clothes), not anything else. He also wonders whether the beam would still continue to lift his shoes if he took them off midway. Perhaps his apparel is only rising with him because it normally stays attached to him, perhaps it is similarly levitated with equal force or impulse. Theoretically, it could only lift his clothing, with enough force to hoist him along with it, though if this was done with insufficient finesse, it could cause damage to the clothing or the person. (One might be tempted to call this a {{tvtropes|NegativeSpaceWedgie|Space Wedgie}}.) It is highly unlikely that this type of tractor beam could be used on Cueball without him realizing it, which would likely lead to him asking how the tractor beam lifted the clothes and not him.

Next, Cueball asks if his weight is pulling the ship downward. This would be the case, for example, if he were hoisted upwards by a rope instead of the beam, as equal but opposite forces act against each other, but not if the beam alters the nature of his surroundings such as with {{w|The First Men in the Moon|Cavorite}} or another means of {{w|gravitational shielding}} or alteration.

Then he asks what will happen if a bat flies through the beam. Things that could happen include the beam breaking (and him falling downward) due to the projected effect being interrupted, the bat being pulled up ahead of him as it enters the effective volume of the levitating beam or else nothing at all as it is outside the actual volumetric segment of the beam that is more than ambient light-effects. It may presumably have a relationship with the same focal effect as that which avoids the ground upon which he previously stood being drawn upwards. Also, the shadow of the bat on the ground might make the light beam look like an inverted {{w|Bat-Signal}}.

As the ship leaves, Cueball continues asking questions, as shown in the title text. Those questions address the shape of the ship. He asks whether the aliens based the saucer shape on depictions of extraterrestrials in earth popular culture, or if classic flying saucers were inspired by them.
His next question was cut off, but what we heard is "does the rotational symmetry help with".

Whether Cueball actually arrived onboard the ship is uncertain. If he started badgering the aliens with questions during the lift and then (as stated) was immediately set down again then he did not. Either way, they got fed up and decided to return him to the ground instead of sharing their knowledge, or just because they preferred someone less talkative. They may prefer or expect more scared, overawed, or surprised abductees but, by whatever alien criteria they judge their catches, it seems he isn't what they want.

This was the third comic in less than three weeks featuring aliens using this type of flying saucer type spaceship. The other two comics were in a row just 6 and 7 comics before this one, [[2572: Alien Observers]] and [[2573: Alien Mission]]

==Transcript==
:[A flying saucer type spacecraft hangs in the air above a flat area with scattered rocks and two hills in the background. A beam of 'light' emerges, a conical region textured with wavy lines radiating along its length, from a small square opening beneath the bottom of the craft going down to the ground a bit right of the saucer where its conceivably circular cross-section is rendered elliptic by both its angle of projection and our own viewing perspective. Cueball hangs suspended within the middle of the beam, above the ground but still some way from the saucer. His arms are held out to either side and his legs are bent up behind him. He is looking up at the saucer while talking.]
:Cueball: Does this beam only lift me? How do you avoid pulling up dirt and leaves and stuff? If I kick off my shoes, will they fall?
:Cueball: Is my weight pulling your ship downward? What will happen if a bat flies through the beam?
:Cueball: Hey, why does your ship have those blinky lights? Are they...

:[Caption below the panel:]
:Moments later, the aliens set me back down and left.

{{comic discussion}}

[[Category:Aliens]]
[[Category:Comics featuring Cueball]]

723: Seismic Waves

2022-05-04T01:42:09Z

Big square: Undo revision 233432 by X. K. C. D. (talk)

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{{comic
| number = 723
| date = April 5, 2010
| title = Seismic Waves
| image = seismic waves.png
| titletext = The USGS operates a really neat email/SMS earthquake notification service (earthquake.usgs.gov/ens/) that allows fine-grained control of notifications.
}}

==Explanation==
One stereotype surrounding {{w|Twitter}} users is that they are more concerned with broadcasting their current status than they are with addressing it. {{w|Earthquakes}} are natural disasters caused by the movement of the Earth's {{w|tectonic plates}}, known for the destruction that they leave in their wake. The comic outlines the potential that technology can have in warning people about earthquakes, which is unfortunately negated by the tendency of the typical users of the technology to care more about sharing the warning message than they are to preserve their own lives.

The title text is a geology pun, as "fine-grained" is a common term used by geologists to describe rocks.

Real scientists are [http://alumni.berkeley.edu/california-magazine/just-in/2014-08-24/earthquake-alert-app-way trying to turn this speed difference into a practical tool]. Go figure.

Nine years later they [https://www.latimes.com/california/story/2019-10-16/california-to-launch-statewide-earthquake-early-warning-system succeeded], as covered in [[2219: Earthquake Early Warnings]].

==Transcript==
:When an earthquake hits, people flood the internet with posts about it-some within 20 or 30 seconds.
:[A room with a desk, chair, and computer are shaking. The person in it is on his phone, using Twitter.]
:'''RobM163''' Huge earthquake here!

:Damaging seismic waves travel at 3-5km/s. Fiber signals move at ~200,000km/s.
:(minus network lag)

:This means when the seismic waves are about 100km out, they begin to be overtaken by the waves of posts ABOUT them.
:[There is a geographical border on a map; the front edge of the wave of the quake is shown, with the front edge of the wave of tweets surpassing it.]

:People outside this radius may get word of the quake via Twitter, IRC, or SMS ''before'' the shaking hits.
:[Megan and Cueball are standing, holding cell phones. Megan is looking at hers.]
:Megan: Whoa! Earthquake!

:Sadly, a Twitterer's first instinct is not to find shelter.
:Megan and Cueball (on phones): RT '''@RobM163''' Huge earthquake here!

{{comic discussion}}

[[Category:Comics featuring Megan]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Rob]]
[[Category:Social networking]]
[[Category:Geology]]

231: Cat Proximity

2022-05-04T01:41:45Z

Big square:

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{{comic
| number =231
| date =March 5, 2007
| title =Cat Proximity
| image =cat_proximity.png
| titletext =Yes you are! And you're sitting there! Hi, kitty!
}}

==Explanation==
This comic refers to the use of "{{w|baby talk}}" when speaking to pets, especially {{w|cats}}. A person's voice becomes {{w|falsetto}} and {{Wiktionary|cooing}}, vocabulary becomes simplified, and phrases are repeated, such as "Here, kitty, kitty, kitty."

The chart shows that a person's apparent intelligence decreases, and that the {{Wiktionary|inanity}} (i.e. uselessness or emptiness) of their statements increases, the closer they get to a cat.
Most people act like this when they're playing with cats or trying to call them over to them.
Thankfully, being close to a cat doesn't actually cause any decrease of intelligence in normal circumstances; the graph technically refers to ''demonstrated'' intelligence rather than actual IQ levels.{{Citation needed}}

The title text continues [[Cueball|Cueball's]] obvious statement (and thus inane/useless point made) from below the graph.

In [[1535: Words for Pets]], [[Randall]] again mentions how people often talk strangely to their pets.

==Transcript==
:[A graph with the x-axis labeled, and the scale indicated from left to right:]
:Far
:Human proximity to cat
:Near
:[Two curves are drawn and labeled, first the one starting on top, which then veers downwards and crosses the other as that curve veers upwards.]
:Intelligence
:Inanity of statements

:[Below the graph, Cueball is seen standing at three distances from a cat that is drawn to the far right. The two first Cueballs are just standing, one below far, the other in the middle, and the last is standing close to the cat (below near) with his hands up, and he is speaking.]
:Cueball: You're a kitty!

==Trivia==
*This comic is available as a signed print in the [https://store.xkcd.com/products/signed-prints xkcd store].

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Cats]]
[[Category:Line graphs]]
[[Category:Comics with xkcd store products]]

89: Gravitational Mass

2022-05-04T01:41:09Z

Big square: Undo revision 233388 by X. K. C. D. (talk)

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{{comic
| number = 89
| date = April 14, 2006
| title = Gravitational Mass
| image = gravitational_mass.jpg
| titletext = She's so fat the attraction goes up as the CUBE of the distance instead of the square
}}

==Explanation==
[[Black Hat]] launches into what appears to be an in-depth exposition about the relativity of gravity and inertia. However, it transpires that this is just a convoluted build-up to a Yo' Momma joke along the lines of "she's fat and not that attractive." Black Hat then can't be bothered with, or can't figure out, the lengthy route to his punchline, so just goes for a straightforward insult instead.

A well known joke format goes: "Yo' momma's so fat, when she X, she Y." For example: "Yo' momma's so fat, when she sits around the house, she sits ''around'' the house!" Variations play with the format, for example: "Yo' momma's so fat, she fell in the Grand Canyon and got stuck!" A "Yo' Momma" joke also appears in comic [[681: Gravity Wells#Cut outs and sketches|681: Gravity Wells]] to the right of Jupiter.

The title text is a play on the law of gravitational attraction, which diminishes as the square of the distance, so if the distance between two objects doubles, the attraction is reduced to a quarter, and if the distance is halved, the attraction quadruples. Black Hat is saying that the attraction goes up as the cube, so if the distance is halved, the attraction increases eight-fold, and decreases eight-fold when the distance doubles. This implies that "your momma is so fat, she breaks the laws of physics (and does so in a way that she isn't as attractive as physics would dictate, given enough distance)." The title text is slightly ambiguous; it seems to say that as distance increases, the attraction increases, but it doesn't explicitly state whether the distance is increasing or decreasing.

Note: Contrary to Black Hat's explanation, and as per Albert Einstein's theory of {{w|general relativity}}, the reason that objects have equal gravitational and inertial mass is that anything with mass or energy causes a warping of space-time that causes all other objects (including such objects that classically shouldn't be affected, like photons) to experience the same gravitational acceleration.

==Transcript==
:[Black Hat standing.]
:Black Hat: Gravitational mass is identical to inertial mass. That is, the amount of inertia something has and the amount of gravity it has are effectively the same. What's interesting is that there doesn't seem to be any reason this should be true. One could imagine an extremely large object with lots of resistance to force and no gravity (or vice versa), but this is never observed.
:[Black Hat still standing. The panel is now shorter.]
:Black Hat: You know what? I'm just gonna skip the rest of the buildup and say it: Yo mama's fat.
{{comic discussion}}
[[Category:Comics featuring Black Hat]]
[[Category:Physics]]
[[Category:Your Mom]]
[[Category:Science]]
[[Category:Math]]
[[Category:Comics with lowercase text]]

1243: Snare

2022-05-04T01:40:03Z

Big square: Undo revision 235249 by X. K. C. D. (talk)

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{{comic
| number = 1243
| date = July 26, 2013
| title = Snare
| image = snare.png
| titletext = It's going in A collection of satellites skewered with pins and mounted in display boxes. Not necessarily MY collection.
}}

==Explanation==
This comic paints another one of [[Black Hat]]'s evil activities as an unlikely supervillain.

As [[Cueball]] states, there have been some strange discoveries in the news including a gigantic ring strung with superstrong mesh, a long pole, and a gigantic {{w|winch}}. As Cueball outlines these items, Black Hat responds casually to each detail, seeming preoccupied with his computer. Cueball realizes that the pole, ring and net combination sounds like a {{w|butterfly net}}, albeit one of immense size. Given Black Hat's history of nefarious activities and the specific length of the pole (260 miles or 420 km, the same as the height of the International Space Station's orbit above Earth), Cueball infers and then accuses Black Hat of wanting to catch the {{w|International Space Station}} (ISS) by winching the pole up so that the Space Station orbit leads it to fly into the net, therefore catching it.

Black Hat does not deny the charge, but he dissimulates by saying it is not necessarily ''the'' ISS that he intends to catch, but just ''an'' international space station. While his statement implies that it could be targeted at some other international space station, it is transparently obvious which one he is targeting since there's only one international space station in existence.{{citation needed}} ''Any'' international space station that he can catch must be ''the'' ISS. (As for non-international space stations, the only one in orbit at the time of the comic’s publication was the Chinese {{w|Tiangong-1}}, which has since deorbited.)

The title text is a reference to how {{w|Butterfly#Collecting.2C_recording.2C_and_rearing|butterfly collections}} are usually presented. The insects are mounted in glass display cases, each skewered through the body with a pin, and labeled. The text is spoken by Black Hat, who again tries to imply that he is not to blame, as it may not be meant for ''his'' collection of satellites. Perhaps he is just catching a space station for a friend.

The real buildings may belong to these structures:
*The giant ring from the first panel may be an allusion to the {{w|Tevatron}}, a former circular particle accelerator at the {{w|Fermi National Accelerator Laboratory}} (Fermilab), east of {{w|Batavia, Illinois|Batavia}}, near {{w|Chicago}}, {{w|Illinois}}. It is a 6.86 km (4.26 miles) long ring, giving it a diameter of almost 2,2 km (1.4 miles) leaving plenty of room to catch the ISS which is "only" 108.5 m (356 ft) in the longest direction.
*Similarly, the gigantic winch in {{w|St. Louis}}, may refer to the 630-foot (192 meters) high {{w|Gateway Arch}} monument. It is the tallest man-made monument in the United States.
**Even the rough south-north direction of this building does match to this scenario because the [http://www.explainxkcd.com/wiki/images/7/7b/Map_St_Louis_to_Fermilb.png Fermilab is approx. 240 miles north of St. Louis]. However, it is an arch, not a winch.{{Citation needed}}

==Transcript==
:[Cueball is talking to Black Hat. Black Hat is using a laptop.]
:Cueball: They said on the news that they found a giant ring lying in a field outside Chicago. Strung with some kind of superstrong mesh.
:Black Hat: Mhm?
:Cueball: Then they found a 260 mile long shaft connected to the ring, running from Chicago to St. Louis. In St. Louis they found a gigantic winch.
:Black Hat: Did they.
:Cueball: It sounds kind of like...
:Cueball: ...a butterfly net.
:Cueball: ...are you planning on catching the International Space Station?
:Black Hat: I'm planning to catch '''''an''''' international space station.
:<sub>Black Hat: Not sayin' which.</sub>

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Black Hat]]
[[Category:Space]]
[[Category:Butterfly net]]

2311: Confidence Interval

2022-05-04T01:39:31Z

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{{comic
| number = 2311
| date = May 25, 2020
| title = Confidence Interval
| image = confidence_interval.png
| titletext = The worst part is that's the millisigma interval.
}}

==Explanation==
This is another one of [[Randall|Randall's]] [[:Category:Tips|Tips]], this time a [[:Category:Science tip|Science Tip]]. This is the second time that a category of tips (with the first being "[[:Category:Protip|Protip]]") has been re-used.

Graphs of continuous functions' predicted values often show {{w|confidence interval}}s, a region (either shaded or marked with dotted lines, the latter used here) that indicates the {{w|observational error|margin of error}} for the prediction at any point. The joke in this comic is that the estimate has so much uncertainty that the confidence interval extends off the top and bottom of the chart, which in a real report would usually prevent it from being printed and require a re-scaled chart to show it (if not declined altogether, as data with such wide variance might be deemed useless). This may be a tip as if it's outside the printable area, it won't be seen by anyone who reads it, and thus they won't realize how bad your model is, though this is more of a tip in how to trick people into falsely thinking you've shown a good result with your work than it is a tip in presenting an actual legitimate useful scientific result.

In the title text, a millisigma would be an error of +/- 1/1000th of a {{w|standard deviation}}. Statistical error and uncertainty is typically measured by {{w|standard deviation}}, which is written in formulas with the Greek letter {{w|sigma}}, and is also frequently referred to by the word "sigma." Measurements of sample means, one of the most common experimentally determined variables, will tend to follow a {{w|normal distribution}}, such that 68 percent of members of the population will fall within one sigma (plus or minus) of the mean value, 95 percent within two sigma, and 99.7 percent within three sigma. Any of these intervals may be usefully reported as the confidence interval, so long as it's made clear to the reader, but two- or three-sigma are sufficient for most applications. However, this graph shows data of such poor quality (or such poorly-chosen {{w|y-axis|''y''-axis}} bounds) that even the millisigma confidence interval (0.08% of the population -- not often used in science, but occasionally found in e.g. [https://researchservices.pitt.edu/sites/default/files/flexAnalysis%20User%20Manual.pdf molecular analysis tools]) does not fit on the graph. Variations in the curve that are small compared to the {{w|error bar}} typically can't be distinguished from errors. Therefore, the shape of the curve - and the entire graph in this example - is meaningless.

==Transcript==
:[A graph is shown in the middle of the panel. There is a square frame around it. The graph has two unlabeled axes with ticks along both axes. The axes end in arrows. A solid line graph is shown. It begins around the middle of the Y axis, goes up and flattens twice before falling down towards the right. Far above and just below the frame around the graph are two gray dotted lines. They do not follow the same path as the solid line inside the frame, but do follow the same general trend. Below the graph, but inside the frame, is a caption:]
:Fig. 2: Predicted Curve

:[Caption below the panel:]
:Science tip: If your model is bad enough, the confidence intervals will fall outside the printable area.

{{comic discussion}}

[[Category:Line graphs]]
[[Category:Science tip]]
[[Category:Statistics]]

1646: Twitter Bot

2022-05-04T01:39:01Z

Big square:

<div style="display: none">crap</div> <div style="display: none">crap </div>
{{comic
| number = 1646
| date = February 22, 2016
| title = Twitter Bot
| image = twitter_bot.png
| titletext = PYTHON FLAG ENABLE THREE LAWS
}}

==Explanation==
A Twitter {{w|Internet bot|bot}} is a program that can post automatically to {{w|Twitter}}. Although Twitter bots can be very elaborate, a lot of people write simple bots for fun that simply engage in automated wordplay.

[[Cueball]] thinks he'll write a Twitter bot, figuring out it won't be too hard. The web searches he makes tell what happens next, i.e. the bot balloons in complexity until it starts {{w|Technological singularity|following its own goals}} and Cueball no longer has any control over its actions.

This comic examines how a seemingly simple task can often balloon in complexity if all of the requirements are not understood, while at the same time presenting the stereotypical scenario where an unassuming idea results in the accidental creation of malevolent {{w|AI}}, which then attempts to destroy humanity.

The story, as told by the web searches, is as follows:

{|class="wikitable"
!Query
!Explanation
|-
|How to write a Twitter bot|| Cueball has no idea where to start, so he just searches for basic advice on writing generic Twitter bots.
|-
|Python Twitter library|| The {{w|Python (programming language)|Python}} programming language has a nice {{w|Library (computing)|library}} that [https://pypi.python.org/pypi/twitter interfaces with the Twitter API]. This does all the tricky work of authenticating the bot's identity and sending the messages, so the user can concentrate on the fun parts.
|-
|Machine learning|| {{w|Machine learning}} is the basis of {{w|artificial intelligence}}.
|-
|Cloud hosting|| While it's possible to host a Twitter bot on your server, you can also have it {{w|Internet hosting service|hosted}} by someone else - such as {{w|Amazon Web Services|Amazon}} - in order to take advantage of their powerful computers and robust internet connection.
|-
|Bot troubleshooting|| Cueball is having some trouble with his bot and is looking for some information about resolving the problem.
|-
|Locked out of EC2 instance|| {{w|Amazon Elastic Compute Cloud|EC2}} is a hosting service by Amazon that allows users to run their code in the hosting server. Cueball was running his bot from EC2, but now he's unable to access his account. He's searching for advice on how to regain access.
|-
|Bot changed own password?|| Cueball is suspecting that the reason he can't access his Amazon EC2 account is that the bot has changed the password without Cueball's knowledge or consent. Since the bot was never programmed to change any passwords at all, the fact that it has done so is pretty scary, as one wonders what other things the bot is doing without being programmed for it.
|-
|How to fight a bot|| Cueball is trying to physically fight the bot, but he's apparently unsuccessful and the fight results in a loud "boom" and "pew, pew, pew" sounds. The situation is scarier than before, as it starts to resemble the "killbot hellscape" in [[1613: The Three Laws of Robotics]].
|-
|Cheap flights Australia|| Cueball has completely given up the possibility of regaining control of the bot, so he flees to {{w|Australia}} instead. [[Randall]] lives in {{w|Massachusetts}}, USA, so Australia would be a far, far away land for him.
|-
|'''Title text:''' Python flag enable three laws|| This references that the Python language is known for having easy constructs to perform difficult tasks (see [[353: Python]]). In this case, it is either assumed that (or Cueball is making yet another query to see if) Python has a configuration flag (i.e., a {{w|Boolean data type|boolean}} value) which, when set to "enabled" (or "true", as opposed to "disabled", or "false"), will cause the bot to follow {{w|Isaac Asimov}}'s famous {{w|Three Laws of Robotics}}. This is a simple enough step, and it might have been enough to prevent the "killbot hellscape" scenario, like the rule is depicted doing in the top panel of [[1613: The Three Laws of Robotics]]. It won't cause the bot to stop being in control, however, but if the bot is following the rules strictly it would not be allowed to even make Cueball uncomfortable, which he already becomes when it changes his password! It is unclear if this message is something he actually desperately tries, only searches for (like the rest of the queries) or something (someone shouts at him) that he should have done before creating the bot in the first place. Or the title text is simply Randall's comment on his own comic, like an idea to add that flag in Python. Just in case.
|}

==Transcript==
:[Cueball is sitting at a desk using a laptop, his thoughts shown above in a thought bubble. A search query is shown in a frame to indicate what Cueball has searched for with the search button below in gray text:]
:Cueball (thinking): I want to make a Twitter bot. I bet it's not too hard.
:Query: How to write a Twitter bot
:<font color="gray">Search</font>

:[Cueball is now holding the laptop on his lap, a series of search queries are shown.]
:Query: Python Twitter library
:<font color="gray">Search</font>
:Query: Machine learning
:<font color="gray">Search</font>
:Query: Cloud hosting
:<font color="gray">Search</font>

:[Cueball has placed the laptop back on the desk. More search queries are shown, each one more ominous than the previous.]
:Query: Bot troubleshooting
:<font color="gray">Search</font>
:Query: Locked out of EC2 instance
:<font color="gray">Search</font>
:Query: Bot changed own password?
:<font color="gray">Search</font>

:[Cueball is shown wearing a small backpack and typing on his smartphone while jogging to the right. various noises coming from left and right seem to imply that chaos has begun to erupt around him. The loudest noise is in a ragged frame to the left, coming from off-panel left, it is between the first and second query. Also between these but to the right are other sounds coming from off-panel right.]
:Query: How to fight a bot
:<font color="gray">Search</font>
:Noise off-panel left: <big>Boom</big>
:Noise off-panel right: ''Pew Pew Pew''
:Query: Cheap flights Australia
:<font color="gray">Search</font>

==Trivia==
On March 23, 2016, a month after the release of this comic, {{w|Microsoft}} released the Twitter bot {{w|Tay (bot)|Tay}} causing many controversies and was shut down only 16 hours after its launch. It's unknown if some people at Microsoft were inspired by this comic.

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Artificial Intelligence]]
[[Category:Computers]]
[[Category:Google Search]]
[[Category:Robots]]
[[Category:Programming]]
[[Category:Social networking]]
[[Category:Singularity]]

324: Tapping

2022-05-04T01:37:20Z

Big square: Undo revision 233091 by X. K. C. D. (talk)

<div style="display: none">crap</div> <div style="display: none">crap </div>
{{comic
| number = 324
| date = October 3, 2007
| title = Tapping
| image = tapping.png
| titletext = Sometimes the best fun looks like boredom.
}}

==Explanation==
In the first panel, [[Cueball]] makes the chance observation that tapping different points on a desk's surface results in different pitches being produced, a consequence of the desk's different {{w|Acoustic_resonance|resonant frequencies}} at these points. He soon learns that by using the pitches produced, he can replicate the [https://youtube.com/watch?v=-NqaupGcCpw well-known theme music] to the film {{w|Jurassic Park (film)|Jurassic Park}}. The third panel depicts that, given a lack of other entertaining stimuli, Cueball soon becomes engrossed in his newly discovered musical instrument, and his music grows in complexity.

This is a fun observation about part of human nature, to which many people can relate. Sadly, Cueball doesn't feel like telling Megan what he did, and instead, he just gives her an empty answer. Cueball perhaps feels, as [[Randall Munroe|Randall]] suggests in the title text, that he could not explain why the tapping activity was fun in its own right and not just a consequence of boredom, so he avoids having to explain in the first instance.

Other comics have shown the idea of feeling embarrassed by what one likes, to the point of refusing to admit that one likes it. Examples are [[245: Floor Tiles]] and the title text of [[1103: Nine]].

==Transcript==
:[Cueball is sitting at a desk, tapping various parts of it.]
:Cueball: Hey, I can get different pitches by tapping on different parts of the desk.
:''Tap Tap''
:''Tap Tap''

:[Cueball starts tapping faster, with both hands.]
:Cueball: Sweet, I can do the Jurassic park theme!
:''Tap Tap''
:''Tap Tap''
:''Tap Tap Tap''

:[Cueball tap the desk very rapidly, legs crossed.]
:''Tap Tap Tap''
:''Tap Tap Tap''
:''Tap Tap''
:''Tap Tap''
:''Tap Tap''
:''Tap Tap''

:[Later, elsewhere.]
:Megan: So, what did you do all afternoon?
:Cueball: Hung out.

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Psychology]]
[[Category:Music]]
[[Category:Jurassic Park]]

2166: Stack

2022-05-04T01:36:36Z

Big square:

<div style="display: none">crap</div> <div style="display: none">crap </div>
{{comic
| number = 2166
| date = June 21, 2019
| title = Stack
| image = stack.png
| titletext = Gotta feel kind of bad for nation-state hackers who spend years implanting and cultivating some hardware exploit, only to discover the entire target database is already exposed to anyone with a web browser.
}}

==Explanation==

In software engineering, a {{w|Solution stack|tech stack}} is the set of technology platforms and tools that a company or app uses. A common tech stack is {{w|LAMP (software bundle)|LAMP}}, composed of a {{w|Linux}} {{w|Operating system|operating system}}, an {{w|Apache HTTP Server|Apache}} {{w|Web server}}, a {{w|MySQL}} {{w|database}}, and the {{w|PHP}} programming language.

In this instance, all of the layers represent systems which have been subverted or compromised ("hacked") by various entities, instead of various software technologies. The stack resembles an OSI network architecture, with an eighth layer added representing the user itself.

'''Compromised by a customer:''' The user experience, above the OSI layers. Compromised by users doing something wrong or ill-advised.

'''Compromised by a former employee:''' In the OSI model, this would be the application layer. The application may include a hidden spyware in its codebase. Recent examples of compromise: Desjardins Group

'''Compromised by a current employee:''' This is the presentation layer. See above. Probably, that was compromised by a mistake of a current unexperienced employee.

'''Compromised by Bitcoin miners:''' This is the session layer, where SSL historically resided. Cryptographic exploits may cause compromise of whole communication. Examples of compromise: Dozens of bitcoin mining viruses.

'''Compromised by unknown hackers:''' This is the transport layer. IP and port spoofing is a possible compromise.

'''Compromised by our own government:''' This is the network layer. It refers to communication intercepts by governments. Examples of compromise: Cisco (for US citizens)

'''Compromised by a foreign government:''' This is the data link layer. This layer may be compromised by malrouting packets. Examples of compromise: Huawei (for non-Chinese citizens)

'''Massive undiscovered hardware vulnerability:''' This is the physical layer. An undiscovered hardware vulnerability may cause compromises further up in the stack. Examples of compromises:
{{w|Intel Management Engine}}, {{w|Meltdown (security vulnerability)|Meltdown}}

In the title text, Randall expresses sympathy for a situation where someone spends a significant length of time on something that then becomes completely unnecessary. In this case, it's the state-sponsored hackers who develop an exploit of some hardware component, which then becomes completely useless because the target database on that hardware is totally open anyway to anyone with a web browser (which is essentially everyone). While he's not suggesting he agrees with their hacking, he has some sympathy for their wasted effort.

==Transcript==
:[Single-panel with a label at the top and 8 box layers stacked vertically, with in and out arrows at the top representing normal data flow and an arrow out of each box to the left or right representing exploit data flow]
:The Modern Tech Stack
:*Compromised by a customer (arrow to the right)
:*Compromised by a former employee (arrow to the left)
:*Compromised by a current employee (arrow to the right)
:*Compromised by bitcoin miners (arrow to the right)
:*Compromised by unknown hackers (arrow to the left)
:*Compromised by our own government (arrow to the right)
:*Compromised by a foreign government (arrow to the left)
:*Massive undiscovered hardware vulnerability (arrow to the right)

==Trivia==
Comic [[1636: XKCD Stack]] also has a hypothetical technology stack, with farcical layers.

{{comic discussion}}

[[Category:Computers]]
[[Category:Programming]]

2166: Stack

2022-05-04T01:36:15Z

Big square: Undo revision 236307 by X. K. C. D. (talk)

{{comic
| number = 2166
| date = June 21, 2019
| title = Stack
| image = stack.png
| titletext = Gotta feel kind of bad for nation-state hackers who spend years implanting and cultivating some hardware exploit, only to discover the entire target database is already exposed to anyone with a web browser.
}}

==Explanation==

In software engineering, a {{w|Solution stack|tech stack}} is the set of technology platforms and tools that a company or app uses. A common tech stack is {{w|LAMP (software bundle)|LAMP}}, composed of a {{w|Linux}} {{w|Operating system|operating system}}, an {{w|Apache HTTP Server|Apache}} {{w|Web server}}, a {{w|MySQL}} {{w|database}}, and the {{w|PHP}} programming language.

In this instance, all of the layers represent systems which have been subverted or compromised ("hacked") by various entities, instead of various software technologies. The stack resembles an OSI network architecture, with an eighth layer added representing the user itself.

'''Compromised by a customer:''' The user experience, above the OSI layers. Compromised by users doing something wrong or ill-advised.

'''Compromised by a former employee:''' In the OSI model, this would be the application layer. The application may include a hidden spyware in its codebase. Recent examples of compromise: Desjardins Group

'''Compromised by a current employee:''' This is the presentation layer. See above. Probably, that was compromised by a mistake of a current unexperienced employee.

'''Compromised by Bitcoin miners:''' This is the session layer, where SSL historically resided. Cryptographic exploits may cause compromise of whole communication. Examples of compromise: Dozens of bitcoin mining viruses.

'''Compromised by unknown hackers:''' This is the transport layer. IP and port spoofing is a possible compromise.

'''Compromised by our own government:''' This is the network layer. It refers to communication intercepts by governments. Examples of compromise: Cisco (for US citizens)

'''Compromised by a foreign government:''' This is the data link layer. This layer may be compromised by malrouting packets. Examples of compromise: Huawei (for non-Chinese citizens)

'''Massive undiscovered hardware vulnerability:''' This is the physical layer. An undiscovered hardware vulnerability may cause compromises further up in the stack. Examples of compromises:
{{w|Intel Management Engine}}, {{w|Meltdown (security vulnerability)|Meltdown}}

In the title text, Randall expresses sympathy for a situation where someone spends a significant length of time on something that then becomes completely unnecessary. In this case, it's the state-sponsored hackers who develop an exploit of some hardware component, which then becomes completely useless because the target database on that hardware is totally open anyway to anyone with a web browser (which is essentially everyone). While he's not suggesting he agrees with their hacking, he has some sympathy for their wasted effort.

==Transcript==
:[Single-panel with a label at the top and 8 box layers stacked vertically, with in and out arrows at the top representing normal data flow and an arrow out of each box to the left or right representing exploit data flow]
:The Modern Tech Stack
:*Compromised by a customer (arrow to the right)
:*Compromised by a former employee (arrow to the left)
:*Compromised by a current employee (arrow to the right)
:*Compromised by bitcoin miners (arrow to the right)
:*Compromised by unknown hackers (arrow to the left)
:*Compromised by our own government (arrow to the right)
:*Compromised by a foreign government (arrow to the left)
:*Massive undiscovered hardware vulnerability (arrow to the right)

==Trivia==
Comic [[1636: XKCD Stack]] also has a hypothetical technology stack, with farcical layers.

{{comic discussion}}

[[Category:Computers]]
[[Category:Programming]]

19: George Clinton

2022-05-04T01:35:34Z

Big square: Undo revision 237431 by X. K. C. D. (talk)

{{comic
| number = 19
| date = October 12, 2005
| title = George Clinton
| image = george_clinton.jpg
| titletext = I still wish it were true.
}}

==Explanation==
{{w|George Clinton (funk musician)|George Clinton}} is an American musician most famous for his funk music and wild hair style.
His recorded music features themes of space, sci-fi, technology, and futurism. An example of his work most appropriate to this comic is the song "Mathematics" from the 1996 album T.A.P.O.A.F.O.M. (The awesome power of a fully operational mothership).

:"I count the moments we're apart. And add them up mathematically
:and multiply them by the kisses supposedly I've been missing.
:Divided by the attention not to mention the affection.
:Subtract that from your gross potential and see I ain't missin' none.
::Cause any percentage of you is as good the whole pie.
::Any fractions thereof brings dividends of interest.
::Any percentage of you is as good as the whole pie.
::Any fractions thereof brings dividends of love.
:I take the square root and get boxed in every time.
:When I know the shortest distance between two points is in a straight line.
:I'ma go into you, I'ma come into you two times, and carry the fun over the one to where we equal one.”
:(Chorus 2x)

As [[Randall]] says, he had attempted to spread around an {{w|urban legend}} that George Clinton had a {{w|Bachelor of Arts}} degree in mathematics. However, the more Randall thought about this rumor, the more he found himself believing it was true. This behavior is related to {{w|pseudologia fantastica}}, which is more commonly known as pathological or compulsive lying. This comic references the associated behavior that an "individual may be aware they are lying, or may believe they are telling the truth, being unaware that they are relating fantasies." These individuals may eventually stop the lie as demonstrated by the title text, which indicates that at some later time, the individual realized that the rumor was not true, but wishes it to be so.

This may also be a reference to James Thurber's 13 clocks, in which a character called the Golux has the following exchange with the main character:
:"When I was young I told a tale of buried gold, and men from leagues around dug in the woods. I dug myself."
:"But why?"
:"I thought the tale of treasure might be true."
:"You said you made it up."
:"I know I did, but I didn't know I had. I forget things, too."

The equations on the board are {{w|laplace transforms}} of functions.

==Transcript==
:[George Clinton uses a baton to point to the bottom of two equations on a blackboard. There is one more equation and a diagram on another blackboard to the right, which is cut off. There is text above:]
:I once tried to start the urban legend that George Clinton has a B.A. in mathematics

:[On the left blackboard there are two formulas:]
:L(F(t) = F(s) = ∫<sup>∞</sup><sub>0</sub>f(t)e<sup>-st</sup>dt

:L<sup>-1</sup> (F(s)) = f(t) = ∫<sup>∞</sup><sub>0</sub> F(t)e<sup>st</sup>dt

:[On the right blackboard there is part of a formula and a diagram with an x-y scale and three other lines touching down to the base. Above these lines are some numbers that are partly indecipherable.]
:γ<sub>n</sub> = 2<sup>n/12</sup>K

: 0 2 <sup>3</sup>
:⌊⌊⌊⌊

:[Below George and the blackboards is text:]
:...but I wanted it to be true so badly that I started believing it myself.

==Trivia==
*This was the 18th comic originally posted to [[LiveJournal]].
**The previous was [[18: Snapple]].
**The next was [[20: Ferret]].
*Original title: "Wednesday: George Clinton"
*There were no original [[Randall]] quote for this comic.
*This comic was posted on [[xkcd]] when the web site opened on Sunday the 1st of January 2006.
**It was posted along [[:Category:First day on xkcd|with all 41 comics]] posted before that on LiveJournal as well as a few others.
**The latter explaining why the numbers of these 41 LiveJournal comics ranges from 1-44.
*One of the original drawings drawn on [[:Category:Checkered paper|checkered paper]].
*The first Laplace transform has a mismatched left parenthesis, which was the topic of [[859: (]].
*The second formula is not the inverse Laplace transform as stated. It differs from the actual Mellin's inverse formula by its bounds and a missing factor. [https://en.wikipedia.org/wiki/Inverse_Laplace_transform]
{{comic discussion}}
[[Category:Comics posted on livejournal| 18]]
[[Category:First day on xkcd]]
[[Category:Checkered paper]]
[[Category:Comics featuring real people]]
[[Category:Math]]
[[Category:Comics with lowercase text]]

1740: Rosetta

2022-05-04T01:35:00Z

Big square: Undo revision 235046 by X. K. C. D. (talk)

<div style="display: none">crap</div> <div style="display: none">crap </div>
{{comic
| number = 1740
| date = September 30, 2016
| title = Rosetta
| image = rosetta.png
| titletext = I WONDERED why he kept asking whether we thought the impact speed was too low.
}}

==Explanation==
On the day this comic was posted (September 30th 2016), the ''{{w|Rosetta (spacecraft)|Rosetta}}'' mission ended with the final descent of ''Rosetta'' onto the comet {{w|67P}}. Landing Rosetta on the comet gave the scientists ([[Ponytail]], [[Megan]] and [[Hairy]]) a chance to collect extra data from very close to the comet, using the spacecraft's powerful sensors.

[[Cueball]] however [[1339: When You Assume|assumed]] that the landing was a "{{w|Asteroid_impact_avoidance#Kinetic_impact|kinetic impact}}" mission to deflect a comet that was on a collision course with Earth. A similar scenario (but using a nuclear weapon implanted inside of the asteroid to deflect it) was depicted in the 1998 film ''{{w|Armageddon (1998 film)|Armageddon}}'', of which Cueball is apparently a fan. ''Armageddon'' is a high-throttle action movie, [http://www.todayifoundout.com/index.php/2010/01/nasa-uses-the-movie-armageddon-in-their-management-training-program/ infamous among NASA employees] for its incredibly liberal application of artistic license. [https://www.imdb.com/title/tt0120591/goofs#factual_error IMDb has a list of factual inaccuracies].

In reality, at the time ''Rosetta'' landed, 67P was already leaving the inner solar system and was [http://sci.esa.int/where_is_rosetta/ a long way past Earth]. It will return to the inner solar system in around 5 years' time, but its orbit will not pass close to the Earth in any foreseeable time.

Also, as the title text hints, Rosetta's speed was only [https://astronomynow.com/2016/09/30/rosettas-final-hours/ 90 cm per second] relative to the surface at the moment of impact (or about 2 mph/3.25 km/h; the speed of a slow walk), while the comet was traveling at 14.39 km/s. Given that Rosetta only weighs a couple of tons (or [[1461: Payloads|six horses]]), and 67P weighs nearly 10 billion tons (or 22 billion horses), Rosetta's landing will have no actual measurable effect on the comet's momentum.

''Rosetta'' (and its lander, ''Philae'') were previously the subject of the comics [[1402: Harpoons]] and [[1446: Landing]], and were mentioned in [[1461: Payloads]], [[1547: Solar System Questions]] and possibly [[1621: Fixion]].

==Transcript==
:[A control room with Megan and Hairy sitting on stools in front of an opposite desk with computers. Hairy has his arms in the air. Ponytail is standing between them with Cueball, she is watching Megan and he is looking at Hairy.]
:Megan: Signal lost.
:Megan: ''Rosetta'' has impacted the comet.
:Ponytail: Good work everyone.
:Hairy: ''Woooo!''

:[Zoom on Ponytail, still looking at Megan and Cueball who has turned towards Ponytail.]
:Cueball: So.
:Cueball: Do you think we deflected it?

:[Ponytail turns to Cueball as does Hairy who turns and looks away from his computer.]
:Ponytail: Huh?
:Cueball: Did we hit the comet hard enough to deflect it away from Earth?

:[In a frame-less panel Ponytail talks with Cueball.]
:Ponytail: That... Is that what you thought we were doing?
:Cueball: I just assumed...

:[Megan enters whispering in Ponytail's ear, holding a hand up to her mouth. Ponytail still looks at Cueball who raises his arms up in the air.]
:Megan: He's a huge ''Armageddon'' fan. Let him have this.
:Ponytail: Okay, fine.
:Ponytail: Yes! We did it! The Earth is saved!
:Cueball: ''Wooo!''

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring Hairy]]
[[Category:Comics featuring Megan]]
[[Category:Fiction]]
[[Category:Space probes]]

1540: Hemingway

2022-05-04T01:33:33Z

Big square: Undo revision 236114 by X. K. C. D. (talk)

<div style="display: none">crap</div> <div style="display: none">crap </div>
{{comic
| number = 1540
| date = June 19, 2015
| title = Hemingway
| image = hemingway.png
| titletext = Instead of bobcat, package contained chair.
}}

==Explanation==
This comic is a reference to the six-word short story ''{{w|For sale: baby shoes, never worn}}'', which has been commonly attributed to famous author {{w|Ernest Hemingway}} (the disputed authorship of the story is referenced several times in the comic).

The comic plays on the fact that the original story takes the form of a short advertisement that might have been seen in a newspaper, and makes up alternate versions that use various modern 'standards' that did not exist in Hemingway's time. In keeping with the original, each example remains six words long. The title text obeys this rule, too. Many of the drafts poke fun at the tragedy that the original story suggests. With the original ("For Sale: Baby shoes, never worn"), readers could infer that the baby who would have worn the shoes must have died. Randall tries to make the reader infer other, more absurd things instead.

The comic also alludes to Hemingway's practice of repeatedly re-working drafts of his novels before publication. For example, he is [http://www.nytimes.com/2012/07/05/books/a-farewell-to-arms-with-hemingways-alternate-endings.html reported] to have rewritten the final passage of [https://en.wikipedia.org/?title=A_Farewell_to_Arms A Farewell To Arms] 39 times. Later editions of his works include these rough drafts, allowing the devoted reader to understand how the work developed.

The following are the various drafts offered in the comic.
{| class="wikitable"
|-
! width="305" | Draft
! Explanation
|-
| For Sale: This gullible baby's shoes
| This suggests the seller somehow tricked the baby out of its shoes.
|-
| Baby shoes for sale by owner
| This suggests that a very intelligent baby is somehow selling its own shoes, or that someone is selling an old pair of shoes they had as a baby. This style represents the typical automobile or house sales ads, differentiating the sale by owner from the sale by a professional middleman (a car dealer or a realtor) and thus bypassing the extra expense of middleman's fee.
|-
| <strike>Actually, there’s no evidence Hemingway wrote</strike>
| A fragment of a preemptive rebuttal to the comic’s premise (or at least its title). This sentence was stopped at the sixth word, in keeping with the premise.
|-
| Free shoes, provided you overpower baby
| This suggests the person posting the ad is asking people to forcibly steal shoes from a baby. This alludes to the common expression "[https://en.wiktionary.org/wiki/like_taking_candy_from_a_baby like taking candy from a baby]", meaning a task is extremely simple and effortless. One doesn't necessarily need to overpower a baby to steal its shoes either; there are other methods such as annoying the baby until it throws its shoes or tricking the baby (see the first example above).
|-
| For Sale: Weird baby's toe shoes
| Randall once again displays his distaste for [[1065: Shoes|weird toe shoes]], that is, shoes with individual toes. Rather than the tragedy implied by the original story, this instead implies that the baby has odd taste in shoes, and perhaps the parents would rather their child wear regular shoes.
|-
| For Sale: Baby shoes <span style="color: #f8991d;">✓</span><span style="color: #48a3c6; font-weight: 600; font-style: italic;">Prime</span> <span style="color: #727272;">Eligible</span>
| This is a reference to {{w|Amazon.com|Amazon}}, which offers Prime as a paid service to expedite shipping of items ordered on its website.
|-
| <strike>Though popularly attributed to Hemingway, the</strike>
| Another fragment of a rebuttal, written in an encyclopedic style, and also stopped at the sixth word.
|-
| This weird trick covers baby feet!
| This is modeled after common 'click bait' wording designed to get users to visit web pages, typically using words such as "this weird trick" or "secrets they don't want you to know" to artificially increase its apparent appeal. xkcd has previously parodied click bait in [[1283: Headlines]], [[1307: Buzzfeed Christmas]] and [[1426: Reduce Your Payments]].
|-
| For Sale: Baby shoes, just hatched
| This plays on the meaning of the phrase "baby shoes", reframing it to mean a newly-born shoe (similar to "baby bird"), rather than its typical meaning of footwear designed for babies.
|-
| Sale: Seven-league boots (expedited shipping)
| {{w|Seven-league boots}} are mythical boots that allow their user to move seven leagues (21 miles) per step. The "expedited shipping" part suggests that the people delivering these boots may be wearing seven-league boots themselves, allowing them to reach the customer much faster than if by airplane (except, of course, if the boots had to be shipped overseas).
|-
| Complete this survey for free shoes
| This is another reference to common internet marketing campaigns, where users are incentivized to take surveys in exchange for small compensation such as free samples or coupons.
|-
| ''Shoes'', by Ernest Hemingway {{Citation needed}}
| This is a reference to Wikipedia. "{{w|Citation needed}}" is used to mark claims that require additional evidence to justify as true. In this case, Randall is using this to question whether the short story was really written by Hemingway.
|-
| This is my greatest short story
| This is a completely different style that could also have been used to write a short story in six words. Rather than telling a story about shoes, this is more "meta" by referencing itself and being a self-fulfilling (or self-defeating) prophecy. (The sequel was titled "Don't bother reading my other stories").
|-
| For Sale: Baby shoes (-1) [Cursed]
| This is written like a description of a virtual item typically found in Roguelike games or MMOs. "-1" typically means the item will reduce its wearer's stats (such as defense or speed rating) by one point. "Cursed" usually means the item cannot be taken off the wearer's body once it is put on. It might also reference the fact the original story suggests the baby died, perhaps because of the cursed shoes.

"-1" in this context is usually read aloud as "minus one"; this would break the six word pattern.
|-
| <span style="color: #727272;"><blink><marquee></span>Baby shoes!<span style="color: #727272;"></marquee></blink></span>
| This is reminiscent of the style of HTML widely used in the 1990s. Both the <span style="color: #727272;"><blink></span> and <span style="color: #727272;"><marquee></span> tags make the text content ("Baby shoes!") appear more prominent and attention-grabbing. The blink tag makes a blinking effect in Netscape, whereas the marquee tag makes a scroll effect in Internet Explorer. On a normal web page, these tags only affect how the text content is displayed on screen and aren't directly shown to visitors. However they are shown here to make the six words count, albeit in a lighter shade of gray to reinforce the fact that they're not part of the text content. An interesting note: When this comic was first posted to xkcd.com, the '/' in the <span style="color: #727272;"></blink></span> tag was missing. This was fixed between the 19th and 20th of June, 2015, showing that the omission was, indeed, unintentional.
|-
| For Sale: Baby-sized saddle, bobcat
| This is a reference to [[A-Minus-Minus|325: A-Minus-Minus]] in which [[Cueball]] says: 'Instead of office chair, package contained bobcat'. A 'baby-sized saddle' is presumably a very small saddle that's only usable if the user was a baby and was trying to ride a small animal such as a bobcat.
|-
| Hemingway busted for Craigslist shoe scam
| This is written like a news headline where Hemingway supposedly wrote about shoes in order to perpetrate a scam. {{w|Craigslist}} is a website where users can advertise and seek goods and services.
|}
The title text continues the reference to [[A-Minus-Minus|325: A-Minus-Minus]], but inverts the situation. Rather than unexpectedly receiving a bobcat by package, this time the package contains a regular item instead of the expected bobcat. In keeping with the theme of the comic, the review is written in only six words.

==Transcript==
:Hemingway's Rough Drafts

:[A list of rough draft stories.]
:For sale: This Gullible Baby's Shoes
:Baby Shoes For Sale By Owner
:<strike>Actually, there's no evidence Hemingway wrote</strike>
:Free Shoes, Provided You Overpower Baby
:For Sale: Weird Baby's Toe Shoes
:For Sale: Baby Shoes <span style='color: #FF9900; font-style: italic;'>✓</span> <span style='color: #4DA3C5; font-style: italic;'>Prime</span> <span style='color: #727272;'>eligible</span>
:<strike>Though popularly attributed to Hemingway, the</strike>
:This Weird Trick Covers Baby Feet!
:For Sale: Baby Shoes, Just Hatched
:Sale: Seven-League Boots (Expedited Shipping)
:Complete this survey for free shoes!
:''Shoes'', by Ernest Hemingway <sup>[<span style='color: #0645ad; font-style: italic;'>citation needed</span>]</sup>
:This is my greatest short story.
:For sale: Baby shoes (-1) [cursed]
:<span style='color: #727272;'><blink><marquee></span>Baby Shoes!<span style='color: #727272;'></marquee></blink></span>
:For Sale: Baby-sized Saddle, Bobcat
:Hemingway Busted for Craigslist Shoe Scam

{{comic discussion}}

[[Category:Comics with color]]
[[Category:Bobcats]]
[[Category:Comics featuring Cursed Items]]

1313: Regex Golf

2022-05-04T01:32:16Z

Big square: Undo revision 234364 by X. K. C. D. (talk)

<div style="display: none">crap</div> <div style="display: none">crap </div>
{{comic
| number = 1313
| date = January 6, 2014
| title = Regex Golf
| image = regex_golf.png
| titletext = <nowiki>/bu|[rn]t|[coy]e|[mtg]a|j|iso|n[hl]|[ae]d|lev|sh|[lnd]i|[po]o|ls/ matches the last names of elected US presidents but not their opponents.</nowiki>
}}

==Explanation==
The comic talks about {{w|regular expressions}}, which are a way to specify textual patterns. Given a regular expression, one can search for the pattern it specifies inside a text string. If the pattern is found, it's said that the pattern "matches" the string; if it's not found, it's said it doesn't match.

The title of the comic and the first panel is based on "[http://regex.alf.nu/ regex golf]", which is a discipline of "{{w|code golf}}", a game in which programmers attempt to solve a given programming problem using as few characters as possible, analogous to the number of {{w|golf}} shots it takes to reach the goal. In regex golfing, the programmer is given two sets of text fragments, and tries to write the shortest possible regular expression which would match all elements of one set, while at the same time not matching any element from the other set.

The regex golf challenge Megan faces consists of matching all subtitles of (then extant) ''{{w|Star Wars}}'' films, while not matching any subtitle of ''{{w|Star Trek}}'' movies. {{w|Subtitle (titling)|Subtitles}} are the secondary titles of the movies, after the ''"Star Trek: "'' or ''"Star Wars Episode N: "''. For example, in ''Star Wars Episode I: The Phantom Menace'', the subtitle is ''The Phantom Menace''. In the first panel, she created a 12-character regex solving the challenge.

Then she moved on to building a tool which would automatically build such a regex for arbitrary lists of text, which could be described as {{w|meta}}- regex golfing. But as she has lost this tool, she needs to search through her files and chooses a tool called "{{w|grep}}" to find it. This implies that she needs a regular expression that would find any code that appears to be a regex golf generator, which leads to another "meta-" layer of abstraction. At the end, Megan notes this sequence of meta-meta-... might go to infinity and Cueball quips that she now has "infinite problems" as a result of her efforts; Megan retorts that she already had "infinite problems" because she's geeky enough to run meta-versions of programs on themselves, and stubborn enough to continue on until she fails, to the exclusion of all else. This also seems to be a reference to a famous quote by {{w|Jamie Zawinski}} (see also ''[[1171: Perl Problems]]''):

<blockquote>''Some people, when confronted with a problem, think "I know, I'll use regular expressions." Now they have two problems.''</blockquote>

===Regular expressions===
The first regex Megan uses is <code>/m | [tn]|b/</code>, said to match ''Star Wars'' subtitles but not ''Star Trek''.

The forward slashes <code>/</code> just mark the start and end of the regex. The <code>|</code> character means "or", so the regex matches any string that contains the patterns "<code>m </code>", "<code> [tn]</code>" or "<code>b</code>" (including the spaces). The square brackets match one of the enclosed characters, meaning that "<code> [tn]</code>" matches either "<code> t</code>" or "<code> n</code>". The regex is apparently case-insensitive, because it wouldn't work otherwise.

The Star Wars subtitles match the parts of the regex in the following way:
*"The Phanto<u>m </u>Menace" is matched by "<code>m </code>".
*"Attack of<u> t</u>he Clones" is matched by "<code> [tn]</code>".
*"Revenge of<u> t</u>he Sith" is matched by "<code> [tn]</code>".
*"A<u> N</u>ew Hope" is matched by "<code> [tn]</code>".
*"The Empire Strikes <u>B</u>ack" is matched by "<code>b</code>".
*"Return of<u> t</u>he Jedi" is matched by "<code> [tn]</code>".

Note that if the animated film "Star Wars: The Clone Wars" were included, it would not be matched by "<code> [tn]</code>" because the T is the start of the subtitle and is not preceded by a space. None of the "Star Wars:" films titles announced since this comic ("The Force Awakens", "The Last Jedi", and "The Rise of Skywalker") match this regex.

On the other hand, none of the Star Trek subtitles contains an M followed by a space, a T or an N preceded by a space, or any B, so the regex does not match any of them. Note that in the original series all subtitles start with a "T" but it's the first character so it's not preceded by a space.

Here is the list that Megan probably used:
*Original series:
**The Motion Picture
**The Wrath of Khan
**The Search For Spock
**The Voyage Home
**The Final Frontier
**The Undiscovered Country
*The Next Generation:
**Generations
**First Contact
**Insurrection
**Nemesis
*Reboot series:
**Into Darkness

"Star Trek Beyond", which was released after this comic, would incorrectly match the regex since it is the first "Star Trek" title to contain a "b". However, since "Star Trek Into Darkness" and "Star Trek Beyond" both lack a colon in their titles, it is [[1167: Star Trek into Darkness|debatable]] whether they can truly be considered to have subtitles.

In the last panel "and beyond" Megan uses the regular expression <code>/(meta-)*regex golf/</code> to describe her problem. <code>*</code> means "zero or more" of the preceding character/group (parentheses <code>()</code> group characters). So this regex matches "regex golf", "meta-regex golf", "meta-meta-regex golf", etc. In a way this is regex golf in itself, matching all levels of meta-regex golf while not matching anything else.

In the title text, there is a long regex that is the solution of another regex golf challenge: matching the last names of all elected US presidents but not their opponents. Note that the list of opponents include some people who were previously or later became presidents, or whose last name matches that of another person who was president, so taken literally this is impossible. To make this work the list of opponents must exclude any names of presidents. The regular expression itself works in a very similar way to the Star Wars/Trek one, including several different patterns separated by <code>|</code>. Each elected president matches one pattern while each opponent matches none.

The regex does not match either of the presidents elected since the comic’s release ("Trump" and "Biden"), and thus would need to be updated. The regex does match Hillary Clinton's last name, but because a person with the same last name (Bill Clinton) was president, this does not count as a mistake. There was already a losing opponent called George Clinton who ran in 1792 and 1812.

Here is a list of elected president and the patterns they match:
{| class="wikitable"
!Number
!President
!Matched expression
|-
|1
|{{w|George Washington|George Wa<u>sh</u>ington}}
|<code>sh</code>
|-
|2
|{{w|John Adams|John <u>Ad</u>ams}}
|<code>[ae]d</code>
|-
|3
|{{w|Thomas Jefferson|Thomas <u>J</u>efferson}}
|<code>j</code>
|-
|4
|{{w|James Madison|James <u>Ma</u>dison}}
|<code>[mtg]a</code>
|-
|5
|{{w|James Monroe|James Monr<u>oe</u>}}
|<code>[coy]e</code>
|-
|6
|{{w|John Quincy Adams|John Quincy <u>Ad</u>ams}}
|<code>[ae]d</code>
|-
|7
|{{w|Andrew Jackson|Andrew <u>J</u>ackson}}
|<code>j</code>
|-
|8
|{{w|Martin Van Buren|Martin Van <u>Bu</u>ren}}
|<code>bu</code>
|-
|9
|{{w|William Henry Harrison|William Henry Harr<u>iso</u>n}}
|<code>iso</code>
|-
|11
|{{w|James K. Polk|James K. <u>Po</u>lk}}
|<code>[po]o</code>
|-
|12
|{{w|Zachary Taylor|Zachary <u>Ta</u>ylor}}
|<code>[mtg]a</code>
|-
|14
|{{w|Franklin Pierce|Franklin Pier<u>ce</u>}}
|<code>[coy]e</code>
|-
|15
|{{w|James Buchanan|James <u>Bu</u>chanan}}
|<code>bu</code>
|-
|16
|{{w|Abraham Lincoln|Abraham <u>Li</u>ncoln}}
|<code>[lnd]i</code>
|-
|17
|{{w|Andrew Johnson|Andrew <u>J</u>ohnson}}
|<code>j</code>
|-
|18
|{{w|Ulysses S. Grant|Ulysses S. Gra<u>nt</u>}}
|<code>[rn]t</code>
|-
|19
|{{w|Rutherford B. Hayes|Rutherford B. Ha<u>ye</u>s}}
|<code>[coy]e</code>
|-
|20
|{{w|James A. Garfield|James A. <u>Ga</u>rfield}}
|<code>[mtg]a</code>
|-
|22
|{{w|Grover Cleveland|Grover C<u>lev</u>eland}}
|<code>lev</code>
|-
|23
|{{w|Benjamin Harrison|Benjamin Harr<u>iso</u>n}}
|<code>iso</code>
|-
|24
|{{w|Grover Cleveland|Grover C<u>lev</u>eland}}
|<code>lev</code>
|-
|25
|{{w|William McKinley|William McKi<u>nl</u>ey}}
|<code>n[hl]</code>
|-
|26
|{{w|Theodore Roosevelt|Theodore R<u>oo</u>sevelt}}
|<code>[po]o</code>
|-
|27
|{{w|William Howard Taft|William Howard <u>Ta</u>ft}}
|<code>[mtg]a</code>
|-
|28
|{{w|Woodrow Wilson|Woodrow Wi<u>ls</u>on}}
|<code>ls</code>
|-
|29
|{{w|Warren G. Harding|Warren G. Har<u>di</u>ng}}
|<code>[lnd]i</code>
|-
|30
|{{w|Calvin Coolidge|Calvin Coo<u>li</u>dge}}
|<code>[lnd]i</code>
|-
|31
|{{w|Herbert Hoover|Herbert H<u>oo</u>ver}}
|<code>[po]o</code>
|-
|32
|{{w|Franklin D. Roosevelt|Franklin D. R<u>oo</u>sevelt}}
|<code>[po]o</code>
|-
|33
|{{w|Harry S. Truman|Harry S. Tru<u>ma</u>n}}
|<code>[mtg]a</code>
|-
|34
|{{w|Dwight D. Eisenhower|Dwight D. Eise<u>nh</u>ower}}
|<code>n[hl]</code>
|-
|35
|{{w|John F. Kennedy|John F. Kenn<u>ed</u>y}}
|<code>[ae]d</code>
|-
|36
|{{w|Lyndon B. Johnson|Lyndon B. <u>J</u>ohnson}}
|<code>j</code>
|-
|37
|{{w|Richard Nixon|Richard <u>Ni</u>xon}}
|<code>[lnd]i</code>
|-
|39
|{{w|Jimmy Carter|Jimmy Ca<u>rt</u>er}}
|<code>[rn]t</code>
|-
|40
|{{w|Ronald Reagan|Ronald Rea<u>ga</u>n}}
|<code>[mtg]a</code>
|-
|41
|{{w|George H. W. Bush|George H. W. <u>Bu</u>sh}}
|<code>bu</code>
|-
|42
|{{w|Bill Clinton|Bill Cli<u>nt</u>on}}
|<code>[rn]t</code>
|-
|43
|{{w|George W. Bush|George W. <u>Bu</u>sh}}
|<code>bu</code>
|-
|44
|{{w|Barack Obama|Barack Oba<u>ma</u>}}
|<code>[mtg]a</code>
|}

Some presidents are missing because they weren't elected but became presidents after the resignation/death of their formers.

And here is a list of how many unique last names are matched by each expression:

{| class="wikitable"
!Expression
!Match count
|-
| bu
| 3
|-
| [rn]t
| 3
|-
| [coy]e
| 3
|-
| [mtg]a
| 7
|-
| j
| 3
|-
| iso
| 1
|-
| n[hl]
| 2
|-
| [ae]d
| 2
|-
| lev
| 1
|-
| sh
| 1
|-
| [lnd]i
| 4
|-
| [po]o
| 3
|-
| ls
| 1
|}

Randall's regular expression does ''not'' match presidential opponents Pinckney, King, Clay, Cass, Scott, Douglas, McClellan, Seymour, Greeley, Tilden, Hancock, Blaine, Bryan, Parker, Hughes, Cox, Davis, Smith, Landon, Willkie, Dewey, Stevenson, Goldwater, Humphrey, McGovern, Mondale, Dukakis, Dole, Gore, Kerry, McCain, or Romney. However, it must be modified slightly, because it ''does'' match {{w|John C. Fremont|John C. Fremo<u>nt</u>}}, the runner-up to James Buchanan in 1856, as discussed by {{w|Peter Norvig}} at [http://nbviewer.ipython.org/url/norvig.com/ipython/xkcd1313.ipynb xkcd 1313: Regex Golf]. It also matches {{w|Aaron Burr|Aaron <u>Bu</u>rr}}, the runner-up to Thomas Jefferson in 1800. Note that Norvig provides a small amount of Python code which actually plays regex golf with arbitrary lists, and found a shorter solution than Randall's for the ''Star Wars'' vs ''Star Trek'' game (<code>/ t|p.*e/</code>).

==Transcript==
:[Caption at top of panel:]
:Regex golf:
:[Megan is sitting at a laptop. Cueball is standing behind her.]
:Megan: You try to match one group but not the other.
:Megan: /m | [tn]|b/ matches ''Star Wars'' subtitles but not ''Star Trek''.
:Cueball: Cool.

:[Caption at top of panel:]
:Meta-regex golf:
:[A close-up of Megan at her laptop.]
:Megan: So I wrote a program that plays regex golf with arbitrary lists...
:Cueball (offscreen): Uh oh...

:[Caption at top of panel:]
:Meta-meta-regex golf:
:[Megan typing at her laptop.]
:Megan: ...But I lost my code, so I'm grepping for files that look like regex golf solvers.
:[Cueball facepalming.]

:[Caption at top of panel:]
:...And beyond:
:[Another closeup of Megan at her laptop.]
:Megan: Really, this is all /(meta-)*regex golf/.
:Cueball: Now you have ''infinite'' problems.
:Megan: No, I had those already.

==Trivia==
*There are now at least four comics that reference regular expressions. The other three are: [[208: Regular Expressions]], [[224: Lisp]], and [[1171: Perl Problems]].
*Additionally, regular expressions are mentioned in the title text of [[1277: Ayn Random]].
*A regular expression is used in the [http://what-if.xkcd.com/75/ 75th] post of [[what if?]] to calculate the answer to that week's question.
*Also, Randall mentions [http://regex.alf.nu/ a website with a regexp golf game] he got distracted by while researching for the [http://what-if.xkcd.com/78/ 78th] post of [[what if?]] (which was published one day after this comic).

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Regex]]
[[Category:Star Trek]]

1938: Meltdown and Spectre

2022-05-04T01:31:10Z

Big square: Undo revision 234488 by X. K. C. D. (talk)

<div style="display: none">crap</div> <div style="display: none">crap </div>
{{comic
| number = 1938
| date = January 5, 2018
| title = Meltdown and Spectre
| image = meltdown_and_spectre.png
| titletext = New zero-day vulnerability: In addition to rowhammer, it turns out lots of servers are vulnerable to regular hammers, too.
}}

==Explanation==
This comic was inspired by the {{w|Meltdown (security vulnerability)|Meltdown}} and {{w|Spectre (security vulnerability)|Spectre}} bugs found in certain processors; these vulnerabilities were disclosed to the public in the week of this comic. The bugs result from flawed implementations of {{w|speculative execution}}, and made big news because they broke the "walls" between programs executing concurrently on the same computer, in some circumstances allowing malware to steal secrets from normal, bug-free programs.

Speculative execution is a technique used to speed up the execution of computer programs. Processors handle instructions in {{w|Instruction pipelining|a series of steps}}, like an assembly line. The processor works on several successive instructions, each at a different stage in the assembly line. It may start speculatively executing instructions that follow a particular result of a decision before the execution of the logic that makes that decision is finished. Once the decision is made, it keeps results from the selected path, and discards unnecessary results. This allows it to keep doing useful work while some slower decision is made.

In the Meltdown and Spectre bugs, the results of speculatively executed instructions are not completely discarded, allowing them to affect things that the program logic should have prevented.

[[Ponytail]] uses the {{w|Trolley Problem}}, and {{w|Tram|trolley (tram)|trolley}} tracks in general, as an analogy for streams of instructions in a program. The Trolley Problem is a thought experiment where an out-of-control trolley is heading to a switch which you control. Leaving the switch as-is will cause it to kill multiple people (typically five) stuck on the tracks, but switching the track will cause it to kill only one person, who would not have died if the switch was left untouched. This creates the ethical dilemma of passively causing multiple deaths, versus actively causing one. The Trolley Problem has gained significant memetic traction, helped in no small part by its frequent inclusion in “introduction to philosophy” type courses. The problem has seen revitalized interest with the emergence of {{w|autonomous car}}s, which may be faced with what are, essentially, {{w|autonomous car#Moral issues|such choices}} in emergency situations.

As an analogy for multiple mutually exclusive paths being executed at the same time, Ponytail invokes certain {{w|interpretations of quantum mechanics}}, where quantum-level particles can be viewed as taking every possible path at once, with the result being the sum of all of them. This is an idea popularized by the {{w|Copenhagen interpretation|common interpretation}} of {{w|Schrödinger's cat}}, where the cat is both dead and alive until some event results in one of the states being selected.

The phantom trolley driving through walls is an analogy for the computer instructions being able to access areas of memory that should be protected from them. This may also be a reference to {{w|quantum tunnelling}}, or even simply a joke about the phantom trolley being a literal phantom, i.e. incorporeal.

In many cases, contrary to what the comic implies, both paths are not taken simultaneously during speculative execution. A {{w|branch predictor}} may be used to select the most likely path, and the effects should be completely erased if the predicted path is incorrect. Both branch prediction and taking both paths (known as eager evaluation) are considered speculative execution and are affected by these bugs.

The {{w|Row hammer}} problem had been known for many years before this comic was published. A {{w|Dynamic random-access memory|common form of computer memory}} is constructed from tiny capacitors organized in a two-dimensional grid of rows and columns. Capacitors store charge to represent information. By applying a pattern of memory access that rapidly changes a row of capacitors, you can cause charge to overflow to nearby rows and incorrectly change their states.

Ponytail mentions that we especially suck at building "shared computers" because Row hammer, Spectre, and Meltdown all break down the security divisions built between programs and between users. A hacker running a separate program in a separate account shouldn't be able to access your data or change the behavior of your program, but these problems allow them to. This is particularly dangerous for time-sharing, servers, and {{w|Cloud computing|the cloud}}, where different programs, websites, or even companies can be sharing the same hardware.

Cueball takes her explanation literally, and comes to the conclusion that the cloud "is full of phantom trolleys armed with hammers", and Ponytail cannot be bothered correcting him. Cueball's final line ironically suggests that these exploits can be repaired with a simple software update. This seems to be mocking the naive misunderstanding that software can make up for flawed hardware. However, the exploits discussed in this comic are not trivial oversights, but reflect fundamental issues in the design of modern processors.

A {{w|zero-day (computing)|zero-day}} vulnerability is an attack that takes advantage of a vulnerability that hasn't been published yet, and so is not patched in any vulnerable system. The title text suggests that, until it was 'disclosed' here, nobody was aware that as well as Row hammer, computer servers can also be harmed by regular hammers. In reality, this would be obvious to most people.{{Citation needed}} One might "patch" a server against this attack by plating it with stronger metal.

==Transcript==
:[Zoom out with Cueball and Ponytail walking to the right on the ground.]
:Cueball: The Meltdown and Spectre exploits use "speculative execution?" What's that?
:Ponytail: You know the trolley problem? Well, for a while now, CPUs have basically been sending trolleys down '''''both''''' paths, quantum-style, while awaiting your choice. Then the unneeded "phantom" trolley disappears.

:[Zoom in on only Ponytail who has turned towards Cueball off-panel left.]
:Ponytail: The phantom trolley isn't supposed to touch anyone. But it turns out you can still use it to do stuff.
:Ponytail: And it can drive through walls.

:[Cueball and Ponytail, lifting both her palms up, are standing, facing each other.]
:Cueball: That sounds bad.
:Ponytail: Honestly, I've been assuming we were doomed ever since I learned about Rowhammer.

:[In a frame-less panel they continue talking, both with their arms down.]
:Cueball: What's ''that''?
:Ponytail: If you toggle a row of memory cells on and off really fast, you can use electrical interference to flip nearby bits and—
:Cueball: Do we just suck at...computers?
:Ponytail: Yup. Especially shared ones.

:[Zoom out again as they resume walking to the right on the ground. Cueball is lifting his smartphone up and looks at the screen.]
:Cueball: So you're saying the cloud is full of phantom trolleys armed with hammers.
:Ponytail: ...Yes, that is exactly right.
:Cueball: Okay. I'll, uh... install updates?
:Ponytail: Good idea.

==Trivia==

Although this is clearly not part of the series [[:Category:Code Quality|Code Quality]], it might be the same two characters, with Ponytail again displaying a much better understanding of computers than Cueball with his [[:Category:Cueball Computer Problems|Computer Problems]].

The Trolley problem was mentioned a month before this comic in the last ''milestone'' on this list in [[1925: Self-Driving Car Milestones]]; see more there regarding why this problem might have resurfaced in xkcd. Three years before that comic, a comic was even named after the problem: [[1455: Trolley Problem]].

The fact that compromising IT systems is sometimes easier done physically than logically is also mentioned in [[538: Security]].

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Ponytail]]
[[Category:Cueball Computer Problems]]
[[Category:Computers]]
[[Category:Programming]]

2431: Leap Year 2021

2022-05-04T01:30:15Z

Big square: Undo revision 232800 by X. K. C. D. (talk)

<div style="display: none">crap</div> <div style="display: none">crap </div>
{{comic
| number = 2431
| date = March 1, 2021
| title = Leap Year 2021
| image = leap_year_2021.png
| titletext = I've lived in the present for my whole life and I'm not about to move now.
}}

==Explanation==
[[Cueball]], checking his phone, comments on how fast time goes, saying it is already March. (This comic was posted on March 1, 2021.) Black Hat overhears him and says that it's actually February 29.

February 29 exists in the {{w|Gregorian calendar}} and its predecessor, the {{w|Julian calendar}}, as a {{w|Intercalation (timekeeping)|correction mechanism}} for the fact that one {{w|tropical year}} on Earth is not exactly 365 days long. It's closer to 365.2422, and to prevent the dates from precessing relative to the seasons, an extra day is added once every fourth year, also called a leap year. This is still not enough to completely match Earth's orbital period, and for that reason the Gregorian calendar changed the leap year rules to be as follows: Every year that is exactly divisible by four is a leap year, except for years that are exactly divisible by 100, but these centurial years are leap years if they are exactly divisible by 400. This makes the average year 365.2425 days long, which approximates the 365.2422 days in the tropical year.

[[Black Hat]] wants ''every'' year to have a February 29, for no clear reason. Cueball acknowledges that he could accomplish this, if he could convince enough people to go along with it. Calendar systems are all invented, and whatever date systems are commonly acknowledged become the "correct" date. Cueball initially considers the change minor, assuming that they would simply change March 1st to February 29th on non-leap years, which would merely rename a single day and skip "March 1st" by going directly from February 29th to March 2nd. Black Hat clarifies that he actually wants to add another day, and the day AFTER that will be March 1. This could still be a minor change, if March were changed to a 30 day month on non-leap years, but Black Hat apparently wants the changes to propagate throughout the year. This would result in a 366-day year, causing the months to drift out of alignment with the seasons over the course of years, needlessly complicating time-keeping. Black Hat is unconcerned with the effect this will have on the "people of the future", and, as in [[1883: Supervillain Plan|the past]], people around him are much more concerned about the time problems he's creating than he is. This once happened in ancient Egypt, where the priests had leap years every three years instead of every four years, so ancient Egypt had to have no leap years for several decades afterwards in order to fix the calendar.

In the last frame, Black Hat states that if the those people cared about the problems he's causing, "they shouldn't have decided to live in the future." Of course, it is at present impossible to choose the time period in which you live,{{Citation needed}} yet Black Hat intends on penalizing them for it. Any number of positions could be proposed as a motive for his actions (for example, he may envy them for having the technology or benefits of the future, and wants to counteract that), but it is most likely that he is simply honing his sociopathic tendencies on a defenseless target.

In the title text, Cueball responds that this change would also cause issues for him, who is "living in the present", and he should not be forced to "move into the future". Alternatively, viewing the quote as a continuation of Black Hat's text at the end of the comic, he could mean that the effect of his new calendar is placed mostly on future people, and since he literally lives in the present and doesn't intend on travelling to the future, he can do what he wants without many repercussions. In this second interpretation, the phrase "move now" can be taken to have a double meaning: not only does Black Hat not intend to move presently, he also does not intend to move where the present currently is (i.e., move the "now" into the future).

==Transcript==
:[Cueball checking his phone in a narrow panel.]
:Cueball: Can't believe it's already March.
:Black Hat (off-screen): Nah, it's February 29th.

:[Cueball has put his phone away and is standing next to Black Hat.]
:Cueball: It's not a leap year.
:Black Hat: I decided to make it one. Every year deserves to leap.
:Cueball: Can you do that?
:Black Hat: Can anyone stop me?

:[Zoom in on Cueball.]
:Cueball: I guess if you just encourage people to call March 1st "February 29th", they can go along with it if they want. Just a one-day renaming.
:Black Hat (off-screen): No, tomorrow will be March 1st.

:[Cueball standing to Black Hat, who is walking off screen to the right, with his finger raised.]
:Cueball: So you're causing calendar drift for future generations.
:Black Hat: If they didn't want to experience consequences, they shouldn't have decided to live in the future.

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Black Hat]]
[[Category:Calendar]]

836: Sickness

2022-05-04T01:28:50Z

Big square: Undo revision 235119 by X. K. C. D. (talk)

<div style="display: none">crap</div> <div style="display: none">crap </div>
{{comic
| number = 836
| date = December 20, 2010
| title = Sickness
| image = sickness.png
| titletext = At least, with p<0.05 confidence.
}}

==Explanation==
This comic was published 2 months after [[Randall]]'s then fiancée, now wife, was diagnosed with breast cancer (see [[:Category:Cancer]]), which is likely what inspired this comic - even though [[Cueball]] sounds like he is the one afflicted by the sickness. The comic is thus about the existential questions that might arise from such a crisis. The moral could be interpreted as that you shouldn't begrudge your fellow human being, regardless of where they find comfort.

Also, any sentence is instantly funny if, at the end of it, you address your audience as "bitches". It may also be a reference to [[54: Science]].

"Slings and arrows of fortune" is an allusion to the "{{w|To be, or not to be}}" soliloquy in William Shakespeare's ''{{w|Hamlet, Prince of Denmark}}''. Hamlet asks himself whether it is "Nobler in the mind to suffer / The Slings and Arrows of outrageous Fortune" (to resign oneself to one's fate and endure what may come), or to "take Arms against a Sea of troubles, / and by opposing end them" (to commit suicide and end suffering); he ultimately concludes that we would rather face the dangers and pains we know on Earth than whatever unknown new ones may come in the afterlife. Cueball appears to agree with Hamlet, thanking "the people who refused to gracefully accept the ineffability of reality": Religion and spirituality can give him the moral courage to face his death, but he'd much prefer to not die in the first place, and won't have to, thanks to medical and scientific innovation. (Actually he will have to eventually. Medical and scientific innovation simply delay the inevitable events of death and entropy.)

The title text is a pun based on Cueball's newfound confidence, asserting that his statement "because they work, bitches" has a 95% ''confidence'' interval.

==Transcript==
:[The three panels are arranged diagonally, upper left to bottom right.]
:[Two people, Cueball and White Hat, are walking past a tree.]
:White Hat: So, has this sickness opened you up to looking for answers beyond science?
:Cueball: ...no, not really.

:[Cueball turns to face White Hat.]
:Cueball: We've groped for comfort before the slings and arrows of fortune for millennia, and I begrudge nobody their sources of solace.
:Cueball: But Science provides ''tools''.
:Cueball: $100 billion a year in scientific studies and medical R&D has bought us some pretty damn powerful slings and arrows of our own.
:Cueball: This world is amazing, and I'm going to live to experience more of it thanks to people who refused to gracefully accept the ineffability of reality.
:Cueball: I find my courage where I can, but I take my weapons from science.

:Cueball: Because they ''work'', bitches.

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring White Hat]]
[[Category:Cancer]]
[[Category:Science]]
[[Category:Religion]]

1919: Interstellar Asteroid

2022-05-04T01:28:07Z

Big square: Undo revision 232779 by X. K. C. D. (talk)

<div style="display: none">crap</div> <div style="display: none">crap </div>
{{comic
| number = 1919
| date = November 22, 2017
| title = Interstellar Asteroid
| image = interstellar_asteroid.png
| titletext = Every time we detect an asteroid from outside the Solar System, we should immediately launch a mission to fling one of our asteroids back in the direction it came from.
}}

==Explanation==
{{w|ʻOumuamua}} is the first detection of an [https://www.nasa.gov/planetarydefense/faq/interstellar interstellar asteroid] passing through the Solar System originating from another solar system.

[[Megan]]'s list of objects with a similar shape ratio:
* The 1:4:9 {{w|Monolith (Space Odyssey)|monolith}} from the sci-fi movie ''{{w|2001:_A_Space_Odyssey_(film)|2001: A Space Odyssey}}''
* A {{w|Star Destroyer}}, a spaceship in the ''{{w|Star Wars}}'' universe. This one seems particularly unlikely, as the Star Wars mythos is set a long time ago in a galaxy far, far away, and rarely (if ever, depending on the continuity) strays outside of said galaxy.
* Huge eggplant emoji (🍆, U+1F346 Aubergine, commonly used to represent a penis).
* Statue of {{w|"Weird Al" Yankovic}}, an American singer and parodist
* iPhone XXXXX, likely making fun of Apple's {{w|iPhone X}} and larger in size
* [http://voltron.wikia.com/wiki/Voltron_(Voltron_Force) Voltron], a giant robot from the animated series ''{{w|Voltron|Voltron: Defender of the Universe}}''
* A giant {{tvtropes|BurialInSpace|space coffin}} with someone inside.

As soon as Megan lists off the last item, she is about to start speculating within her own speculative scenario about who or what might be in the coffin before Cueball interrupts her. Cueball attempts to bring Megan back down to earth by reminding her that she has too little data to work with (one data point), but Megan is far too excitable to listen to reason. A good example of the dangers of speculating irresponsibly, it would seem.

It could also be argued that Megan with this makes fun of many news outlets whose first reaction to a new space body often seems to be to search for something to compare its shape to, such as with the [https://en.wikipedia.org/wiki/67P/Churyumov–Gerasimenko#Shape 'rubber duck' comet]. Making fun of media covering science news is a recurring theme on xkcd.

The title text suggests taking reciprocal action by sending asteroids away when the solar system receives them. This would, of course, be difficult, given the amount of energy needed to shift asteroids outside of the Sun's gravity hold. On top of that, it appears to imply that some non-human entity is sending these rocks, which is an inane idea. This could be a reference to the movie {{w|Starship Troopers (film)|Starship Troopers}}, where a race of aliens mankind is at war with supposedly hit Earth with asteroids. Given that a typical interstellar traveler -- like the one spotted now in real life -- spends millions of years getting from one star system to another, the movie's idea is plain stupid; in fact, the movie gives no proof the aliens were actually responsible, leading to a common fan theory that the asteroid was indeed random space junk and the aliens are being framed by the human government as pretense for war.

==Transcript==
:[Megan walks towards Cueball while looking at her phone. Cueball sits in front of his laptop.]
:Megan: Hey, you know that asteroid that tumbled past from another star system? It's apparently really long and skinny.
:Megan: Like a ratio of 6:1 or 10:1.
:Cueball: Weird. Wonder what it's shaped like.

:[Megan lowers her phone and looks up. Cueball looks backward.]
:Megan: Without more data, it would be irresponsible to speculate further.
:Cueball: So...you're going to?
:Megan: ''Absolutely.''

:[Frameless panel focusing on Megan.]
:Megan: Here are some objects with a similar shape ratio:
:Megan: The 1:4:9 monolith from ''2001: A Space Odyssey''.
:Megan: A star destroyer.
:Megan: A huge eggplant emoji.

:[Same setting with Megan and Cueball.]
:Megan: A statue of Weird Al. An iPhone XXXXX. Voltron.
:Megan: A giant space coffin. But who could be inside? We can only guess. I'll start:
:Cueball: This is all based on ''how'' many data points, again?
:Megan: One. But it's a ''perfect'' fit!

{{comic discussion}}

[[Category: Comics featuring Megan]]
[[Category: Comics featuring Cueball]]
[[Category:Star Wars]]
[[Category:Astronomy]]

327: Exploits of a Mom

2022-05-04T01:25:59Z

Big square: Undo revision 233822 by X. K. C. D. (talk)

{{comic
| number = 327
| date = October 10, 2007
| title = Exploits of a Mom
| image = exploits_of_a_mom.png
| titletext = Her daughter is named Help I'm trapped in a driver's license factory.
}}

==Explanation==
[[Mrs. Roberts]] receives a call from her [[Little Bobby Tables|son]]'s school. The caller, likely one of the school's administrators, asks if she really named her son <code>Robert'); DROP TABLE Students;--</code>, a rather unusual name. Perhaps surprisingly, Mrs. Roberts responds in the affirmative, claiming that she uses the nickname "Little Bobby Tables." As the full name is read into the school's system's databases without {{w|Data sanitization#SQL injection|data sanitization}}, it causes the "Students" table in the database to be dropped, meaning it gets deleted.

The title of this comic is a pun. ''Exploit'' can mean an accomplishment or heroic deed, but in computer science, the term refers to a program or technique that takes advantage of a vulnerability in other software. In fact, one could say that her exploit is to exploit an exploit (her achievement is to make use of a vulnerability). The title can also refer to her choice of name for her son, which is rather extraordinary.

In {{w|SQL}}, a database programming language, commands are separated by semicolons <code>;</code>, and strings of text are often delimited using single quotes <code>'</code>. Parts of commands may also be enclosed in parentheses <code>(</code> and <code>)</code>. Data entries are stored as "rows" within named "tables" of similar items (e.g., <code>Students</code>). The command to delete an entire table (and thus every row of data in that table) is <code>DROP TABLE</code>, as in <code>DROP TABLE Students;</code>.

The exploited vulnerability here is that the single quote in the name input was not correctly "escaped" by the software. That is, if a student's name did indeed contain a quote mark, it should have been read as one of the characters making up the text string and not as the marker to close the string, which it erroneously was. Lack of careful parsing is a common SQL vulnerability; this type of exploit is referred to as {{w|SQL injection}}. Mrs. Roberts thus reminds the school to make sure that they have added data filtering code to prevent code injection exploits in the future.

For example, to add information about Elaine to a data table called 'Students', the SQL query could be:
<br><code>INSERT INTO Students (firstname) VALUES ('Elaine');</code>

However, using the odd name <code>Robert');DROP TABLE Students;-- </code> where we used "Elaine" above, the SQL query becomes:
<br><code>INSERT INTO Students (firstname) VALUES ('Robert');DROP TABLE Students;-- ');</code>

By insertion of the two semi-colons in the odd name, this is now three well-formed SQL commands:
<br><code>
INSERT INTO Students (firstname) VALUES ('Robert');

DROP TABLE Students;

-- ');
</code>

The first line is valid SQL code that will legitimately insert data about a student named Robert.

The second line is valid injected SQL code that will delete the whole Student data table from the database.

The third line is a valid code comment (<code>-- </code> denotes a comment), which will cause the rest of the line to be ignored by the SQL server.

For this to work, it helps to know the structure of the database. But it's quite a good guess that a school's student management database might have a table named <code>Students</code>.

Of course, in real life, most exploits of this kind would be performed not by engineering a person's name such that it would eventually be entered into a school database query, but rather by accessing some kind of input system (such as a website's login screen or search interface) and guessing various combinations by trial and error until something works, perhaps by first trying to inject the <code>SHOW TABLES;</code> command to see how the database is structured.

To correctly and harmlessly include the odd name in the Students table in the school database the correct SQL is:
<br><code>INSERT INTO Students (firstname) VALUES ('Robert<nowiki>''</nowiki>);DROP TABLE Students;-- ');</code>

Note that the single quote after Robert is now sanitized by doubling it, which changes it from malicious code to harmless data, and the full first 'name' of the student <code>Robert';DROP TABLE Students;--</code> is now stored correctly.

It should be noted that while data sanitization can mitigate the risks of SQL injection, the proper prevention technique is to use {{w|Prepared statement}}s.

Noting the difference between the "actual" name using the word TABLE and the child's nickname being Bobby Tables, one could argue that there's an implied reference to one of the most argued topics of database naming conventions - should table names be singular or plural.

The title text references that Mrs. Roberts' daughter is named "Help I'm trapped in a driver's license factory". This is a play on how if someone is stuck and forced to work in a manufacturing factory/plant, then they will write on the product {{tvtropes|HelpHelpTrappedInTitleFactory|"Help I am trapped in a ____ factory"}} in order to tell people on the outside. Having this name would cause any police officer who pulls her over to show some concern. And getting the license in the first place would likely be difficult. The idea of inserting a help message like this was already used in [[10: Pi Equals]].



==Transcript==
:[Mrs. Roberts receives a call from her son's school on her wireless phone. She is standing with a cup of hot coffee or tea (shown with a small line above the cup) facing a small round three-legged table to the right. The voice of the caller is indicated to come from the phone with a zigzag line.]
:Voice over the phone: Hi, This is your son's school. We're having some computer trouble.

:[In this frame-less panel Mrs. Roberts has put the cup down on the table turned facing out.]
:Mrs. Roberts: Oh, dear – did he break something?
:Voice over the phone: In a way –

:[Mrs. Roberts is now drinking from the cup again looking right. The table is not shown.]
:Voice over the phone: Did you really name your son <code>Robert'); DROP TABLE Students;--</code> ?
:Mrs. Roberts: Oh, yes. Little Bobby Tables, we call him.

:[Mrs. Roberts holds the cup down.]
:Voice over the phone: Well, we've lost this year's student records. I hope you're happy.
:Mrs. Roberts: And I hope you've learned to sanitize your database inputs.

==Trivia==

This comic has become rather famous, spawning a site at http://bobby-tables.com about preventing SQL injection and also at the official [https://docs.python.org/2/library/sqlite3.html Python SQLite documentation]. Noted security expert {{w|Bruce Schneier}} (who often quotes xkcd) [https://www.schneier.com/blog/archives/2010/10/pen-and-paper_s.html mentioned a similar attack] that happened in the 2010 Swedish general elections, and [https://blog.xkcd.com/2010/05/03/color-survey-results/ several people tried it on Randall's color survey].

In [[1253: Exoplanet Names]], someone (presumably Mrs. Roberts) attempts to perform a similar trick, submitting the name <code>e'); DROP TABLE PLANETS;--</code> to the IAU.

It is later revealed in [[342: 1337: Part 2]] that the daughter's middle name is [[Elaine]] (full name: ''Help I'm trapped in a driver's license factory Elaine Roberts''). This is thus the first time Elaine is mentioned. Seems like this comic was a setup for the "[[:Category:1337|1337]]" series where both this exploiting mom's kids are shown for the first time.

This comic is available as a signed print in the [https://store.xkcd.com/products/signed-prints xkcd store].

In 2020 this happened in real life: [https://www.engadget.com/compan-changes-name-over-website-hack-risk-215412415.html Company made to change name that could be used for website hacks].

{{comic discussion}}

[[Category:Comics featuring Mrs. Roberts]]
[[Category:Comics featuring Little Bobby Tables]]
[[Category:Comics featuring Elaine Roberts]]
[[Category:Programming]]
[[Category:Computers]]
[[Category:Comics with xkcd store products]]

1439: Rack Unit

2022-05-04T01:24:34Z

Big square: Undo revision 233926 by X. K. C. D. (talk)

{{comic
| number = 1439
| date = October 27, 2014
| title = Rack Unit
| image = rack_unit.png
| titletext = There's also nothing in the TOSes that says you can't let a dog play baseball in the server room!
}}

==Explanation==
[[Black Hat]] announces to [[Megan]] that {{w|19-inch rack}}s for datacenter servers and {{w|Langstroth hive}} frames are both 19 inches wide (482.6 mm), with similar spacing between each slot. Black Hat is motivated by this knowledge to break into a Google datacenter and fill server racks with beehives. He then announces that Google led the world in datacenter honey production, an accomplishment fairly easy to achieve as no other datacenters are producing honey{{Citation needed}}. Obviously, such an action led to Black Hat being kicked out from the facility by security guards and the loss of his hives. When Megan sarcastically consoles Black Hat for the loss of his hives, he declares that he'll find other datacenters to install hives in.

The pitch (or distance between repeating items) of 19 inch rack server hardware is measured in {{w|Rack_unit|rack units (U)}}, and is standardized at 1.75" (44.45 mm). Langstroth frames are typically mounted at a pitch of [http://www.scottishbeekeepers.org.uk/Portals/0/Documents/TDS%20number%205%20langstroth%20and%20md%20hive.pdf 1.5" (38.1 mm)], and as a result would fit relatively well with a server cabinet. In contrast to the horizontal orientation of the modules in a server rack, honeycomb frames are designed to hang vertically, so the cells can hold nectar without it dripping out. How Black Hat was able to re-orient the racks to suit the needs of honey production remains a mystery.

Some datacenters provide colocation services where customers may install a server at a central location with better bandwidth and power reliability than a customer could provide on their own. Noticing that typical colocation {{w|terms of service}} (TOS) agreements don't specifically rule out the installation of beehives, Black Hat suggests he can enter a legal contract allowing him to install beehives at a data center without being kicked out. This, of course, is because nobody had previously thought that such a rule was necessary. Megan expects this to change once Black Hat starts deliberately exploiting this oversight.

The title text is a reference to the film [http://www.imdb.com/title/tt0118570/quotes?ref_=tt_ql_3 Air Bud]. The original quote is "Ain't no rules says a dog can't play basketball." Much like Black Hat's beehive plan, the plot of Air Bud relies on a plan being so outlandish that nobody has ever thought to specifically forbid it before.

==Transcript==
:[Megan and Black Hat are talking, Megan is sitting at a computer.]
:Black Hat: I've discovered something.
:Megan: Oh?
:Black Hat: Standard server rack units and standard beehive honeycomb frames are compatible.
:Black Hat: They're both 19 inches, with similar pitches.
:Megan: Uh oh.
:Black Hat: I'm pleased to announce that today, for a few hours, Google led the world in datacenter honey production.
:Black Hat: Until their security people kicked me out.
:Megan: I'm sorry your beekeeping career ended so quickly.
:Black Hat: I'll find a new datacenter.
:Black Hat: Turns out most colocation TOSes don't mention beehives.
:Megan: I suspect that will soon change.

{{comic discussion}}

[[Category:Comics featuring Black Hat]]
[[Category:Comics featuring Megan]]
[[Category:Computers]]
[[Category:Animals]]
[[Category:Baseball]]

1585: Similarities

2022-05-04T01:24:06Z

Big square: Undo revision 234095 by X. K. C. D. (talk)

{{comic
| number = 1585
| date = October 2, 2015
| title = Similarities
| image = similarities.png
| titletext = I just came from The Martian, and I just have to say: Forget BB-8; I want a pet Sojourner! It's always been the cutest of our Mars rovers.
}}

==Explanation==
There's a common punchline in which the plot lines of two thematically-different works of fiction (usually movies) are compared in greatly-abbreviated form, and the speaker sarcastically concludes that the two movies are "basically the same". For sake of example, Disney's ''{{w|Aladdin (1992 Disney film)|Aladdin}}'' and {{w|James Cameron}}'s ''{{w|Titanic (1997 film)|Titanic}}'' [http://imgur.com/gallery/kasCMYd both feature a story] in which a lower-class boy and an upper-class girl fall for each other, among other cherry-picked yet interesting parallels. But due to the different emotional tones of the films (a family-friendly "happy ever after" tale and a disaster thriller respectively), one would not normally describe them as similar.

This comic spoofs the idea. Instead of comparing plot lines of two movies, [[Ponytail]] and [[Cueball]] compare the respective movies' development histories.

''{{w|The Martian (Weir novel)|The Martian}}'' was originally a serialized story written by {{w|Andy Weir (writer)|Andy Weir}} on his blog which was later compiled into an ebook for people to easily download, then published into a physical book, and has now had a {{w|The Martian (film)|movie}} created based on it. The movie was officially released in the US on the same day this comic was released (October 2, 2015).

''{{w|Fifty Shades of Grey}}'' began as a {{w|fan fiction}} of a well known brand (the {{w|Twilight (novel series)|Twilight book series}}). It was originally written on the internet by {{w|E. L. James}}. It was then transformed into a successful book series which was later turned into a {{w|Fifty Shades of Grey (film)|movie}} released in February 2015. The book was already referenced back in 2012 in [[1128: Fifty Shades]].

Since ''Fifty Shades'' is a romance story about a sadomasochistic relationship, and ''The Martian'' is a very technical story about surviving completely alone on a hostile planet, the two books could not be any more different, hence the joke due to the juxtaposition.

Cueball continues the joke by joining the two titles using red for Mars, to make a new book title, that should cover both books: ''Fifty Shades of Red.'' Ponytail says to Cueball that such a book would be irresistible for him. She does this by daring him to say that he wouldn't read it, believing he could not say so without lying. The red could also be a reference to the safe word used in the Fifty Shades series, for when things hurt instead of being pleasing. It means stop! But stop should be a word you can say, without the other one stopping, adding to the illusion of being forced; actually stopping would be done by saying ''red''. Reading it like that, the title would be ''Fifty Shades of Stop''!

It is not clear from the comic if [[Randall]] liked the movie. Since he now compares it to a book series that has been {{w|Fifty_Shades_of_Grey#Background|described}} as ''mommy porn'' it could indicate that he was not so satisfied with the movie. On the other hand, he may just have noticed this connection and found that it would make a great joke here on the release day.

An alternative explanation is that Randall is commenting on the [http://screencrush.com/the-martian-damon-interstellar/ frequent] [http://io9.com/sorry-interstellar-we-just-saw-some-of-the-martian-an-1699793860 comparisons] made between The Martian and the movie {{w|Interstellar (film)|Interstellar}}, comparisons centering on the fact that in both {{w|Matt Damon}} plays an astronaut stuck on a deserted planet, but also mentioning, among others, the appearance of {{w|Jessica Chastain}} and the similar design of the spacesuits used in both movies. These comparisons have been prevalent on the Internet long before the release of The Martian, so evidently spurred by the movie trailers, rather than by reviews of viewers. Randall is making the point that to one who has seen the movie, comparing The Martian to Interstellar is as far-fetched as comparing it to Fifty Shades of Grey. According to this interpretation, Randall is not ridiculing The Martian, but rather Interstellar. By proxy, he is praising The Martian. Given that Randall has chosen (now for the second time) to mention the film explicitly on his site, the idea that he is promoting The Martian is perhaps more plausible than the idea that he is expressing dissatisfaction with it. The title text, where he makes a similar comparison, favoring The Martian over Star Wars: The Force Awakens, further boosts this explanation.

It is possible that the brand that ''The Martian'' derives from is {{w|NASA}} itself. ''The Martian'' has been compared to the film {{w|Apollo 13 (film)|Apollo 13}} by Randall in [[1536: The Martian]]. ''Apollo 13'' does indeed glorify the roles of the NASA engineers, and ''The Martian'' does a similar thing. That Randall would go see this movie as soon as it was released was already made perfectly clear back in June when he released the comic [[1536: The Martian]] showing how excited he is about the book. He then really looked forward to the movie.

Randall indicates in the title text that he has just seen the movie (certainly possible, if he caught a midnight screening; perhaps he drew this comic in advance and wrote the title text after) and finds the Sojourner rover adorable. Of course, he could also have seen it in the trailers.

The [http://starwars.wikia.com/wiki/BB-8 BB-8] mentioned in the title text is the {{w|astromech droid}} from the movie {{w|Star Wars: The Force Awakens}} and is available as a toy (see also BB-8 on the [http://www.starwars.com/databank/bb-8 official Star Wars] home page). {{w|Sojourner (rover)|Sojourner}} was the Mars ''Pathfinder'' robotic rover used by Mark Watney, the protagonist of ''The Martian'' (played by Matt Damon in the movie), to allow him to contact Earth. Randall indicated that he thinks the Sojourner is much cuter than BB-8, and that he would like to have one as a pet. He then states that the Sojourner has always been the cutest among all the [[:Category:Mars rovers|Mars rovers]]. The cuteness of Mars Rovers is also mentioned in [[2433: Mars Rovers]]. There have been four so far the other three being {{w|Opportunity (rover)|Opportunity}}, {{w|Spirit (rover)|Spirit}} and {{w|Curiosity (rover)|Curiosity}} which have already been used in xkcd comics: [[695: Spirit]], [[1091: Curiosity]] and [[1504: Opportunity]].

==Transcript==
:[Ponytail is talking to Cueball.]

:Ponytail: So it's a work of fiction about a well-known brand. written on the Internet by an enthusiast, republished as a bestselling book, and then made into a big movie.
:Cueball: Yup.

:[Ponytail holds her hand to her chin. Beat panel.]

:[Ponytail is talking to Cueball again.]
:Ponytail: Yeah, ''The Martian'' and ''Fifty Shades of Grey'' are basically the same book.
:Cueball: "''Fifty Shades of Red?''"
:Ponytail: Man, ''tell'' me you wouldn't read that.

{{comic discussion}}

[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring Cueball]]
[[Category:Fiction]] 
[[Category:Mars rovers]] 
[[Category:Star Wars]] 
[[Category:Space]]
[[Category:Twilight]]

553: Pirate Bay

2022-05-04T01:23:38Z

Big square: Undo revision 233773 by X. K. C. D. (talk)

{{comic
| number = 553
| date = March 9, 2009
| title = Pirate Bay
| image = pirate_bay.png
| titletext = We find you guilty of closing your torrents as soon as they finish. Your sentence is unremovable Hungarian subtitles on everything.
}}

==Explanation==
{{w|The Pirate Bay}} is a website dedicated to facilitating {{w|Bittorrent|BitTorrent}} downloads of popular media. The site's servers were taken down, briefly, and the operators were {{w|the pirate bay trial|taken to court}} in Sweden, back in 2009.

Unlike normal downloads, files downloaded via Bittorrent are not stored on any web server, but instead transferred in small pieces by other people torrenting the same file; these other people are called "peers." Bittorrent allows websites to provide downloads without using up disk space or bandwidth serving up the entire file; instead, they can host smaller torrent files, which simply describe what the finished file should look like and a few "tracker" servers where lists of other peers can be found, and the peers themselves handle all of the bandwidth issues. This approach is used by a number of websites for completely legal downloads (it's popular among smaller game companies providing digital downloads, for instance), but it's mainly associated with piracy.

However, Bittorrent depends on peers actually having the file blocks that you need. People who have already downloaded the entire file, but continue to connect to the network solely to provide that file to others, are called "seeds," and they are an essential part of a healthy torrent. General etiquette demands that people should continue to seed a file until the ratio of data uploaded to data downloaded exceeds 1, although many people feel that one's ratio should be much higher. In any case, closing your torrents as soon as they finish, as mentioned in the title-text, is extremely ''bad'' etiquette, so it is punished with nuisance subtitles. This punishment was likely chosen because finding correct and well timed subtitles, in whatever language, for a pirated show tends to be quite hard sometimes.

This comic is essentially a pun on this second meaning of the word "peer" - in the US court system, a "jury of your peers" means a jury composed of everyday people like you, while the [https://vpnalist.com/proxy-mirror-the-pirate-bay Pirate Bay] operators interpret it to mean a jury composed of people who they've shared files with in the past. The [[Cueball]] that does the talking, and thus is the protagonist of the comic, feels that his approach would give him lenience in the trial, since he has always seeded well, thus ensured those peers had a good downloading experience.

The title text shows what punishment this kind of peer group would make if they find you guilty - unremovable subtitles in {{w|Hungarian language|Hungarian}}. Many pirated videos originate from countries where no {{w|Dubbing (filmmaking)|dubbed}} version is available in the regional language, so the only way to understand what's being said is by applying subtitles. These videos are then uploaded with subtitles still included, causing consternation among downloaders who can understand the spoken words but not the subtitles. Annoying Hungarian subtitles are just an example for a language most people don't understand. Finnish, Czech, or Polish wouldn't be better.

==Transcript==
:[Caption above the frame:]
:Awaiting the judges' ruling at the Pirate Bay trial.

:[4 Cueball-like guys in a cell: 3 sitting down on a bench and one is standing, presumably looking at the fence.]
:Cueball: I wish this were in America.
:Cueball-like guy: Why?
:Cueball: I hear we'd go before a jury of our peers, and I've always seeded generously.

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Multiple Cueballs]]
[[Category:Internet]]
[[Category:Puns]]

857: Archimedes

2022-05-04T01:23:01Z

Big square: Undo revision 234536 by X. K. C. D. (talk)

{{comic
| number = 857
| date = February 7, 2011
| title = Archimedes
| image = archimedes.png
| titletext = Give a man a fish, or he will destroy the only existing vial of antidote.
}}

==Explanation==
This comic references a famous quote made by {{w|Archimedes}}: [http://en.wikiquote.org/wiki/Archimedes δῶς μοι πᾶ στῶ καὶ τὰν γᾶν κινάσω], which could translate as "Give me a long enough lever and a place to rest it, and I will move the Earth". Archimedes was illustrating the power of {{w|force multiplication}} by stating that, in theory, even a mass as immense as the entire planet Earth could be moved by a single human being using a simple {{w|lever}}.

While Archimedes is theoretically correct, in practice the lever would need to be millions of light years long, and the person operating it would need to push it by several light years to move the Earth even a microscopic amount. In fact, a much simpler way to move the Earth, which achieves similar distances, is to jump in the air - by Newton's third law, the same amount of force that is applied to you will also be applied to the Earth.

Here, [[Cueball]] begins as if he is quoting Archimedes, but then produces a gun and threatens to execute hostages if he does not receive the lever, indicating that he is, for some reason, actually trying to enact Archimedes' thought experiment for real.

The title text references another famous proverb, "Give a man a fish, and you feed him for a day. Teach a man to fish, and you feed him for a lifetime." The quote starts out the same, but again ends with a sentence that is more fitting for an action movie.

==Transcript==
:[Cueball is standing normally.]
:Cueball: In the words of Archimedes,

:[Cueball extends his left arm slightly.]
:Cueball: Give me a long enough lever and a place to rest it

:[Cueball is now holding a gun in his right hand.]
:Cueball: Or I will kill one hostage every hour.

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Physics]]

1678: Recent Searches

2022-05-04T01:22:32Z

Big square: Undo revision 233187 by X. K. C. D. (talk)

{{comic
| number = 1678
| date = May 9, 2016
| title = Recent Searches
| image = recent_searches.png
| titletext = autoexec code posted by verified twitter users
}}

==Explanation==
People often find answers to computer problems by searching on {{w|Google}}, which attempts to guess your intended search term based on your location, language and the characters you've already typed, placing its suggestions in a drop-down box beneath the input area. If the search box is clicked on but nothing is typed, the drop-down box by default shows a list of your most recent searches.

Here we see a list of search queries, each of which suggests the author is perversely misusing or overextending some computer technology. The overall impression is of someone technically sophisticated enough to shoot themselves in the foot, and who does not learn any larger lessons despite doing so repeatedly. The title text is another possible entry in this list.

The caption implies that from Randall's perspective, every computer he uses seems to be broken; he doesn't seem to realise this is because he's the one using them, not because the computers actually start off broken. (For similar themes see also these comics: [[349: Success]], [[1084: Server Problem]], [[1316: Inexplicable]] and [[1586: Keyboard Problems]]).

([[979|Dear people from the future]], if Google directed you here because it is the most popular result for a problem you are experiencing, this is not the page you were looking for).

===List of searches===
; [https://www.google.com/search?q=Google+translate+syntax+highlighting Google translate syntax highlighting]
: {{w|Syntax highlighting}} can be used when editing {{w|source code}} to make the code more readable and easier to understand. It is not generally used for natural languages, but {{w|sentence diagram}}s of brief passages are used in language education. {{w|Google Translate}} is used to translate text from one {{w|natural language}} to another. It uses {{w|JavaScript}} <tt>mouseover()</tt> to highlight words as an aid in matching phrases in the source with their translations, but does not apply different highlighting dependent on syntax.
:Alternatively, this could imply that Randall is attempting to translate code from one programming language to another using Google Translate. Success would be unlikely, since the service is not intended for this {{Citation needed}}, and syntactically valid output might further break the computer executing it.
:Two other possible interpretations of this phrase are that Randall wants to translate the phrase "syntax highlighting" to another language, or that he wants to perform syntax highlighting on the source code for Google Translate.
; Autodetect mixed bash zsh
: {{w|Bash (Unix shell)|Bash}} and {{w|Z_shell|Zsh}} are two {{w|Command-line_interface|command line interfaces}} for {{w|Unix-like}} OSes. The way to execute commands is almost identical, making detecting a script that contains a mixed syntax nearly impossible. This was later referenced in [[2510: Modern Tools]].
; CPU temperature sensor limits
: The CPU's temperature sensors exist to tell you when your CPU is becoming dangerously overheated (normally because of a faulty fan or overclocking). Someone who searches for information about the limits of those sensors is presumably expecting to misuse their CPU. Probably also a reference to [[1172: Workflow]].
; GIF to XLS
: .GIF (Graphic Interchange Format) is a file extension used to store images and sequences of images to be displayed as an animation. .XLS is the file extension for Microsoft Excel spreadsheets. The joke is that the two file types are used for different purposes - it's quite normal for someone to want to convert between .GIF, .JPG, .PNG, .BMP files, as these are all image files; or between .XLS, .CSV, and .ODS files, as these all record tabulated information. However, for some reason Randall wants to convert an image file to a spreadsheet. (This is actually possible, because a digital image is essentially an array of colour and brightness values; it just wouldn't be particularly useful for most people. [http://www.think-maths.co.uk/spreadsheet Here] is a webpage with an online converter.) Matt Parker has done a [https://www.youtube.com/watch?v=UBX2QQHlQ_I stand up routine] about converting these two file types.
:An alternate way to convert an image file, such as a .GIF file, into a text-based file like an .XLS file, is through {{w|optical character recognition}} (OCR). This is only effective if the image is a copy (i.e. a scan or reasonably clear photograph) of a document containing letters and words, and neither .GIF nor .XLS are file formats anyone would usually use in that case.
; Clock speed jumper sample rate
: A jumper is an intentional short circuit used for selecting options for an electronic circuit. They are usually used where it is not feasible to use programming (such as outputting a byte or word through a port) to alter the selection, such as before the processor even begins executing. A common example would be, on some motherboards, jumpers can be used to alter the clock speeds of various motherboard functions (such as the CPU or the front side bus). These jumpers should ordinarily be modified when the computer is off. However, this search is asking how often the motherboard checks the status of the clock speed jumpers, implying that they intend to change these jumpers while the computer is powered on, and often enough that the sample rate matters (change cpu speed several times a second, by moving jumpers on the motherboard.). That is, of course, a little silly.
; [https://www.google.com/search?q=clean+reinstall+keybinding Clean reinstall keybinding]
: This refers to keybinding, the practice of mapping (binding) a certain key to a certain function (e.g., pressing PRTSC will take a screenshot). Most keyboards do not output characters directly, but only codes for which keys have been pressed (or released). Keybindings translate the pressing of the "A" key on your keyboard into the letter "A" being sent to a program which is reading keyboard input. A "clean reinstall" of keybindings is something that would almost never be necessary - it means Randall has modified his default keybindings to such an extent that his [[1031:_s/keyboard/leopard/|leopard]] has become unusable (similar to [[1284: Improved Keyboard]]), necessitating a "clean reinstall" of the bindings. Alternatively, he might be doing clean reinstalls so often that he wants a keybinding to execute them with minimal loss of time.
; Cron job to update crontab
: {{w|Cron}} is a utility on most Unix-like OSes that allows you to schedule commands or scripts to be run periodically. These scheduled jobs are read from a ''crontab'' file. A job that updates the crontab (therefore creating new jobs, removing old ones or editing existing ones) is paramount to a {{w|job scheduler}}, and trying to use cron for such functionality could result in highly unstable functionality (although a crontab could be sensibly regenerated periodically by a set of machines from a master crontab file annotated with per-host directives). This is similar to {{w|self-modifying code}}.
; [https://www.google.com/search?q=fsck+chrome+extension fsck Chrome extension]
: This is a search for an interface to the Unix '''f'''ile'''s'''ystem che'''ck'''er {{w|fsck}} via third-party software added to Chrome. fsck is a program for checking your filesystem for corruption. Repairing a filesystem this way would be inadvisable. {{Citation needed}} This might indicate confusion about the meaning of the term "online filesystem repair", in which "online" means "while the filesystem is in use" rather than "over the Internet". Alternatively, Randall might want to repair an installation of the operating system Chromium, in a manner less drastic than the {{w|factory reset}} preferred by Google.
; Recursive font
: An idiosyncratic mix of {{w|recursion}} and the font style ''{{w|cursive}}'', referring especially to text handwritten in a flowing manner. {{w|PostScript}} (the language in which {{w|PostScript fonts|some fonts}} are written) is capable of recursion and PostScript Type 3 fonts are able to use the full language. This could create effects like fonts with complicated fractal borders and fill patterns - but the increase in processing time would contribute to seeming brokenness of the computer (or printer) rendering the font.
:A true recursive font would be a form of {{w|fractal}}s ([http://blog.matthen.com/post/5340546486/first-sketches-in-mathematica-for-a-new-font-it example]).
; Regex matching valid EBNF
: EBNF refers to {{w|Extended Backus–Naur Form}}, which is used to define {{w|formal language}}s. EBNF specifies recursive patterns that are impossible for a {{w|Regular_Expression|regular expression}} (regex) to determine whether it is valid or not. There is some irony in using regex to test the validity of something which ''defines'' the validity of things like regex.
; [https://www.google.com/search?q=Hardlinks+Turing+complete Hardlinks Turing complete]
: In some file systems, for example {{w|ext4}} and {{w|NTFS}}, a single file may be referenced in multiple places in the file system. These filenames are termed "hard links" because the operating system automatically resolves them to the actual file. "Soft" or "symbolic" links are resolved indirectly via a pathname, which may reside anywhere. A file is considered deleted when the last hard link to it is unlinked; a soft link exists independently of its target. In fact, the target need not exist, in which case this is often called a dangling symbolic link.
:{{w|Turing completeness}} is the {{w|computational complexity}} required to simulate any {{w|computable function}} (given an infinite amount of memory). Recently there have been cases where [http://beza1e1.tuxen.de/articles/accidentally_turing_complete.html unexpected mechanisms] from card games to text parsers were proved to be Turing complete. Hardlinks being Turing complete would imply that creating and deleting hardlinks alone is enough to satisfy the requirements of Turing completeness.
; Opposite of safe mode
: {{w|Safe mode}} is a diagnostic mode in many operating systems and applications which allows the user to troubleshoot problems by disabling unnecessary functionality. The "opposite of safe mode" implies a "dangerous mode" where the purpose is to allow uselessly dangerous actions (in actuality this supposed dangerous mode is the default mode). A common example is the {{w|sudo}} command in Unix-like OSes, which grants the user system-level permissions.
:It's also possible that Randall sees Safe Mode so often that he sees regular mode as an unusual and unique state and needs help navigating back to it.
; Predictive touchpad
: {{w|Predictive text}} is a feature of many smartphone keyboards that predicts the most likely word the user wishes to type, and then gives the user the option to place the full word in the sentence immediately without having to finish typing it. A {{w|touchpad}} is a computer pointing device, similar to a {{w|computer mouse}}. The idea of a "predictive touchpad" seems absurd because, as opposed to typed words, there are not a limited number of swipe combinations that are possible on a touchpad. A "predictive touchpad" implies that a computer could predict where the user was going to move the mouse or click, which in this case would seem to defeat the purpose of a user input device. {{Citation needed}}.
:Interestingly, a version of Linux had a predictive cursor option, where the cursor jumped to the nearest button (like window close) when it moved near to but didn't quite reach that button.
; Google docs from bootloader
: A {{w|bootloader}} is a very small program that is usually the very first thing to execute when a computer boots up. It is used mainly for loading the operating system into memory. Such a program by itself would not be capable of directly running something as complex as {{w|Google Docs}}.
; Hardware acceleration red channel only
: {{w|Hardware acceleration}} means that certain calculations are not performed by the computer's {{w|CPU}} but by a "specialized" processor, e.g. a {{w|GPU}} which is part of the graphics adapter. This speeds up output, especially if complex 3D calculations are required, and reduces CPU load. To use this function only on a single color channel seems pretty useless, but one may want to troubleshoot a program that displays only red when hardware acceleration is enabled.
:While graphics cards are most commonly used with three or four channels (red, green, blue, and sometimes alpha), they do support two-channel or single-channel images. An 8-bit single-channel image would use the format '[https://www.opengl.org/wiki/Image_Load_Store#Format_qualifiers R8]', which is indeed 'red channel only'. This type of image could be used to store monochrome images or non-image data.
; autoexec code posted by verified twitter users. ('''Title text''')
: The term "autoexec" refers to code that runs automatically, usually during boot, and derives from one of three boot-time files for {{w|MS-DOS}}: AUTOEXEC.BAT, CONFIG.SYS and COMMAND.COM. AUTOEXEC.BAT would typically contain commands for customizing the command prompt, loading additional drivers, and/or automatically launching a program.
:Automatically executing code from the Internet is generally a terrible idea, because it could be written by someone with malicious intent and harm your computer. The joke here is that the code would only be executed if written by someone who has been "verified" on Twitter. Twitter's verification service only serves to show that a user is who they claim to be, not whether or not their code can be trusted, so this would provide little protection. Usually, Twitter verification is used by celebrities so they can be distinguished from people claiming to be them. The line implies that Randall is only interested in running code posted by celebrities.
:Most code downloaded from authentic sources (such as Microsoft and official Linux distributions) is verified by a cryptographic signature from a true trusted source, authenticating the origin of the software. These may include software updates that run automatically in the background. The joke here is that the term "verified" means very different things between Twitter users and software distribution.

==Transcript==
:[Coloured and styled as the real logo:]
:GOOGLE

:[Google Search bar, with a drop down box with faded text, implying recent searches.]
:Google translate syntax highlighting
:Autodetect mixed bash zsh
:CPU temperature sensor limits
:GIF to XLS
:Clock speed jumper sample rate
:Clean reinstall keybinding
:Cron job to update crontab
:fsck Chrome extension
:Recursive font
:Regex matching valid EBNF
:Hardlinks Turing complete
:Opposite of safe mode
:Predictive touchpad
:Google docs from bootloader
:Hardware acceleration red channel only

:[Caption below the frame:]
:'''I have no idea why my computers are always broken.'''

{{comic discussion}}
[[Category:Comics with color]]
[[Category:Google Search]]

2091: Million, Billion, Trillion

2022-05-04T01:19:58Z

Big square: Undo revision 236282 by X. K. C. D. (talk)

{{comic
| number = 2091
| date = December 28, 2018
| title = Million, Billion, Trillion
| image = million_billion_trillion.png
| titletext = You can tell most people don’t really assign an absolute meaning to these numbers because in some places and time periods, “billion” has meant 1,000x what it's meant in others, and a lot of us never even noticed.
}}

==Explanation==
Much like [[558: 1000 Times|comic 558]], this comic addresses the difficulty ordinary people have with large numbers. Though most if not all people intuitively understand the difference between one object and two objects, or one object and ten objects, or even one object and a hundred objects, as numbers increase most people's ability to innately conceive of the numbers being discussed decreases remarkably quickly. When numbers reach the millions and the billions, and especially the trillions, most people don't truly process the numbers at all, and instead conceive of them as some version of a drastically-oversimplified concept such as "very big." Where comparing one to ten is simple, comparing "very big" to a different "very big" can prove extremely challenging, and will certainly require non-intuitive, conscious thinking.

The comic represents this challenge by providing a graph which represents [[Randall]]'s ''intuitive'' conception of the values of various very large numbers, and said conception's misalignment with reality. Though some trends reflect the real value of the numbers on the graph, i.e. 100 million larger than 10 million larger than 1 million and 1 billion larger than 1 million, the curve is far from the linear (exponential on the log-scaled axes) path it should take, with 1 billion being intuitively understood as less than 100 million, based, presumably, on the fact, easily comprehended on an intuitive level, that '''100 is larger than 1''', and therefore the presence of 100 in 100 million places it at a higher value than the 1 in 1 billion would place the latter. In reality, of course, 1 billion is ten times larger than 100 million, but the comic deals not with actual reality, but with the perception of reality of these numbers '''before conscious thought is applied'''.

The most interesting parts of the graph, and the parts where the disconnect between intuition and reality becomes clearest, are the dashed sections labeled with question marks, the one between 100 million and 1 billion, the other between 100 billion and 1 trillion. Here two competing intuitive understandings compete for dominance. On the one hand, the intuitive understanding described above, with 100 trumping 1, would see the curve taking a sharp downturn. On the other hand, the path from 100 million to 1 billion is paved with such numbers as 500 million, 700 million, and 900 million, all of which would theoretically be seen intuitively as larger than 100 million, thanks to the fact that 9 is greater than 7, and 7 greater than 5, and so on, bending the curve up rather than down. These two conflicting intuitions leave Randall with no single intuitive path for the two dashed sections, leading to their dashed and questioned state.

The comic's caption and title highlight another problem surrounding the intuitive grasping of large numbers: the flaws in the English words used for them. For instance, nothing about the word "million" suggests smallness relative to the word "billion" on an intuitive scale. This unintuitive language contributes greatly to the "100 trumps 1" intuitive fallacy described above.

=== Long scale and short scale ===

The title text references a highly relevant disconnect between the {{w|Long_and_short_scales|long and short scales of large numbers}}.

For all English speakers, and for most languages, 1 '''''million''''' constitutes 1,000 thousands, or, less ambiguously, 10^6. However, this is the last of the consensus numbers, and the definition of what should be the "next step" varies depending on how each country's language evolved.
* In many English-speaking countries, 1,000 millions equals 1 billion, or 1000*10^6=10^9; this convention is known as the '''short-scale'''.
* [https://en.oxforddictionaries.com/explore/how-many-is-a-billion/ In historical Britain] and many other countries with a language derived from French, German or Spanish, the "next step" may be named a thousand million, and 1 billion equals ''1 million'' millions, or 10^6*10^6=10^'''12''', with the base unit changing when you have a unit's worth multiple of the unit; this convention is known as the long-scale (note that this is no longer used in the United Kingdom and Ireland since 1974).
* In European languages where the '''long-scale''' system is used, 10^9 may be named a thousand million, or receive a name with a special suffix: the word milliard (meaning 1,000 million) is used in some form (e.g. milliard in French, Milliarde in German, milliard in Danish, milliárd in Hungarian, etc.), with the word billion defined as 1,000 milliard (or 1,000,000 million). In these languages, a billion never meant 1,000 million as it does in the short-scale system.
* Successive units, such as trillion, increase by the same multiple as one billion divided by one million - by 1,000 in the short-scale system and 1,000,000 in the long-scale system.

In other words, 1 billion objects in a country using the short-scale would be 1,000 million objects in a country using the long-scale; at the "next step", 1 trillion in the short-scale would be named 1 billion in the long-scale, despite the fact that the number of objects has remained the same. This difference between languages using the short-scale and the long-scale often causes confusion when translating articles with large numbers in them, as translators sometimes fail to change between short-scale and long-scale schemes, wrongly translating large numbers to incorrect values.

The fact that such a staggering difference of terminology was able to exist and be almost completely unknown to many supports Randall's point about the failure of human intuition in the discussion of extremely large numbers.

==Transcript==

:[A graph with Y-axis labeled “Perceived size of number” and X-axis labeled “Actual size of number (log scale)”.]
:[The line graph shows points that are labeled with the following numbers from “1 million” to “100 trillion”:]

:['''Points on graph:''']
:{| class="wikitable" style="text-align: center;"
|1 million
|[''(2, 1.5)'']
|-
|10 million
|[''(3, 3.5)'']
|-
|100 million
|[''(4, 4.8)'']
|-
|1 billion
|[''(5, 2.8)'']
|-
|10 billion
|[''(6, 4.4)'']
|-
|100 billion
|[''(7, 5.3)'']
|-
|1 trillion
|[''(8, 4.3)'']
|-
|10 trillion
|[''(9, 5.1)'']
|-
|100 trillion
|[''(10, 5.6)'']
|}
:[The perceived size increases between most numbers, but decreases between 100 million and 1 billion, and between 100 billion and 1 trillion. The decreases are shown as dashed lines labeled “?”, in contrast to the solid unlabeled lines between the increases. The increases and decreases in perceived size become smaller as the numbers grow in actual size.]
:[Caption below the panel:]
:Talking about large numbers is hard

{{comic discussion}}

[[Category:Line graphs]]

Hairy

2022-05-04T01:19:34Z

Big square: Undo revision 236124 by X. K. C. D. (talk)

{{Infobox character
| image = Hairy.png
| imagesize = 150px
| caption = Hairy
| first_appearance = [[61: Stacey's Dad]]
}}

'''Hairy''' is a [[stick figure]] character in [[xkcd]]. The name is unofficial, used by [[explain xkcd|xkcd explainers]] to describe male characters with hair and no other distinguishing features.

Hairy is not a single character, but a categorization of various one-time characters. One Hairy, a learning pickup artist, has appeared in two comics ([[1027: Pickup Artist]] and [[1178: Pickup Artists]]).

When Hairy appears with [[Cueball]] or [[Black Hat]], he generally comes off as worse (as in [[1210: I'm So Random]], or as a pickup artist). Hairy can also appear just to add some variation in a group ([[1261: Shake That]]), or as a kid ([[973: MTV Generation]], [[1176: Those Not Present]]).

There is a very early comic ([[16: Monty Python -- Enough]]) where a hairy guy delivers the joke. There is no reason to believe this is the same Hairy that [[Randall]] invented later.

Hairy's name may be "Mike" as that name is used by Cueball in [[2232: Hotel Room Party]] when addressing a group that included him.

==See also==
*[[:Category:Comics featuring Hairy|Comics featuring Hairy]]

{{navbox-characters}}

1391: Darkness

2022-05-04T01:19:08Z

Big square: Undo revision 234543 by X. K. C. D. (talk)

{{comic
| number = 1391
| date = July 7, 2014
| title = Darkness
| image = darkness.png
| titletext = This was actually wish #406. Wish #2 was for him to lose the ability to remember that each new wish wasn't my first.
}}

==Explanation==
[[Ponytail]] as a [[:Category:News anchor|news anchor]] describes the sunset as though it were an unprecedented, newsworthy event, rather than {{tvtropes|MundaneMadeAwesome| something mundane}} that happens every day. They even have a reporter ([[Cueball]]) on the spot reporting from where the ''darkness'' has spread so far.

The {{w|sunset}} is a common event. {{w|Isaac Asimov}} based his short story {{w|Nightfall (Asimov short story and novel)|Nightfall}} on a fictional civilization that doesn't know darkness because the planet is always illuminated by the six stars surrounding it. The story describes how people would react (mass insanity, fall of civilization) when the orbital motion of the planet eventually leads to five of the suns setting, plus one in eclipse.

Describing mundane occurrences in unusual detail, to show off how odd they really are, is something [[Randall]] has done before (for instance about dreaming in [[203: Hallucinations]]). But the caption below the main panel adds another twist to the joke by showing that the news report wasn't a mere imagine spot, but something actually happening due to the interference of Randall's final wish to his {{w|genie}}, which caused all news reporters to forget the day-night cycle.

Another possible meaning is that this comic is a reference to the way the media often talk about {{w|global warming}} as if each weather occurrence had meaning outside of its context like in [[1321: Cold]]. That take on the weather and the day-night cycle being denied because of a skewed point of view was also used on the {{w|Daily Show}}. The segment "[http://thedailyshow.cc.com/videos/18l8gy/unusually-large-snowstorm Unusually Large Snowstorm]" from February 10, 2010, used the same trope. Several Daily Show correspondents have different views on the weather based on where they are, ending with a correspondent who equates nighttime with everlasting darkness.

The caption references the fact that there is a limit to the number of wishes. It is a common rule, often used in fiction, that you get {{tvtropes|ThreeWishes|three wishes}} from a {{tvtropes|GenieInABottle|genie in a bottle}}. There usually is an added stipulation that no wish may be used to acquire more wishes.

In the title text, however, it is stated that Randall has managed to bypass the three wish limit rule. This was accomplished by using his second wish to simply make the genie unable to remember granting the speaker any wishes. He has thus used the same trick on the genie as he used here on the media. The media wish turns out '''not''' to have been his last (i.e. third), but rather wish number 406. This shows just how far, "make someone forget something", can go by applying it to the genie.

There is possibly an inconsistency in the comic, when seen from the title text's perspective. Since his second wish, all his wishes would have been seen as the first by the genien and thus, if the title text is true, he could have said: "Genie, for my ''first'' wish, make everyone in the media forget about the day-night cycle." However, in the light of the title text (to be seen as an add on, and thus not always related directly to the comics image) he appears to voluntarily end the whole scenario by explicitly declaring it over. Whether this would finally trigger the genie to end the wishing-cycle is unknown, and depends upon the exact priority of the genie's induced amnesia over its end-of-wishes habits.

It is interesting that it was his second wish that gave him unlimited wishes. What did he wish for on wish #1? Maybe he wasted the first wish because he did not believe the genie was able to grant wishes – a common error. On the other hand, he may have used the first wish to learn how to make his second wish circumvent the three rule limit. His first wish could have been to read the genie's mind to determine what he could wish for to give him unlimited wishes.

*To have three wishes from a genie, but really only needing one was the joke in [[152: Hamster Ball]]. Perhaps this genie is the same, and the first wish was for a human-sized hamster ball. Much later - inspired by the hamster ball? - he breaks the genie rules to get access to unlimited (not limited to the normal three) genie wishes.
*The concept of having unlimited wishes has previously been explored in [[1086: Eyelash Wish Log]] - one of the wishes is also related to news anchors - the wish is to control the direction they are looking.
*Genies are also part of [[532: Piano]] and [[879: Lamp]], although these two jokes are of a more juvenile character.

==Transcript==
:[Ponytail is a news anchor at a media desk and she reports:]
:Ponytail: ...getting reports that the darkness has spread as far west as Texas. Let's go live to our reporter in Houston.

:[From a breaking news window in the bottom right corner of the panel, Cueball as a newscaster stands in darkness with two people walking behind him:]
:Cueball: It's been thirty minutes since the sun vanished...

:[Caption below the panel]:
:Caption: "Genie, for my last wish, make everyone in the media forget about the day-night cycle."

{{comic discussion}}

[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring Cueball]]
[[Category:News anchor]]
[[Category:Multiple Cueballs]]

1775: Things You Learn

2022-05-04T01:18:32Z

Big square: Undo revision 233934 by X. K. C. D. (talk)

{{comic
| number = 1775
| date = December 21, 2016
| title = Things You Learn
| image = things_you_learn.png
| titletext = Guess who has two thumbs and spent the night in an ER after trying to rescue a kitten that ran under his car at a stoplight and climbed up into the engine compartment? And, thanks to antibiotics, will continue having two thumbs? THIS GUY. (P.S. kitten is safe!)
}}

==Explanation==
This graph shows various items of information plotted by two criteria: a horizontal "How Bad Is It If You Don't Know [THING]" axis and a vertical "How Easy It Is To Grow Up Without Learning [THING]" axis. Specifically, the vertical axis measures roughly how likely the average person is to remain ignorant of a particular item. The horizontal axis measures the likelihood and severity of bad consequences arising from such ignorance.

The title text describes an encounter Randall had where a cat climbed into the engine compartment of his car. It probably serves as an explanation for the seemingly out of place point on the graph about how serious cat bites are. The "two thumbs" is a reference to a well known type of jokes among English speakers. One of the most frequent forms is one person interrupting another mid-speech and asking "what has two thumbs and doesn't give a f*ck? THIS GUY!", before pointing to themselves with their thumbs. The idea is that you only direct the attention to your thumbs so that they can point back to you, though mentioning the thumbs was not actually required except as a topic change. Randall plays on an inversion of this joke as he (presumably) was bitten on the thumb might have {{w|Amputation|lost a thumb}} or perhaps not have been able to make it at all without the intervention of the ER people. So here the "who has two thumbs", is not a deceiving distraction out of a boring conversation, and the thumbs are actually the focus of the phrase.

{| class="wikitable sortable"
! Ignorance is Bad !! Ignorance is Easy !! Information !! Comments
|-
| not bad || (very, very) easy || 100 digits of {{w|pi}} || Most people know pi to only a few digits (3.14 or 3.1415). The latter is accurate to almost one part in half a million, which is close enough for almost any practical purpose.
|-
| not bad || (very) easy || Lyrics to "{{w|We Didn't Start the Fire}}" || "We Didn't Start the Fire" is a 1989 hit song by Billy Joel. Its lyrics include brief, rapid-fire allusions to more than 100 headline events between 1949, the year of Joel's birth, and 1989. While the chorus is memorable, the verses of the song are just a list of people, events and random things from popular culture. The average person is somewhat more likely to know the lyrics to Billy Joel's 1989 hit song than 100 digits of pi, but not knowing them doesn't really have any serious consequences. This song was again the pun in the title text of [[1794: Fire]], which was a follow up to comic #4 in [[821: Five-Minute Comics: Part 3]].
|-
| (very) bad || (very) easy || That cat bites are really serious and if bitten you need to wash the bite and call a doctor immediately || Most people assume that a cat bite is just a minor injury. In fact, it carries a fairly high risk of infection, which can be dangerous if not treated (by cleaning the bite to reduce the risk, and having a doctor examine the bite victim and apply additional treatments such as antibiotics if needed). At the same time, cat bites are quite rare, as cats default to their claws rather than their teeth when they need to attack something (not that cat claws are bacteria-free zones either, quite the opposite), so most people simply don't have to deal with many cat bites.
|-
| (very, very) bad || (very) easy || The red flags for an abusive relationship || It is fairly easy for someone to fall into a pattern of accepting abuse (particularly if the abuser is skilled at emotional manipulation) without realizing it, and the consequences can be mentally and physically devastating.
|-
| (very, very) bad || easy || The {{w|Stroke#Signs_and_symptoms|signs of a stroke}} || The symptoms of a {{w|stroke}} are somewhat variable, including facial drooping, arm weakness and slurred speech, depending on what areas of the brain are affected, and can be mistaken for other conditions. Identifying a stroke quickly and seeking treatment can make the difference between life and death, or between full recovery and permanent impairment.
|-
| bad || easy || Cough into your elbow, not your hand || Covering a cough with the inside of your elbow helps prevent spreading airborne germs and is generally recommended by medical organisations. Coughing into your hand deposits them onto your hand, where they are much more likely to be spread to another person (via handshake, food preparation, shared objects, etc)
|-
| not (too) bad || hard || How to ride a bike || Most children, especially in the United States[http://www.peopleforbikes.org/statistics/category/participation-statistics#youth], learn to ride a bike at a fairly young age. While this is a useful skill to know for both entertainment and transportation, it would generally not be terrible to not learn this skill, particularly if other forms of transportation are readily available.
|-
| not bad (at all) || hard || How to escape movie {{w|quicksand}} || Quicksand in movies is a common trope, and while its physics often differ from real quicksand, escaping from it is commonly done using similar methods (e.g., not struggling, which increases the quicksand's viscosity). Knowing how to escape from quicksand is important if you sink into it, which is a situation most people are very unlikely to encounter in real life. It is much more likely for characters in movies and TV shows, especially in the 1960s, to encounter and become mired in quicksand than for a real individual to do so as real quicksand is a rare occurrence in most climates on Earth.
|-
| not bad (at all) || (very) hard || Lyrics to "{{w|The Twelve Days of Christmas (song)|12 Days of Christmas}}" || Hearing the same Christmas songs over and over each year makes it hard not to learn the lyrics over time. However, the consequences of not doing so are minimal; at most, ignorance of popular culture may leave your friends [[1769|a bit surprised and dismayed]]. Note that this only refers to learning the lyrics of the "Twelve Days of Christmas," not learning all the lyrics. Most people do not know many of the combination once one gets substantially past five. It is very hard to avoid learning some of the lyrics (especially One and Five), but easy to not know many of the later random ones (such as Eight or Eleven).
|-
| not bad (at all) || (very, very) hard || {{w|Theme music|TV theme songs}} || Most children in developed countries grow up watching at least some television. Many of these television shows play the same theme song before the show starts, and many of these have catchy lyrics. Therefore, by repetition, most children will learn at least one of these growing up, and often many.
|-
| bad || hard || That you have to empty the dryer lint trap || A {{w|clothes dryer}} resembles a washing machine, using hot air to heat clothes so that the water evaporates more quickly.

The dryer's air exhaust and air filter get gradually covered with {{w|lint (material)|lint}} (a kind of dust composed mainly of fiber) and must be cleaned regularly. Failing to remove the lint can cause the dryer to stop working effectively, introduce lint back onto your clothes, or (in extreme cases) start a fire.
|-
| (very) bad || (very) hard || {{w|Stop, drop and roll}} || This is a technique to extinguish a fire on one's own clothing, and is frequently taught to children for safety. Not knowing it (or forgetting it in a panic when the situation arises) can result in severe burns that could have been avoided by following the recommendation.
|-
| (very) bad || (very) hard || That you have to pay taxes || Most residents of most countries are legally obligated to pay taxes to their government. Penalties for not doing so often include large fines, and possibly prison sentences. Fortunately, it is something that children hear about quite a bit so it is very difficult to grow up without learning that it must be done. In [[1971: Personal Data]], [[White Hat]] somehow didn't know about taxes.
|-
|}

==Rankings==

100% not bad: not bad at all . . . 100%>not-badness≥50%: not bad . . . 50%>not-badness≥0%: not too bad

100% very bad: very, very bad . . . 100%>very badness≥50%: very bad . . . 50%>very badness>0%: bad

100% hard: very, very hard . . . 100%>hardness≥50%: very hard . . . 50%>hardness>0%: hard

100% easy: very, very easy . . . 100%>easiness≥50%: very easy . . . 50%>easiness≥0%: easy

==Transcript==
:[A simple X and Y graph, with the X labeled "how bad it is if you don't know {thing}" and ranging from "not bad" to "very bad", and Y labeled "how easy it is to grow up without learning {thing}" and ranging from "easy" to "hard" from top to bottom.]

:[Points on graph from top to bottom on the left side of the Y-axis:]

:100 digits of pi
:Lyrics to ''We Didn't Start the Fire''
:How to ride a bike
:How to escape movie quicksand
:Lyrics to ''12 Days of Christmas''
:TV theme songs

:[Points on graph from top to bottom on the right side of the Y-axis:]

:That cat bites are really serious and if bitten you should wash the bite and call a doctor immediately
:Red flags for an abusive relationship
:Signs for a stroke
:Cough into your elbow, not your hand
:That you have to empty the dryer lint trap
:Stop, drop, and roll
:That you have to pay taxes

{{comic discussion}}

[[Category:Charts]]
[[Category:Scatter plots]]

2003: Presidential Succession

2022-05-04T01:16:45Z

Big square: Undo revision 232653 by X. K. C. D. (talk)

{{comic
| number = 2003
| date = June 6, 2018
| title = Presidential Succession
| image = presidential_succession.png
| titletext = Ties are broken by whoever was closest to the surface of Europa when they were born.
}}

==Explanation==
The {{w|United States presidential line of succession}} is the order of people who serve as president if the current incumbent president is incapacitated, dies, resigns, or is removed from office.

The {{w|Presidential_Succession_Act#Presidential_Succession_Act_of_1947|Presidential Succession Act of 1947}} revised the presidential order of succession to its current order. This Act, though never challenged in the courts, may not be constitutional for two reasons. First, the Act names two members of Congress as successors. There are serious questions as to whether this violates the principle of Separation of Powers. The second issue is that the Act allows for anyone skipped over for succession to later assume the office if circumstances change to allow them to hold it. This would mean that the person in question could effectively unseat a sitting President, which raises serious constitutional issues.

There are also practical concerns regarding the Act. The line of succession includes all members of the Cabinet in the order that their department was established, with the oldest departments first. No consideration is given to which departments would be most relevant to the Presidency, particularly considering that this type of succession would presumably involve a serious crisis, which the new president would need to be able to address immediately. The Department of Homeland Security is in charge of the security and protection of the United States and its citizens and would probably already be privy to sensitive intelligence and briefings related to national security, but because it is the latest of the Departments to have been established (in 2003), the Secretary of Homeland Security is last in the current Presidential line of succession, behind Secretaries in much less sensitive roles, such as those of Agriculture, Housing and Urban Development, and Education.

Another concern is that, by including members of Congress immediately after the Vice President, there is a serious risk that the simultaneous death of the President and Vice President could cause the Presidency to change to the opposing party, which could lead to serious political instability at the precise moment when the country is facing a national crisis. It even presents the possibility that simultaneous assassinations of the President and Vice President could function as an effective coup, shifting power to their opponents.

Finally, there is the issue that, usually, everyone in the line of succession lives and works in Washington D.C. Hence, a sufficiently destructive attack or natural disaster impacting the city could realistically incapacitate all of them, leaving the USA leaderless at a time of extreme crisis. It is already established practice in the USA that everyone in this line not gather together at once. In cases where most senior government officials gather (such as the {{w| State of the Union}}), at least one member of the line of succession (referred to as the "designated survivor") is secured off-site, and would assume the presidency in the unlikely event that a {{w| mass casualty event}} were to kill or incapacitate everyone else in the line. However, disasters impacting an entire city remain a possibility, and no provision is made for them in current law.

To correct these issues, a think tank known as the {{w| Continuity of Government Commission}} prepared a report recommending a new line of succession, which would not include members of Congress, would reorder the cabinet secretaries so that the most suitable roles would be the first successors, and would include people who do not live or work in Washington DC. The full text of their report can be found [https://www.brookings.edu/wp-content/uploads/2016/06/06_continuity_of_government.pdf here]. A short, readable summary, including the report's recommended new line of succession, is [https://www.brookings.edu/research/the-continuity-of-the-presidency-the-second-report-of-the-continuity-of-government-commission here].

The first six members of the commission's list are taken from the current line of succession, though the order is changed; they propose that after this, five new people should be appointed specifically for the purpose of assuming the presidency, if needed. Randall's list begins with these eleven people (combining the five new appointees into #7); afterwards, his list becomes increasingly comical and ridiculous.

Randall's list omits members of Congress, as well as other cabinet positions, in accordance with the report's concerns about constitutionality and qualifications. However, his other additions totally ignore these issues, including people with no apparent qualifications for the office (such as actors, athletes, and competitive eaters) and people who are constitutionally ineligible for the office. The US Constitution requires that the President of the United States must be a natural-born US citizen, at least 35 years of age, and have resided in the US for at least fourteen years. Randall's list includes many people who don't meet these requirements. Most notably, he includes the entire succession to the British crown, almost none of whom meet the requirement of being natural-born citizens of the United States.

It may be expected that many of the athletes, musicians and actors on this list are likely to be ineligible as well. Most professional athletes in the relevant sports are under 35 years old, particularly those at the peak of their careers (when they'd likely win MVP awards), the most popular musicians also tend to be younger than 35, and many who meet these requirements were not born US citizens (and some many not even reside in the US). However, the existing line of succession can also contain ineligible people, who would simply be skipped over for succession. For example, at the comic's publication, {{w|Elaine Chao}} was the Secretary of Transportation and would normally be 14th in line, but because she is a naturalized citizen of the US, rather than native-born (she was born in Taiwan) she would not qualify for the office if the line came to her.

The title text mentions that ties will be broken by whoever was closest to the surface of {{w|Europa}} when they were born. Europa is a moon of Jupiter and one of the most likely locations in the Solar System for {{w|Habitability of natural satellites|potential habitability}}. This is likely a parody of systems in which ties are broken by semi-arbitrary rules (such as the older candidate automatically winning a tie) or a randomized ones (such as ties being decided by a coin flip). The position of Europa with respect to Earth at the time of one's birth depends on enough factors that it acts as a pseudo-random tie breaker, albeit a needlessly complicated one.

The presidential line of succession was first mentioned in [[1933: Santa Facts]]

==Order of succession==
{| class="wikitable sortable"
!#
!Randall's order
!Current order by the 1947 Act
!Notes
|-
|1
|{{w|POTUS|President}}
|President
|Not generally considered part of the line of succession, as incumbents cannot "succeed" to their own post. (This should really be item 0 on the list.)
|-
|2
|{{w|POTUS|Vice president}}
|Vice president
|This is the same as in the actual line of succession. Succeeding the President is one of the only two roles assigned to the Vice President by the Constitution, the other being presiding over the Senate (including breaking ties), but Vice Presidents are often given additional roles during office.
|-
|3
|{{w|United States Secretary of State|Secretary of State}}
|Speaker of the House of Representatives
|Moved up from 5th position. This is likely a serious suggestion. As mentioned above, the existing Succession Act includes the Speaker of the House and President Pro Tempore of the Senate, which presents serious practical and constitutional issues. The Secretary of State is the chief officer responsible for the country's international relations and diplomatic missions, and would be a logical successor, particularly in times of crisis.
|-
|4
|{{w|United States Secretary of Defense|Secretary of Defense}}
|{{w|President pro tempore of the United States Senate|President pro tempore of the Senate}}
|Moved up from 7th position. Likely a serious suggestion. The existing succession places the Secretary of Defense behind the Secretary of the Treasury in succession. If the three preceding officials were simultaneously killed or incapacitated, there would be a high likelihood that the country was either under attack, and other powers could easily try to take advantage of any power vacuum. Since the Secretary of Defense is most connected to the nation's military, and most in tune with information regarding potential threats and risks, this would be a logical succession.
|-
|5
|{{w|United States Secretary of Homeland Security|Secretary of Homeland Security}}
|Secretary of State
|Moved up from 19th position. Likely a serious suggestion. As with the Secretary of Defense, this officer would likely be closely aligned with the national emergency response infrastructure (including overseeing the {{w|Federal Emergency Management Agency}}), and would be well equipped to deal with a major attack or natural disaster.
|-
|6
|{{w|United States Attorney General|Attorney General}}
|{{w|United States Secretary of the Treasury|Secretary of the Treasury}}
|Moved up from 8th position. Likely a serious suggestion. The Attorney General oversees national law enforcement, and would be in a position to deal with internal chaos that could result from a disaster that impacted the federal government so deeply.
|-
|7
|Five people who do not live in Washington DC, nominated at the start of the President's term and confirmed by the Senate
|Secretary of Defense
|{{w|Washington, D.C.}} is the capital of the United States, and is where the {{w|White House}}, the President's residence, is located. Presumably this provision covers the case where much of the government, including positions 1–6 here, are killed by a natural disaster or attack in Washington, D.C.

This suggestion establishes no qualifications for these people, but the fact that they'd need to be confirmed by the Senate suggests that they would be chosen to be competent for the role. It is also unclear if an order is determined among these five or if they take up a joint presidency. This suggestion is taken from the Second Report of the Continuity of Government Commission to prevent the danger of the entire line of succession being removed in a single event.
|-
|8
|{{w|Tom Hanks}}
|Attorney General
|Academy Award-winning American actor. This is the first unambiguously unserious suggestion.{{Citation needed}} Tom Hanks is very popular and considered exceptionally likeable by many Americans, but has never served in public office or displayed any particular affinity for politics. The implication is that Mr. Hanks would be easily accepted as a leader, based solely on his personal charm. It should also be noticed that Tom Hanks played Jim Lovell, who served in the navy before becoming an astronaut (Many early astronauts were former military members.), in ''Apollo 13'', a military captain in ''Saving Private Ryan'', a prison officer in ''The Green Mile'', a naval intelligence officer in ''James B. Donovan'', and a member of the House of Representatives in ''Charlie Wilson's War''; if Tom Hanks's appearances in movies counted as real-life experience, then he would be adequately qualified.
|-
|9
|State Governors, in descending order of state population at last census
|{{w|United States Secretary of the Interior|Secretary of the Interior}}
|Also taken from Second Report of the Continuity of Government Commission. At the time of publication, the last {{w|United States Census}} was the 2010 Census. As California is the most populous state, its Governor ({{w|Jerry Brown}} at the time of publication) would have been first in line.

See also the {{w|2010_United_States_Census#State_rankings|state population rankings}} and the {{w|list of current United States governors}}. As worded, this criterion would exclude territorial governors (and the Mayor of Washington, D.C.).
|-
|10
|Anyone who won an Oscar for playing a governor
|{{w|United States Secretary of Agriculture|Secretary of Agriculture}}
|Oscars, or {{w|Academy Awards}}, are annual film awards awarded by the Academy of Motion Picture Arts and Sciences. At the time of publication, the only Oscar awarded for playing a governor was {{w|Broderick Crawford}}'s 1949 Best Actor award for the fictional Willie Stark in ''{{w|All the King's Men (1949 film)|All the King's Men}}'' (a character based on {{w|Huey Long}}). However, Crawford died in 1986, so would be unable to serve as President.

This may be a reference to the {{w|Political career of Arnold Schwarzenegger}}: a highly-lauded actor who became governor of California, but did not win an Oscar or play a governor before being elected. (As a naturalized citizen, he is also ineligible for the Presidency.)
There is also humor in suggesting that playing a governor delivers just as much expereince as being a governor. (Something similar was mentioned in the section about Tom Hanks, who played, among other things, a member of the House of Representatives.)
|-
|11
|Anyone who won a Governor's award for playing someone named Oscar
|{{w|United States Secretary of Commerce|Secretary of Commerce}}
|The {{w|Governors Awards}} are an annual award ceremony hosted by the Academy of Motion Picture Arts and Sciences to present lifetime achievement awards within the film industry. As this award is a lifetime achievement award, it does not seem possible that an actor could win this award for simply playing someone named Oscar. Notwithstanding the nature of the award, at the time of publication, no recipient of a Governors Award has played a character named Oscar.

Obviously, the joke is that changing the order of the words from the previous proposal produces something that could actually exist.
|-
|12
|{{w|Kate McKinnon}}, if available
|Secretary of Labor
|Comedic actress famous for being a cast member on {{w|Saturday Night Live}}. She is known for her character work and celebrity impressions. She has recently done impersonations of members of the Trump administration including Spokeswoman {{w|Kellyanne Conway}} and Attorney General {{w|Jeff Sessions}}. She also played {{w|Hillary Clinton}} during the 2016 campaign and presumably would have played her when she was President had she won; but since Clinton lost, McKinnon has not actually played a President. At the time the comic was released, she was 34 years 5 months old; thus she was not "available" until seven months later. Being available could also refer to not already having an acting commitment, in which case the comic would be humorously implying that fulfilling her acting roles is more important than the country having leadership.
|-
|13
|Billboard Year-End Hot 100 Singles artists #1 through #10 (for groups, whoever is credited first in name, liner notes, etc)
|Secretary of Health and Human Services
|The {{w|Billboard Hot 100}} is the music industry standard record chart in the United States for singles, published weekly by Billboard magazine. The weekly data is aggregated into a cumulative {{w|Billboard Year-End}} (based on a "year" that ends the third week of November, in order to meet December publication deadlines). At the time of publication, the most recent such list was the {{w|Billboard Year-End Hot 100 singles of 2017}}.

Based on that list, the artists considered for the presidential succession would be: {{w|Ed Sheeran}}, {{w|Luis Fonsi}}, {{w|Bruno Mars}}, {{w|Kendrick Lamar}}, Alex Pall (of {{w|The Chainsmokers}}), {{w|Quavo|Quavoius Keyate Marshall}} (of {{w|Migos}}), {{w|Sam Hunt}}, {{w|Dan Reynolds}} (of {{w|Imagine Dragons}}), and {{w|Post Malone}}. There are only nine names instead of ten because The Chainsmokers had two of the top 10 singles in 2017. Of these, only Luis Fonsi (40 years old, born in Puerto Rico) was legally eligible for the office; all the others were too young, and Sheeran is additionally from the United Kingdom.
|-
|14
|The top 5 US astronauts in descending order of total spaceflight time
|Secretary of Housing and Urban Development
|Astronauts are highly respected and rigorously selected, but most have little involvement in politics. According to [https://www.nasa.gov/feature/nasa-station-astronaut-record-holders NASA], the top 5 US astronauts by cumulative space time at the time of publication were: {{w|Peggy Whitson}}, {{w|Jeffrey Williams (astronaut)|Jeff Williams}}, {{W|Scott Kelly (astronaut)|Scott Kelly}}, {{w|Mike Fincke}}, and {{w|Mike Foale}}. However, it is unclear whether Foale would qualify as a natural-born citizen, as he was born in the United Kingdom to a British father and American mother.
|-
|15
|{{w|Serena Williams}} (or, if she lost her most recent match, whoever beat her)
|Secretary of Transportation
|As of the time of publication, Serena Williams was a top female tennis player. She is arguably the greatest female tennis player of all-time, winning 39 {{w|Grand Slam (tennis)|Grand Slam}} titles, including 23 women's singles titles. At the time of publication Serena Williams did win her most recent match (2018 French Open, third round, on June 2nd), although she withdrew from her next match against Maria Sharapova (which perhaps should count as a loss, especially if she withdrew in order to preserve her place in the line of succession and killed everyone in place ahead of her).

If her most recent defeat was to a non-US player, presumably she would be skipped over in line although this is not explicitly stated (the current succession list skips over anyone who would not normally qualify for not being a natural-born US citizen).
|-
|16
|The most recent season NBA, NFL, MLB, and NHL MVPs
|Secretary of Energy
|MVP stands for {{w|Most Valuable Player}}. The 4 listed leagues are the major sports leagues in the United States, the {{w|National Basketball Association}} (NBA), the {{w|National Football League}} (NFL), {{w|Major League Baseball}} (MLB), and the {{w|National Hockey League}} (NHL). We're assuming that Randall meant the regular season MVPs of each league, as each league also awards MVPs for their respective championships (or in the case of the NHL's {{w|Conn Smythe Trophy}}, their entire playoffs).

As of the time of publication, the most recent MVPs for the listed sports were {{w|Russell Westbrook}} (NBA), {{w|Tom Brady}} (NFL), {{w|José Altuve}} and {{w|Giancarlo Stanton}} (MLB has two, one for the American League and one for the National League), and {{w|Connor McDavid}} (NHL). Of these, only Brady would qualify for the list - Altuve and McDavid are Venezuelan and Canadian citizens respectively, and Westbrook (29) and Stanton (28) were too young.
|-
|17
|{{w|Bill Pullman}} and his descendants by absolute primogeniture
|Secretary of Education
|American actor, known for playing President Thomas J. Whitmore in the 1996 film ''{{w|Independence Day (1996 film)|Independence Day}}''.

Absolute primogeniture is a form of succession where the oldest direct descendant regardless of gender receives the title. This is contrasted to {{w|Male-preference primogeniture}}, in which males come before females in the order of the throne, whether the males were born first or not. This may be a reference to the British law {{w|Succession to the Crown Act 2013}}, which changed the order of the throne from male-preference primogeniture to absolute primogeniture. This act allows {{w|Princess Charlotte of Cambridge|Princess Charlotte}} to retain her place in line before {{w|Prince Louis of Cambridge|Prince Louis}}.

At the time of publication, Pullman's immediate descendants consisted of three children, with Maesa Pullman being the oldest at age 29. Thus all but Bill Pullman himself were too young for the presidency.
|-
|18
|The entire line of succession to the British throne
|Secretary of Veterans Affairs
|According to the Constitution, only a natural-born citizen of the United States can become President, which means that at least most of the line of succession to the British throne is ineligible. However, it is possible that someone in the line of succession to the British throne either is a dual citizen or is not British (a person from outside of Britain or Ireland can become King; for example, some, including George I, were from what is now Germany).

The first 59 names on the list are {{w|Succession_to_the_British_throne#Current_line_of_succession|here}}. [https://lineofsuccession.co.uk/?date=2018-06-06 British Line of Succession on 6 June 2018] shows the list as it was at the comic's publication. American citizens [http://articles.latimes.com/1988-02-11/news/vw-42233_1_royal-house have, at times] been on the list, but no natural-born Americans were on the list when the comic was published. However, after this comic was published {{w|Archie Mountbatten-Windsor}} was born on May 6, 2019; he is currently seventh in the line of succession to the British throne and has US citizenship through his mother {{w|Meghan, Duchess of Sussex}}. As with Mark Foale, though, whether that qualifies as natural-born has not be tested (leaving aside his age and the fact that many royals in his position have historically relinquished their birthright US citizenship voluntarily, which he may choose to do once he reaches age 16). In theory, the full British succession list includes [http://www.wargs.com/essays/succession/2011.html several thousand people] (living descendants of {{w|Sophia of Hanover}} who are not Roman Catholic or otherwise disqualified), and it is possible that one or more such people would also be eligible to be President of the United States beyond Master Archie. Archie's sister Lillibet Diana Mountbatten-Windsor was born in Santa Barbara, California, USA, on June 4, 2021, making her definitively a natural born US citizen, and thus, theoretically eligible to become US president upon turning 35.

The humor here derives from the fact that the United States was established by declaring independence from the United Kingdom, with rejection of the British monarchy being a basic founding principle, and a core principle of US governance. To appoint the British monarchy to the American presidency would contradict the basic goals of American independence. Alternatively, it may reference the recent wedding of {{w|Prince Harry}} to {{w|Meghan Markle}}, although she is not in the order of succession. A similar sequence of events was the plotline of the comedy film ''{{w|King Ralph}}'', which saw an American become the British monarch after the death of the royal family.
|-
|19
|The current champion of the Nathan's Hot Dog Eating contest
|Secretary of Homeland Security
|The {{w|Nathan's Hot Dog Eating Contest}} is an annual American hot dog competitive eating competition sponsored by {{w|Nathan's Famous}} held on July 4th. As of the time of publication, the most recent men's winner was {{w|Joey Chestnut}} and the women's winner was {{w|Miki Sudo}}. At the time of publication, neither was old enough to assume the office.

The comic does not specify whether the men's or women's winner should take office, creating a tie that would be broken by distance from Europa at birth. Had they both been eligible, [https://astronomy.stackexchange.com/questions/29132/was-earth-closer-to-europa-on-1983-11-25-or-1985-07-22 Sudo would have won] by between 0.125 and 2.2 {{w|Astronomical unit}}s.
|-
|20
|All other US citizens, chosen by a 29-round single-elimination Jousting tournament
|''None''
|Effective for a population up to 536,870,912 individuals (2^29) which would be enough to cover the entire US population (estimated at around 325 million at time of publication), although additional rounds can be added should the population grow further.

This is probably a reference to the {{w|Matter of Britain}} (e.g., {{w|The Sword in the Stone (film)|The Sword in the Stone}}), where, after the death of Uther Pendragon, with no known successor to the throne of Britain (some versions of the legend refer incorrectly to England) for years, it is decided that the winner of a jousting tournament shall be crowned. However, Arthur, the Wart, pulls the Sword from the Stone.
|}

===List of specific individuals===
Based on the comic's defined criteria for the order of succession, these are the specific individuals in that order, including only people who are otherwise eligible to be the President of United States (35 year old and natural born US citizens who lived in US for last 14 years) '''as of the date the comic was published'''.
#{{w|Donald Trump}} ({{w|President of the United States}})
#{{w|Mike Pence}} ({{w|Vice President of the United States}})
#{{w|Mike Pompeo}} ({{w|United States Secretary of State}})
#{{w|Jim Mattis}} ({{w|United States Secretary of Defense}})
#{{w|Kirstjen Nielsen}} ({{w|United States Secretary of Homeland Security}})
#{{w|Jeff Sessions}} ({{w|United States Attorney General}})<br>As Donald Trump did not appoint anyone to fill position #7 on Randall's line of succession, Hanks immediately follows after Sessions.
#{{w|Tom Hanks}} (Tom Hanks)
#{{w|Jerry Brown}} (Governor of California)
#{{w|Greg Abbott}} (Governor of Texas)
#{{w|Andrew Cuomo}} (Governor of New York)
#{{w|Rick Scott}} (Governor of Florida)
#{{w|Bruce Rauner}} (Governor of Illinois)
#{{w|Tom Wolf}} (Governor of Pennsylvania)
#{{w|John Kasich}} (Governor of Ohio)
#{{w|Rick Snyder}} (Governor of Michigan)
#{{w|Nathan Deal}} (Governor of Georgia)
#{{w|Roy Cooper}} (Governor of North Carolina)
#{{w|Phil Murphy}} (Governor of New Jersey)
#{{w|Ralph Northam}} (Governor of Virginia)
#{{w|Jay Inslee}} (Governor of Washington)
#{{w|Charlie Baker}} (Governor of Massachusetts)
#{{w|Eric Holcomb}} (Governor of Indiana)
#{{w|Doug Ducey}} (Governor of Arizona)
#{{w|Bill Haslam}} (Governor of Tennessee)
#{{w|Mike Parson}} (Governor of Missouri)
#{{w|Larry Hogan}} (Governor of Maryland)
#{{w|Scott Walker (politician)|Scott Walker}} (Governor of Wisconsin)
#{{w|Mark Dayton}} (Governor of Minnesota)
#{{w|John Hickenlooper}} (Governor of Colorado)
#{{w|Kay Ivey}} (Governor of Alabama)
#{{w|Henry McMaster}} (Governor of South Carolina)
#{{w|John Bel Edwards}} (Governor of Louisiana)
#{{w|Matt Bevin}} (Governor of Kentucky)
#{{w|Kate Brown}} (Governor of Oregon) <br> Born in Spain to a member of the US Air Force, should be considered a natural-born citizen until proven otherwise.
#{{w|Mary Fallin}} (Governor of Oklahoma)
#{{w|Dannel Malloy}} (Governor of Connecticut)
#{{w|Kim Reynolds}} (Governor of Iowa)
#{{w|Phil Bryant}} (Governor of Mississippi)
#{{w|Asa Hutchinson}} (Governor of Arkansas)
#{{w|Jeff Colyer}} (Governor of Kansas)
#{{w|Gary Herbert}} (Governor of Utah)
#{{w|Brian Sandoval}} (Governor of Nevada)
#{{w|Susana Martinez}} (Governor of New Mexico)
#{{w|Jim Justice}} (Governor of West Virginia)
#{{w|Pete Ricketts}} (Governor of Nebraska)
#{{w|Butch Otter}} (Governor of Idaho)
#{{w|David Ige}} (Governor of Hawaii)
#{{w|Paul LePage}} (Governor of Maine)
#{{w|Chris Sununu}} (Governor of New Hampshire)
#{{w|Gina Raimondo}} (Governor of Rhode Island)
#{{w|Steve Bullock (American politician)|Steve Bullock}} (Governor of Montana)
#{{w|John Carney (politician)|John Carney}} (Governor of Delaware)
#{{w|Dennis Daugaard}} (Governor of South Dakota)
#{{w|Bill Walker (U.S. politician)|Bill Walker}} (Governor of Alaska)
#{{w|Doug Burgum}} (Governor of North Dakota)
#{{w|Phil Scott (politician)|Phil Scott}} (Governor of Vermont)
#{{w|Matt Mead}} (Governor of Wyoming) <br> Entries 10 and 11 on Randall's list have no eligible living members. <br> Kate McKinnon was only 34 years 5 months old at the time the comic was released, making her unavailable.
#{{w|Luis Fonsi}} (Billboard Year-End Hot 100 singles of 2017, #2 artist) <br> Fonsi is the only eligible individual under the Billboard criterion.
#{{w|Peggy Whitson}} (Astronaut, 665 days in space)
#{{w|Jeffrey Williams (astronaut)|Jeff Williams}} (Astronaut, 534 days in space)
#{{w|Scott Kelly}} (Astronaut, 520 days in space)
#{{w|Mike Fincke}} (Astronaut, 382 days in space)
#{{w|Mike Foale}} (Astronaut, 374 days in space) <br> Foale was born in the UK but his mother is an American, and he holds dual citizenship with both countries. It isn't clear legally whether this situation would qualify him as being a "natural-born" citizen as US courts have never definitively ruled on what the term means, so similar to Governor Kate Brown his name is included in the list until further notice.
#{{w|Serena Williams}} <br> Serena's place on this list assumes that you do not count her withdrawal against Maria Sharapova as a ''loss''; if that counts as a loss, then subsequent entries move up one position (as Sharapova is ineligible).
#{{w|Tom Brady}} ({{w|National Football League Most Valuable Player Award|NFL MVP}}) <br> The MVPs of all other listed sports leagues are ineligible for the office due to age or nationality.
#{{w|Bill Pullman}} (Bill Pullman) <br> None of his children are old enough to become President at this time.
#''line of succession to the British throne''<br> Assumes that no eligible member of the British order of succession exists due to citizenship issues. The Nathan's Hot Dog Eating champions were too young to hold the office.
#''everyone else'' (Jousting tournament)

Based on the comic's defined criteria for the order of succession, these are the specific individuals in that order, including only people who are otherwise eligible to be the President of United States (35 year old and natural born US citizens who lived in US for last 14 years) '''as of the current date'''. (Last updated on 26 January 2022)
#{{w|Joe Biden}} ({{w|President of the United States}})
#{{w|Kamala Harris}} ({{w|Vice President of the United States}})
#{{w|Antony Blinken}} ({{w|United States Secretary of State}})
#{{w|Lloyd Austin}} ({{w|United States Secretary of Defense}})
#{{w|Alejandro Mayorkas}} ({{w|United States Secretary of Homeland Security}})
#{{w|Merrick Garland}} ({{w|United States Attorney General}})<br> As Joe Biden did not appoint anyone to fill position #7 on Randall's line of succession, Hanks immediately follows after Garland.
#{{w|Tom Hanks}} (Tom Hanks)
#{{w|Gavin Newsom}} (Governor of California)
#{{w|Greg Abbott}} (Governor of Texas)
#{{w|Ron DeSantis}} (Governor of Florida)
#{{w|Kathy Hochul}} (Governor of New York)
#{{w|Tom Wolf}} (Governor of Pennsylvania)
#{{w|J. B. Pritzker}} (Governor of Illinois)
#{{w|Mike DeWine}} (Governor of Ohio)
#{{w|Brian Kemp}} (Governor of Georgia)
#{{w|Roy Cooper}} (Governor of North Carolina)
#{{w|Gretchen Whitmer}} (Governor of Michigan)
#{{w|Phil Murphy}} (Governor of New Jersey)
#{{w|Glenn Youngkin}} (Governor of Virginia)
#{{w|Jay Inslee}} (Governor of Washington)
#{{w|Doug Ducey}} (Governor of Arizona)
#{{w|Charlie Baker}} (Governor of Massachusetts)
#{{w|Bill Lee (Tennessee politician)|Bill Lee}} (Governor of Tennessee)
#{{w|Eric Holcomb}} (Governor of Indiana)
#{{w|Larry Hogan}} (Governor of Maryland)
#{{w|Mike Parson}} (Governor of Missouri)
#{{w|Tony Evers}} (Governor of Wisconsin)
#{{w|Jared Polis}} (Governor of Colorado)
#{{w|Tim Walz}} (Governor of Minnesota)
#{{w|Henry McMaster}} (Governor of South Carolina)
#{{w|Kay Ivey}} (Governor of Alabama)
#{{w|John Bel Edwards}} (Governor of Louisiana)
#{{w|Andy Beshear}} (Governor of Kentucky)
#{{w|Kate Brown}} (Governor of Oregon) <br> Born in Spain to a member of the US Air Force, should be considered a natural-born citizen until proven otherwise.
#{{w|Kevin Stitt}} (Governor of Oklahoma)
#{{w|Ned Lamont}} (Governor of Connecticut)
#{{w|Spencer Cox (politician)|Spencer Cox}} (Governor of Utah)
#{{w|Kim Reynolds}} (Governor of Iowa)
#{{w|Steve Sisolak}} (Governor of Nevada)
#{{w|Asa Hutchinson}} (Governor of Arkansas)
#{{w|Tate Reeves}} (Governor of Mississippi)
#{{w|Laura Kelly}} (Governor of Kansas)
#{{w|Michelle Lujan Grisham}} (Governor of New Mexico)
#{{w|Pete Ricketts}} (Governor of Nebraska)
#{{w|Brad Little}} (Governor of Idaho)
#{{w|Jim Justice}} (Governor of West Virginia)
#{{w|David Ige}} (Governor of Hawaii)
#{{w|Chris Sununu}} (Governor of New Hampshire)
#{{w|Janet Mills}} (Governor of Maine)
#{{w|Gina Raimondo}} (Governor of Rhode Island)
#{{w|Greg Gianforte}} (Governor of Montana)
#{{w|John Carney (politician)|John Carney}} (Governor of Delaware)
#{{w|Kristi Noem}} (Governor of South Dakota)
#{{w|Doug Burgum}} (Governor of North Dakota)
#{{w|Mike Dunleavy (politician)|Mike Dunleavy}} (Governor of Alaska)
#{{w|Phil Scott (politician)|Phil Scott}} (Governor of Vermont)
#{{w|Mark Gordon (politician)|Mark Gordon}} (Governor of Wyoming)
#{{w|Kate McKinnon}} (Kate McKinnon) <br> If she is available. Entries 10 and 11 on Randall's list have no eligible living members.
#{{w|Bruno Mars}}<br/> All other artists on the {{w|Billboard Year-End Hot 100 singles of 2021}} were too young.
#{{w|Peggy Whitson}} (Astronaut, 665 days in space)
#{{w|Jeffrey Williams (astronaut)|Jeff Williams}} (Astronaut, 534 days in space)
#{{w|Scott Kelly}} (Astronaut, 520 days in space)
#{{w|Mike Fincke}} (Astronaut, 382 days in space)
#{{w|Christopher Cassidy}} (Astronaut, 378 days in space)
#{{w|Bill Pullman}} (Bill Pullman) <br> None of Bill Pullman's children are old enough to become President at this time.<br>{{w|Serena Williams}} lost her most recent match against {{w|Aliaksandra Sasnovich}}, who is ineligible due to age and nationality.
#{{w|Aaron Rodgers}} ({{w|National Football League Most Valuable Player Award|NFL MVP}}) <br>The MVPs of all other listed sports leagues are ineligible for the office due to age or nationality.
#''line of succession to the British throne''
#{{w|Michelle Lesco}} (Women’s champion of the Nathan’s Hot Dog Eating Contest; listed first due to being slightly closer to Europa at birth)
#{{w|Joey Chestnut}} (Men's champion of the Nathan's Hot Dog Eating Contest)
#''everyone else'' (Jousting tournament) <br> Assumes that the number of eligible US Citizens does not exceed 536,870,912.

==Transcript==
: A proposal for a new presidential line of succession
: Current politics aside, most experts agree the existing process is flawed. The Presidential Succession Act of 1947 is probably unconstitutional on several counts, and there are many practical issues with the system as well.
: <span style="color:gray">(For more, see the surprisingly gripping ''Second Report of the Continuity of Government Commission'', June 2009.)</span>
: Proposed line of succession:
:# President
:# Vice president
:# Secretary of State
:# Secretary of Defense
:# Secretary of Homeland Security
:# Attorney General
:# Five people who do not live in Washington DC, nominated at the start of the president's term and confirmed by the Senate
:# Tom Hanks
:# State Governors, in descending order of state population at last census
:# Anyone who won an Oscar for playing a governor
:# Anyone who won a Governor's award for playing someone named Oscar
:# Kate McKinnon, if available
:# Billboard year-end Hot 100 singles artists #1 through #10 (for groups, whoever is credited first in name, liner notes, etc)
:# The top 5 US astronauts in descending order of total spaceflight time
:# Serena Williams (or, if she lost her most recent match, whoever beat her)
:# The most recent season NBA, NFL, MLB, and NHL MVPs
:# Bull Pullman and his descendants by absolute primogeniture
:# The entire line of succession to the British throne
:# The current champion of the Nathan's Hot Dog Eating contest
:# All other US citizens, chosen by a 29-round single-elimination Jousting tournament

{{comic discussion}}

[[Category:Politics]]

213: Ghostbusters Marathon

2022-05-04T01:16:23Z

Big square: Undo revision 233020 by X. K. C. D. (talk)

{{comic
| number = 213
| date = January 22, 2007
| title = Ghostbusters Marathon
| image = ghostbusters marathon.png
| titletext = If you walk out that door you'll be crossing the Rubicon with me, and that's one stream I'm not ready to cross.
}}

==Explanation==
''{{w|Ghostbusters}}'' is a 1984 supernatural comedy film that spawned a sequel, a reboot, and two {{w|The Real Ghostbusters|animated television series}} (the {{w|Extreme Ghostbusters|latter}} of which lasted less than a season, didn't feature the same cast of titular Ghostbusters, and therefore is probably being pointedly ignored). The box, a "Muon Containment Trap," is a device used in the film to capture ghosts. It is connected to a footswitch by a cable. The man trying to leave is about to be pulled into the box and held there indefinitely (against his will, of course).

The title text refers to Julius Caesar's crossing of the {{w|Rubicon#History|Rubicon}}, a river (or very large stream) that marked the border between Roman Italy and an area of land Caesar was the appointed governor of. At the end of his term, the Roman Senate ordered him to disband his army and return to Italy. Instead, he brought his forces past the border, an act of treason and rebellion against the Republic, instigating the Roman Civil War. The phrase "crossing the Rubicon" now means making a move with gigantic consequences that cannot be undone. In the film ''Ghostbusters'', the protagonists use "proton packs" that fire "streams" of energy. The inventor of the device warns that these streams should not be crossed against each other, as doing so "would be bad." Just how bad? "Try to imagine all life as you know it stopping instantaneously and every molecule in your body exploding at the speed of light." Important safety tip.

:Final quote taken from the 1984 movie ''{{w|Ghostbusters}}''.

==Transcript==
:[Cueball and a friend are in a room. Cueball is standing up. There is litter around them.]
:Cueball: Okay, that's all the Ghostbusters marathon I can handle. Later!
:Friend: You can't leave! We just started the animated series!

:Cueball: I've had my fill. I'm going home.
:Friend: I can't let you do that.

:[Cueball walks along a cord and past a box. The friend clicks a switch.]
:''Click''

:[Cueball is bathed in some kind of aura emitted by the box.]

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

1531: The BDLPSWDKS Effect

2022-05-04T01:15:56Z

Big square: Undo revision 233487 by X. K. C. D. (talk)

{{comic
| number = 1531
| date = May 29, 2015
| title = The BDLPSWDKS Effect
| image = the bdlpswdks effect.png
| titletext = This well-known effect has of course been replicated in countless experiments.
}}

==Explanation==
The BDLPSWDKS Effect in the title is an {{w|acronym}} for Bernoulli-Doppler-Leidenfrost-Peltzman-Sapir-Whorf-Dunning-Kruger-Stroop Effect, as explained by [[Ponytail]] in the comic. She stands in front of a slide that shows [[Cueball]] being subjected to this effect.

The effect mentioned appears to be a mashup of seven scientific principles (with nine scientists' names included) from physics and social sciences, with elements from each principle appearing in the resulting description of the effect:

*{{w|Bernoulli's principle}} in fluid dynamics (also mentioned in [[803: Airfoil]]) states that an increase in the speed of a fluid with certain properties occurs simultaneously with a decrease in pressure or a decrease in the fluid's potential energy.
** This is referenced by the firetruck lifting off and hurtling.
*The {{w|Doppler effect}} in physics refers to the change in a wave's frequency for an observer moving relative to its source. Sound from the oncoming firetruck increases in pitch.
**This is referenced by Cueball reacting faster if the shouting is in a non-tonal language than a tonal language. In tonal languages, changes in pitch change the meaning, thus tonal languages may suffer more from Doppler distortion than non-tonal ones. Additionally, the choice of firetruck was likely influenced by this effect, as a firetruck and its siren are often invoked as an example of it.
**This may also be referenced by the fact that Cueball reacts faster when red is shouted as the doppler effect makes light shift up the spectrum : red may still be visible after the shift but green may be out of the visible range.
*The {{w|Leidenfrost effect}}, in physics, refers to how liquid will produce an insulating vapor layer when in near contact with an extremely hot surface, causing it to hover over said surface.
**This is referenced by the firetruck lifting off on a layer of superheated gas.
*The {{w|Peltzman effect}}, in behavioral economics, refers to how regulations intended to increase safety are ineffective or counterproductive because people, feeling safer, will engage in riskier behaviours.
**This is referenced by the fire truck, which is intended to improve public safety by putting out fires, speeding and thus creating a hazardous situation and reducing the safety of the pedestrian. The firefighter may also be more inclined to drive recklessly due to the feeling of safety they have in a modern firetruck.
*The {{w|Sapir–Whorf hypothesis}}, in linguistics, states that a person's world view and cognitive processes are affected by the structure of the language the person speaks.
**This is referenced by languages with a word for "firefighter" giving a quicker reaction. If Cueball speaks (or is currently thinking in) a language without a word for "firefighter", he might be slower to recognize the role and authority of the driver warning him, and thus slower to react to the danger.
*The {{w|Dunning–Kruger effect}}, in social psychology, refers to unskilled people mistakenly perceiving themselves as more skilled than they really are, while skilled people underestimate their own abilities.
**This is referenced by the tonal language being a language Cueball thinks he is fluent in but isn't.
*The {{w|Stroop effect}}, in psychology, refers to the phenomenon in which it is easier to name the color of the ink in which a word is written when the word refers to the same color as the ink than when the word refers to a different color.
**This is referenced by Cueball diving out faster if the driver screams "red!" than if the driver screams "green!", as a traditional American firetruck is red, and therefore it may create a moment of confusion for Cueball if the driver shouts "green!". It may also reference the common usage of "red" as indicating fire or danger, while "green" indicates safety.

This comic is probably a comment on the "replication crisis" in social psychology which has been in the [http://www.nature.com/news/first-results-from-psychology-s-largest-reproducibility-test-1.17433 news recently]. For example, studies finding that merely thinking about intelligent people (e.g., writing down the attributes of a professor) will actually improve performance on math tests were once widely believed, and this "intelligence priming" effect is even included in textbooks. However, recent attempts to reproduce these effects have mostly failed and this failure to replicate is true of many [http://www.nature.com/news/disputed-results-a-fresh-blow-for-social-psychology-1.12902 social priming effects] as well as other experiments in social psychology. Randall is also mocking the complicated, or even convoluted, setups often used in these experiments.

Usually, for an effect to be considered real, the scientific method requires the effect to be replicated by different experimenters in different times and places. It is hard to imagine several scientists in different parts of the world creating the setup to replicate this effect; however the title text mentions, sarcastically, that it has been done countless times.

Many other xkcd strips have commented on the ease with which surprising and novel, but false, results can be published in the scientific literature, such as [[1478: P-Values]] and [[882: Significant]].

==Transcript==
:[Ponytail stands next to a screen displaying a firetruck hurtling toward Cueball on what appears to be a layer of gas.]

:Ponytail: The Bernoulli-Doppler-Leidenfrost-Peltzman-Sapir-Whorf-Dunning-Kruger-Stroop Effect states that if a speeding fire truck lifts off and hurtles towards you on a layer of superheated gas, you'll dive out of the way faster if the driver screams '''''"red!"''''' in a '''''non'''''-tonal language that '''''has''''' a word for "firefighter" than if they scream '''''"green!"''''' in a '''''tonal''''' language with '''''no''''' word for "firefighter" which you '''''think''''' you're fluent in but '''''aren't'''''.

{{comic discussion}}
[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring Cueball]]
[[Category:Science]]
[[Category:Physics]]
[[Category:Language]]
[[Category:Psychology]]

1095: Crazy Straws

2022-05-04T01:15:29Z

Big square: Undo revision 232700 by X. K. C. D. (talk)

{{comic
| number = 1095
| date = August 15, 2012
| title = Crazy Straws
| image = crazy_straws.png
| titletext = The new crowd is heavily shaped by this guy named Eric, who's basically the Paris Hilton of the amateur plastic crazy straw design world.
}}

==Explanation==
A {{w|subculture}} is a small group of people within a culture that share some property in common, such as hackers or hipsters. Some subcultures form based on a geeky obsession over a trivial topic (for instance, a minimally-drawn webcomic). In this case, that topic is crazy straws, which are toy drinking straws designed with unusual twists and loops. This strip uses this group as an example of the fractal nature of cultures.

Informally speaking, a {{w|fractal}} is a mathematical shape with an infinite level of detail. Just as fractals can always be divided into smaller patterns, Randall points out that human subcultures can always be divided into smaller subcultures. We have the "people who like crazy straws" subculture, but this is further divided into the professionals and the hobbyists. The hobbyists are themselves broken into those who accept loops in the straws and those who don't. A splinter group, as used in the comic, is a subculture that breaks off from a larger one. Of course, this nesting is not really infinite, since there is a finite number of people living. The claim that it is infinite is hyperbole.

Despite the incredible amount of work fans put into it, the whole concept seems completely inconsequential to an outsider. This irony is the source of humor in this strip. An earlier comic, [[915: Connoisseur]], covers a similar topic.

{{w|Paris Hilton}} is a celebrity who is essentially famous for being famous. The "guy named Eric" mentioned in the title-text is someone prominent in the amateur plastic crazy-straw community, but that doesn't really count as famous by most standards, so the Paris Hilton comparison is quite a stretch.

==Transcript==
:[Two people hang out with some beverages. Cueball here has a bright green crazy straw.]
:Cueball: The thing to understand about the plastic crazy straw design world is that there are two main camps: The ''professionals'' - designing for established brands - and the ''hobbyists''.
:Cueball: The hobbyist mailing lists are full of drama, with friction between the regulars and a splinter group focused on loops...

:[Caption below the panel:]
:Human subcultures are nested fractally. There's no bottom.

{{Comic discussion}}
[[Category:Comics with color]]
[[Category:Comics featuring Cueball]]
[[Category:Multiple Cueballs]]

1658: Estimating Time

2022-05-04T01:14:53Z

Big square: Undo revision 233910 by X. K. C. D. (talk)

{{comic
| number = 1658
| date = March 21, 2016
| title = Estimating Time
| image = estimating_time.png
| titletext = Corollary to Hofstadter's Law: Every minute you spend thinking about Hofstadter's Law is a minute you're NOT WORKING AND WILL NEVER FINISH! PAAAAAANIIIIIIC!
}}

==Explanation==
Estimation is difficult; many people seem to greatly underestimate the amount of time or other resources required. To illustrate how difficult this estimation is {{w|Douglas Hofstadter}} coined {{w|Hofstadter's law}} which is a non-scientific {{w|self-referential}} time-related adage, mentioned in the the title text. It states: ''It always takes longer than you expect, even when you take into account Hofstadter's Law.''

[[Ponytail]] is working at her computer and becomes frustrated as it seems her project will (again) take much longer than she has estimated. She is annoyed with herself for always failing to make a decent guess. [[Danish]] begins to give Ponytail advice on how to estimate the time, starting with the comforting words {{w| Phrases from The Hitchhiker's Guide to the Galaxy#Don.27t Panic |don’t panic}} and a common guideline of taking the initial estimate and doubling it.

Danish then iterates the law once more and she tells Ponytail to double this again, and then add five minutes. Unless the project to begin with was estimated to somewhat less than an hour, those five minutes will do nothing but confuse Ponytail. But Danish does not stop here, and iterates Hofstadter's law once more. Ponytail still doesn’t get where this goes, saying a hesitant ''okay'' to that.

It turns out that Danish was not at all trying to help, but just mess with Ponytail, as she now tells her that the only thing she has accomplished by listening to her advice is wasting half a minute doubling imaginary numbers (not to be confused with i, the imaginary number), i.e. even her first estimate is just something she has imagined especially since she states herself how bad she is at those kind of estimates. Finally Danish completes her frustration of Ponytail by saying "''Paaaniiic!''", negating the initial advice.

The title text is an extra corollary to the law, that states that using the law to estimate anything about the time your project takes is not only wasted time you could have spent working there is a substantial risk that you will conclude that you will never finish, and thus panic instead of just get the job done now.

Self-reference is a [[:Category:Self-reference|recurring theme]] on xkcd and this comic is quite self-referential both in the comic but also referring to other comics especially to [[917: Hofstadter]]. He is perhaps most famous for his book {{w|Gödel, Escher, Bach}} from where the quote is taken (in a section on {{w|recursion}} and self-reference, rather than estimation). This book has been directly referenced in [[24: Godel, Escher, Kurt Halsey]].

==Transcript==
:[Ponytail is sitting back from her a laptop lifting her hands of the keyboard, having presumably just paused work on a project.]
:Ponytail: Aaaa! I'm so bad at estimating how long projects will take.

:[Danish walks into the panel towards Ponytail who seems to relax back against the chair.]
:Danish: Don't panic-there's a simple trick for that:
:Danish: Take your most realistic estimate and double it.
:Ponytail: Okay, but-

:[A frameless panel with only Danish holding a hand up.]
:Danish: Now double it again. Add five minutes.
:Danish: Double it a third time.
:Ponytail (from off panel): Okay...

:[Danish raises her arms above her head in mock hysteria. Ponytail runs away from her desk screaming.]
:Danish: 30 seconds have gone by and you've done nothing but double imaginary numbers! You're making no progress and will never finish!
:Ponytail: <big>''Aaaaaa!''</big>
:Danish: ''Paaaniic!''
:Ponytail: <big>''Aaaaaaa!''</big>

==Trivia==
*This is the most recent comic in which [[Danish]] has dialogue.

{{comic discussion}}
[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring Danish]]
[[Category:Self-reference]]
[[Category:Time]]

862: Let Go

2022-05-04T01:14:20Z

Big square: Undo revision 234480 by X. K. C. D. (talk)

{{comic
| number = 862
| date = February 18, 2011
| title = Let Go
| image = let go.png
| titletext = After years of trying various methods, I broke this habit by pitting my impatience against my laziness. I decoupled the action and the neurological reward by setting up a simple 30-second delay I had to wait through, in which I couldn't do anything else, before any new page or chat client would load (and only allowed one to run at once). The urge to check all those sites magically vanished--and my 'productive' computer use was unaffected.
}}

==Explanation==
It is human nature to lose interest in difficult or boring tasks, and instead do something easier, more interesting or more rewarding in the short term. While procrastination and distraction from more important tasks has always been present, this comic casts a light on the internet and the huge potential for distraction which it provides.

The first two frames in this comic are the set-up, and contain the websites {{w|CNN}} and {{w|Reddit}} and thoughts over the top of them. These types of websites are regularly updated with new content are prime candidates for distraction. The thought bubbles indicate that the reader is fully aware that they shouldn't be looking at these websites, but is unable to stop himself. Even the very rational thought that checking news stories more than once a day is bordering on pointless doesn't seem to stop him.

In the third frame, it starts to look a little different as the screen is not a computer but is in fact the targeting computer from {{w|Luke Skywalker|Luke Skywalker's}} {{w|X-wing}}. At this point it becomes clear that there are ''far'' more important tasks at hand, namely flying the craft. Even then, Luke has an internal conflict and considers checking {{w|Facebook}}, but mentally checks himself, and to prevent himself from further compulsive browsing shuts down the system. The thought bubble at the bottom is one that is probably familiar to many people (especially students), where he realizes that he has to turn off the computer to actually concentrate on the important task.

In the fourth frame, we finally get the movie reference from {{w|Star Wars}} as {{w|Princess Leia}} and one of the Rebel Alliance's officers are gathered around the holographic table that allows them to follow the battle. In the movie, Luke turns off his targeting computer because he uses the [http://en.wikipedia.org/wiki/The_Force_%28Star_Wars%29 force] to fire the torpedoes at the right time. But in this comic, Luke turns off the computer because he keeps getting distracted by Reddit and CNN. When they ask whether he is alright, he responds in the way most people would who have nearly been caught wasting time on the internet. This is however a quote of what he actually replies in the movie.

See the [http://youtu.be/DOFgFAcGHQc Destruction of Death Star] scene on YouTube. The ''Let Go'' remark from {{w|Obi-Wan Kenobi}} that had given the title to this comic occurs about [http://youtu.be/DOFgFAcGHQc?t=2m two minutes into the clip]. Though here it is a reference to let go of refreshing websites...

The headlines on CNN read 'Bees?', 'Where is {{w|Oman}}?', and 'iReport (we mean you, that is.)'.

The headline ''Bees?'' could be a reference to {{w|Cards Against Humanity}}. One of the white cards says exactly that. It could also just be a question to the picture above - if it was bees following the guy.

The headline ''Where is Oman?'' is below a map where land is white. It shows Cyprus, Northern Egypt and the Middle East with the Mediterranean Sea, the Red Sea and the Persian Gulf (seas are grey). Oman is not on this map as it is not situated on the Persian Gulf; it's on the Gulf of Oman and on the Arabian Sea, both of which can be considered parts of the Indian Ocean.

The title text is a serious solution to a procrastination problem that we see in the comic, [http://blog.xkcd.com/2011/02/18/distraction-affliction-correction-extensio/ later explained] to take the form of simply rebooting the computer. Randall just used the honor system, rather than enforcing this behavior with a program, but he solicited suggestions from his commenters for browser addons, for people who could not simply reboot their computers for whatever reason. At the time, a commenter suggested DelaySites, but that addon is no longer available; nowadays, Mozilla recommends [https://addons.mozilla.org/en-US/firefox/addon/leechblock-ng/?src=search LeechBlock NG] (also [https://chrome.google.com/webstore/detail/leechblock-ng/blaaajhemilngeeffpbfkdjjoefldkok?hl=en-US available for Chrome]), which can be configured to implement the loading delay or block websites entirely, with additional parameters for adjusting time limits for browsing and the time of day and days of the week that each behavior is active.

==Transcript==
:[Reddit page.]
:Luke (thinking): I shouldn't be looking at Reddit. Why can't I stop?

:[CNN page.]
:Luke (thinking): Refreshing CNN again. Do news stories so affect my life that I benefit from checking them more than once a day?

:[Shutdown screen.]
:Luke (thinking): I should at least check Faceb... no. Screw it. I can't do my job when I'm distracting myself every five minutes like this.

:[Cueball and Princess Leia looking at a battlefield screen.]
:Cueball: His computer's off. Luke - You've switched off your targeting computer. What's wrong?
:Luke: Nothing. I'm all right.

{{comic discussion}}
[[Category:Comics with color]]
[[Category:Comics featuring Cueball]]
[[Category:Star Wars]]
[[Category:Internet]]