Panama Canal

Explanation:
The Panama Canal is, as the name suggests, a canal through the country of Panama. It is important for bridging the Atlantic and Pacific oceans, and is an important trade route. The canal is in Panama because this is the narrowest piece of land for crossing between the two oceans. When the Panama Canal was being proposed, several alternate routes were suggested such as the recently-revived Nicaragua Route .
Cueball says that when the Panama Canal connecting the Caribbean Sea to the Pacific Ocean was being planned, he proposed an alternate route that connects the Arctic Ocean to the Great Southern Ocean . At the time, the northern terminus would have been inaccessible, because the Arctic Ocean was almost completely covered by ice. His suggested route runs somewhat to the east of the continental divide and has a total length of slightly over ten thousand miles, in contrast to the real-life canal which is only fifty miles long. The extra length and more-rugged terrain make his proposal much more difficult to build and maintain than the real-life Panama Canal. [ citation needed ]
Moreover, while the real-life canal significantly shortens the travel distance between major cities on the east and west coasts of the Americas, his alternative offers little benefit over traveling north or south in either the Atlantic or Pacific oceans. In fact, with the lack of currents that can aid travel and the slow speed required to traverse canal locks, it would be significantly slower. In addition, ships would have to wait approximately 100 years for global warming to melt the ice in the Arctic Ocean along the northern coast of North America sufficiently for them to enter or exit the northern end of the canal. (However, since construction of this canal might take even longer, the ice might not be a problem by the time it was completed.)
The title text references the now-existing Panama Canal, and the fact that Randall's canal would need to cross it at some point. The title text suggests that crossing two canals would have to be done via aqueduct , instead of the more useful at-grade crossing , most likely at Gatun Lake , which would allow boats to travel between the two canals by simply connecting them. The humor here is that this canal would be one of the most ambitious construction projects in history; an aqueduct being added to the costs is an expense on the same scale of needing an extra screw to hold something in on Apollo 11. The route depicted appears to cross the Mackenzie, Missouri, Rio Grande, and Amazon rivers anyway, so only this additional crossing is apparently "unreasonable."
[Cueball is standing in front of a poster with two maps showing the Americas. He is pointing to the right one with a stick he is holding in his hand. Specifically to the red line going through the Americas from the Arctic sea above Canada near Alaska, down through North America, through the middle of Central America down through the middle of South America to end up in the Antarctic sea below the tip of South America. On the map to the left there is a similar red line indicating the Panama Canal crossing the thinnest part of Central America from the Pacific Oceanto the Atlantic Ocean. Both lines end in small dots on either "side" of the continent. The two maps have labels above them:] Atlantic-Pacific option Arctic-Antarctic option
[Caption below the panel:] I still don't understand why the Panama Canal planners rejected my proposal.


New Robot

Explanation:
The comic is a commentary on how many robots and engineering products are labeled as being for “Search and Rescue” purposes.
Search And Rescue (SAR) involves entering an unknown, possibly hazardous disaster-stricken environment, identifying humans or other items of interest which may be hidden, partly (or completely) buried, or injured, and then figuring out how to safely extract the target and deliver it to safety.  These tasks are hard enough for humans and are even more challenging for robots, which generally work better in well-controlled situations.  This is why many robot challenges are themed around search-and-rescue; the techniques that are developed for handling such challenging circumstances can be applied to make other robots (such as robotic caretakers, autonomous cars, AI-assisted medicine, and other lucrative applications) more robust.
The comic may be remarking that 'search and rescue' may be used as a cover for developing robots that will actually be tasked to 'search and destroy'.  (See: lethal autonomous weapons .)  Although search-and-rescue is a function that militaries perform, a robot that can satisfactorily perform a search-and-rescue task can easily be adapted to more destructive purposes.  Randall has previously written about his concerns about human authorities misusing military robots in 1968: Robot Future .
The joke is that the group of engineers who built the robot did it just because it would be cool to have a robot that can induce lightning strikes and has a grappling gun like the hook shot from (The Legend Of) Zelda. Realizing that they need to have an actual purpose for the robot the engineer presenting the robot makes up the reason that it could be used for search and rescue operations. The grappling gun can be used to pull people out or supply food to people stuck in a place. In the case that there is a dangerous amount of charge present in the atmosphere lightning can be induced which will protect other objects and people from lightning. Also, the helium sphere can allow the balloon to float in places that are hard to reach.  (Another possible interpretation is that the question "What is the robot for?" meant why do the helium sphere and grappling gun need to have a robot — and the answer means that the robot is to rescue those who are hit by either the lighting or the grappling gun.)
The Hookshot is a type of grappling hook that is a recurring piece of equipment in The Legend of Zelda video game franchise, first appearing in the 1991 game The Legend of Zelda: A Link to the Past . It is a machine consisting of a chain and hook, which can be used by Link , the protagonist and player character of Zelda . When used, the chain extends and sends the hook attached to it towards its target. If the hook latches onto certain objects, Link reels himself in towards that object. Link can also use it to pull enemies and objects towards him. Although it is referred to by the traditional 'Hookshot' name, the traditional Hookshot involves a bladed tip that mounts in wood; the grappling gun equipped on the robot is more reminiscent of the later Clawshot , which grasps its target on contact.
In theory, the Hookshot-esque function of the robot could be used for anchoring purposes - a useful function for a flying robot in search-and-rescue situations. If it is using a Clawshot design, it could also conceivably seize the parties in need of rescue. However, merely by comparing the grappling device to the Hookshot, it is clear that its attachment was specifically designed in an effort to replicate the game's tool.
The title text ominously suggests that since there are more rescue robots than required for the number of people needing rescue, another robot project will be used to place people in need of rescue, or destroy search-and-rescue robots.  (Even more ominously, it is possible that this may be the project that creates a need for rescue, as the fires caused by the lightning strikes could be the disaster from which rescue is needed.)
[Ponytail is standing on a raised platform with a robot behind her, talking to someone off-screen. The spherical floating robot is equipped with a grappling gun and an antenna that "zaps" a lightning bolt at the floor below it.] Robot: ZAP Ponytail: Our robot floats using a helium sphere, which is highly charged and can induce lightning strikes. Ponytail: It moves using a grappling gun like the hook shot from Zelda . Off-screen voice: What is the robot for ? Ponytail: Uh Ponytail: It could help with search and rescue after disasters.
[Caption below the panel:] "It could help with search and rescue" is engineer-speak for "we just realized we need a justification for our cool robot."


1921 Fact Checker

Explanation:
This comic shows a 1921 newspaper article with information about the Pilgrims coming to America. Randall has a 'grudging respect' for the author, who feels the information is so unimportant that no fact-checking has been done, and has enough integrity to inform the reader of this.
The Kansas City Sun referenced by the comic was a newspaper in Kansas City, Kansas that ran from 1892 to 1924(?). (Interestingly, there was also a Kansas City Sun in Kansas City, Missouri that ran from 1908 to 1924.)
PolitiFact , mentioned in the title text, is a fact-checking project which evaluates the truth or falsity of various statements made by politicians and other people involved in U.S. politics. The positions on its rating scale are "True", "Mostly True", "Half True", "Mostly False",  "False", and "Pants on Fire", the last position being reserved for the most egregiously "false" claims. "Mostly Whatever", the rating identified in the title text, is presented by Randall as a rating that could apply to claims that have so little relevance or interest that they are not worth checking. See also 1712: Politifact .
[In a panel with light-gray background is a block of text:] An investigator claims to have discovered in some dusty archives that back in the days when the Pilgrims landed each person coming to America from England was required to bring with them eight bushels of corn meal, two bushels of oatmeal, two gallons of vinegar and a gallon each of oil and brandy.
In view of the fact that nothing of importance hinges on the truth or falsity of this statement, not much time need be consumed to ascertain whether this is truth or fiction. —Kansas City Sun Friday, May 6 th , 1921
[Caption below the panel] I have a grudging respect for this 1921 newspaper fact-checker.


Industry Nicknames

Explanation:
"Big industry" is a common nickname used to describe monopolistic or near-monopolistic practices in the United States. To be "in someone's pocket" means this person can readily influence the subject's behavior, whether by bribe, blackmail, law, threat, lobbying, social status, finances, freedoms, or affection.
Of the 8 industries listed, Big Tobacco and Big Pharma are nicknames that are commonly used. The mining industry may be referred to in this context by sector, as Big Coal or Big Oil (Randall uses the term "big hole", which sounds similar to these.  Most but not all forms of mining involve large holes.) The U.S. automobile industry was until recent decades referred to as "Detroit," later meaning only the Big Three automobile manufacturers before falling out of common usage. Big Ag is sometimes used to describe the farming and agricultural industry, and while the rest are purely fictional, Randall could be imagining a possible future in which these industries become big players in the political arena. "Big Foot" is likely a reference to the mythical creature Bigfoot .  Those who have been on the rough end of how large organizations can push not only individuals but entire communities around in a mafia-like way may take issue with a medical board being equated with such groups.
Chansey , mentioned in the title text, is a type of female-only Pokémon who carries around an egg in her marsupial-like front pouch. For Chansey the phrase "in the pocket of Big Egg" would be rather literal, except that the egg is in her pocket, rather than the other way around. Randall does not specify why Chansey would be a "threat" or why a Pokémon would be bribing people. Perhaps because, if being in the pocket of Big Egg is bad, and Big Egg is in the pocket of Chansey, then Chansey controls Big Egg and is the one to worry about.
[A line chart is shown going from left to right between two small vertical stop lines. On the line are eight dots spread out unevenly from close to each end. The most central dot is the one with furthest distance to the nearest dots, having almost the same distance in both direction the nearest dots. The other dots are in some cases very close. Beneath each dot there goes a line down to a label written beneath each line. Above the chart there is a big title and below that an explanation. Below that again, there is a small arrow pointing to the right with a label above it.] Nicknames for Industries and Organizations Ranked by how silly it sounds when you say someone is "In the pocket of..."
[Arrow label:] Sillier
[Labels for the eight dots from left to right:] Cigarette companies: "Big Tobacco" Drug companies: "Big Pharma" The farming industry: "Big Ag" Automakers: "Big Car" The International Equestrian Federation: "Big Horse" The Board of Podiatric Medicine: "Big Foot" The mining industry: "Big Hole" The American Egg Board: "Big Egg"


Emojidome

Explanation:
This was the ninth April fools' comic released by Randall . The previous fools comic was 1975: Right Click from Sunday April 1, 2018. The next became 2288: Collector's Edition , which was delayed two days and released on Friday April 3, 2020.
The interactive comic began at noon ET (16:00 UTC) on April 1, 2019, and ended a day later. In it, users were shown two emojis and voted for their favorite before the time ran out. 512 different emojis were paired against each other in a cup or bracket system, with only one winner. See more below under How it worked .
Brackets - like the one in this comic, for finding the best emoji - are a recurring theme in xkcd. It is also relevant for this time of year, and two years ago in 2017, the first comic in April, 1819: Sweet 16 from April 3rd was a bracket, referencing March Madness . The 2019 version of the National Collegiate Athletic Association College basketball national championship tournament began March 19th and ends April 8th 2019. So this comic could also be said to reference this, although it is not so explicit here. Earlier Randall made another large and "silly" bracket in 1529: Bracket (which someone then actually made into an online voting system, just like in this comic).
The title is a reference to the movie Mad Max Beyond Thunderdome , which had the tagline:  "Two men enter. One man leaves." The "Thunderdome" in the film is a gladiatorial arena where conflicts are resolved by a duel to the death.
In the final round, the Milky Way emoji (🌌) won against the Hedgehog emoji (🦔). The comic was updated to show the result.
Clicking the comic links to a bracket of 128 emojis showing the winners: https://xkcd.com/2131/emojidome_bracket_round_of_128.png
In the first round, the voting period for each bout lasted 37.5 seconds. The voting period for each bout doubled for the second, third, and fourth rounds. The voting period for each bout for the fifth round through the end was 26 minutes. The entire bracket took 24 hours 6 minutes.
Remaining time of a given bout was shown on a timer beneath the voting buttons. If the time remaining was one minute or greater, the time was shown rounded to the nearest minute (e.g., "Remaining Time: 26 minutes"); thus the minute would change on the half minute (e.g., "2 minutes" changed to "1 minute" at 1 minute 30 seconds). If the time remaining was less than a minute, the time was shown in seconds (e.g., "59 seconds"). When there were two (sometimes three) seconds remaining, the timer would display "Time's Up!" through the end of the bout and for a couple of seconds after the end of the bout while the images for the next bout were loading. Then the next bout would appear and the results of the previous bout would be added to the list of past bouts, with the most recent bout at the top.
Commentary was displayed above the images for each bout, and changed occasionally through the bout. In the first round, the commentary was made up of some stock phrases with a few custom phrases mixed in. Later commentary was tailored to suit each match-up and provided live updates on how each bout was progressing. A final comment was included in the list of past bouts.
The competing candidates were periodically overlaid with colored hearts that floated up from the vote button oscillating in a triangle wave pattern before disappearing above the candidate. Below the current competition, the results of past bouts were shown with the "loser" displayed in greyscale, the winner in color, and the final robot-commentator comment on that match.
The commentary appeared to suggest that there was some real-time feedback from the results of the competition. For instance, "It seems like our friends over Australia is joining the fun" appeared in the commentary. So did "We are getting a lot of questions on this today. This is live commentary, folks." https://i.imgur.com/8kPwjou.png , directly declaring that the commentary is live.
Note that the schedule might show different emoji pictures than the main voting screen, presumably because of fonts. The image is pre-rendered.
The competing candidates are chosen in order of Unicode value at first, resulting in similar emojis being compared. Examples include:
😜 squaring off against 😛 - two emojis playfully sticking their tongues out
🤩 squaring off against 😍 - two smiling emojis with symbols for eyes
😂 squaring off with 🤣 - two emojis that are crying in laughter/joy.
The original title text "🤼🤼🤼🤼🤼🤼🤼🤼" consisted of eight wrestler emojis. This likely represented the round of 8, where the eight winners then can turn to the winner next to them and continue the quarterfinals, etc. The title text was updated after the final round.
Notably, it appears the eggplant emoji (🍆) and the peach emoji (🍑) were left out of the bracket, alongside the middle finger emoji (🖕). The eggplant and peach are frequently used to represent a penis and vulva/buttocks, respectively. There has been no statement from Randall on why they were left out.
A robot face announcer-emoji (🤖) and a link to the full bracket was added at 38 minutes in. https://www.xkcd.com/2131/emojidome_bracket.png shows 512 emojis in a single-elimination tournament. https://www.xkcd.com/2131/emojidome_bracket_256.png was added later and shows the 256 emojis that competed on the second round. https://www.xkcd.com/2131/emojidome_bracket_round_3.png was added for the third round. https://www.xkcd.com/2131/emojidome_bracket_round_4.png was added for the fourth round. The round 3 bracket was later updated with results during the Volcano vs Owl fight. There was an error where the flying saucer had beaten the stars, which was not the case.
A new bracket image was created for the Round of 32 which seems to be updated with new results as they come in. https://www.xkcd.com/2131/emojidome_bracket_round_of_32.png
It is not clear how the winner is decided when both emojis tied for first. This has happened twice: in Cupcake vs. Birthday Cake (🧁 vs. 🎂) with 3658 points each, where the Birthday Cake (🎂) was declared winner, and in the very first match of Grinning Face vs. Grinning Face With Smiling Eyes (😀 vs. 😁), in which no votes were cast, but the Grinning Face With Smiling Eyes (😁) was declared winner. Both of these tied bouts occurred in round 1, and both declared winners lost their subsequent match in round 2.
Real data with results (clicks) can be seen as JSON-websocket at https://emojidome.xkcd.com/2131/socket , transposed into a more human-readable format at https://leet.nu/tmp/xkcd-2131.html .
https://phiresky.github.io/emojidome/ , made by a redditor , shows the brackets along with the final scores and comment.
[This was an interactive and dynamic comic during April 1st from its release until its completion. But the final and current image, will be the official image to transcribe. But the dynamic part of the comic as well as the "error image" displayed to services that could not render the dynamic comic is also transcribed here below.]
[The final picture shows the winner of the gold medal in the Emojidome bracket tournament, as well as the runner up with the silver medal. There is no text. The winner is the "Space", "Stars" or "Milky Way" emoji, which is shown with a blue band on top of a dark blue band on top of an almost black background, indicating the light band of the Milky Way in the night sky. Stars (in both five point star shape and as dots) in light blue are spread out in all three bands of color. The large gold medal with its red neck string, is floating close to the middle of the picture, lacking any kind of neck in space to tie it around. To the left of the gold medal is the runner up, the brown Hedgehog, with light-brown face. It clutches the smaller silver medal, also with red neck string, which floats out there in space. The hedgehog with medal is depicted small enough to fit inside the neck string on the gold medal.]
[This is an example of how the comic appeared during the competition. The example includes one of the final winner, Space's, matches. The dynamic part of the comic is transcribed below:] [At the top center of the comic, the two emojis battling it out are shown next to each other. The emojis displayed in the comic used the twemoji icon set. A different emoji set was shown in links to image of the tournament brackets. These matches are called bouts in the comic. The emoji from the top (or left) of the bracket is shown to the left. In this case it was space, night sky, milky way or stars vs Maglev train. Between them is the following text:] VS
[There are two buttons one below each of the two emoji. If pressed the buttons became red. They could be pressed multiple times each match. The buttons have text on them:] Vote Vote
[From the buttons colored hearts are released, often in bundles, and then they wave up across the emoji who's button they emanated from.]
[Below the buttons there is and indicator showing how long the current battle is open for further votes. In the example the text is:] Remaining time: 24 minutes
[The time began at "26 minutes" during the final rounds. It changed to "1 minute", with 1 minutes and 30 seconds left, and then 30 seconds later to "60 seconds" counting down to a few seconds. Then, before reaching 2 or 3 seconds it changed (a bit too early) to "Time's up!" Shortly there after a new bout would begin.]
[Above the two emoji at the very top is a comment. The commentator is shown as a robot emoji. The comment often changed during the long final rounds. In the current example the text is:] "~future~"
[But there would have been several others during the match. Given that Space won the entire Emojidome, the train lost this match. Often a final comment was posted just as the result was in. These final messages was then put at the top of the list of past bouts (matches). These bouts was displayed at the bottom of the comic below the remaining time. To the left was the following text:] Past bouts:
[Below this text was a list of all previous matches, showing the two emojis, with the loser grayed out, with their final comment next to them. As soon as there where more than three a scroll bar appeared to the right, making it possible to scroll down through all these previous matches. As it was 512 emojis to begin with, there were 256 bouts in the first round, and then 255 the rest of the way to the final for a total of 511 bouts at the end. Here are the the text of the three matches that can be seen in the example (the grayed out loser was Sushi, Bee and Wizard):] 🌋 vs 🍣 "Sushi has received a technical disqualification for being very very cooked" 🐝 vs 🦉 "Owls well that ends well" 🦔 vs 🧙 "The Wizard didn't do it"
[All the final bouts remarks, as well as the match ups, the score of votes, and all the other comments coming at the top during each bout can be found below in the round 1 to round 9 sections. They are thus not only a transcript.]
[Finally at the bottom of the comic below the scroll-able version of the past bouts, there was a link to images of the brackets, beginning with the full long one of all 512 emojis, and the zooming in and out, plus updating with results along the way. The link was a text that explained what the link was for. In the current example the link text, which is link blue, was:] Full bracket for today's comic (round 3).

[This is the image that appears when JavaScript fails or other errors occur. This is what embeds and automated programs usually see, as they load down dynamic comics. The transcript for this image is below the image:] [A tournament bracket tree is shown with eight participants each on the left and right side, for a total of sixteen, all of which are the 😰 emoji ("Face With Open Mouth and Cold Sweat"). From both sides towards the middle the brackets reduce to eight, then four, two, and one line where the latter join to a rectangle in the middle. Below is an explanation of why this is seen instead of the correct comic. It is due to an error with JavaScript. This is also why the sad emoji is used in all sweet sixteen places.]
Visit xkcd.com to participate
If you are on xkcd.com, then you're seeing this because of something something JavaScript.
Listen, websites are hard 😰


Percentage Styles

Explanation:
On March 29, 2019, The AP Stylebook changed a long-standing rule that forbade press writers from using the percent sign (%) when writing percentages. This had long been a controversial rule, leading to much debate over the preferable way to write percentages, before the Associated Press finally conceded the point.
The comic lists the best to worst ways in which you can write out phrases that are phonetically the same as "65%".  They go from the common "65%" and "65 percent" to "65 per cent," which is not common in Randall's area and time, to the eccentric "sixty-five%" and "65 per¢" (using the cent currency symbol) which are not used in normal writing and would stand out like a sore thumb when read. The middle option, "65 per cent", was common in older literature, along with "65 per cent.", using "cent." as an abbreviation for "centum", which is Latin for "hundred". ("per" in Latin translates to "through", "for", and several other English prepositions.) The entire string would translate to "65 for every hundred." "Per cent" is more widely used in British English than in American English today.
A small gap between the ends of the bar and the best and worst options may suggest the existence of even better and worse options not listed in this comic, such as "6ty5/¢".
Other abbreviations not mentioned in the comic include "pct.", "pct" or "pc". See Percentage .
The title text references the ambiguity of hard and soft C in English. In Classical Latin, "C" is always pronounced like "K". However, in English, most "C"s before E, I and Y (including "percent") are soft, and pronounced like "S". In academia, Latin students are taught the Classical Latin pronunciations of words , rather than the pronunciation used by the Catholic church. Some students of Latin may adopt the Latin pronunciation of English words derived from Latin. Such people may tend more to pronounce, even when not the correct choice, "celtic" like "keltic" (this is the correct choice, except for the basketball team ), "caesar" like "kaiser", or "cent" like "kent" (although since this involves obviously saying something others aren't going to understand unless they took the same classes, it might as well be "per kentum").
People sometimes train a cat out of a bad behavior, such as scratching upholstery, by spritzing the cat with water when the cat does the undesired behavior. In this case, Randall's friends found him so annoying they trained him out saying "per kent" by spraying him with water every time he pronounced it that way. Training people this way was previously a punchline in 220: Philosophy , while training a cat this way was previously a punchline in 1786: Trash .
65% This is the standard way of writing percentages. Randall's approval acceptability is 98%. 65 percent This one has no space, it is more common in American English. Rating: 97 percent 65 per cent This one has a space, it is more common in British English. Rating: 86 per cent Sixty-five% This one writes out the number, but not the percent sign. Rating: Sixty% 65 per¢ This one uses the cent symbol in place of the word cent, which is incorrect in this context, as cent here does not refer to a currency. Rating: 2 per¢
Percentage styles in order of acceptability [A long vertical line is shown with five dots on it.] [Label at the top:] Best [Dot labels from top to bottom:] 65% [very short distance] 65 percent [at roughly quarter scale] 65 per cent [at roughly half scale] Sixty-five% [at the end] 65 per¢


EHT Black Hole Picture

Explanation:
This comic references the Event Horizon Telescope , an international project dedicated to imaging black holes Sagittarius A* and M87* with angular resolution comparable in size to their event horizons.  The first image of M87 was released to the public on Wednesday, April 10, 2019, five days after this comic's release, and appeared on the same day in the comic 2135: M87 Black Hole Size Comparison .
The image was produced from data gathered since 2006, collected by over a dozen radio telescopes around the world and combined through a process called interferometry .  Normally, a telescope's resolution is limited by the size of its aperture, but by recording radio signals at multiple sites, the minute differences between the signals can be digitally processed into an image with much higher resolution.  The telescopes used for the EHT are in Hawaii, North and South America, Europe, and Antarctica, and so the effective diameter of the collective EHT is almost the size of the Earth itself.  As each telescope recorded observations of the black holes, the results were written to hard drives and mailed to observatories at MIT and the Max Planck Institute for Radio Astronomy for processing.  Astronomical recordings can involve astronomical amounts of data, so the raw, original, feed from a telescope may never be stored if it is too dense -- it is instead processed live by computers to capture the information of interest, and the processed result is stored.
The first image released by the EHT was expected to be in April 2017, but unforeseen events delayed it by two years, to April 2019.  Randall predicts this trend will continue, and makes a joke by analogy to real-world difficult experiences capturing important moments.
Luckily this comic was not in any way prophetic, and five days after this comic was released the EHT team released a black hole picture for the world to enjoy.
The comic shows Cueball giving a press conference on the recent photographing of a black hole.  However, the photograph is a disappointment, caused by the spectacular failure of several systems:
Obviously, it would be quite impractical to fail to reliably provide this in an astronomical system. Cueball describes the system as being like Pinterest , where JavaScript prevents you from right-clicking on an image so that you could save it (or at least attempts to, there are many workarounds).
Cueball states that they then tried to take a screenshot, but the key combination to make a screenshot instead turned off the monitor where the picture was being displayed whenever they tried to use it, requiring extra time and effort each attempt in order to return to the view of the black hole. This could reference the fact that many mobile devices incorporate the power button in their screen shot combination and the power button can also turn off the screen.  Laptops and operating systems may also have undocumented key combinations that blank the screen, which users can accidentally press when in a hurry and create further stress for themselves. Content under DRM may also prevent screenshots, and attempting to screenshot a protected video will result in a black image.
As a last act of desperation, Cueball took out his phone and attempted to take a photo of the screen showing the black hole, but by that time, the observation had ended, and the photo was lost.
In reality, none of this should be an issue as the picture would be immediately saved by the system and would not need to be downloaded from the site, but NASA especially knows that developers of a system can never predict the obscure happenstances that can combine to create failure at the end.
Cueball then states that they would try to take a picture of a black hole again next year.
The title text explains that (after presumably five years of annual tries), the picture failed again as the telescope was too zoomed in and only captured a featureless square. Since a black hole by definition returns no light sent to it, the photograph would be entirely black. Researchers however are primarily presumably trying to obtain images of the more interesting edge known as an accretion disc , which could actually be meaningfully photographed.  The joke is that the black hole could only be photographed once a year, and in each year some incidental set of mistakes combined to prevent the photograph from actually being shared with anybody.  This could be a reference to the cosmic censorship hypothesis , which states that a "naked" singularity cannot be viewed from outside an event horizon, where in this case the censor is some kind of "butterfly of doom" that bedevils astronomers who attempt to image one anyway, similar to some interpretations of the Novikov self-consistency principle (a possible resolution to various time travel paradoxes which asserts that any event which would lead to a paradox must have probability zero).
[Cueball is standing behind a lectern, with "Press Conference" and the EHT logo displayed on a projector screen behind him.] Cueball: We linked up our observatories, got everything aligned, and there it was: Cueball: The first image of a black hole!
[Zoom in on Cueball. A question is asked from off panel.] Off-panel question: Can you share the picture? Cueball: Well, here's the thing...
[Cueball lifts his arm holding his hand with its palm up.] Cueball: Turns out our telescope feed is like Pinterest, where you can't right-click to save an image. Cueball: So we tried to take a screenshot, but the key combination kept turning off the display instead.
[Zoom back out to show that the image on the projector screen has changed to show a blurry picture of a white computer screen against a black background. The EHT logo remains at the bottom of the projector screen.] Cueball: I grabbed my phone and tried to take a picture of the screen, but I was too slow. The observation had ended. Cueball: We're planning to try again next year, and we'll definitely record the screen this time.


Too Much Talking

Explanation:
Cueball has recently returned from a party, something which is unusual since Cueball has mostly been shown as an introverted type. Like most introverts, social interactions and obligations have worn him out, and different from most after-party regrets, he appears to have "talked too much."
While at the party, he has likely expressed opinions that might be rejected or seen as embarrassing by his social circle or society as a whole, and is now remorseful and embarrassed he said such things. In his shame, he recedes under his bed, but evidently he finds new opinions to feel strongly about, and quickly returns to society.
The title text presents a suggestion that will likely not go over well, as forcing those at a party to quietly listen to you is a great way to kill the party. It also does not allow others to respond to said opinions before moving on to the next.
[Cueball is walking into the panel from the right] Off-screen: How was the party? Cueball: Taaalkiiiiiiing Cueball: Blablablabla Cueball: I talked so much. Too much? Probably. Cueball: My face is tired.
[Cueball moving to retreat under a bed] Cueball: So many conversations. Cueball: I'm worried that all my opinions are bad. Why did I talk so much? Cueball: Time to hide under my bed and never speak to another human again.
[The bed is shown, presumably with Cueball under it.]
Five minutes later... [Cueball crawling out from under the bed] Cueball: I have some new opinions. Off-screen: That didn't take long.


M87 Black Hole Size Comparison

Explanation:
This comic shows the picture of the M87 black hole by the Event Horizon Telescope that was published on the same day as this comic. Overlaid on the picture is a scale image of the Solar System, showing the Sun, Pluto (one of the most well-known dwarf planets ) and its orbital path, and Voyager 1 , a deep-space probe and the current farthest probe from Earth. The comic is quite similar to 1551: Pluto , in which Randall overlaid annotations onto the recently-released first images of Pluto taken by the New Horizons spacecraft.
The point of the comic is to celebrate the release of this image by the Event Horizon Telescope, referenced two comics earlier, in 2133: EHT Black Hole Picture , as well as to indicate the hugeness of M87 and the awe-inspiring thing that space is.  This image has been widely publicized as being the first image ever of a black hole.  Science had no visual evidence of black holes at all until 2012 .
In the title text Randall hypothesizes that if the Sun were at the center of M87, Voyager would be outside the event horizon. This is confirmed by a 2015 study in which the Schwartzchild radius of M87* was found to be 5.9x10^-4 pc, as opposed to the distance of 7.04x10^-4 pc, at the time the comic was written, between Voyager 1 and the Sun.
The comic's scale seems to be slightly small; while the orbit of Pluto should be about 4.9 microarcseconds across, in the comic it's about 3.9 microarcseconds across.
[Caption above the panel:] Size comparison: The M87 Black Hole and Our Solar System
[Caption at top left of the panel:] EHT Black Hole Image Source: NSF
[An image of the M87 black hole captured by the event horizon telescope on the day that this comic was published is shown, in the shape of a thick red-and-yellow ring on a black background.]
[A white ring about 1/4 of the diameter of the central black portion of the image is labelled with an arrow:] Pluto
[A small white circle at the center of the image is labelled with an arrow:] Sun
[A small white dot on the right hand edge of the central black portion of the image is labelled with an arrow:] Voyager 1


Election Commentary

Explanation:
This comic is a joke about the way newscasters commentate elections, and how they make it far more complicated than it needs to be in an election in which the candidate with the most votes wins. It's not uncommon for these methods to be used to imply the election is neck-and-neck long past the point one candidate has an insurmountable lead.
Smith has 55384 votes, while Jones has 59102 votes. Instead of comparing the votes as one number, and admitting that Jones' four thousand vote lead is likely going to earn him the win, Cueball compares each digit to see which is larger. Smith's digits in the hundreds, tens, and ones are all higher than Jones', so ultimately he implies that Smith has a chance to win, if only he could pull ahead in the thousands digit and secure a dramatic upset. In reality all that matters is who has the higher total number of votes.
It should be noted that for U.S. Presidential elections, the candidate with more votes does not necessarily win. Each state (plus the District of Columbia) gets a certain number of votes, and the victor in those states usually (though not always) receives all of the state's votes. In that specific case, tracking individual victories (though in states, not in digits) is actually highly relevant to who wins. That said, the comic appears be depicting something on a much smaller scale, such as a municipal or district election, which is likely to use the more common most-votes-wins method of election.
The title text is a similarly satirical twist on a common news comment during elections. Candidates often employ different strategies during the election season, with varying degrees of success. For example, if a strategy collected many votes (or important votes, see above paragraph), then it could be said that the area it affected was "crucial". Here, the area affected by Jones' strategy (an entire place value) is said to have been crucial — an obvious claim, seeing as greater place values always result in greater amounts indicated.
[Cueball is presenting a graphic on his left that shows two names followed by five digits] Cueball: Smith is leading in 3 of the 5 digits, and is tied in another. But Jones has a solid lead the thousands place, if Smith can't catch up there, it's over.
Smith: 5 5 3 8 4 Jones: 5 9 1 0 2
[In each column, the higher number is marked with a check mark and the lower with a cross and greyed out. The fives in the leftmost column are marked "tie"]
[Caption below the panel:] A lot of election commentary just consists of unnecessarily convoluted ways to add up who has more votes.


Text Entry

Explanation:
In this comic, Randall remarks upon something that he considers to be an absurdity of modern living; that in spite of our amazing advances in technology, there still exist user interfaces in 2019 where a person has to "pick letters" to type, a somewhat clunky and inefficient method of text entry. This can be seen when doing searches in a TV guide menu or in menus for streaming options like Netflix or Hulu . Some of these menus may allow for voice searches or support bluetooth keyboards , but the traditional method is still to select letters via a cursor.  Many controllers for devices only have a few buttons, which makes it necessary to use schemes such as scrolling around a picture of a keyboard to laboriously select letters, making this extremely inconvenient and annoying to users. The fact that these haven't been replaced with better interfaces comes as a surprise to Randall, hence him  believing it to be the second most weird thing in 2019. Cueball is probably looking up Our Planet which was a popular Netflix series when this comic was released. Cueball has spelled out "O U R [space] P L" so far.
Randall references the " high score " in an arcade game . When achieving a high score in an arcade game, the user typically is able to enter their name or initials into the machine. These are entered by picking letters one by one (and usually under a time limit, for extra fun and/or stress ), as the comic mentions.
The title text mentions the keyboard system Dvorak , a recurrent theme on xkcd, which is a keyboard layout patented by August Dvorak and William Dealey . As the Dvorak layout is optimized for more efficient typing with two hands, it is unlikely that using it would be more efficient than a standard Qwerty when limited to cursor entry methods. Another drawback would be that the Dvorak layout is visually unfamiliar to most people, even to many Dvorak typists who rarely look at their keyboard and instead rely on muscle-memory to find keys. As such it could be confusing for users to use for TV selection menus compared to either the more visually familiar Qwerty layout or showing letters in alphabetical order. Alternately, Randall may be referring to Dvorak’s placement of frequently used letters clustered in the center as a potential slight improvement over the linear A-Z layout of such interfaces (a half-measure offered ironically, of course).
Although the focus of this comic is on the text entry method, Randall prefaces the comic with what he considers to be the actual weirdest thing about 2019: that Donald Trump is the president of the United States of America. Randall had previously expressed support for Trump's opponent, Hillary Clinton, in the comic 1756: I'm With Her which preceded the 2016 US Presidential Election. In that comic he did not mention Trump. Although several comics may have a relation to Donald Trump becoming president, this is the first time ever , Donald Trump has been mentioned by his full name in a standard xkcd comic. (In 1939: 2016 Election Map he is referred to by his surname).
[Ponytail and Cueball are sitting on a couch, with Megan standing behind them.  Cueball is pointing a remote at a television. The word space is written inside a frame.] Television: O...U...R...SPACE...P...L... Remote: Click Click Click
[Caption below the panel:] The weirdest thing about 2019 is obviously that Donald Trump is president, but I think the second weirdest is that you sometimes still have to type stuff in by picking letters on a screen one at a time with a cursor like you're entering a high score in a 1980s arcade game.


Wanna See the Code?

Explanation:
This comic is the fifth and latest comic in the Code Quality series:
Cueball declares that he has written a script to automate some (presumably time-consuming or tedious) task, which pleases Ponytail at first... until she remembers how messy Cueball's code tends to be, and gets worried.
Cueball offers to show her his code, but Ponytail remarks that it sounds like he's creepily inviting her to see a dead body. Magnanimously, Cueball accepts the comparison, noting that his code does have at least one similarity to a deceased corpse: although unpleasant, if Ponytail allows it to go unchecked, it causes problems which will get increasingly worse over time. In the "dead body" analogy, a recently-deceased corpse is easier to deal with than one that has been left for a few weeks, which will be decayed, unpleasantly smelly, and will likely have attracted disease-spreading vermin.
Ponytail then makes a near threatening comment where she says that he is lucky that people understand both that his code causes more problems than it solves and that dead bodies create more problems than they solve. Most likely this means that they understand that killing him would cause more problems than it solves (the problem solved would no doubt be his code).
This may be a reference to the concept of technical debt in software development: the idea that an initially poor implementation accrues a sort of "compound interest" over time, becoming increasingly difficult to repair the longer it is left unfixed. This happens because any future development might have to take unorthodox or unrecommended measures to work around the problems that are already there, making the system increasingly complex and fragile the more that is added to it.
In the title text, "downstream" has a double meaning, as it is a term that applies to a situation where a dead body would decompose in or near some river, and as well to a software engineering concept: In the river situation, the dead body will contaminate the water or groundwater that it feeds from and have consequences for organisms that come in contact with that water. In the software engineering analogue, "downstream" refers to software derived from, or depending on, "upstream" software like the cadaver that Cueball devised. The causality with flowing water and software is reasonably comparable: both can be seen as a stream of atoms that are (almost) endlessly divisible and recombinable.
[Cueball is walking, talking to Ponytail, who is offscreen.] Cueball: I wrote a script to automate that thing. Ponytail: Oh cool! Ponytail: ...wait, you wrote it? Ponytail: Oh no.
[Cueball and Ponytail are standing next to each other and talking.] Cueball: Wanna see the code? Ponytail: I would, if you hadn't said that in the tone of voice of "Wanna see a dead body?"
[Same scene as before, except Cueball has his hand on his chin.] Cueball: My code is sort of similar to a dead body, in that you can either come look at it now, or wait a few weeks until it becomes a problem. Ponytail: And because you're lucky that the people around you understand that they create more problems than they solve.


Email Settings

Explanation:
The comic shows some email settings with a few less-than-helpful options.
Plain text is self-explanatory; plain text with no special formatting options. HTML means that it can have markup to allow for bold text, colors, etc. CSS is in reference to Cascading Style Sheets, which is a styling option often combined with HTML, but useless on its own. With emails, it is typically used as inline CSS.
Email Settings [A list of controls with radio buttons and checkboxes] Default reply behavior ( ) Reply ( ) Reply All (*) Forward to address book
Vacation autoresponder (*) While on vacation ( ) Always
[x] Reply to all newsletters with "Thank you for the newsletter!"
Attachment limit ( ) 300 KB (*) 1.4 MB ( ) 5 MB (Beta)
Default email format (*) Plain text ( ) HTML ( ) CSS
[x] Reply to HTML emails with "Whoa, buddy, what's all this code?"
Character set ( ) ASCII (Unicode 0-127 only) (*) Non-ASCII (Unicode 128+ only)
Smart autocomplete ( ) Do not suggest replies ( ) Suggest replies (*) Automatically respond to all emails with suggested reply
Important emails (*) Show ( ) Hide
Show unread email count... (*) Now ( ) On my projected day of death
Signature (*) "That's my email. Hope you liked it!" ( ) None


Reinvent the Wheel

Explanation:
" Reinventing the wheel " is an idiom/metaphor that refers to duplicate effort to recreate something that has already been created or perfected previously without adding any value in the process. The phrase relates to the idea that the round wheel was invented a long time ago and there is no way to make it better, as a circle is the most optimal shape. While the phrase includes the word "wheel", it isn't typically directly associated with the wheel but instead uses the word "wheel" because of the easily understandable meaning - a simple object with no improvements that can be made. That being said, we have actually reinvented the wheel at one point in time - a tire is a modern improvement to the wheel, which reduces bumps and shocks that people in the car would feel from uneven road surfaces.
In this comic, Beret Guy works for an automotive company (or this is his own company ), and he is explaining to Ponytail their decision to not reinvent the wheel for the automobiles that they produce, using the phrase in a literal sense instead of figuratively.  Instead of determining for themselves what wheel to use, they want to use whichever wheel is presumably considered the "best" wheel by the world, using a daily Google image search for "wheel" to determine the highest ranked wheel, and then using that wheel on the vehicles they produce that day. In reality, this would be a very bad way of choosing the wheels of the automobiles Beret Guy's company produces. In addition to being extremely inefficient, as they might have to change the wheels they use every day, it may also result in copyrights and lawsuits against his company.
The point of the comic is to make fun of programmers who take the idea that you should never reinvent the wheel too seriously. When these people have a problem, they may Google to find a solution to that problem, and when they find a piece of online code, they use it in their own code, even if it wasn't initially designed to handle the task for which it is being used and thus may have unintended side effects or other issues.
Another way that programmers may go too far in avoiding reinventing the wheel is in using external dependencies.  It can be valuable to use external libraries, especially for applications where certain tasks have strange edge cases that a 'reinvention' is likely to miss or require lots of development effort to correctly implement (like time ).  However, using someone else's code means taking on the risk of security vulnerabilities, and when the library is updated on live installations, the user also takes on the risk that the library might become unavailable or otherwise break.  In this case, Beret Guy's company updates their wheel "library" on a daily basis from Google's image search.  Google is unlikely to shut down a core search product, but they might change the API that Beret Guy's company uses (unless he's just going to their website himself), and they have been known to shut down projects that people like, such as Google Reader .  On the day this comic was released, Randall changed the Header text of xkcd, adding a reference to Google Reader .
The popular programming language Python manages external dependencies with packages called "wheels" which are "published to the cheese shop", which may or may not be an intended reference.
In any event, Beret Guy is in effect reinventing the wheel by doing a new search for wheels on Google Images every day. If the wheel he finds on Google Images on a given day is suitable for his company's needs, the company would likely be better off using the same wheel on succeeding days (unless circumstances change which make that unfeasible), compared to trying to doing a new search for wheels every day. In addition, Beret Guy's company might be forced to create new wheel-producing machinery every day, although if Beret Guy can transmit soup and air through electrical cords, it may simply be a matter of copying the image then pasting it in real life.
The title text indicates that Beret Guy is currently using bicycle wheels for his vehicles, requiring his vehicles to be lighter as bicycle wheels cannot carry a lot of weight.  He says this "reduce[s] overhead", which is both literally true, that his vehicle weighs less, and refers to the usual figurative desire of reducing overhead costs of development by using external libraries. If the former interpretation is correct, this raises the question of why Beret Guy's company didn't try to lighten the load of its vehicles beforehand. Finally, the narrator (supposedly Beret Guy) explains that at one point a wheel of cheese was near the top of the Google images search. If it had reached the top, it would have been disastrous as a wheel of cheese is completely unsuited for use as a vehicle's wheel. [ citation needed ] Beret Guy implies that his company would have used it if it reached the first position even though he knows that it would be unsuitable for usage in vehicles, further demonstrating Beret Guy's lack of business knowledge.
On the day the comic was released a bicycle wheel came up first when searching for "wheel", see image in the Trivia section below.
[Beret Guy is talking to Ponytail.] Beret Guy: We don't want to reinvent the wheel, so every day we Google image search "wheel", and whatever object comes up, that's what we attach to our vehicles. Beret Guy: Sure, external dependencies carry risks, but so far they've all been pretty good wheels.


UI vs UX

Explanation:
UI vs UX is a discussion in software engineering of the differences between user interface design (UI) and user experience design (UX). As explained in the comic, UI design is typically concerned with the elements of the interface that a user encounters, while UX design is more concerned about the user's overall experience in using such interface. UX design can be seen as more holistic & abstract than UI. This comic extends the idea, adding increasingly all-encompassing, abstract & fanciful design perspectives.
To start, the two real categories are:
UI - Elements of the interface that the user encounters This standard software engineering practice involves trying to come up with a user interface - icons, colors, placement or text and elements, etc. that works well together, that isn't confusing, and that hopefully makes it easy for the user to view the information they need to digest, as well as make whatever choices the user is expected to make.  They also look at things like how long it takes to move from one screen or task to another, etc. UX - The user's experience of using the interface to achieve goals Sometimes a UI designer makes choices that they think are easy for the user, but it turns out not to be as easy as expected when it comes to real users and practical situations. So the UX designer focuses on observing how a user uses a product, both how they use the user interface as well as other less technical aspects of their experience such as how they come to find out about the product, what they tell others about the product, etc.
The comic takes this to absurd levels by adding these additional categories:
UZ - The psychological roots of the user's motivation for seeking out the interaction The comic says that UZ is the investigation of the psychological roots of why the user even wants to use the interface. This is not normally something that computer programmers do [ citation needed ] , and is usually best left in the hands of psychologists [ citation needed ] . "The psychological roots of motivation" is a buzzword phrase from management theory which may not have a particularly well-defined meaning. Motivation is itself the psychological root of behavior. While motivations certainly have causes, they are usually not clear enough to meaningfully treat in formal or clinical contexts. Uα - The user's self-actualization " Self actualization " is the most abstract, immaterial form of motivation, meaning the need to find comfort in one's own goals and achievements. Available only when more material needs such as those for food, shelter, warmth, security, and a sense of belonging are met, it forms the pinnacle of Maslow's hierarchy of needs . α is alpha , the first letter of the Greek alphabet. It's often used to show the "beginning" or "first" of something (including in philosophical contexts). And as the first Greek letter, it can be thought of "beyond Z" in a sense; the Atlantic hurricane name list uses the Greek alphabet this way, for example (as 944: Hurricane Names alludes to). UΩ - The arc of the user's life "The arc of one's life," means the overall thematic elements present in a person's existence. It occurs in the philosophical humor novel The World According to Garp , which remarks on how easily the arc of any human life can turn on a single sexual relationship. Continuing the philosophical theme, Ω is omega , the last letter of the Greek alphabet. As such, it's often used to show the "last", "end", or "ultimate" of something. U∞ - Life's experience of time "Life's experience of time" is a very rare phrase which does not seem to have a coherent meaning across the handful of times it occurs. ∞ (U+221E) is the mathematical symbol for infinity , again furthering the philosophical abstraction. U ⬤ - The arc of the moral universe "The arc of the moral universe is long, but it bends toward justice," is a famous line from a speech by Martin Luther King , referring to the slow pace at which social progress is often achieved, and paraphrasing parts of a 1853 sermon by abolitionist minister Theodore Parker : "I do not pretend to understand the moral universe. The arc is a long one. My eye reaches but little ways. I cannot calculate the curve and complete the figure by experience of sight. I can divine it by conscience. And from what I see I am sure it bends toward justice." President Obama had the sentence from King's speech woven into a rug in the Oval Office. The ⬤ is a filled-in circle the size of the letters around it, represented here by the Unicode " black large circle " character ( U+2B24 ). Continuing the philosophical abstraction, it comes well after the Greek alphabet and most mathematical symbols in Unicode, and is especially unlikely to be used as a text character in its own right like this. [ citation needed ]
The title text refers to a higher power bending the moral arc, but mirrors the UI and UX categories, with the implication that the list continues in a spiral through ever more rarefied levels of higher powers, with even less likely symbols denoting them.
U[unprintable glyph] - The elements a higher power uses to bend that moral arc Essentially UI for the higher power's moral arc bending utility. U[even more unprintable glyph] - The higher power's overall experience bending that moral arc Essentially UX for the higher power's moral arc bending utility.
[Two underlined headings are above two columns of text with seven lines. The left "symbol" (labelled "Designer") is explained by the text to the right (labelled "What they are responsible for").]
UI: Elements of the interface that the user encounters
UX: The user's experience of using the interface to achieve goals
UZ: The psychological roots of the user's motivation for seeking out the interaction
U∝: The user's self-actualization
UΩ: The arc of the user's life
U∞: Life's experience of time
U⚫: The arc of the moral universe


Dangerous Fields

Explanation:
This is a graph of fields of study, ordered by how likely one is to die because of something that that field studies, with mathematics being the least dangerous and gerontology being the most. Gerontology, the scientific study of old age, is shown as much more dangerous than the other fields, so it is far on the right side of the graph. The joke is in the distinction between the danger of studying the thing, and the overall death rate from the thing.  Studying aging doesn't put you at much more risk of aging than the general population.  However, studying volcanoes is likely to put you in dangerous environments.
The title text is about Epidemiology , the study of health and disease conditions in populations. In the event of an epidemic, there is a strong chance that epidemiologists in the search for the cause, transmission, and treatment will be exposed and become victims of the disease in their own right. However, the title text refers more broadly to the role of epidemiology in maintaining detailed statistical records of diseases and other causes of death, such that eventually any epidemiologist (whatever the cause of death) will become one of their own statistics.
[A line chart is shown going from left to right with two arrows on either side. On the line are ten dots spread out unevenly from close to each end. The first four dots are clustered together on the left side. Then follows 5 more dots unevenly spaced, all to the left of center. On the far right of the line, near the end, there is one dot. Beneath each dot, there goes a line down to a label written beneath each line. Above the chart, there is a big title and below that is an explanation. Below that again, there is a small arrow pointing to the right with a label above it.] Probability that you'll be killed by the thing you study By field
[Arrow pointing right, labeled:] More likely
[Labels for the ten dots from left to right:] Mathematics (0 pixels from first field, 0.00% of overall range of fields) Astronomy (9px, 1.35%) Economics (16px, 2.40%) Law (22px, 3.30%) Criminology (77px, 11.56%) Meteorology (96px, 14.41%) Chemistry (156px, 23.42%) Marine Biology (166px, 24.92%) Volcanology (206px, 30.93%) Gerontology (666px, 100.00%)


Disk Usage

Explanation:
Many personal computers provide a way to obtain a graphical breakdown of how their storage space is being used, most commonly by representing the filesystem as a pie chart in which each slice represents the proportion of the total storage space being taken up by a particular item.
In this comic, Randall has illustrated the usage of his hard disk drive in just such a way, although as is common for him, the items in his hard drive start off seemingly normal and become increasingly strange:
Photos Digital photographs are a common item to be stored on a hard disk; many people take lots of photographs with their smartphone or a camera and will commonly transfer them to a disk drive for safekeeping, editing, or organizing. With the high resolution of modern cameras and the ease of taking photos, it is common for photo collections to consume a significant amount of disk space. Good photos On the flipside, the ease of taking photographs means that it is very easy to take bad photographs, particularly as most people are not experienced at photography. The pie chart is rather bluntly indicating that of the many photographs Randall has taken, only a vanishingly small fraction of them are actually good. Documents On a file system, "Documents" is generally used as a catch-all term for the user's personal files. Everything you've streamed since 2017 Streaming is a term that refers to accessing audio or video content on the Internet without downloading the entire media file first - it is instead played while it's being retrieved. An example of streaming is watching a YouTube video. Assuming a weekly 2h live stream (@4Mbps) between 2017-01-01 and 2019-04-29, these recordings would be 425GB in size. When these files take up 6% of all the used disk space, the full amount of used space would be roughly 7TB, which is plausible, given the rise of 10TB hard disks in 2016 . It might also be referring to temporary media files that were stored on the disk while it was being "streamed" for viewing or listening from the Internet and never deleted when done. A single five-year old PowerPoint presentation Almost a tenth of the entire disk space is taken up by a single file, a presentation made five years ago in Microsoft PowerPoint . It's unclear why Randall has kept this file or why it is so huge - possibly it is important to him for some reason, or perhaps he can't bear the thought of throwing information away, regardless of how much storage it requires. While it's possible that the file may genuinely be long or detailed enough to require so much space, it could also be that the file is bloated due to PowerPoint's strategy of converting compressed graphics to full-resolution bitmaps for historical cross-platform compatibility . This has been known to result in PowerPoint decks that are much larger than the sum of their component files. "System" This would be files related to the computer's Operating System . While these files will generally show up on a disk usage analysis, it is generally recommended to leave them alone, as they may be critical to the computer's operation. A well-known trolling tactic involves tricking unsuspecting users into deleting their critical system files (eg. the "System32" folder on Windows), which renders the operating system unusable. Unused Parkinson's law , the computer storage corollary, says that data expands to fill the space available for storage.  As such, this sliver representing the unused portion of the storage device will always be tiny. "Cache" The operating system and other programs often keep copies of data they've used or downloaded in case they need to use that data again; such data is usually stored in cache files.  Often these can be deleted without too much ill effect, but some programs have different ways of deleting their own cache files. "Other" People attempting to organize their files will often end up creating a directory called "Other" or "Misc" for any files that they could not categorize. On Randall's hard disk, this "Other" directory takes up a significant amount of disk space, indicating that either his categorization system isn't working very well, or he doesn't have the discipline to properly maintain his file organization. Alternatively, this could be a category defined by the usage report, which would include anything it can't categorize - often a strangely large portion of the files. Why are there two full backups of my phone from 2015 deep in a settings folder? Full backups of an old phone may have been stored to "settings" by a version of backup or file synchronization software which wanted to keep the resulting backup images in a location away from user control so they would be less likely to modify any of their component files, which might, for example, tend to clobber new versions with the modified old versions. Renaming a device under such circumstances might lead to duplicate backup images.
Another possible explanation is that folder names like "Other", "Cache" and "System" refer to storing porn while trying to hide this fact by using unsuspicious folder names. Hence the quotes.
Alarmingly, the "Unused" portion of the pie chart is extremely small, which means the disk is nearly full with very little remaining capacity. Users don't usually worry about what is using space on their computer disk until they get an alert about the disk running out of space - this is likely when a user would resort to viewing this type of graph to figure out what they can delete to free up disk space.
The title text references the management UI of a hypothetical disk cleaning utility. The following options are mentioned in its menu:
Optimize space usage A common nondescript phrase often found in such tools. Encrypt disk usage report Often, one might want to encrypt data on the disk, not reports about said data. This may suggest that the unusual disk usage is embarrassing enough that the user may want to encrypt the usage report, preventing other people from reading it. Convert photos to text-only Plain-text documents take less space than pictures. The most high-compression option would be to replace the photo file with a text file containing a short description of the photo, for example using an AI algorithm like CaptionBot . Scanned documents can be automatically transcribed (OCR). However, applying such an algorithm to photos will result in garbage. One alternative, could be that the tool turns image files into text files by changing the extension to .txt. This would not save any space, and would only make the files more difficult to open. Another alternative would be converting the images into so called ASCII art , by converting regularly sampled blocks of pixels to ASCII characters that closely approximate the general shape and at times color of those pixels, potentially saving a general impression of the content of the images while significantly reducing file size. Delete temporary files Another real option. Temporary files are often not deleted automatically, so deleting them can save a significant amount of disk space. Delete permanent files A made-up term, that might refer to the user's documents, pictures, etc. You would not want to delete them. Delete all files currently in use Deleting files that are in use would most definitely result in data loss or program crashes, including perhaps even the program doing the deleting, making it effectively single-use. Windows explicitly disallows deleting open files & Linux, etc. provide locking mechanisms to prevent it, since it can cause data loss. Deleting all open files would be catastrophic, especially if it included system utilities & the kernel. If the program is capable of deleting all files in use anywhere on the planet, it would be considerably worse (& looking at these options, it's hard to say for sure the program won't try to go that far). Optimize menu options Those options could really do with some optimization. (a reference to the first entry?) Download cloud, Optimize cloud Here, the cloud probably refers to cloud storage (online storage). Cloud storage would be too large by many orders of magnitude to fit, let alone download onto a desktop computer, but in 908: The Cloud , the cloud is depicted as (ultimately) running on a single desktop-sized server in Black Hat 's house.  Perhaps the "Optimize cloud" option would be used to enable such an arrangement. Upload unused space to cloud "Uploading empty space" is a) impossible and b) would result in less space being available, which is the opposite of what a disk cleaner utility is supposed to do. Note that "unused space" may contain actual data. Often, when a file is deleted, the operating system just marks the content as available. The result is that it stays there until overwritten by new data. There are many data recovery tools that takes advantage of it in order to "undelete" files.
[This comic shows a pie chart with 10 slices, each with a label and a line pointing to these ten different sized slices. There is a caption above the chart:] Disk Space Usage Report
[The labels on each slice is given in anti-clockwise order starting from the 12 o'clock position. The percentages are estimated from the image and are noted in the square brackets before the transcript:]
[18%] Photos [1%] Good Photos [3%]: Documents [6%]: Everything you've streamed since 2017 [9%]: A single five-year-old PowerPoint presentation [21%]: "System" [2%]: Unused [9%]: "Cache" [23%]: "Other" [8%]: Why are there two full backups of my phone from 2015 deep in a settings folder?


Adjusting a Chair

Explanation:
This comic shows Cueball 's attempts to adjust a swivelling chair. This comically culminates in a massive chair with a big central seat and several other chairs branching off of it as Cueball continues learning how to to adjust it. The chair also apparently has so many controls it takes two hours to discover them all (although Cueball may have shown off his newly-discovered abilities in the mean time, so it might not take two hours of continuous experimentation).
As many people have experienced, these chairs can be quite difficult to raise, lower, or manoeuvre if one does not know how. Typically, the chairs have multiple knobs and levers underneath the seat, which requires the user to rely on muscle memory to find them, since these levers are commonly used while sitting in the chair. There are often several ways to manipulate each control (may be rotated, moved laterally, vertically, or axially.) One usually needs to experiment with the levers and knobs in a new chair to understand how to work the chair, and it appears Cueball is experimenting with them.
Each step gets farther away from what real-life office chairs could do. In sequence, Cueball finds his chair doing more and more surprising things:
The title text refers to a common claim on such chairs, that the chair offers 360 degrees rotation and several degrees of freedom. This is a double entendre, depending on if "360 degrees" or "degrees of freedom" is interpreted as an object. However, here it means there are 360 mechanical degrees of freedom , which is the number of independent parameters that define the configuration of an object; in other words, the chair has 360 different levers and options, far more than a standard chair [ citation needed ] .
[Cueball is shown adjusting a chair by pressing a button on the bottom of the chair. There is a caption in a frame over the top of the panel:] Adjusting a chair:
[The seat back of the chair swings backward with him rather fast as shown by a few movement lines.] Chair: Clunk
[Cueball leans forward against the new chair position and presses another button.]
[The chair extends to several times its previous height, very fast as shown by many lines beneath the seat.] Chair: Hiss
[At the top of this very high seat Cueball leans forward and presses another button.]
[The seat expands in all directions, so Cueball only sits in the middle of it with his legs on top of the inflated cushion.] Chair: Poof
[The chair is now a massive contraption. It has 5 bases, each with wheels as the original chair. The main's seat is in the middle of the contraption with a single trunk going up from the five bases connecting them and the large cushion of the seat. Two entire chairs are branching out from underneath this central seat, they are each hanging in a thin wire more or less upside down to each side of the main trunk. Two poles are coming up from the central seat, each with a new seat and two back-to-back seat backs. Yet another seat is supported by a thin rod connecting the two top seats, looking almost like a table between the two chairs. Cueball is still on the main seat's cushion. He is holding on to one of the poles above him as he leans down and attempts to press yet another button beneath the seat. There is a caption in a frame over the top of the panel:] Two hours later...


Heists And Escapes

Explanation:
The top six panels show a stylized version of various options where people try to get into or out of rooms. There are always two xkcd figures trying to get into or out of a room. One is always rattling, possibly at a locked door. While no door is drawn, the position of their hands indicates this. The second figure always has their hands at head height, possibly looking for weaknesses in the structure. The characters in each panel vary and there seems to be no specific pattern to them.
The six top panels show these scenarios:
At the end, Randall proposes a combination of all of these things, and also combining it with others, to form the "greatest escape room game of all time":
The escape room begins in a small room, shown with Cueball and Megan standing inside, who likely represent the participants of the escape room. An arrow leads out from that room into a larger bank, where some more characters labeled The Dead, referencing The Battle of Winterfell, are standing. An arrow leaves from them that merges into Cueball and Megan’s, implying they join them as they escape the room.
The arrows continue outside the bank, into a larger room labeled Truman Show , inspired by the film where the protagonist was living in a constructed reality show, although he did not know it. The path branches upwards around or into Kevin McCallister’s house, with the arrows inside spitting yet again, either exiting the house again or entering Kevin McCallister’s subconscious, a reference to the movie Inception . The arrows once again split and continue either downwards or to the right, both exiting McCallister’s house.
The path to the right splits, the top path crossing Styx , a river in Greek mythology that forms the boundary between Earth and the Underworld, represented by Dante’s Inferno, taken from The Divine Comedy , and the other returning to the line that leads downwards. The line that leads to Dante’s Inferno is met by the line that leads around Kevin McCallister’s house. It can be assumed that this is not a breaking into the underworld as portrayed in some movies, but due to the simplicity of the paths (note that unlike for the escape the line just crosses Styx) it is the possibility of failing prior puzzles and dying. In that case the escape room puzzle would continue with escaping from the underworld to rejoin the puzzles.
Both paths lead downwards back across Styx, rejoining the other lines below McCallister’s house. The lines continue to the bank and spit to either re-enter the bank or exit the escape room entirely. The line that re-enters the bank either returns to The Dead or into the bank’s vault, which the line also exits the escape room.
The title text refers to this article , which claims that Kevin McCallister is dead, and is actually a ghost.
[Seven different room scenarios are shown with characters attempting to get inside or outside, each with a label below them.]
[Cueball and Ponytail trying to exit a room.] Escape rooms
[Cueball and Megan trying to enter a room.] Heist movies
[A small version of Cueball stands in the middle of a room while a Hairy on the left and Cueball on the right are trying to enter.] Home Alone (1990)
[A room is shown inside a larger room. Two characters try to enter from outside and two others try to exit from the inner room while Megan and Cueball are standing between them.] The Battle of Winterfell
[Four rooms are shown inside of each other. Two characters try to enter from outside while three Cueballs in each room are standing while asleep.] Inception (2010)
[Smaller rooms are recursively shown inside of larger ones, with two characters trying to escape from each.] The Divine Comedy (1320)
[At the bottom a more complicated combination of various rooms shown in gray, with arrows labeled with question marks showing escape routes for two characters in black. On the left is a large room labelled Truman Show, and on the right is the nine-level Dante's Inferno. Between them is the river Styx. Inside the Truman Show are the Bank, which contains a Room with the two people in it, a Vault with a money bag in it, and The Dead; and Kevin McCallister's House and Subconscious.]
[Label in the bottom in black:] My plan for the greatest escape room game of all time
Judging by the depicted scene, the Battle of Winterfell referenced in the comic seems to refer to the battle taking place in the 3rd episode of the 8th season of the TV show Game of Thrones. While there is no official naming of all battles in the show, this is in line with the naming on most blogs and other discussions published around the premiere of that episode. However several wikis and other more long term reviews of the show refer to this battle as the "Battle of Ice and Fire". On these sites the "Battle of Winterfell" refers to the battle in the 10th episode of the 5th season between Stannis Baratheon and the Boltons.


Waiting for the But

Explanation:
Often arguments are made in the form of "I think X, but Y", where Y is almost but not quite contradictory to X. More specifically, the argument would go "I am not [something generally considered distasteful], but [a more specific statement most people consider part of that general statement]". The first part of such a statement can sometimes be viewed as an apology or an excuse because the person talking knows that the second part might upset people. A common example would be "I'm not a racist, but I don't think we should let refugees from Africa into Europe." The idea of denying help to people from Africa will be seen as racist by many people, so the speaker tries to preempt that opinion of themself.
In this comic, Cueball is having a conversation with Ponytail , who lists several seemingly unrelated but agreeable positions, such as reducing car accidents , treating arson as a serious crime, and approving of "No Animals were Harmed" disclaimers in modern media, with Cueball wondering when the "but.." of the statement will come, and conjuring increasingly outrageous images of what Ponytail could have in mind that involves violating all of them, for example some sort of reckless fiery car stunt involving animals.
The title text gives another example of a sentence that will probably be followed by a "but". Multi-level marketing schemes and the Spanish Inquisition are both considered bad in very different ways, so the implication that if the speaker has to apologize in advance for sounding like defending both of them, they must have a remarkably troubling idea in mind, involving somehow using a version of the Spanish Inquisition as an MLM scheme.
Another possible explanation would be that when people hear a sentence that starts with "Listen, I'm" they tend to wait for the "but", and the longer it takes the more tension it may cause them, while the speaker may never intend to say "but". Similar ideas were used for 365: Slides and 559: No Pun Intended .
[Ponytail is talking to Cueball, while holding her hands up with both palms up. Cueball is thinking as shown with a thought bubble.] Ponytail: Listen, I'm all in favor of reducing car accidents, I think arson is a serious crime, and I'm a big fan of those "No Animals Were Harmed" disclaimers at the end of movies... Cueball (thinking): Uh-oh.
[Caption below the panel:] The longer you have to wait for the "but", the worse whatever comes after it is going to be.


Appendicitis

Explanation:
Cueball , representing Randall , is visiting Doctor Ponytail , this time to diagnose some medical condition. From her description, zapped you with energy beams , it sounds like they just took an x-ray image , maybe in the form of a CT scan , and Ponytail is following up on the results. It appears that he may have appendicitis , the title of the comic, which could be treated through antibiotics , or through an appendectomy surgery.
As is typical for Doctor Ponytail, she characterizes the diagnosis in a strange and not-entirely-helpful way, in this case likening Cueball's inflamed appendix to a social uprising or rebellion. In some ways, this is not a bad metaphor - Cueball is an organism, and as such, functions best when all of his organic parts are working correctly in unison. People often express the similar sentiment of being "betrayed by their own body" to describe a biological function that isn't working right. However, Doctor Ponytail insists on talking only in metaphor, preventing Cueball from getting any useful medical detail about his condition.
Antibiotic treatment is described as using "chemical / biological weapons", while the appendectomy is described as "victory through the sword". She further describes more extreme "battle tactics", like crushing all other rebellions in his body. Lastly, she mentions "salting his abdomen" to prevent other rebellions. This is a reference to the salting the earth tactic in battle, which was a ritual to symbolize a curse on a conquered city and would have theoretically hindered future crop production, thus preventing that city from being rebuilt. It is likely that the medical usage would be the application of saline solution, salt in water, which is used for cleaning wounds.
After all this explanation, Cueball begins to question Ponytail's methods, and requests to see a different doctor to get a second opinion .
The title text appears to be Randall speaking directly to the reader addressing a recent appendicitis and his current health state. He continues the comic's joke with a meta reference pondering the repercussions if his organs subsequently discover this comic. The title text of 2508: Circumappendiceal Somectomy , from August 2021, seems to indicate that while antibiotics may have cured this event, a later infection required surgery anyway, a bit more than two years after this comic was released.
[Cueball is seated on an medical examination table, clutching his stomach, while Ponytail stands dressed in a doctor's coat holding a file on a clipboard in her left hand.] Ponytail: Well, we zapped you with energy beams, and it looks like one of your stupid organs is a traitor. Cueball: ...which one? Ponytail: I dunno, appendix? Gallbladder? One of the little ones that sucks. Cueball: What should I do?
[Closeup on Ponytail. She holds her left hand in a clenched fist.] Ponytail: You could quash the revolt with the ruthless deployment of chemical and biological weapons. Cueball (off-screen): ...antibiotics? Ponytail: But certain victory comes only through the sword . Cueball (off-screen): Surgery.
[Closeup on Ponytail with her fists raised.] Ponytail: While we're inside, we'll look around-if we see any signs of insurrection elsewhere, we will not hesitate to act. There can be no armistice. Your parts must fall in line or be crushed. Cueball (off-screen): Um.
[Zoom out again to the entire scene. Ponytail points her left hand up.] Ponytail: When the battle is won, we will salt your abdomen so no new organs can ever sprout up to trouble you again. Cueball: Maybe I should get a second opinion. Ponytail: Only if you care what a weaker doctor would say.


Cubesat Launch

Explanation:
A CubeSat (aka U-class spacecraft) is a miniature artificial-satellite with cubic dimensions of 10 cm × 10 cm × 11.35 cm (~ 4 in × 4 in × 4.5 in), and masses of about 1.33 kg (2.9 lbs) per unit. CubeSats are put into orbit from the International Space Station or launched as secondary payloads. As of January 2019, at least 900 CubeSats have successively achieved orbit, and at least 80 have been destroyed in launch failures. Their common functions include: Earth observation, amateur radio transmitters, as well as testing prototype small-satellite technology.
The comic begins with Megan telling Cueball that being officially part of a CubeSat launch is fairly expensive (starting at around $40,000), [1] but she has an idea for a much cheaper alternative: use a fishing line on a drone to attach to a rocket (that is similar visually to the European Vega rocket) just before launch, with the CubeSat attached to the other end of the fishing line so it gets pulled into space.
In reality, this plan would fail for multiple reasons.
Upon realizing her plan, Cueball immediately responds with "uh-oh", indicating his concern, but Megan assures him that it will be fine, before piloting the drone towards the rocket. She successfully connects the drone to the rocket, and the rocket lifts off.
Whatever her plan was, it goes wrong almost immediately. The unexpected force on the rocket from the side causes it to tilt and go off course. Perhaps if the rocket's control software employed adaptive control techniques, it could have maintained control in the presence of this unexpected force. It is implied that it's not due to the comparatively small force of the CubeSat, but because Cueball is standing on the fishing line. However in real life the force from Cueball stepping on the line would still be very small and would be unable to cause a scenario like this. Megan and Cueball get tangled in the fishing line and are carried away. While the fate of the rocket is not shown, it is likely that its unplanned attitude change would activate the automatic termination sequence or result in manual activation of the destruction protocol.
Megan and Cueball miraculously survive and are brought to an investigative board to explain their actions. Megan attempts to defend herself using flawed logic: something was bound to go wrong sooner or later, so it's not her fault that she was the cause. This logic does not account for the fact that this particular rocket's chance to crash was greatly increased by the drone attempting to connect to it. She isn't totally to blame for the accident anyways, since the launch should have been scrubbed as soon as the drone came anywhere near the rocket, and the failure of Mission Control to do so is negligence on their part, and hence they are more responsible for the failure of the mission than Megan and Cueball as they did not follow proper protocol and allowed the launch to occur under unsafe conditions.
The title text describes that the supposedly huge damages they caused were partly covered by the earnings from a water skiing championship, which Cueball and Megan presumably won by being dragged across the water by the rocket. This might be a tangential reference to an incident in the Tintin adventure The Black Island , wher Thomson and Thompson blunder into and win an aerobatics competition when they compel a mechanic with no flying experience into taking off in pursuit of that volume's antagonists. Alternatively, it may simply be a case of the title text being largely irrelevant to the comic itself and simply something Randall found funny.
This topic of CubeSats has been covered in older comics: 1866: Russell's Teapot and in 1992: SafetySat .
[Megan is holding a cube attached by a string to a quad-copter drone flying above her head. She talks to Cueball standing next to her.] Megan: A spot on a CubeSat launch costs a lot, but you can get a drone and a spool of fishing line for cheap. Cueball: Uh oh.
[A wide shot of Megan flying the drone with the cube at her feet while Cueball stand behind her looking after the drone that flies up to the left.] Megan: No no, watch. Megan: This is gonna go great.
[Wide shot of a rocket standing on its launch pad with the support tower. The, now very small, drone is approaching, string attached, from the right.]
[Slim shot of the rocket as the drone attaches to the rocket, just under the tip with the payload. The string goes down and out to the right.] Megan (off-panel): Perfect!
[A huge cloud is emitted from the bottom of the rocket as it lift off the ground every so slightly.] Foom
[As the rocket is taking off it begins tilting in the direction of the string. Two off-panel voices come from Megan and Cueball's direction.] Off-panel voice #1: Should it be tilting already? Off-panel voice #2: Hey, move your leg.
[Close up of Megan and Cueball struggling in tangle of string that surrounds Megan while she is holding the cube in one hand and the remote for the drone in the other. Cueball uses both hands to try and help her out of the tangle. The string goes out to the left towards the rocket.] Megan: Ugh, let go, I can get- Cueball: -No, lift your other arm-
[Three slim panels follow, one above the others, of the rocket, with string, tilting increasingly to the right and down as if pulled by the string. In the final panel of the three the tip of the rocket is now further than where the string goes down to the bottom of the panel. So the string now goes back left from where it is attached to the rocket, rather than to the right as in all previous panels.]
[Megan entangled in the string with the cube in her hand and Cueball hanging below her holding on to the string, are flying through the air, as the string goes up right, and with small lines drawn above it to indicate it is moving to the right. On the ground Science Girl holds a hand to her mouth looking up at them, while a guy looking like Cueball runs away with hands over his head.] Megan and Cueball (screaming): Aaaaaa
[A disheveled looking Megan and Cueball both with plaster casts on their arms stand before four people, Hairbun, another Cueball like guy, Ponytail and Hairy. They are the members of an interview panel and are sitting behind a desk like table with a large label on its front:] Launch accident investigation board Megan: Listen. Megan: Space exploration is never going to be completely safe.