Ceres

Explanation:
Ceres is the largest known asteroid and the smallest known dwarf planet . Megan sits at her computer and tells Cueball how exciting it will be when Dawn will discover what is the cause of the "stupid white dot" on Ceres.
Dawn is a probe sent by NASA in 2007 to examine the asteroid belt . Having already visited the protoplanet Vesta in 2012, Dawn is now scheduled to arrive at Ceres on March 6, 2015. Dawn's initial images of Ceres were released two days before this comic, quickly inspiring questions about the white spot . The spot was first noticed in photographs taken by the Hubble Space Telescope .
" Inspected By No. 6 " refers to a series of quality assurance stickers used by US clothing manufacturers. Individual inspectors, each assigned a number, randomly sample products for workmanship. Accepted items are marked with that inspector's sticker. The presumed joke is that the white spot is a large sticker indicating that Ceres has passed inspection. This might also be a reference to The Rift's M6 being stationed at Ceres inspecting a crater.
CERES (Certification of Environmental Standards) is also the name of a food inspection company based in Germany. Both the food inspection company and the dwarf planet are named for Ceres , the ancient Roman harvest goddess from whom English derives the word " cereal ."
The title text extends the joke to the planet Earth, where salmonella can be found. Salmonella are harmful microorganisms that are sometimes found in food products subject to improper handling or overlong storage. Mixing the realms of astronomical objects and food once more, the title text concludes that the planet Earth clearly hasn't been tested by CERES since salmonella can be found on it.
The Dawn mission is mentioned in 1532: New Horizons .
[Megan sitting in front of her laptop talks to Cueball who stand behind her.] Megan: Dawn has almost reached Ceres. Megan: I'm excited that we'll finally learn what that stupid white dot is.
[Current version of Dawn's best picture of Ceres and the white spot is shown.]
[As Dawn get's closer the pictures improve and in the second version the white spot shows to have black markings.]
[In the last zoom in on Ceres, the white dot resolves to a badge with clear black text:] Inspected by No. 6


Star Wars

Explanation:
This is another comic based on pointing out just how much time has passed since the release of a particular film. The same basis is found in 1393: Timeghost and 891: Movie Ages , and a similar theme is used in 647: Scary and 973: MTV Generation . Many people remember going to see major films at the time of release, and in their mind it may seem like "just a few years ago". In reality however, many years have passed, and it comes as a shock to realise just how long ago it was.
In the first panel, Cueball states that we are approaching the Back to the Future date (October 21, 2015), which is the date that protagonist Marty McFly travels to in Back to the Future Part II , released in 1989. Megan adds that we're even closer to May 13, 2015, the " Star Wars tipping point".
The original first set of Star Wars films was released as a trilogy over the span of 6 years, with the third one, Return of the Jedi being released on May 25, 1983. After that, no films were released for 16 years until The Phantom Menace on May 19, 1999, the first in a trilogy of prequels. Thus up until now, the length of time between the two films, 5,839 days , has been greater than the time between the latter film and the present. Megan points out that May 13, 2015 will mark 5,839 days after the release of The Phantom Menace , meaning that for the first time the release date of the two films will be closer together than the latter film is to the present day.
In the final panel, Cueball points out how weird it is that he (along with most other people) are regularly surprised at the passage of time, given how predictable time is by its very nature. Megan's last line is a reference to the famous opening text used in all Star Wars films, "A long time ago in a galaxy far, far away...". It's also a reference to the many changes that have been made to the original Star Wars trilogy (e.g. new CGI effects) as it's been released and rereleased.
The title text repeats the opening text from the films, inserting Megan's suggestion for changing the duration, and extending it to include the Hubble constant for adjusting the distance estimation. The Hubble constant is a value that describes an estimated rate of expansion of the universe. This expansion means that during the 40 years that have passed since the release of the first Star Wars movie, the "galaxy far, far away" has gotten even farther away.
[Cueball and Megan are walking together.] Cueball: We're almost at the Back to the Future date. Megan: We're even closer to the Star Wars tipping point. Cueball: The what?
[Diagram showing a timeline from before 1980 to about 2020. Markers on the line indicate the release date of Return of the Jedi , the release date of The Phantom Menace , and May 13th, with arrows showing the intervals in between these three points.] Megan: On May 13th, The Phantom Menace will have come out closer to Return of the Jedi than to the present Cueball: Wow.
[Cueball and Megan stop walking. Megan is in a reflective pose with her hand on her chin.] Cueball: It's weird how I'm constantly surprised by the passage of time when it's literally the most predictable thing in the universe. Megan: You know, "A long time ago" should have "Plus four more decades" added in rereleases.


P-Values

Explanation:
This comic plays on how scientific experiments interpret the significance of their data. P-value is a statistical measure whose meaning can be difficult to explain to non-experts, and is frequently wrongly understood (even in this wiki) as indicating how likely that the results could have happened by accident. Informally, a p-value is the probability under a specified statistical model that a statistical summary of the data (e.g., the sample mean difference between two compared groups) would be equal to or more extreme than its observed value.
By the standard significance level, analyses with a p -value less than .05 are said to be 'statistically significant'. Although the difference between .04 and .06 may seem minor, the practical consequences can be major. For example, scientific journals are much more likely to publish statistically significant results. In medical research, billions of dollars of sales may ride on whether a drug shows statistically significant benefits or not. A result which does not show the proper significance can ruin months or years of work, and might inspire desperate attempts to 'encourage' the desired outcome.
When performing a comparison (for example, seeing whether listening to various types of music can influence test scores), a properly designed experiment includes an experimental group (of people who listen to music while taking tests) and a control group (of people who take tests without listening to music), as well as a null hypothesis that "music has no effect on test scores". The test scores of each group are gathered, and a series of statistical tests are performed to produce the p -value. In a nutshell, this is the probability that the observed difference (or a greater difference) in scores between the experimental and control group could occur due to random chance, if the experimental stimulus has no effect. For a more drastic example, an experiment could test whether wearing glasses affects the outcome of coin flips - there would likely be some amount of difference between the coin results when wearing glasses and not wearing glasses, and the p -value serves to essentially test whether this difference is small enough to be attributed to random chance, or whether it can be said that wearing glasses actually had a significant difference on the results.
If the p -value is low, then the null hypothesis is said to be rejected , and it can be fairly said that, in this case, music does have a significant effect on test scores. Otherwise if the p -value is too high, the data is said to fail to reject the null hypothesis, meaning that it is not necessarily counter-evidence, but rather more results are needed. The standard and generally accepted p -value for experiments is <0.05, hence why all values below that number in the comic are marked "significant" at the least.
The chart labels a p -value of exactly 0.050 as "Oh crap. Redo calculations" because the p -value is very close to being considered significant, but isn't. The desperate researcher might be able to redo the calculations in order to nudge the result under 0.050. For example, problems can often have a number of slightly different and equally plausible methods of analysis, so by arbitrarily choosing one it can be easy to tweak the p -value. This could also be achieved if an error is found in the calculations or data set, or by erasing certain unwelcome data points. While correcting errors is usually valid, correcting only the errors that lead to unwelcome results is not. Plausible justifications can also be found for deleting certain data points, though again, only doing this to the unwelcome ones is invalid. All of these effectively introduce sampling bias into the reports.
The value of 0.050 demanding a "redo calculations" may also be a commentary on the precision of harder sciences, as the rest of the chart implicitly accepts any value following the described digit for a given description; if you get exactly 0.050, there's the possibility that you erred in your calculations, and thus the actual result may be either higher or lower.
Values between 0.051 and 0.06 are labelled as being "on the edge of significance". This illustrates the regular use of "creative language" to qualify significance in reports, as a flat "not significant" result may look 'bad'. The validity of such use is of course a contested topic, with debates centering on whether p -values slightly larger than the significance level should be noted as nearly significant or flatly classed as not-significant. The logic of having such an absolute cutoff point for significance may be questioned.
Values between 0.07 and 0.099 continue the trend of using qualifying language, calling the results "suggestive" or "relevant". This category also illustrates the 'technique' of resorting to adjusting the significance threshold. Appropriate experimental design requires that the significance threshold be set prior to the experiment, not allowing changes afterward in order to "get a better experiment report", as this would again insert bias into the result. A simple change of the threshold (e.g. from 0.05 to 0.1) can change an experiment's result from "not significant" to "significant". Although the statement "significant at the p <0.10 level" is technically true, it would be highly frowned upon to use in an actual report.
Values higher than 0.1 are usually considered not significant at all, however the comic suggests taking a part of the sample (a subgroup ) and analyzing that subgroup without regard to the rest of the sample. Choosing to analyze a subgroup in advance for scientifically plausible reasons is good practice. For example, a drug to prevent heart attacks is likely to benefit men more than women, since men are more likely to have heart attacks. Choosing to focus on a subgroup after conducting an experiment may also be valid if there is a credible scientific justification - sometimes researchers learn something new from experiments. However, the danger is that it is usually possible to find and pick an arbitrary subgroup that happens to have a better p -value simply due to chance. A researcher reporting results for subgroups that have little scientific basis (the pill only benefits people with black hair, or only people who took it on a Wednesday, etc.) would clearly be "cheating." Even when the subgroup has a plausible scientific justification, skeptics will rightly be suspicious that the researcher might have considered numerous possible subgroups (men, older people, fat people, sedentary people, diabetes suffers, etc.) and only reported the subgroups for which there are statistically significant results. This is an example of the multiple comparisons problem , which is also the topic of comic 882 .
If the results cannot be normally considered significant, the title text suggests as a last resort to invert p<0.050, making it p>0.050. This leaves the statement mathematically true, but may fool casual readers, as the single-character change may go unnoticed or be dismissed as a typographical error ("no one would claim their results aren't significant, they must mean p<0.050"). Of course, the statement on its face is useless, as it is equivalent to stating that the results are "not significant".
[A two-column table where the second column selects various areas of the first column using square brackets.] P-value Interpretation
0.001 0.01 0.02 0.03 Highly Significant 0.04 0.049 Significant 0.050 Oh crap. Redo calculations. 0.051 0.06 On the edge of significance 0.07 0.08 0.09 0.099 Highly suggestive, relevant at the p<0.10 level ≥0.1 Hey, look at this interesting subgroup analysis


Troubleshooting

Explanation:
This comic revolves around the complexity of modern software and its sometimes low quality. Many problems that users experience are not obvious or straightforward, and methods for correcting the root cause of the problem requires invoking unrelated actions that happen to cause a desired side-effect. Knowing the non-obvious cause, the desired side effect, and how to trigger the unrelated feature that causes it requires memorization of lots of "stupid computer knowledge" rather than general principles and logical investigation of the software.
One particular example of an illogical fix to a software problem is depicted in the comic. Here, Cueball is trying to help Hairy resolve the problem of a program that is not responding to any mouse clicks. Cueball surmises that this is not due to abnormal behavior of the software (such as freezing ), but rather because either the user or the software itself has opened a modal dialog window outside of the main screen area, where it can not be seen. Modal dialog windows block access to the rest of the application, by seizing the sole focus of the user input. They are valid GUI tools and are used when the software needs the user's input before it can proceed further. However, opening such a window and placing it outside of the visible screen area ("off-screen") will make the window both inaccessible and invisible to the user, precluding them from closing it and re-gaining access to the software.
One non-obvious way to repair such a problem is to switch the screen resolution; this in itself does not fix the problem, but the resolution switch also forces the operating system to redraw all windows on the desktop, and some operating systems will also validate the coordinates of all windows and adjust these coordinates so that the windows do not end up in off-screen area. In this scenario, it is used as a side-effect to fix the problem, because operating systems rarely provide other, more obvious ways to bring off-screen windows back to the visible area.
By saying "Why is that even possible?", Hairy is quite correct in pointing out that the best way to address this problem at its root would be for the operating system developers to prevent the creation of windows off-screen, preemptively avoiding a whole class of window management problems before they can occur. For example, such mechanisms could validate coordinates during window creation, thus making sure that the dialog window would always be accessible and visible. Such a mechanism exists on OS X, but not on Windows, which the majority of desktop/laptop computers are running at the time of this comic's release.
In general, one can sort the possible solutions to the problem being discussed in the following order of preference, from best to worst:
The title text refers to the fact that two different and unrelated software packages can have confusingly similar names, even if the usage and features of those two packages can vary wildly, and knowing the implications of using one instead of the other is a case of "stupid computer knowledge". Knowing the difference between a Chrome app , a cell phone app-style application, delivered from the Chrome web store, designed to be run in the Chrome browser, and a Chrome extension , a browser extension installed into the Chrome browser, delivered from the Chrome web store, designed to modify the behavior of the browser itself, is a subtle distinction that may not be immediately apparent to users who might just have the name of the software they are looking for. Google Hangouts is an example of a product that exists as both a Chrome app and a Chrome extension, whose windows are more similar to each other than to normal Chrome browser windows; and confusingly, it's possible to be signed into one account with the app and another with the extension, especially when your employer or school uses Apps for Business/Education.
In many cases, Randall (or Cueball, his avatar) loves to help people using his specific knowledge (see 208: Regular Expressions ). But when the trick is "stupid", he would prefer the programmers to fix the problem definitively so he never has to rely on this trick anymore.
[Hairy sitting at a desk with laptop, with Cueball standing behind him.] Hairy: Wait, why can't I click anywhere? Cueball: I don't... Ugh, It opened a dialog box offscreen. Hairy: Why is that even possible? Cueball: It really shouldn't be. But you can fix it by changing your screen resolution to trigger a window cleanup. Hairy: Seriously? Cueball: I know, I know...
To be honest, I can't wait for the day when all my stupid computer knowledge becomes obsolete.


Super Bowl

Explanation:
In this comic, Cueball , representing Randall , explains that even though he does not care about sports and is tempted to be scornful about others' obsession with them, he understands that people feel vulnerable about stuff they care about. And he will for sure be fed up with all the talk about the Super Bowl discussions and arguments over the coming weeks. (The comic was released on a Friday two days before Super Bowl XLIX , the championship game of the 2014 NFL season held on 2015-02-01).
However, since other people tolerate his interest in odd things like meteorology and the Philae lander (see 1324: Weather and 1446: Landing ), he recognizes that he should show the same consideration to them. This is an invocation of the Golden Rule , "Do unto others as you would have them do unto you".
In the last frame, he tells us that instead of celebrating the sports event on Sunday, he will be celebrating friendship (through listening to his friends) and, as a side note, snacking (as they are very frequently brought to Super Bowl-watching events). This suggests that the value of friendship trumps the discomfort of watching human activities that seem uninteresting to him – and of course, the free snacks also help ameliorate his discomfort.
The title text continues the " My Hobby " trope characteristic of some xkcd comics: here, Randall references people who scornfully refer to popular sports such as football, basketball, and/or baseball as "sportsball" and creates discomfort for them by pretending to be interested in this imaginary sport. This makes it appear as though they are in fact interested in sports when they are not, exposing their snobbishness. (It is worth noting that there is a Wii U game by that name .)
In a distant past, Cueball spent his time differently during the Super Bowl - see 60: Super Bowl . (This was the second time that two xkcd comics have shared the exact same name ). The year after he continued the trend with a Super Bowl related comic to "celebrate" the event: 1640: Super Bowl Context . Between the 2006 comic and this one there were no other Super Bowl related comics coming out in relation to the Super Bowl.
See also 1107: Sports Cheat Sheet and two other comics where he jokes with sport in general: 904: Sports and 1507: Metaball . He again directly mentions lack of knowledge in 1859: Sports Knowledge .
[Cueball standing.] Cueball: I don't know much about sports, which can be culturally isolating, so it's tempting to get vocal and defensive about not following them. Cueball: Caring about something makes people vulnerable, so not caring gives you power.
[Pictures of a weather map and Philae in the background.] But I know things I'm into don't always sound interesting to 100% of the people around me, and it means a lot when they sometimes try to listen anyway - and maybe even find themselves sharing some of my excitement!
[Cueball pointing to self.] Cueball: So while everyone is going on about the Super Bowl on Sunday, let me tell you what I'll be doing:
[Cueball standing again.] Cueball: Listening! Cueball: Hooray for friendship! Cueball: Also, eating snacks. Cueball: Hooray for snacks!
This comic shares title with 60: Super Bowl , published February 6, 2006. This appears to be only the second time that two xkcd comics have borne the same name. The first was 786: Exoplanets , published August 30, 2010, and 1071: Exoplanets , published June 20, 2012.


API

Explanation:
This comic presents a web site designed for human readers as if it had an API ( application programming interface ) designed for machine-to-machine web service . An API is a set of instructions about a computer program, intended to be used by developers of other computer programs, so the two programs can interoperate more easily. The documentation explains how to send commands to the program, and how the output will be returned.
Many web APIs are designed to return data in XML format. But in this case, the XML is XHTML , a version of the language that is used by most web pages. The "requested data" is the actual content (e.g. a blog post), and "documentation" refers (in an obscure way) to the parts of a web page that control how it looks on the screen (e.g. CSS and perhaps JavaScript layout code). The
"documentation" may also be DTD which tells the XML parser info about this particular XML format, i.e. XHTML.
In order for a program to process a generic web site designed for human viewing, the program needs to use web scraping techniques, which often break when the web site design changes in subtle ways that a human might never notice. Therefore, developers prefer to have proper APIs with well-defined machine-readable formats, stable interfaces and documentation that actually describes the semantics of the data.
For example, Google has an official API for version 3 of their Youtube web service . But developers who don't want to hassle with the required API key or the costs associated with its use sometimes just scrape the regular YouTube web site . So someone could publish this comic with a YouTube URL as a convoluted hint to developers that there is an alternative to the official API.
The API keys section is a step-by-step description of how a web page is protected with HTTP Secure (HTTPS). The Transport Layer Security (TLS) protocol uses an elliptic curve Diffie–Hellman (ECDH) key signed using Rivest-Shamir-Adleman (RSA) encryption, which is stored in an X.509 certificate. Normally, the browser or operating system does this behind the scenes, so most web developers and users do not need to know these details.
The access limits mentioned in the title text says that the API can be used for 86,400 seconds each day. At first this may appear to be a strange arbitrary number, however it is in fact the total number of seconds in 24 hours, essentially meaning there is no limit on most days. The International Earth Rotation and Reference Systems Service (IERS) is the organization that decides when to add leap seconds , which account for slight anomalies in the Earth's rotation as compared to the mean solar day . These leap seconds will mean that the website is available for one extra second occasionally, although IERS decisions are based on actual Earth rotation rates and they of course wouldn't respond to requests for leap seconds in order to lengthen the number of seconds that a web site would be available for in a given calendar day.  The API does not discuss the issue that some days have 23 or 25 hours due to daylight saving time in the U.S. and summer time in Europe and some other places. This suggests that the web service tracks time via UTC .
[Cueball sitting at a desk staring at a computer screen.] API Guide Request URL format: http://~~~.com/<username>/<item ID>
Server will return an XML document which contains: The requested data. Documentation describing how the data is organized spatially.
API Keys To obtain API access, contact the X.509-authenticated server and request an ECDH-RSA TLS key... If you do things right, it can take people a while to realize that your "API documentation" is just instructions for how to look at your website.


NowPlaying

Explanation:
There are a variety of applications that post a user's music-listening habits on their preferred social network. In this comic, Randall takes that notion to its extreme, envisioning a program that does this note-by-note, rather than just song-by-song. As songs play several dozen notes a minute (and some songs, many more), this would lead to the flooding of friends' notification streams. In the example, the software is sharing the notes that Brian is listening to; and his friends Mike and Caitlin are getting annoyed with the number of posts they are receiving.
There are typically many hundreds of notes in any song.  Any song with more than a single line of music contains multiple different notes whose names according to the English convention are communicated here. All but the slowest songs will require reporting dozens to hundreds of notes every minute (a single glissando may cover a dozen or more notes in less than a second), meaning that anyone who can see your stream of posts will be literally inundated by posts from the service. Even if you could keep up with the speed of the posted notes that someone is listening to, the similarity in phrases in many songs (especially pop songs, e.g. Pachelbel's Rant ) means that many different songs may include the same sequence of notes, though possibly in different octaves or at different speeds.
The comic's title alludes to the fact that you can "play a song" but can also "play a note." It may also allude to the visual similarities between the hash/pound/ number sign (#) and the sharp sign (♯). C sharp , above Mike's comment, is the only note not given by a single letter (after the correction - see Trivia ).
The title text continues the joke of this new musical service: If you click on the post, it takes you to search results for the note on various online music store. Since many songs in similar keys contain at least some of the notes posted, you would be given a list of a large part of the music you can buy in any on-line music stores. Of course this is at least as useless as being told which note someone is listening to.
The notes appear to be the beginning of I'll Be There For You by The Rembrandts , the title music of the TV series " Friends ".  This could be an internal reference to the idea that it "notifies" (converts into musical notes) your "friends" of the notes (a play on words ).
Or we've been nerd sniped .
[A social network news feed with user images for each of the three different contributors. The top of the first post is partly obscured, and for the last post only half of the first line is visible.]
[Partially Visible] Brian is now listening to: E Today • 3:28 PM
Brian is now listening to: A Today • 3:28 PM
Brian is now listening to: B Today • 3:28 PM
Brian is now listening to: D Today • 3:28 PM
Brian is now listening to: C sharp Today • 3:28 PM
Mike What the hell Today • 3:28 PM
Brian is now listening to: B Today • 3:28 PM
Brian is now listening to: A Today • 3:28 PM
Caitlin Can someone call him? Today • 3:28 PM
Brian is now listening to: A Today • 3:28 PM
Brian is now listening to: E Today • 3:29 PM
[Partially Visible] Brian is now listening to: A
My new social music service notifies your friends about what notes you're listening to.


Quotative Like

Explanation:
In this comic, Megan mentions an article on the use of the word " like " as a quotative . Cueball makes a joke on this by managing to use the word "like" three times in a seven word sentence.
The "quotative like" is regularly given as an example of the decline of the English language. It is used to introduce a quotation or impersonation, although what follows may not be a verbatim quote, but rather conveys the general meaning of the original phrase. Although it is modern in terms of the English language, examples of its use can be found all the way back in 1928. The song " Cobwebs " by the American singer-songwriter Loudon Wainwright III blames Jack Kerouac and The Many Loves of Dobie Gillis character Maynard G. Krebs for starting the vogue of using the word "like" as a quotative. In the early 1980s, the stereotypical Valley Girl made substantial use of the quotative like, which may be the main origin of its contemporary use.
In the second panel Megan mentions that, in a newspaper article , the linguist Patricia Cukor-Avila is like: "Eventually all the people who hate this kind of thing are going to be dead, and the ones who use it are going to be in control."
The author is presumably making the point that language is inherently fluid, and the meanings of words exist only by common understanding, which means that, as more and more people grow up with the new usage, it will become increasingly accepted. Most resistance will come from the older generation, which means it will diminish over time.  While it has long been popular to criticize modern developments that are seen as steps backward (see 1227: The Pace of Modern Life ), such criticisms are usually in vain, as they are typically made by the older generation against the younger generation, and the latter is always guaranteed to outlive the former [ citation needed ] .
The quote, however, doesn't actually say why the older generation will die out, leading Cueball to speculate that Dr. Cukor-Avila is plotting (or warning of) some sort of genocide against people who dislike the use of the quotative like. Megan points out a much more likely interpretation (although this is not mentioned directly in the article), that those people will die of old age, but Cueball persists, saying he'll err on the side of caution and make sure to use the quotative like more often, thereby hoping to be spared from the genocide.
The title text applies quotative like to the Book of Genesis (specifically, Genesis 1:3 : "God said, 'Let there be light,' and there was light"), the first book of the Hebrew Bible (the Tanakh) and the Christian Old Testament. When researching the history of language etymologists take great effort to find the earliest usage of a word or phrase, which may be used to show a historical precedence.
[Megan referring to a published article she is holding.] Megan: I found this article on the linguistics of the "Quotative Like". Cueball: Like, when you're like, "She was like"? Megan: Yeah. Megan: It features a quote from a linguist, Patricia Cukor-Avila: "Eventually all the people who hate this kind of thing are going to be dead, and the ones who use it are going to be in control." Cueball: Wow. Turns out linguists are pretty hardcore. Megan: I think she means dead from old age. Cueball: I'm gonna start using "like" more, just in case.


Apollo Speeches

Explanation:
As explained in the comic, Nixon staffer William Safire wrote two speeches for the United States President to deliver, depending on whether or not the Apollo 11 return launch was successful. When the outcome of an event (moon landing, military actions, etc.) can't be predicted with sufficient certainty, it is a common practice for " contingency speeches " to be prepared.
The rest of the comic runs with this theme, making the false claim that Safire had written several other such contingency speeches for increasingly unlikely possibilities. First listed are a couple pages from the real contingency speech to be delivered in the event that the astronauts were left stranded on the Moon. Lying on top of that is a speech to be delivered in the case that the spacecraft went missing altogether, which was relatively unlikely. The speeches after that deal with the following highly unlikely or impossible contingencies:
The astronauts had stolen the ship and piloted it towards Mars, which was clearly not feasible
While the crew could have redirected the ship while sending insulting messages to Earth, the spacecraft lacked the power to fly to Mars within any reasonable period of time by several orders of magnitude or the supplies for the astronauts to survive such an extended trip. At the time of production for this strip in 2015, several governments and private companies have designs on Martian colonization.
More astronauts than expected were found in the recovered ship
The appearance of three additional astronauts ventures into the realm of possibility normally reserved for science fiction and Twilight Zone episodes.
The ship had hit the U.S.S. Hornet and crushed Nixon
The USS Hornet was the ship that recovered the Apollo 11 astronauts after they completed their return mission by landing their command module in the Pacific Ocean; President Nixon himself was on board to greet them upon their return. Apollo 11 famously landed in the Pacific Ocean, and the single ship tasked with its recovery would be a very small target to hit for the technology even if that had been the intent, which it was of course not. Spiro Agnew was, in 1969, Vice President of the United States, and thus next in line for the presidency. This joke plays off the extreme improbability of the ship, and indeed President, being hit and triggering a succession, causing "President Agnew" to address the world.
This is not as implausible as it sounds. The re-entry guidance had become good enough by Apollo 11 that the destination point of the capsule was moved several hundred yards from the carrier's position for exactly this reason. Such a collision had been the subject of jokes at NASA, until one day an engineer came to Gene Kranz and said, "the more I think about it, the less I think it is a joke."
The re-entry craft had been sold for scrap and crushed along with the astronauts inside
Apollo 11 observed a strict quarantine procedure after landing. This possibility requires extraordinary incompetence and unholy zeal for recycling programs. The command module was historically recovered, examined, and is now on permanent display in the National Air and Space Museum . Primary sources state that the astronauts were allowed to leave the craft before it was put on display [ citation needed ] .
The title text builds upon this last contingency speech, delving into the pathos of the horror of the spacecraft's recycling and its passengers' resulting deaths despite the U.S.'s commitment to recycling initiatives.
[Commentary above the speeches.] In 1969, Nixon staffer William Safire wrote a speech for the president to deliver if the Apollo 11 return launch failed, stranding the doomed astronauts on the Moon. Uncovered in 1999, it is often called the greatest speech never given. Today, the full set of Safire's contingency speeches has been found.
In event astronauts stranded on Moon Fate has ordained that the men who went to the Moon to explore in peace will stay on the Moon to rest in peace. [Here, several lines from the original speech are cut.] In ancient days, men looked at stars and saw their heroes in the constellations. In modern times, we do much the same, but our heroes are epic men of flesh and blood. Others will follow, and surely find their way home. Man’s search will not be denied. But these men were the first, and they will remain the foremost in our hearts. For every human being who looks up at the Moon in the nights to come will know that there is some corner of another world that is forever
In event spacecraft goes missing Neil Armstrong, Edwin Aldrin, and Michael Collins went to the Moon as ambassadors of peace for all mankind, and all mankind prays that they may yet return safely home. We are separated from the Moon by a vast gulf of space, against which their tiny vessel appeared as but a drifting speck. For a few brief seconds, we took our eye off them, and despite days of desperate searching, never again was their vessel sighted from Earth. While these men are lost, they are not forgotten, and their sacrifice will not
In event astronauts abscond with spacecraft We do not know what led Armstrong, Aldrin and Collins to betray the trust we placed in them, abandon their mission, and steer their vessel toward Mars. Nor do we know what compelled them to transmit such hurtful messages back to Earth, heaping contempt on their onetime home. But whatever the cause of their dereliction, I call upon the United States to commit itself, before this year is out, to launching a mission to chase down Apollo 11 and return its crew to earth to face justice. We must not rest until
In event spacecraft returns with extra astronauts While there is much we do not understand, tonight all of earth is united in celebrating the safe return of our brave explorers. We of course have many questions, and in the days and weeks to come we will demand answers. How many souls were truly aboard Apollo 11 when it launched? Who are the six men now in quarantine aboard the USS Hornet? What happened
In event spacecraft hits U.S.S. Hornet, crushing Nixon President Agnew : Tonight, we have experienced a great national triumph and a great national loss. We take joy in the safe return from the Moon of Neil Armstrong, Edwin Aldrin, and Michael Collins, but that joy is tempered with sorrow as we mourn our president’s tragic death beneath their wayward capsule. Richard Nixon wholeheartedly supported our courageous astronauts as they carried the hopes and prayers of Earth to the heavens, and in the moment of their homecoming, he himself has departed on that ultimate voyage. As we grieve, we must rededicate ourselves to the cause for which our president
In event spacecraft accidentally sold for scrap and crushed with astronauts inside My fellow Americans, I am as shocked and appalled as you at this stunning and


Friendship

Explanation:
A " Bromance " is a modern slang term for a strong non-romantic relationship between two male humans. It is a portmanteau of the words brother, meaning a close male friend (aka "bro"), and romance.
Although current in popular media, some commentators have criticized the implicit homophobia in the term, suggesting that it denotes cultural discomfort at relationships of emotional closeness between men.
In this comic, Randall is implying the Wikipedia page for the word "bromance" should more accurately represent what most bromances actually are: friendships. This could be a joke to reference the fact that some males prefer to not call friendships as such, for fear of looking unmasculine, or being confused as a gay couple. The comic makes light of the fact that the word bromance and friendship are interchangeable, and should be treated as such.
The comic later contains parts of the edited article, mocking the use of "bromance" in popular culture, implying that "friendships" can be used just as easily to describe platonic male relationships.
Despite supposedly vandalizing the "bromance" article, the article is titled "friendship", giving a similar result to word-replacement browser extensions, as in 1031: s/keyboard/leopard/ .
The title text implies Randall does not agree with Wikipedia vandalism, except in the case of bromance/friendship, and also militia/fanclub, possibly to make light of the harsh sounding word in a negative light. This is probably because many of his comics include fake wikipedia entries, and many people, inspired by the comic, actually make the edit happen.
A later comic called 1746: Making Friends , was also not so much about friendship, but rather about vultures...
[A Wikipedia style layout is shown for extracts from an article titled Friendship.]
Friendship From Wikipedia, the free encyclopedia A Friendship is a close non-romantic relationship between two (or more) men, a form of affectional or homosocial intimacy. [1] Contents [ hide ] 1 Etymology 2 Characteristics 3 Portrayal of friendship 3.1 Celebrity and fictional friendships 3.2 Historical and political friendships 3.3 Gay-straight friendships 4 See also 5 References Etymology Friendship is a portmanteau of the words friend and ship . Editor Dave Carnie coined the term in the skateboard magazine Big Brother in the 1990s to refer to the sort of relationships that develop between skaters who spend [...] Portrayal of Friendship Celebrity and Fictional Friendships A number of celebrities have engaged in friendships with fellow celebrities. Examples include Ben Affleck and Matt Damon , described as "perhaps the pioneering friendship in showbiz history" [9] which led to a hit off-broadway play [...] Friendship on television has also become more commonplace, with some critics tracing its origins back to shows such as The Odd Couple . [14] In October 2008, TV Guide placed Gregory House ( Hugh Laurie ) and James [...] The Japanese and Korean music industry actively encourages friendship among male celebrities (particularly members of boy bands ) as part of the fan service to please the audience. [19][20] In fiction, what had once been called buddy films have to a degree been rebranded as friendship films, although [...] Historical and political friendships Politically, the relationship between Bill Clinton and Al Gore has been called a precursor to the friendship. [6] The relationship between George W. Bush and former press
[Below the extracts is this caption:]
How to improve the "Bromance" Wikipedia article
In the wake of this comic, several Wikipedia pages were vandalized, among them Bromance , Militia organizations in the United States , Militia (United States) , and Friendship . All these pages were semi-protected by an administrator against further attempts for a week after this comic was published.
The day this comic was published, a vote to delete the Bromance article was initiated on Wikipedia.


Vacuum

Explanation:
According to quantum mechanics there is tremendous energy density in space-time itself: this is known as: vacuum energy , zero point energy, vacuum foam, etc. So far we don't know any way to tap into this energy.
In the cartoon, Beret Guy appears to be making a silly mistake, confusing the "vacuum" referred to in calculations of the theoretical energy density of space time with a vacuum cleaner , which is also commonly referred to as just a "vacuum".
Cueball tries to correct him, but it turns out that Beret Guy really is able to tap into this fundamental source of energy. Having such strange and impossible powers is second nature to Beret Guy, as can be seen in many of his appearances – for instance in 1388: Subduction License .
But even though Beret Guy now claims the Universe is his to command (a sentence used by Jafar from Aladdin , but a similar intent is also stated by the crazy villain in many movies ), Cueball is not fazed by this and simply asks, in the title text, if Beret Guy would use the vacuum for its intended purpose and clean the living room. This seems to imply Beret Guy has previously, perhaps repeatedly, taken an action that would normally imply he was going to clean the living room (such as taking a broom or some other cleaning implement that is not the vacuum) and done something unexpected with it instead (such as flying off on it).
On an additional note, many scientific breakthroughs in history have been made because the person making them did not realize they were supposedly impossible, such as spin-stabilized magnetic levitation . This comic could be seen as a nod to that.
It seems that Cueball borrows one of Beret Guy's vacuum cleaners later in 1826: Birdwatching . A normal vacuum cleaner would not be able to do what Cueball's presumably does to birds in that comic!
[Beret guy is holding an upright vacuum cleaner upside-down by the handle, waving it around above his head.]
[The vacuum cleaner is upright on the ground, and Beret guy is standing on its body, wiggling the handle.] Cueball: What are you doing? Beret Guy: Trying to unlock the tremendous energy of the vacuum.
[Beret guy rides the vacuum cleaner as it begins to lift off, propelled upward by an unknown force.] Cueball: That’s not what that— Beret Guy: —Ha ha! It works!
[Beret guy flies away on the vacuum cleaner.] Cueball: I said, that’s— Beret Guy: The universe is mine to command!!


Tornado

Explanation:
A merry-go-round (or carousel) is an amusement ride consisting of a (usually) slowly rotating circular platform with seats for riders. These seats are traditionally wooden horses. Merry-go-rounds usually rotate slowly, as it is a children's ride. [ citation needed ] The implication is that a tornado have made a merry-go-round spin much faster, creating the "fun" and "awesome" experience described by the news commentator. In reality such an event would most likely destroy the merry-go-round or at least damage it in a way that would keep it from spinning, such as by breaking an axle or bearing. Barring damage to the merry-go-round itself, if the tornado caused it to spin much faster than normal, anyone riding it at the time would likely be thrown off and injured due to the increased centrifugal force .
The title text refers to the spinning teacup ride which consists of several circular units ("teacups") that seat several people each. They rotate around their center axis, while simultaneously orbiting the center of the entire ride, exposing people to acceleration in rapidly shifting, seemingly random directions. The second tornado system, as reported in the title text, had multiple vortices , similarly rotating around a common center, that attached themselves to each of the "teacups", also spinning them faster than normal operation of the ride would have. This is, of course, even less likely (to happen, and to result in no injuries if it did) than the single-vortex tornado on a merry-go-round.
Tornadoes are a recurring subject on xkcd. This setup is a variety of the news anchor category , but since Cueball is not in a studio it cannot be included in that category.
[Cueball is a news commentator holding a microphone while standing in front of a small village with three (intact) houses behind him.] Cueball: The tornado touched down directly over a merry-go-round, in what victims are calling a "fun" and "awesome" disaster.


Flowcharts

Explanation:
Note : A flawed version of this comic was posted at first and then quickly a correct version was uploaded. But this gave rise to several misunderstandings and confusion. See the Trivia section below.
This comic is a flowchart style, like many. Interestingly, the first option, Do you like flowcharts? loops back to itself if you say Yes . As the yes lines of other options point to the type of graph they describe (for example, the yes line of Do you like line graphs? points to a line graph), this may be interpreted as a recursive reference to the flowchart itself, although it points to the option itself rather than the START node. Also, this may cause the reader who actually likes flow charts to go into an endless loop of choosing Yes , until they are so annoyed by flowcharts that they do not like them anymore and can progress by saying No .
After asking about flowcharts, the reader is asked whether they like line graphs . If they follow the yes line, it becomes a line graph where "Time" is the x-axis and "Your Happiness" is the y-axis, and shows that your happiness increases with time. If you don't like line graphs, they are asked the same question about scatter plots where again the lines turn into the points and the axis of such a plot.
Taking yet another line, the reader is asked "Charge a battery?" If they follow the line marked yes they are asked whether they are A/C or D/C current and are led to a portion of the flowchart which resembles a circuit diagram of a rectifier bridge with a battery connected to it.
If the reader follows the "no" line, they are asked if they like spirals. If they choose "no" they are asked whether they would take the path of least resistance . This part of the flowchart resembles a circuit diagram, and the word " resistance " is a pun because resistance can have several meanings. In electricity it is an electrical quantity that measures how the device or material impedes the electric current flow through it. Going left is the "Never" option, which goes through extra resistors and a diode, therefore making the "Yes" option the "path of least resistance". However, when asked if you choose the path of least resistance and answers never it could also mean that you do not try to avoid a little trouble.
Whether they choose "Yes" or "No", they arrive at "Do you like when people find the golden spiral in random images?" If they choose "yes" the line fades into a drawing of a golden spiral, and we see that the flowchart is structured around it. If they choose "no" they are asked if they are tired of flowcharts. If not, they are taken to the beginning to start over again. If they are tired, the line points to the "random" button on the xkcd website.
The title text and the faint image of a golden spiral parody the fact that the golden spiral is superimposed on nearly everything . The golden spiral is a spiral that has the growth rate of the golden ratio, a number that has inspired both artists and mathematicians alike. However, people try to find the golden ratio in seemingly random objects, and they fall to confirmation bias when drawing a golden spiral on top that seemingly fits. The comic links to [1] , where one can see exactly that- golden spirals Randall "found" in random photographs. This may be a spoof of the viral video Illuminati Confirmed . The limit of the ratio of two consecutive terms of the Fibonacci sequence is equal to the golden ratio, so a Fibonacci spiral matches up almost perfectly for a good reason, unlike the coincidental matchings of the pictures in the mobile site link.
This comic bears reminiscence of 730: Circuit Diagram , although it is not exactly the same idea. Putting a golden spiral over other things was again used in 2322: ISO Paper Size Golden Spiral , like the spiral page on xkcd which this comic is a link to.
[A flow chart. The first option the start box is white text on a black rectangle. The other boxes are rhombuses standing on edge. Except for the first there are always two options going out. Most only have one option coming in, but there are exceptions with two options going in.] Start [One arrow points to the first real choice.] [Below the text on the two options going out from each option will be indented. The top of these two options will be the one to be mentioned first below. Then the chart will be mapped like this going back to the previous unfinished option.] Do you like flowcharts? Yes No [Yes goes back where it came from.] Do you like line graphs? Yes No Data or axis? Line Axis [The line is just a line – but now as the line in a line graph.] Time or your happiness? Time Your happiness [These two lines turn into the x and y axis of the line graph.] Scatter plots? Yes No Data or axis? Data Axis [The data line turns into the points in a scatter plot.] X or Y? X Y [These two lines turn into the x and y axis of the scatter plot.] Help charge a battery? Yes No Are you A/C or D/C?, A/C D/C Positive or negative phase? + - [The D/C option also goes to this next option, but directly. This next rhombus looks like a part of a circuit diagram.] Positive or negative DC terminal? + - [These two lines goes to the + and – poles of a battery.] Like spirals? No Yes Take the path of least resistance? Never Yes [Never goes through two resistors and a diode before reaching the point of the Yes option, which then also goes though yet another resistor. Both thus end at the same option, which is also the one that Yes to like Spirals ends up at:] Do you like when people find the golden spiral in random images? Yes, even though it's total BS. No, it's total BS. [Yes option takes the chart into a fading line that turns into a golden spiral spanning the whole chart.] Tired of flowcharts yet? No Yes, I want to look at something else [No takes you back to the start box at the top.] [Yes takes you out of the comic and points to the Random button at xkcd.]


Fundamental Forces

Explanation:
Cueball is acting here as someone teaching physics at a basic level, perhaps a high school science teacher. He seems to understand the general idea of the four fundamental forces , but his understanding gets progressively more sketchy about the details. The off-panel audience, probably a student or class, is interested, but quickly begins to realize Cueball's lack of understanding. Instead of acknowledging the problem directly, Cueball simply blusters onwards.
The comic also outlines how progressively difficult it gets to describe the forces. Gravity was first mathematically characterized in 1686 as Newton's law of universal gravitation , which was considered an essentially complete account until the introduction of general relativity in 1915. The electromagnetic force does indeed give rise to Coulomb's law of electrostatic interaction (another inverse-square law , proposed in 1785), but a much more comprehensive description, covering full classical electrodynamics , was only given in Maxwell's equations around 1861. The strong and weak forces cannot easily be summarized as comparably simple mathematical equations. It's possible that Cueball does understand the strong and weak interactions, but is completely at a loss when he tries to summarize them.
The strong force doesn't act directly between protons and neutrons but between the quarks that form them. Unlike gravity and electromagnetism, the strong force gets stronger with increasing distance : It is loosely similar to the restoring force of an extended spring . However, all stable heavy particles are neutral to the strong force, due to being made up of three " colors " (or a color and the appropriate "anticolor") of quarks. Between protons and neutrons there is a residual strong force, analogous in some ways to the van der Waals force between molecules. This residual strong force is carried by pions and does decrease rapidly and exponentially with distance due to the pions having mass.
The weak force is much weaker than electromagnetism at typical distances within an atomic nucleus (but is still stronger than gravity), and has a short range, so has very little effect as a force . What it has instead is the property of changing one particle into another. It can cause a down quark to become an up quark, and in the process release a high-energy electron and electron anti-neutrino. This is known as beta decay , a form of radioactivity. Over even shorter distances, and much higher temperatures , the weak interaction and electromagnetism are essentially the same, thus being merged to form the electroweak force . The electroweak force was also mentioned in a later comic, 1956: Unification .
The title text refers to the fact that it is gravity that appears to be the simplest and easiest to understand of the four forces, but turns out to be the hardest to reconcile with a coherent (quantum) understanding of all four forces together .
[Cueball is holding his hands up while giving a lecture to an off panel audience.] Cueball: There are four fundamental forces between particles: (1) Gravity , which obeys the inverse square law: F gravity = G m 1 m 2 /d 2 Off panel audience: OK...

[Cueball is still holding his hands up while continues the lecture to the off panel audience.] Cueball: (2) Electromagnetism , which obeys this inverse-square law: F static = K e q 1 q 2 /d 2 ...and also Maxwell's equations Off panel audience: Also what?

[Zoom in on Cueball as he continues the lecture to the off panel audience.] Cueball: (3) The strong nuclear force , which obeys, uh ... ...well, umm... ...it holds protons and neutrons together. Off panel audience: I see. Cueball: It's strong.

[Cueball finishes the lecture to the off panel audience and spreads out his arm for the final remark.] Cueball: And (4) the weak force . It [mumble mumble] radioactive decay [mumble mumble] Off panel audience: That's not a sentence. You just said “Radio- Cueball: – And those are the four fundamental forces!


Atoms

Explanation:
This comic shows another quirky and fantastical ability of Beret Guy .
In this comic, Megan is preparing a sample of what appears to be some mineral for elemental analysis . It seems to be some kind of silicate containing a small amount of iron (a common example of this would be red sandstone ), and she is running a test to see if it contains beryllium (a rarer element whose best-known natural form is as a component of emerald ).  Such analyses typically involve many instruments and steps to prepare the sample.  However, Beret Guy seems to be able to identify all the elements the substance is composed of just by eyeballing it, making him perhaps the perfect elemental analysis instrument.
To confirm this, Megan asks Beret Guy what he sees when he looks at her face, expecting that a normal person would describe the arrangement of colors and features that they see. Since Beret Guy sees the atoms Megan is composed of (mostly oxygen, carbon and hydrogen ) he only notices the unusual atoms. In this case he sees the metal atoms her dental fillings are composed of. This shows his "atomic vision" extends beyond the surface of the substances. Megan finds this bizarre and asks Beret Guy what is wrong with him. He states that he has always suspected he contains too much zinc , which he believes makes people think he is weird, thus missing Megan’s point: what is weird is not Beret Guy’s elemental content, but his ability to apparently see everything as atoms sorted by element.
High zinc intake ( zinc toxicity ) can cause nausea, vomiting, pain, cramps and diarrhea. It also reduces copper absorption, which affects the immune system. However, it does not grant superhuman sensory abilities. [ citation needed ] That is solely a function of tin .
The comic continues the theme of Beret Guy’s naive misunderstandings of scientific terminology turning to be literally true.  In a previous comic his misinterpretation of the notion of energy in the vacuum resulted in him gaining significant superpowers.
In the title text, the concept is taken even further: Beret Guy found his dad indistinguishable from a dog.  This is likely because all mammals are essentially made of the same basic elements.  Absent a distinguishing element from either his dad or the dog, they would appear to be the same.  He could, however, apparently distinguish his mother because she contained plutonium .  This is a very unusual occurrence that cannot possibly occur naturally in humans. [ citation needed ] Some possible explanations are:
It is also possible that the presence of plutonium in his mother may be the source of his own differences: radioactive exposure (in this case, potentially in utero) is a common source of super powers in comic books and other fiction (though unfortunately, this does not work in real life [ citation needed ] ).
It's not clear whether his mother's plutonium is related to his "too many zincs".  One explanation for Beret Guy having too much zinc could be that his mother's plutonium changed into zinc through the process of radioactive decay .
Beret Guy’s mother containing plutonium is probably intended as a whimsical explanation of his powers, since it is a trope in fiction for radioactivity to cause superpowers.
It is worth noting that the verbs "recognized" and "had" in the title text are written in past tense. This presents the possibility that Beret Guy's mother passed away due to radiation sickness from exposure to the radiation originating from the plutonium in her middle. This possibility is further evidenced when Beret Guy adds "I never did ask her why...", indicating that he may no longer have the opportunity to do so.
The English physicist Henry Moseley discovered the law relating the atomic number of elements with their characteristic x-rays when bombarded by free electrons, providing physical evidence for the periodic table , the Bohr Model of the atom and the concept of atomic number . In doing so he developed a method of identifying elements in a substance by bombarding them in a vacuum with electrons and using x-ray diffraction methods to measure the resulting X-rays. A famous French chemist brought him a complicated mixture of Rare Earth elements , many of which had only recently been discovered, to test his method. Within a short time, Mosley amazed the chemist by identifying all the elements by number using his method and referring to his chart to name them. This comic may therefore be subtly alluding to this method by suggesting that Beret Guy's eyes can fire electrons at anything he looks at and "read" the resulting X-ray radiation, giving him the ability to identify the composite elements in a similar manner.
[Megan stands at a table and is preparing a sample for some kind of analysis in a device, when Beret Guy walks in.] Beret Guy: What’re you doing? Megan: Testing a sample for beryllium. Beret Guy: That? Yeah, there’s a bunch of berylliums. Megan: How do you know?
[Megan turns to Beret Guy who takes the sample and looks at it.] Beret Guy: Look at it! See? Tons of oxygens and silicons, a few irons but definitely some berylliums too! Can’t you see them?
[They continue to talk.] Megan: No, I can’t see a list of the atoms in a thing by looking. Beret Guy: How do you tell what things are?
[Zoom in on Megan.] Megan: This is ridiculous. Look at me. What do you see? Beret Guy (off-panel): You have tons of metal in your face. Lots of fillings, I guess?
[Megan stares at Beret Guy who takes a looks at his own arm.] Megan: What’s wrong with you? Beret Guy: Too many zincs? I’ve always worried I had too much zinc and everyone thought I was weird.
Could possibly explain 452: Mission if he believes all carbon based objects to be scones.


Stories of the Past and Future

Explanation:
It's long been common for narrative works to be set in the past, and this tendency goes back to ancient mythology. The opposite approach, setting a work in a speculative future, has been less common prior to modern times. The oldest example Randall presents is from 1733, but it didn't really become a trend until well into the 19th century, and didn't become really common until the 20th century.
For works set in the future, particularly in the near future, there's a real possibility that audiences will still read or watch it past the date in which is was set, allowing them to compare the real world of this era to the one the author projected. This doesn't make the work less valuable, necessarily, but it does make the limits of such speculation painfully obvious, and tends to make the future presented there look dated and quaint . Randall labels these futuristic works as "obsolete".
For works set in the past, there's an opposite and somewhat more subtle effect.  Once the work itself is old enough, audiences tend to forget that they were intended as historical fiction in the first place. If an old work is set in the past, it's often assumed that they were set in their own time, not in the still more distant past. That impacts how we experience the work, because we tend to assume that it's a faithful representation of its own time, not a later interpretation that was intended to be old (and possibly nostalgic) even in its own time.
On top of this, in a similar situation to the failed attempt at futurology , for future-facing works of fiction, even a conscientiously faithful 'historic' film can age badly. Later understanding of previously hazy historical situations can be developed between the time of the fictional work being authored and your experience of it.
To demonstrate those impacts, this chart sorts various works by the year they were created, graphed against how far in the past or future they were originally set.  Lines on the chart are added to separate when each work ceases to work as either a prediction or as a period piece . For future works, the cut-off is obvious: if it was set in a year prior to the current year, we know that the predictions are obsolete (and can easily determine how accurate or inaccurate that future is).  Hence, at the time the chart was written (in 2015), works like 1984 and 2001: A Space Odyssey are obsolete, while works like Star Trek , which take place in a more distant future, are still theoretically possible. ( Back to the Future Part II is deliberately right on the line, as it was set in 2015).
For the past works, Randall sets the cut-off as when the work itself is older than the events in question were when it was first written/made.  Hence, modern audiences are unlikely to realize that the Epic of Gilgamesh was intended to sound ancient, even when it was new, or that novels like Les Miserables were intended as historical fiction, or even that films like Chinatown or shows like Happy Days were intended as period pieces when they were made.  To modern audiences, we just see an old work set in an old time, and tend to assume that the two periods were the same.
The setup of the chart points to the reality that, in process of time, more and more works will cross those lines. Future audiences will likely assume that films like Apollo 13 and Schindler's List were made around the time of the events in question. And modern science fiction works, if they're still remembered in the future, will become just as obsolete as past works.  And Randall even indicates "this chart" on the chart, apparently acknowledging that it will become dated as time goes by.
How to read the graph:
For example, "Water Margin" was published in the 14th century (x ~= 1300) and relates events from the 12th century, about 200 years before its publication (y ~= 200 in the past). Another example: The film The Bridge on the River Kwai was released in 1957 and it was set around 14 years before (~1942-43).
Taking the "years in the past" on the y-axis to be read as negatives like in most graphs one can write
Thus it's clear that the definitions of the lines are consistent with each other as they follow similar but inverted functions.
The graph uses variable logarithmic scales , adjusting the scale in various regions to the temporal density of works being plotted. If the scale were linear, the graph would in fact represent a (bidimensional) Minkowski diagram , which depicts the moving cones of past and future in spacetime as one's present advances in time.
The title text jokes that 2001 cuts from prehistoria to the future before The Flintstones theme can become recognizable. This references the fact that, despite being primarily set in what was then the future, the film opens in the ancient past, thus appearing in both parts of the graph, with one part being very close to The Flintstones . This plays on the fact that one of these was a very serious work and the other a playful animated show that was intended as family comedy.
Differences listed in bright red are "former period pieces." Differences listed in dark red are other works set in the past. Differences listed in bright green are "obsolete" works set in the future. Differences listed in dark green are other works set in the future.
Asterisks (*) after a year of publication denote that it applies to the first installment in a series that spanned more than one year.
You can sort by a specific column in this table by clicking on its header.
Date of publication [A logarithmic scale running horizontally, from 3000 BCE to past 2015 CE.] Years in the future [A logarithmic scale running vertically, from 1 billion down to 0.] Stories set in the future (science fiction, prediction) Stories set in 2015 [A line divides this region into two. The upper side is labelled "still possible"; the lower side is labelled "obsolete".] [From left to right.] Memoirs of the Twentieth Century [1700, 265 years in the future] Looking Backward [1888, 112 years in the future] Golf in the Year 2000 [1892, 108 years in the future] The Time Machine [1895, 800 thousand to 30 million years in the future] Enoch Soames [1916, circa 60 years in the future] 1984 [1949, 35 years in the future] A Week in the Wales of the Future [1957, 76 years in the future] The Jetsons [1962-63, 100 years in the future] Star Trek [1966-69, 300 years in the future] 2001: A Space Odyssey [1968, 33 years in the future] Space: 1999 [1975-77, 24 years in the future] 2010: Odyssey Two [1982, 28 years in the future] Transformers (TV series) [1984-87, 20 years in the future] 2061: Odyssey Three [1987, 74 years in the future] Star Trek: The Next Generation [1987-94, circa 500 years in the future] Back to the Future Part II [1989, 26 years in the future] Zero Wing [1989, 112 years in the future] Terminator 2 (1995 portion) [1991, 4 years in the future] 3001: The Final Odyssey [1997, 1004 years in the future] Enterprise [2001-2005, 150 years in the future] This chart [2015, 0 years in the future] Years in the past [A logarithmic scale running vertically, from 0 down past 1 billion to "Big Bang"] Stories set in the past (History, Period Fiction) Stories written X years ago and set 2X years ago [A line divides this region into two. The upper side is labelled as follows.] Former period pieces Stories set in the past, but created long enough ago that they were published closer to their setting than to today. Modern audiences may not recognize which parts were supposed to sound old. [From left to right.] The Epic of Gilgamesh [ circa 2100 BCE, 600 years in the past] The Iliad [ circa 800 BCE, 450 years in the past] History of the Peloponnesian War [ circa 390 BCE, 10 years in the past] Book of Genesis [ circa 500 BCE, 4000 years in the past] Ashokavadana [ circa 100 BCE, 300 years in the past] Gospels (various estimates) [ circa 250 CE, 24 to 75 years in the past] The Pillow Book [1000 CE, 5 years in the past] Water Margin [ circa 1300, 195 years in the past] Richard III [ circa 1590, 115 years in the past] Julius Caesar [1599, 1650 years in the past] King John [ circa 1600, 500 years in the past] Henry IV [ circa 1600, 190 years in the past] King Lear [ circa 1606, 3000 years in the past] Henry VIII [ circa 1612, 105 years in the past] The Last of the Mohicans [1826, 69 years in the past] Rip Van Winkel [1819, 31-51 years in the past] A Tale of Two Cities [1859, 60 years in the past] Moby-Dick [1851, anywhere from 4 to 14 years ago] "Some years ago--never mind how long precisely..." Les Miserábles [1862, 30 years in the past] Treasure Island [1883, 130 years in the past] A Connecticut Yankee in King Arthur's Court [1889, 2000 years in the past] Gone with the Wind [1936, 70 years in the past] Lest Darkness Fall [1939, 550 years in the past] Casablanca [1942, 1 year in the past] Oklahoma! [1943, 37 years in the past] The Ten Commandments [1956, 1400 years in the past] The Bridge on the River Kwai [1957, 13 years in the past] Gunsmoke [1952-61, 80 years in the past] The Flintstones [1960-66, 100,000 years in the past] Catch-22 (book) [1961, 18 years in the past] The Great Escape [1963, 20 years in the past] Asterix Lawrence of Arabia The Music Man Bonnie and Clyde 2001: A Space Odyssey (prologue) American Graffiti Patton Catch-22 (movie) [1970, 27 years in the past] Chinatown Blazing Saddles Apocalypse Now Happy Days Grease M*A*S*H Annie (play) Roots Chariots of Fire Star Wars (IV-VI) Annie (movie) The Right Stuff Back to the Future Gandhi Platoon Dirty Dancing Back to the Future Part III The Wonder Years JFK The Sandlot Schindler's List Raptor Red Apollo 13 Star Wars (I-III) The Big Lebowski Evita Saving Private Ryan The Prince of Egypt Freaks and Geeks Hotel Rwanda I Love the '80s That '70s Show Pearl Harbor Ice Age I Love the '90s United 93 300 10,000 BC Year One The Wolf of Wall Street I Love the 2000s Mad Men Downton Abbey Star Wars (VII-IX)


Dress Color

Explanation:
This comic shows two drawings of a woman wearing the same dress, but with different background (and body) colors. The two drawings are split with a narrow vertical portion of an image from the web.
The comic strip refers to a dress whose image went viral on Tumblr only hours before the strip was posted and soon showed up also on Reddit , Twitter , Wired and on The New York Times .
Due to the dress's particular color scheme and the exposure of the photo, it forms an optical illusion causing viewers to disagree on what color the dress actually seems to be. The xkcd strip sandwiches a cropped segment of the photographed dress between two drawings which use the colors from the image against different backgrounds, leading the eye to interpret the white balance differently, demonstrating how the dress can appear different colors depending on context and the viewer's previous experiences.
Both dresses have exactly the same colors actually:
Below is an illustration demonstrating that the "colors" of the dresses are the same by connecting them with two lines with the above-mentioned colors (all the way!) and another which has one side flipped and merged into the other:

Similar types of illusions can be seen at Wikipedia's optical illusion page and for instance here at echalk (the latter page requires Flash®player).
This image has sparked surprisingly heated debate in many internet communities. A select few individuals may have prior experience with optical illusions of this ilk, but because this particular image went viral - it got heavy exposure over such a short amount of time - it reached millions of people who aren't so familiar with these sorts of mind tricks. To the uninitiated, the color of the dress seems immediately obvious; when others cannot see it their way, it can be a surreal (even uncomfortable) experience.
As an aside, the retailer Roman Originals would later confirm the dress was blue with black lace , and that a white dress with gold lace was not offered among the clothing line.
The title text refers to the game show Let's Make a Deal , hosted by Monty Hall, which was famous for having contestants pick among several doors which either had a real prize (for example, a car) or a joke prize (for example, a goat). Randall states that people find the dress color issue just as baffling as if upon opening the chosen door no one can agree if the item behind the door is a car or a goat. This is a reference to what has become known as the " Monty Hall problem :" if there are two goats and a prize behind three doors, the contestant has chosen a door, and one of the unchosen doors is opened to reveal a goat, should the contestant change his/her choice? Statistically, the answer is yes, but many people find this counterintuitive; discussion of this problem in Parade magazine touched off public outrage similar to the viral dress image.
Randall is presumably pointing out how ridiculous it is for people who don't understand the underlying science to become so adamant in defending their beliefs. A spoof of the "Monty Hall problem" previously appeared in 1282: Monty Hall , where Beret Guy decides to take the goat.
[Two images of a woman in a dress on each side of an image of a close up of a real dress with the same colors. On the left, she is colored blue on a dark blue background, while on the right, she is brown against a white background. Her dress is the same color in each panel - the same as the real one in between.]


Meeting

Explanation:
Beret Guy 's business, as previously seen in 1032: Networking and 1293: Job Interview , is going well, although it is unclear why. The common theme in these three comics is that Beret Guy misuses common business cliches. The following are examples and phrases that Randall is likely making a joke about:
[Beret Guy is shown in silhouette. Above Beret Guy there is a black sign with white (and grey) text. Above this is his address to those in the meeting:] Beret Guy: Welcome to a meeting! I'm almost out of words, so I'll keep this short. Just wanna touch bases. [White text in the black sign ( .website in grey):] CompanyName.website If you're reading this, the web server was installed correctly.™
[Beret Guy stands in front of an office chair and a table talking.] Beret Guy: First, a few updates. We've learned from the state police that the self-driving car project we launched by accident during this morning's carpool has come to an end about 90 miles outside of town. Very exciting!
[Pony tail sits at the table.] Beret Guy [off-panel]: Profits are up. Sales, any luck figuring out who our customers are? Ponytail: Nope. Money keeps appearing, but we have no idea how or why. Beret Guy [off-panel]: Great!
[Back to the situation from frame two.] Beret Guy: Oh, and one last thing—I saw a cool red beetle in the hall. Can someone add it to the bug tracker? [person off-panel]: Just did! Beret Guy: Thanks!


Insurance

Explanation:
Cueball in this comic, as is often the case, is some sort of programmer or at least logically minded person. He reads through the terms that are handed to him, and finds some sort of loophole. This is a play on the fact that programmers often find loopholes in programs and code, and exploiting them is nothing more than a "cool find" or an interesting idea. More importantly, programmers try to prevent loopholes, which is why it is important to be able to identify them.
The insurance agent foresees this, and explains that this "cool hack" is actually just an instance of insurance fraud , which is highly illegal. The comparison here is that exploiting a program's faults can be regarded as interesting or fun, while exploiting the faults in a legal document will often result in some sort of legal repercussions (however, sometimes legal loopholes are exploited by individuals or corporations in ways that are not illegal).
The insurance agent is also already prepared for the following question - how he knew Cueball would be looking for loopholes, and it's because many programmers visit him.
The title text provides another example: While airport luggage security certainly is exploitable, walking out with every piece of luggage from the conveyor belt would be easily noticeable and would result in being arrested for theft, and many annoyed travelers.
1469: UV also contains a case of insurance fraud.
The term hacking in IT is ambiguous and goes from code development (in particular in the opensource community) to the fact of "using a hack ". A hack would then refer to a tricky piece of code doing the intended job in a way that the framework or project in which it is inserted was not intended to. To the general public, 'hacking' a system would normally refer to some illegal way of achieving a goal against the will of the original developers of the system, like getting a copy of all the data available or taking advantage of some unwanted behavior, but a more distinctive term for such an exploitation (maliciously or after an invitation to perform legitimate penetration testing) would be 'cracking'.
This comic is making fun of what IT hacks would look like in real world. Surely, taking lots of luggage from an airport is technically possible and probably not so difficult, but first, it looks weird, and second, it's also obviously illegal. The weirdness of such behavior is more obvious in real life than in IT.
It is worth noting that it is currently popular on social media sites to share small tricks to make one's life easier.  This is called "life hacking", or "hacking your life" .
[Cueball is standing in front of a desk, which a man sits behind. The man is presumably an insurance agent, and is handing Cueball a paper.] Insurance agent: Here's a page explaining the terms of your new fire insurance policy.
[Zoom in on Cueball as he reads the paper.]
[Cueball starts to ask the insurance agent a question when he hands Cueball yet another paper.] Cueball: Hey, what if I- Insurance agent: And here's a page explaining that the "cool hack" you just thought of is called "insurance fraud". We already know about it and it's a crime. Cueball: Oh. Right. How did- Insurance agent: I see a lot of programmers here.


Hard Reboot

Explanation:
This comic is about using a simple and unrelated trick to work around a problem, instead of spending a long time solving the cause of the problem.
Swap space is an area of a computer's hard drive reserved for use when the computer runs out of RAM. Ideally, RAM + SWAP >= MAX, where MAX is the amount of memory the computer will ever try to use at the same time. However, some (broken) programs may keep requesting memory from the system until computer runs out of resources (a memory leak ), or the system may be misconfigured to run more and more programs simultaneously. Rebooting the computer will empty the RAM and swap space so resources can be reallocated, but this only temporarily alleviates the underlying issue. Determining the root cause of the problem is often nontrivial.
It would take Randall anywhere between 1 and 10 hours to figure out why the server is running out of swap space, and possibly more to actually fix the problem. Alternatively, Randall could just take 5 minutes and plug the server into a light timer. This attitude to problem solving is in contrast to the attitude shown in 974: The General Problem .
Timers like the one in the comic typically have four switches or notches per hour, so using the timer would replace an unpredictable and indefinite loss of service with a regular 15 minute downtime event once a day. Also, it can be scheduled during, say, the middle of the night when most users are sleeping to minimize disruption.
The correct method of scheduling a regular reboot would be using a cron task, but perhaps the server is "crashing" in such a dramatic manner that cron, or shutdown, or init stops working. The comic title alludes to this, in that a "hard" reboot scheduled with an analog timer is more guaranteed to work than a "soft" one scheduled with cron.
If a memory leak is not present, the problem might be fixable by simply increasing swap space; however, if there is a more complex underlying issue, this is the first step along the path of 10 hours of troubleshooting. As a general stereotype, the type of person who has a home server is probably also the kind of person who would start by 'just' increasing the swap size, and before they know it has spent 10 hours completely engrossed in the challenge of fixing the problem. (See 349: Success )
The subtitle reads "Why everything I have is broken". This indicates that Randall frequently finds himself doing non-standard workarounds that temporarily solve a problem but may ultimately damage the system to the point of becoming nonfunctional. Indeed, a kitchen/light timer used to cut power to a server overnight may affect the server's performance if it is in the middle of a process when the reboot happens. Alternatively, this can be interpreted to mean that everything Randall has is broken and held together by metaphorical duct tape.
The title text's first sentence reveals that Randall is aware that looking further for a fix is futile: The problem is caused by a bug which has already been analyzed and is known to be triggered by using the system in the very way Randall is using it. He may get around the bug by changing what the system does, but then it would not provide the services he needs anymore. It may also refer to bug trackers, where someone found out and posted what causes the issue, but the bug is marked as "Unresolved," "Waiting," or "Will not fix."
It is not clear why the title text refers to a kitchen timer while the comic itself refers to a light timer. It might be a small error, or it might be that Randall just considers these to be two synonymous terms. Typically, however, a kitchen timer refers to an alarm that will go off, rather than a timer that cuts power to a device like a light timer.
The title text's second sentence refers to the fact that operating system bugs take a long time to be solved, hence the solution of "wait[ing] a few years until I don't want that combination of things anymore." Humor in that sentence is found in the fact that readers will anticipate "wait a few years until..." would be followed by "the bug is fixed", however, Randall is indicating that usually his needs change before the bugs get fixed, or that he has very low confidence in that the bug will be fixed in time, if ever. This play on expectations is a common comedic trope.
[Inside a frame there are two pictures. To the left there is a section of a computer screen with white text on a black background. The screen is covered in lines of illegible text.] [Above the screen it says:] Figuring out why my home server keeps running out of swap space and crashing: [Below the screen it says:] 1-10 hours
[To the right there is a frame with a drawing of a timer plugged into a power port with cable running off to the side.] [Above the frame it says:] Plugging it into a light timer so it reboots every 24 hours: [Below the frame it says:] 5 minutes
[Below the main frame.] Why everything I have is broken


Art Project

Explanation:
This comic appears to be satirizing art in two different ways. From one perspective, Randall is describing various art forms in unusual ways (e.g., a portrait by Cueball , a video for Megan , and perhaps live performance by Ponytail ). From another perspective, Randall might be making fun of time-lapse photography movies. YouTube has a robust collection of videos taken from stitching together pictures or short video clips taken every day or every week; in the 2015 Academy Awards , one of the Best Picture nominees, Boyhood , used a similar method, filming short sequences annually over the course of 12 years.
In each case, the art described is simpler than it sounds, and some might not consider it art. A picture of oneself "every hundred years" will only happen once or twice in a lifetime; a "picture every 1/24th of a second" is the traditional frame rate of cinema cameras for film production, and "watching my face age in real time" is just life.
Then finally another Megan-like character, possibly a relatively demure Danish , pokes fun at all of them by simply watching their attempts at "art" while she eats a burrito. Randall may also be referencing the many perspectives on art by leaving this comic open to several interpretations.
The use of a burrito as a punchline representing someone who is grounded in reality instead of engaging in esoteric pursuits has been seen before in 1269: Privacy Opinions .
The title text is just more snark, claiming that it's their most ambitious project ever, if the sole criterion for ambition is the amount of guacamole that one has to eat.
[Four people stand next to each other.] Cueball [taking a selfie with his smart-phone]: I'm doing an art project where I take a picture of myself every hundred years. Megan [filming herself with her smart-phone]: I'm doing an art project where I take a picture of myself every 1 /24 th of a second. Ponytail [pointing to her face with both hands]: I'm doing an art project where you can come to my house and watch my actual face age in real time. Girl with long black hair [holding a burrito]: I'm doing an art project where you all do those things while I eat a burrito.


New Products

Explanation:
This comic points out an apparent paradox in product performance: Many products that are criticized by techies when first announced go on to great success, and many that are heavily hyped are total flops. The product in question may be a reference to the Apple Watch , which was announced around the time of this comic's release.
The title text imagines a product that fits into the second, third and fourth categories:
Kim Dotcom is a controversial entrepreneur and convicted fraud . He changed his surname to "Dotcom" because of the dot-com stock market bubble that made him a millionaire. He fits perfectly into the mold of someone well-known to programmers and engineers (as well as New Zealanders), but perhaps not so much to your average Joe.
Taken together, these imply that an untrustworthy and potentially malicious company has an exciting new idea that may eventually come out in successful form, gains control of a large amount of medical information, but ultimately result in lawsuits not just from investors but from misled consumers (category 3). Because the initial release will be a flop (category 2), there is some time to prepare before the successful use of this idea becomes a reality (also category 2), at which point that or some other company will gain control of a large amount of people's medical something (category 4). Once this happens you could expect dramatic repercussions; this is why the title text suggests to dig a bunker while there is still time.
Predicting the success or failure of a new product based on what engineers and programmers are saying about it
[A two-column table illustrating this. The headings are actually standing above the table.]
If they say... It means... "It doesn't do anything new" The product will be a gigantic success. "Why would anyone want that?" "Really exciting" The product will be a flop. Years later, its ideas will show up in something successful. "I've already preorded one" "Wait, are you talking about <unfamiliar person's name>'s new project?" The product could be a scam and may result in arrests or lawsuits. "I would never put <company> in charge of managing my <whatever>." Within five years, they will.


Terry Pratchett

Explanation:
This comic is a tribute to the late Sir Terry Pratchett . It came out the day after the renowned fantasy author died.
The comic quotes a (slightly abridged) passage from Wings , one of the three books of The Bromeliad Trilogy (also known as The Nome Trilogy ), a series of children's books by Sir Terry.
During the first five panels of the comic Cueball reads the quoted passage in his book Wings . This passage describes what Masklin thinks about when he told Grimma that they "were going to get married, and all she could talk about was frogs." He then recounts what she told him about a type of tree frog that are found in bromeliad flowers where they lay their eggs, which hatch into tadpoles, and then live most of their lives in a single plant. See a description of this plot point when it happened in Diggers . She—amongst other things—muses about the fact that they are blind to the rest of the Universe, and that most people are blind to them.
After reading this Cueball puts the book down and walks off, and soon finds that he himself has been living at the bottom of a flower much like the frogs in the bromeliad. This is an allegory for a common praise of the best fantasy and science-fiction writing: That by reflecting our own world in a different context, it allows us to better see ourselves. In the allegory, Cueball's journey to the edge of the leaf is a representation of broadening one's horizons, perhaps even in ways that are somewhat frightening.
On a more literal level, the concept of living on a flat surface with a precipice at the edge is explored at length in the Discworld series, Pratchett's most iconic work. Both this series (wanting to own it all) and the space all of Terry Pratchett's books would take up on a bookshelf are the subject of 625: Collections .
The title text continues, more directly, the point previously made allegorically. It thanks the late Sir Terry, noting that his fictional worlds allowed us to better see the real world. "How big our world is" also ties into another point raised in the quoted passage, that there are countless amazing things happening around us all the time without our knowledge.
Terry Pratchett was also referenced in panel 18 of 1052: Every Major's Terrible .
A similar tribute comic was also dedicated to Steve Jobs , the day after he died, in 961: Eternal Flame , to Gary Gygax , three days after he died, in 393: Ultimate Game , and to John Conway , two days after he died, in 2293: RIP John Conway .
[Cueball is reading a book over the first four panels at the top of the comic. He shifts position from sitting, leaning back on one hand, laying down on his belly to finally sitting more upright. Above these four panels and breaking the frame of the outer panels of the comic we see what he reads during these four panels:]
I told her we were going to get married, and all she could talk about was frogs. She said there's these hills where it's hot and rains all the time, and in the rainforests there are these very tall trees and right in the top branches of the trees there are these like great big flowers called... bromeliads, I think, and water gets into the flowers and makes little pools and there's a type of frog that lays eggs in the pools and tadpoles hatch, and grow into new frogs and these little frogs live their whole lives in the flowers right at the top of the trees and don't even know about the ground, and once you know the world is full of things like that, your life is never the same.
— Masklin, Terry Pratchett's The Bromeliad Trilogy
[Below are four more panels. Cueball stops reading in the book. Leaves the book and begins to walk. Walks out on a leaf from a big flower. Finally, zooming in on him at the edge of the leaf, he looks down and sees what is below the flower.]


Arbitrage

Explanation:
In economics and finance , arbitrage is the practice of buying cheaply on one market whilst immediately selling at a higher price on another market, taking advantage of the price difference to make relatively risk-free profit. In real-world liquid financial markets , arbitrage helps the market to converge on one price for a product. Arbitrageurs are the individuals performing this act to equalize the prices in those markets and hopefully make a profit.
The place where Cueball and Hairy are eating is giving away unlimited free potato / tortilla chips , probably serving the same function as a bread basket, being a cheap but welcome appetizer while patrons wait for their orders. Hairy is acting as an arbitrageur by collecting the chips to later resell them. This is much to the consternation of Cueball, who is (depending on how you interpret the simple art-style) holding his hands up in front of his mouth in shock, covering the lower half of his face in shame, covering his eyes out of denial, sliding his palms down the front of his face in disgust, face palming in exasperation, or eating chips – possibly all in sequence.
Trying this strategy in the real world would not work. Customers leaving the restaurant with bags of chips might well be barred from the establishment. More simply, the restaurant is under no obligation to keep refilling the bowls indefinitely; if a customer's demands for more chips became unreasonable, they could simply refuse to bring any more. In either case, it's highly unlikely that a customer could leave with enough chips to offset the cost of even an inexpensive meal. Additionally, there would likely be a problem of a lack of demand, given the absence of a secondary market . Case in point: would you buy open bags of perishable, presumably hand-soiled chips? Didn't think so.
In the caption below the comic, Randall suggests that society only functions because we don't take people like Hairy "out to dinner"; we generally have an aversion to dealing with people with such extreme self-interest, bordering on sociopathic behavior. Traditional theories of capitalism are based on the concept that people will act in their own economic self-interest, but in reality this is usually limited by both legal strictures and unspoken social norms. There are many aspects of society that are only possible because we trust most people to keep their self-interested actions within reasonable bounds. We see from Cueball's reaction that he is appalled by what Hairy is doing in believing he can profit from the apparent generosity.
A distinguishing feature of social animals , rather than animals simply sharing a habitat , is that they perform tasks that benefit their group. All such societies rely on some situations where the individual is not working purely on short term self-interest. The payoff for this is generally that co-operation makes things better for the group as a whole. Most people would find Hairy's behavior embarrassing and shameful, and thus would not socialize with people who behave like that. By rejecting such individuals, society protects itself from such people.
The title text mentions the invisible hand . In economics this is a metaphor used by Adam Smith to describe unintended social benefits resulting from the individual actions of self-interested parties. In the context of arbitrage, the invisible hand compels all of a given fungible substance to be sold for the same price, as a result of the actions of individuals like Hairy who are only seeking personal profit. The invisible hand is a sort of personification of the market; in the title text, the person has become so real that it can be sent a text message, but, despite presumably being able to hold a phone, the Hand doesn't reply (it IS only a hand). It is tempting to wonder why Randall/Cueball is texting it in the first place - not, presumably, to invite it to dinner, since the market would doubtless behave just as Hairy is doing. As it is invisible, though, perhaps it would at least be less embarrassing to sit at a table with.
[Cueball and Hairy are sitting at a table with a bowl of chips in the middle. Hairy is taking chips from the bowl on the table with one hand, and his other hand is dropping chips into a large bag behind him. Cueball is double facepalming.] Hairy: They're the ones giving chips away! Hairy: If they don't see the arbitrage potential, sucks for them. [On the bag is written: Chips.]
In a deep sense, society functions only because we generally avoid taking these people out to dinner.
The invisible hand of the market is also mentioned in 958: Hotels .
The same idea was previously used in 1110: Click and Drag , where a person takes free drinks to resell . Later, 1721: Business Idea implies a similar plan to extract wealth out of a small market inefficiency that, in reality, would be far too onerous to exploit; in this case, premium gasoline at regular price. See also the what if? Cost of Pennies regarding why it would not be worth trying these kind of ventures out.