https://www.explainxkcd.com/wiki/api.php?action=feedcontributions&user=172.70.86.12&feedformat=atomexplain xkcd - User contributions [en]2024-03-28T17:00:20ZUser contributionsMediaWiki 1.30.0https://www.explainxkcd.com/wiki/index.php?title=Talk:630:_Time_Travel&diff=300670Talk:630: Time Travel2022-12-06T19:28:13Z<p>172.70.86.12: </p>
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<div>Dear Future Husband...better toast it right. [[User:Elvenivle|Elvenivle]] ([[User talk:Elvenivle|talk]])<br />
<br />
I believe Cueball is in fact eating a bagel. --[[User:Alexbuzzbee|Alexbuzzbee]] ([[User talk:Alexbuzzbee|talk]]) 04:16, 21 March 2016 (UTC)<br />
<br />
"Likely" the year of her birth? Cueball disclosed it as "technically true"! [[User:SilverTheTerribleMathematician|SilverTheTerribleMathematician]] ([[User talk:SilverTheTerribleMathematician|talk]]) 16:39, 6 December 2022 (UTC)<br />
:Only that she travelled from then, not that she was born then. Marty McFly travelled from 1985, but was clearly born in the '60s, so the year he might say he came from (similarly technically true, whether telling people in 1955, 2015, 1885 or just in 1986, a year after he started going to eras and returning from them) isn't necessarily and indication of his birth-year. Assuming he even ''has'' a birth-year in any given timeline...<br />
:We can be (time-machines aside) sure that she was born no later than then (...or then plus ''nine months'', perhaps?). With time-machines, all bets are off! [[Special:Contributions/172.70.86.61|172.70.86.61]] 19:19, 6 December 2022 (UTC)<br />
<br />
:PS, SilverTTM... Welcome to the <s>Future</s> ''Wiki''. Just because I think you were ''mis''pedantic this particular time, from your other edits I can see you're the kind of person to appreciate the place. I'm no official greeter, or anything, but greetings anyway. I don't know if you've been interacting ''just'' as an IP, before today, but it looks like you might fit in just fine anyway. [[Special:Contributions/172.70.86.12|172.70.86.12]] 19:28, 6 December 2022 (UTC) (same as the above IP, whether or not this looks the same)</div>172.70.86.12https://www.explainxkcd.com/wiki/index.php?title=Talk:2707:_Astronomy_Numbers&diff=300637Talk:2707: Astronomy Numbers2022-12-06T09:40:47Z<p>172.70.86.12: comment re kph vs mph</p>
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<div><!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--><br />
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First time I've ever seen a completely blank page. [[User:IJustWantToEditStuff|IJustWantToEditStuff]] ([[User talk:IJustWantToEditStuff|talk]]) 20:27, 5 December 2022 (UTC)<br />
:Everyone's enthralled by ChatGPT. [[Special:Contributions/172.69.22.35|172.69.22.35]] 04:01, 6 December 2022 (UTC)<br />
<br />
It's also notable that something weighting 12 solar masses will collapse into black hole on it's own, unless it resist collapse through thermal pressure like stars. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 21:26, 5 December 2022 (UTC)<br />
<br />
The Earth moves relative to the sun at 66,000 MPH. In what frame of reference is it 65 MPH? It isn't like Randall to get a number wrong. Maybe the magnitude of the distance from Earth to Sun changes at a closer rate, but even this is nearly 180 MPH if I'm calculating correctly. [[User:Mannerisky|Mannerisky]] ([[User talk:Mannerisky|talk]]) 21:37, 5 December 2022 (UTC)<br />
: You're thinking orbital speed, she's talking orbital oscillation. That is, the speed at which the distance between earth and sun changes. [[Special:Contributions/198.41.242.240|198.41.242.240]] 21:51, 5 December 2022 (UTC) ADDITION: Orbital oscillation has both a mean/average factor and a current factor (which is at it slowest while at the apsides, and given the context the one being calculated) [[Special:Contributions/198.41.242.85|198.41.242.85]] 22:46, 5 December 2022 (UTC)<br />
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I get the sense that the thing that they're planning for January 1st is a precisely-timed new year's party and nothing to do with space exploration. {{unsigned|172.71.242.156}}<br />
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Someone removed my interpretation of the title text because "nobody else thinks the title text means [referring to astronomers using laser pointers to point at a distant star]" - so I'll democratize it: does anyone else think my interpretation holds water? I'm happy to remove it if nobody else thinks it makes any sense, but honestly it's the only thing that I initially thought he meant. I mean, he's got a bit of a history in astrophysics and definitely has been to a few star parties with astronomers pointing at Betelgeuse and Polaris and whatnot. I think it'd be odd if that wasn't in mind at all writing that title text. What do you guys think? [[Special:Contributions/172.70.214.150|172.70.214.150]] 06:45, 6 December 2022 (UTC)<br />
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; Obligatory ChatGPT explanation<br />
<br />
:'''Me:''' The following is a transcript from the latest xkcd comic. Please write an explanation of the comic: ''[transcript copied verbatim from [https://www.explainxkcd.com/wiki/index.php?title=2707:_Astronomy_Numbers&oldid=300614#Transcript its current state] omitted]''<br />
<br />
:'''[https://chat.openai.com/chat ChatGPT:]''' In the xkcd comic, Ponytail and Cueball are discussing Earth's orbit around the sun. Ponytail notes that Earth will be approaching the sun at a rate of 65 miles per hour on January 1st. Cueball responds, "Weird?" Ponytail explains that they usually see only complex and incomprehensible numbers in astronomy, and seeing a "normal" number like 65 miles per hour feels wrong to them. This reflects the common perception that numbers in the sciences, especially astronomy, are often complex and difficult to understand. Earlier in the comic, Ponytail also expresses skepticism at a "normal" number when Megan in coat tells them that their cat weighs 12 lbs. Ponytail suggests that it must actually weigh either 10-20 or 1040 instead. Megan responds by saying that the cat's weight is actually 3x10-30 solar masses, which Ponytail finds more acceptable.<br />
<br />
I wish superscipts would survive copy-paste, but I have to admit it's better than the esoterica-laden verbosity that's up now.<br />
<br />
:[Take two, using the prompt prefix, "The following is the wikitext transcript from the latest xkcd comic. Please write an explanation of the comic in wikitext. The title text should be explained in a seperate paragraph at the end:"<br />
<br />
::'''ChatGPT:''' In the latest xkcd comic, two characters are discussing an elliptical orbit and the rate at which Earth is approaching the sun. One character, Ponytail, is suspicious when she sees a normal number (65 miles per hour) in their calculations and suggests that scales in astronomy should all be incomprehensible. This is a reference to the fact that astronomical numbers are often very large or very small, and can be difficult for non-astronomers to comprehend.<br />
<br />
::Earlier in the comic, Ponytail is at the vet with her cat, and the vet tells her that the cat weighs 12 lbs. Ponytail finds this ridiculous, as nothing weighs 12. She suggests that the cat must weigh 10<sup>-20</sup> or 10<sup>40</sup> instead. The vet then tells her that the cat weighs 3x10<sup>-30</sup> solar masses, which Ponytail finds more acceptable.<br />
<br />
::The title text jokes about adopting a cat that weighs 12 solar masses, which would be extremely large. Laser pointers would love chasing it, as it would be an impressive target.<br />
<br />
:Meh.]<br />
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I propose we create a [https://beta.openai.com/examples/default-summarize bot to summarize the transcript] with the text-davinci-003 API and paste it into the top of discussion whenever the Transcript is expanded more than 10%. Yays and nays? [[Special:Contributions/172.71.154.39|172.71.154.39]] 03:55, 6 December 2022 (UTC)<br />
:'''Yea.''' Both have a few serious but easily noticed and easily correctable flaws, but both are far better than the borderline-trolling six paragraph wall of text for the simple, silly joke we have at the moment. [[Special:Contributions/172.69.33.245|172.69.33.245]] 06:09, 6 December 2022 (UTC)<br />
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Why is it as big as 65 mph? Where did the 65 mph figure have come from? A formula? Taking a linear change from minimum velocity (-500 m/s 12 weeks earlier), 4 days before the perihelion gives 86 kph (53 mph), three days gives just 64 kph (40 mph). But those are surely too big, since the rate of change of radial velocity would be slowest around perihelion and aphelion. I wouldn't expect the above-calculated rate of change until weeks out from perihelion. [[Special:Contributions/172.68.210.5|172.68.210.5]] 08:23, 6 December 2022 (UTC)<br />
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Surely the really weird thing is an astronomer using non-SI units? [[Special:Contributions/172.70.86.12|172.70.86.12]] 09:40, 6 December 2022 (UTC)</div>172.70.86.12https://www.explainxkcd.com/wiki/index.php?title=2700:_Account_Problems&diff=2996582700: Account Problems2022-11-22T15:54:42Z<p>172.70.86.12: /* Explanation */ Clearly a bit of zombie grammar, left in after a tense change.</p>
<hr />
<div>{{comic<br />
| number = 2700<br />
| date = November 18, 2022<br />
| title = Account Problems<br />
| image = account_problems_2x.png<br />
| imagesize = 538x272px<br />
| noexpand = true<br />
| titletext = My password is just every Unicode codepoint concatenated into a single UTF-8 string.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a VISIBLE ZERO WIDTH SPACE. Please change this comment when editing this page. Do NOT delete this tag too soon.}}<br />
<br />
[[Cueball]] asks [[Ponytail]] to help him because he can't log in to his account. Having attempted to fix [[:Category:Cueball Computer Problems|Cueball's tech issues]] in the past, Ponytail replies with dread. Cueball promises that "It's a normal problem this time", and Ponytail agrees to look at it. But then Cueball reveals that he has included a {{w|Null character|null string terminator character}} in his password when creating an account and now he can't log in.<br />
<br />
In computer systems, every {{w|Character (computing)|"character"}} (letter, digit, punctuation, etc.) is represented as an integer. For example the lowercase letter 'a' is represented as the number 97, and the digit '1' is represented as the number 49 (when using the {{w|ASCII}} character encoding or {{w|Unicode}} character encoding). A {{w|String (computer science)|"string"}} refers to a sequence of characters, and can be used to store arbitrary text (for example names, messages, passwords). Strings can be arbitrarily long, so some mechanism must be used to record their length. One approach is to store the length explicitly ({{w|String_(computer_science)#Length-prefixed|Pascal string}}). Another approach is to mark the end of the string using a specific character, usually the {{w|null character}} (which is represented as the number 0); such strings are called {{w|null-terminated string}}s, and are used by the {{w|C (programming language)|C programming language}}. Both approaches have advantages and disadvantages. A limitation of null-terminated strings is that they cannot be used to represent text containing embedded null characters. This is usually not a problem, because normal text never contains null characters. However, if somehow a null character were to end up in the string, it would cause problems: any code that uses that string would assume this null character marks the end of the string, so the string would effectively be truncated.<br />
<br />
Account registration systems often place requirements on passwords in an attempt to encourage users to pick stronger passwords. For example, they might ask that the password include at least one "special character" (such as <code>!@#$%^&*</code>). Cueball misunderstood this requirement as referring to characters such as the null character (which is more accurately referred to as a {{w|ASCII#Control_characters|control character}}). Cueball managed to type the null character as part of his password somehow (on some systems it is possible to type the null character using {{w|Null_character#Representation|certain keyboard shortcuts}} such as <code>Ctrl</code>+<code>Space</code>, <code>Ctrl</code>+<code>@</code>, <code>Ctrl</code>+<code>2</code>, or <code>Alt+0</code> {{w|Alt_code|using the number pad}}), but the software running the registration system was poorly written and could not cope with this &ndash; it allowed him to create an account with that password, but then when he tried to log in with the same password the system didn't accept it. <br />
<br />
It's unclear how that particular situation might arise in real software, but here are similar situations that can easily happen in practice: Suppose a website's registration form allows the user's new password to have up to 20 characters, but due to a programmer error the login page only accepts passwords with up to 18 characters. If the user picks a medium-length password (say with 12 characters), all is well. But if the user picks a password with 20 characters, they will be able to register but they won't be able to log in (which is what happened to Cueball). Another possibility is that the password creation logic differed from the password authentication logic. This could happen if passwords are "trimmed" before hashing (or storage) inconsistently. When the password is stored, it is trimmed but when it is then looked up it is not (or vice versa). In such a case, the password lookup will fail.<br />
<br />
The title text describes a password which is "just" every Unicode character concatenated into a single string. {{w|Unicode}} is a standard for representing characters from many writing systems, and it has 149,186 characters[https://en.wikipedia.org/wiki/Unicode#Versions] as at the time of this comic (with new characters being added over time). A password consisting of all of those characters would be extremely long; it would be impractical to type by hand, and would be too long for pretty much all account registration systems. (A "codepoint" is the number assigned to a character, and {{w|UTF-8}} is a common encoding system for representing each Unicode codepoint as a sequence of {{w|byte}}s.) Also, since Unicode includes the null character, the password would have the same issue as Cueball's password. Further, if the account registration system treats the null character as a string terminator (as in C), then the password would be equivalent to an empty password (assuming it contains the Unicode codepoints in order, starting with the null character).<br />
<br />
==Trivia==<br />
<br />
* User input containing unsafe characters has previously appeared in the famous comic [[327: Exploits of a Mom]].<br />
<br />
* Here are some additional situations where passwords with special characters might stop working:<br />
** The registration form allows passwords to contain null characters, but the login form strips null characters (for example because it was written by a different developer/team, or because it has been updated over time). When Cueball tries to log in, the login form strips the null characters, so the resulting password can ''never'' match such a stored password (which contains a null character).<br />
** The password system allows the input of Unicode characters at first, but is later changed to only accept ASCII passwords. Users who included non-ASCII characters like é or ö in their password are locked out of their account because they are no longer allowed to submit those characters.<br />
<br />
* There are several techniques that can be used to safely handle passwords and other user inputs that might contain unsafe characters such as the null character:<br />
** Validate: Check whether the user input contains unsafe characters, and if it does display an error message to the user.<br />
** Sanitize: Remove unsafe characters from the user input to prevent them from causing problems.<br />
** Encode/quote/escape: Replace each unsafe character with an appropriate sequence of characters (depending on the context). For example, a null character can be included in a {{w|URL}} by encoding it as <code>%00</code>. This technique is not very relevant to password handling, but is relevant for example when {{w|Cross-site_scripting#Non-persistent_(reflected)|including user input in generated web pages}} or [https://www.cloudflare.com/learning/security/threats/sql-injection/ passing user inputs to database queries].<br />
** For the specific case of null characters: Use a string representation that supports null characters (e.g. Pascal strings), and be very careful not to pass such strings to functions that can't handle embedded null characters.<br />
<br />
* Failure to handle strings containing null characters correctly can result in security vulnerabilities. For example, including a null character in crafted input may allow a user to read or write files that they are not supposed to be able to access.[https://insecure.org/news/P55-07.txt][https://elixirforum.com/t/static-and-session-security-fixes-for-plug/3913]<br />
<br />
* In C, a string is usually stored in a block of memory that is allocated to have a known size. The maximum size of string that can be stored in such a buffer is one character less than the buffer's size, since the last character is used for the null terminator. Language functions that operate on strings, such as those that return the length of a specified string or which compare two strings, look for the terminator as a marker. However, there is a risk in using this feature: if that terminator is somehow overwritten by some other value, a function which assumes that there is still a stopping point may go far beyond the intended region of memory before it happens to find an unrelated terminator or otherwise is forced to stop looking. This can have serious security implications, as well as the potential for bugs and crashes. Instead, safe programming uses versions of the string functions that include a specification of the maximum allowed length. For example, the <code>strlen()</code> function takes a pointer to a string, counts the number of characters until it encounters a null terminator, and returns that number: the length of the string not including the terminator. The <code>str'''n'''len()</code> function takes a pointer to a string and a maximum length, and counts characters until it either finds a terminator or reaches the maximum.<br />
<br />
* The number of the xkcd comic is 2700. When interpreting this as two concatenated octal numbers \27 + \00 it represents both the {{w|End-of-Transmission-Block_character|ETB}} as well as the null character, both of these characters possibly leading to problems when processed in legacy systems (e.g. mainframe computers). When interpreting 2700 as hexadecimal 0x27 + 0x00 numbers it represents the ' character and the null character - a sequence that could lead to [[327: Exploits of a Mom|SQL injection]] when it is placed in unescaped form inside of a SQL command.<br />
<br />
==Transcript==<br />
:[Cueball carries an open laptop over to Ponytail, holding in in both hands. The screen shows a box filling the screen with some text on lines. Ponytail is sitting in an office chair with her laptop at her desk. She has turned her head away from the computer looking at Cueball's screen.]<br />
:Cueball: Can you help me with my account?<br />
:Ponytail: Oh no.<br />
<br />
:[Cueball holds his laptop up in front of Ponytail who has turned the chair so she faces him, with her hands in her lap. Her table is not drawn.]<br />
:Cueball: No no, I promise it's a normal problem this time.<br />
:Ponytail: Okay. Fine. What is it?<br />
<br />
:[Cueball holds both hands out palm up towards Ponytail who is sitting with his laptop in her lap typing on it.]<br />
:Cueball: I included a null string terminator as part of my password, and now I can't-<br />
:Ponytail: '''''How?!'''''<br />
:Cueball: They said to use special characters!<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Comics featuring Ponytail]]<br />
[[Category:Cueball Computer Problems]]</div>172.70.86.12https://www.explainxkcd.com/wiki/index.php?title=2700:_Account_Problems&diff=2996532700: Account Problems2022-11-22T14:28:45Z<p>172.70.86.12: /* Trivia */ It couldn't assume a stopping point if the mark s gone, and the onward behaviour is constrained by safeguards/errors/whatever it intrudes into...</p>
<hr />
<div>{{comic<br />
| number = 2700<br />
| date = November 18, 2022<br />
| title = Account Problems<br />
| image = account_problems_2x.png<br />
| imagesize = 538x272px<br />
| noexpand = true<br />
| titletext = My password is just every Unicode codepoint concatenated into a single UTF-8 string.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a VISIBLE ZERO WIDTH SPACE. Please change this comment when editing this page. Do NOT delete this tag too soon.}}<br />
<br />
[[Cueball]] asks [[Ponytail]] to help him because he can't log in to his account. Having attempted to fix [[:Category:Cueball Computer Problems|Cueball's tech issues]] in the past, Ponytail replies with dread. Cueball promises that "It's a normal problem this time", and Ponytail agrees to look at it. But then Cueball reveals that he has included a {{w|Null character|null string terminator character}} in his password when creating an account and now he can't log in.<br />
<br />
In computer systems, every {{w|Character (computing)|"character"}} (letter, digit, punctuation, etc.) is represented as an integer. For example the lowercase letter 'a' is represented as the number 97, and the digit '1' is represented as the number 49 (when using the {{w|ASCII}} character encoding or {{w|Unicode}} character encoding). A {{w|String (computer science)|"string"}} refers to a sequence of characters, and can be used to store arbitrary text (for example names, messages, passwords). Strings can be arbitrarily long, so some mechanism must be used to record their length. One approach is to store the length explicitly ({{w|String_(computer_science)#Length-prefixed|Pascal string}}). Another approach is to mark the end of the string using a specific character, usually the {{w|null character}} (which is represented as the number 0); such strings are called {{w|null-terminated string}}s, and are used by the {{w|C (programming language)|C programming language}}. Both approaches have advantages and disadvantages. A limitation of null-terminated strings is that they cannot be used to represent text containing embedded null characters. This is usually not a problem, because normal text never contains null characters. However, if somehow a null character were to end up in the string, it would cause problems: any code that uses that string would assume this null character marks the end of the string, so the string would effectively be truncated.<br />
<br />
Account registration systems often place requirements on passwords in an attempt to encourage users to pick stronger passwords. For example, they might ask that the password include at least one "special character" (such as <code>!@#$%^&*</code>). Cueball misunderstood this requirement as referring to characters such as the null character (which is more accurately referred to as a {{w|ASCII#Control_characters|control character}}). Cueball managed to type the null character as part of his password somehow (on some systems it is possible to type the null character using {{w|Null_character#Representation|certain keyboard shortcuts}} such as <code>Ctrl</code>+<code>Space</code>, <code>Ctrl</code>+<code>@</code>, <code>Ctrl</code>+<code>2</code>, or <code>Alt+0</code> {{w|Alt_code|using the number pad}}), but the software running the registration system was poorly written and could not cope with this &ndash; it allowed him to create an account with that password, but then when he tried to log in with the same password the system didn't accept it. <br />
<br />
It's unclear how that particular situation might arise in real software, but here is a similar situation that can easily happen in practice: Suppose a website's registration form allows the user's new password to have up to 20 characters, but due to a programmer error the login page only accepts passwords with up to 18 characters. If the user picks a medium-length password (say with 12 characters), all is well. But if the user picks a password with 20 characters, they will be able to register but they won't be able to log in (which is what happened to Cueball).<br />
<br />
The title text describes a password which is "just" every Unicode character concatenated into a single string. {{w|Unicode}} is a standard for representing characters from many writing systems, and it has 149,186 characters[https://en.wikipedia.org/wiki/Unicode#Versions] as at the time of this comic (with new characters being added over time). A password consisting of all of those characters would be extremely long; it would be impractical to type by hand, and would be too long for pretty much all account registration systems. (A "codepoint" is the number assigned to a character, and {{w|UTF-8}} is a common encoding system for representing each Unicode codepoint as a sequence of {{w|byte}}s.) Also, since Unicode includes the null character, the password would have the same issue as Cueball's password. Further, if the account registration system treats the null character as a string terminator (as in C), then the password would be equivalent to an empty password (assuming it contains the Unicode codepoints in order, starting with the null character).<br />
<br />
==Trivia==<br />
<br />
* User input containing unsafe characters has previously appeared in the famous comic [[327: Exploits of a Mom]].<br />
<br />
* Here are some additional situations where passwords with special characters might stop working:<br />
** The registration form allows passwords to contain null characters, but the login form strips null characters (for example because it was written by a different developer/team, or because it has been updated over time). When Cueball tries to log in, the login form strips the null characters, so the resulting password can ''never'' match such a stored password (which contains a null character).<br />
** The password system allows the input of Unicode characters at first, but is later changed to only accept ASCII passwords. Users who included non-ASCII characters like é or ö in their password are locked out of their account because they are no longer allowed to transmit those characters.<br />
<br />
* There are several techniques that can be used to safely handle passwords and other user inputs that might contain unsafe characters such as the null character:<br />
** Validate: Check whether the user input contains unsafe characters, and if it does display an error message to the user.<br />
** Sanitize: Remove unsafe characters from the user input to prevent them from causing problems.<br />
** Encode/quote/escape: Replace each unsafe character with an appropriate sequence of characters (depending on the context). For example, a null character can be included in a {{w|URL}} by encoding it as <code>%00</code>. This technique is not very relevant to password handling, but is relevant for example when {{w|Cross-site_scripting#Non-persistent_(reflected)|including user input in generated web pages}} or [https://www.cloudflare.com/learning/security/threats/sql-injection/ passing user inputs to database queries].<br />
** For the specific case of null characters: Use a string representation that supports null characters (e.g. Pascal strings), and be very careful not to pass such strings to functions that can't handle embedded null characters.<br />
<br />
* Failure to handle strings containing null characters correctly can result in security vulnerabilities. For example, including a null character in crafted input may allow a user to read or write files that they are not supposed to be able to access.[https://insecure.org/news/P55-07.txt][https://elixirforum.com/t/static-and-session-security-fixes-for-plug/3913]<br />
<br />
* In C, a string is usually stored in a block of memory that is allocated to have a known size. The maximum size of string that can be stored in such a buffer is one character less than the buffer's size, since the last character is used for the null terminator. Language functions that operate on strings, such as those that return the length of a specified string or which compare two strings, look for the terminator as a marker. However, there is a risk in using this feature: if that terminator is somehow overwritten by some other value, a function which assumes that there is still a stopping point may go far beyond the intended region of memory before it happens to find an unrelated terminator or otherwise is forced to stop looking. This can have serious security implications, as well as the potential for bugs and crashes. Instead, safe programming uses versions of the string functions that include a specification of the maximum allowed length. For example, the <code>strlen()</code> function takes a pointer to a string, counts the number of characters until it encounters a null terminator, and returns that number: the length of the string not including the terminator. The <code>str'''n'''len()</code> function takes a pointer to a string and a maximum length, and counts characters until it either finds a terminator or reaches the maximum.<br />
<br />
* The number of the xkcd comic is 2700. When interpreting this as two concatenated octal numbers \27 + \00 it represents both the {{w|End-of-Transmission-Block_character|ETB}} as well as the null character, both of these characters possibly leading to problems when processed in legacy systems (e.g. mainframe computers). When interpreting 2700 as hexadecimal 0x27 + 0x00 numbers it represents the ' character and the null character - a sequence that could lead to [[327: Exploits of a Mom|SQL injection]] when it is placed in unescaped form inside of a SQL command.<br />
<br />
==Transcript==<br />
:[Cueball carries an open laptop over to Ponytail, holding in in both hands. The screen shows a box filling the screen with some text on lines. Ponytail is sitting in an office chair with her laptop at her desk. She has turned her head away from the computer looking at Cueball's screen.]<br />
:Cueball: Can you help me with my account?<br />
:Ponytail: Oh no.<br />
<br />
:[Cueball holds his laptop up in front of Ponytail who has turned the chair so she faces him, with her hands in her lap. Her table is not drawn.]<br />
:Cueball: No no, I promise it's a normal problem this time.<br />
:Ponytail: Okay. Fine. What is it?<br />
<br />
:[Cueball holds both hands out palm up towards Ponytail who is sitting with his laptop in her lap typing on it.]<br />
:Cueball: I included a null string terminator as part of my password, and now I can't-<br />
:Ponytail: '''''How?!'''''<br />
:Cueball: They said to use special characters!<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Comics featuring Ponytail]]<br />
[[Category:Cueball Computer Problems]]</div>172.70.86.12https://www.explainxkcd.com/wiki/index.php?title=Talk:978:_Citogenesis&diff=299422Talk:978: Citogenesis2022-11-19T14:04:50Z<p>172.70.86.12: </p>
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<div>Bonus points if the editor citing the work is also the person who created the fake source!'''[[User:Davidy22|<span title="I want you."><u><font color="purple" size="2px">David</font><font color="green" size="3px">y</font></u><sup><font color="indigo" size="1px">22</font></sup></span>]]'''[[User talk:Davidy22|<tt>[talk]</tt>]] 06:59, 2 February 2013 (UTC)<br />
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The title text is not addressed in the explanation. I've read some popular science books, but they do not seem to suffer the problem cited there. Maybe there's a particular brand of pop science that is very susceptible to that sort of problem? --[[User:Quicksilver|Quicksilver]] ([[User talk:Quicksilver|talk]]) 17:48, 17 August 2013 (UTC)<br />
:We probably never will know, but as the comic itself says: Google is your friend! I found a nice story at the [http://forums.xkcd.com/viewtopic.php?t=76475 xkcd forum] belonging to the German minister {{w|Karl-Theodor zu Guttenberg}}. I have added this to the trivia section.--[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 12:00, 18 August 2013 (UTC)<br />
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On a more amusing note, it is impossible to actually verify half of the obscure references on Wikipedia, as they are often magazines or books unlikely to be kept by typical libraries. One could easily fake an obscure reference if you know of a book with a title that seemingly pertains to the subject matter, but you know that the book had a printing run of less then 10,000 copies.<br />
[[Special:Contributions/108.162.215.63|108.162.215.63]] 18:09, 14 May 2014 (UTC)<br />
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Note however, that this would only work if the information is so obscure that there are no conflicting sources.<br />
[[User:Benjaminikuta|Benjaminikuta]] ([[User talk:Benjaminikuta|talk]]) 21:26, 10 February 2017 (UTC)<br />
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On a less amusing note it costs 30 dollars/pounds/euros to get a copy of a scientific article that may or may not be useful for journalists that may or may not have free access to said data. Or you could get a pirated copy of it from a suicidal source and have the FBI come after you instead.[[User:Weatherlawyer| I used Google News BEFORE it was clickbait]] ([[User talk:Weatherlawyer|talk]]) 13:24, 22 January 2015 (UTC)<br />
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This article doesn't actually explain the self-sustaining cycle that is the point of the article. It references citogenesis and where the word was derived, and references wikipedia. None of that explains the "fake article" -> "news writer references article" -> "wiki editor adds citation of news writer" -> "fake article referenced in other news". [[User:Cflare|Cflare]] ([[User talk:Cflare|talk]]) 18:56, 9 September 2014 (UTC)<br />
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Actually in the comic, citogenesis looks very similar to cyclogenesis.[[User:Weatherlawyer| I used Google News BEFORE it was clickbait]] ([[User talk:Weatherlawyer|talk]]) 13:24, 22 January 2015 (UTC)<br />
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What happened to the "portmanteau" in paragraph 2? [[User:SilverMagpie|SilverMagpie]] ([[User talk:SilverMagpie|talk]]) 22:41, 3 January 2017 (UTC)<br />
:Never mind, I fixed it. [[User:SilverMagpie|SilverMagpie]] ([[User talk:SilverMagpie|talk]]) 22:42, 3 January 2017 (UTC)<br />
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I'm curious if the doubled "was" in the first panel was an intentional "easter egg" of the kind of carelessness that may be typical of somebody vandalizing Wikipedia with fake information, or if it was unintentional on Randall's part. Perhaps we'll never know. [[Special:Contributions/172.69.63.123|172.69.63.123]] 19:47, 12 October 2020 (UTC)<br />
:I had that exact same thought when I read it. I believe it's highly possile it was intended. [[User:The Cat Lady|-- The Cat Lady]] ([[User talk:The Cat Lady|talk]]) 21:56, 23 August 2021 (UTC)<br />
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An example I once encountered of a much sloppier attempt at citogenesis: the article for a small, unincorporated community, near where I grew up claimed that [place] "is home to the art of cheddar winking." It cited a book that did not exist, whose ISBN number was for the Book of Mormon. [[Special:Contributions/172.69.48.150|172.69.48.150]] 13:40, 26 February 2021 (UTC)<br />
: Another, slightly more prominent example was that a German politician [https://en.wikipedia.org/wiki/Karl-Theodor_zu_Guttenberg Karl-Theodor zu Guttenberg] who carries 10 given names. An unknown editor managed to slip an 11th given name into the list: Wilhelm. At first it was reverted, because there was no source. The unknown editor reverted it back. A slightly careful writer checked Wikipedia just in time to see the "Wilhelm" and took it at face value. Many other careless writers followed, some even claimed that Guttenberg would give his full name in interviews and include Wilhelm in the list (obviously those interviews never happened and were just fabricted). Which in turn then was used as a reference ("Google is your friend, people!") for the Wikipedia article. Took some time to get the false name out of the article. [[Special:Contributions/162.158.203.15|162.158.203.15]] 10:11, 4 June 2021 (UTC)<br />
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[https://www.bbc.co.uk/news/the-reporters-63622746 Related and interesting]... [[Special:Contributions/172.70.86.12|172.70.86.12]] 14:04, 19 November 2022 (UTC)</div>172.70.86.12https://www.explainxkcd.com/wiki/index.php?title=File_talk:BlackHat_head.png&diff=298964File talk:BlackHat head.png2022-11-17T21:00:09Z<p>172.70.86.12: Undo revision 298932 by While False (talk)</p>
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<div>Sorry if he looks stretched -- MediaWiki bug with the cache. It should fix itself in a while. [[User:Alpha|Alpha]] ([[User talk:Alpha|talk]]) 00:57, 7 March 2013 (UTC)</div>172.70.86.12https://www.explainxkcd.com/wiki/index.php?title=2697:_Y2K_and_2038&diff=2986312697: Y2K and 20382022-11-12T13:40:32Z<p>172.70.86.12: /* Explanation */ Those who fail to learn from Computer History are doomed to repeat it (or at least resit the exams).</p>
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<div>{{comic<br />
| number = 2697<br />
| date = November 11, 2022<br />
| title = Y2K and 2038<br />
| image = y2k_and_2038_2x.png<br />
| imagesize = 527x190px<br />
| noexpand = true<br />
| titletext = It's taken me 20 years, but I've finally finished rebuilding all my software to use 33-bit signed ints.<br />
}}<br />
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==Explanation==<br />
{{incomplete|Created by a Y2K-BRICKED BOT (MADE JAN 1, 1970). Do NOT delete this tag too soon.}}<br />
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[[File:Year 2038 problem.gif|thumb|An animation of the 2038 bug in action. The {{w|integer overflow}} error occurs at 03:14:08 UTC on 19 January 2038.]]<br />
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The Y2K bug, or more formally, the {{w|year 2000 problem}}, was the computer errors caused by two digit software representations of calendar years incorrectly handling the year 2000, such as by treating it as 1900 or 19100. The {{w|year 2038 problem}} is a similar issue with timestamps in {{w|Unix time}} format, which will overflow their {{w|Signed number representations|signed}} 32-bit binary representation on January 19, 2038.<br />
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While initial estimates were that the Y2K problem would require about half a trillion dollars to address, there was widespread recognition of its potential severity several years in advance. Concerted efforts among organizations including computer and software manufacturers and their corporate and government users reflected unprecedented cooperation, testing, and enhancement of affected systems costing substantially less than the early estimates. On New Year's Day 2000, few major errors actually occurred. Those that did usually did not disrupt essential processes or cause serious problems, and the few of them that did were usually addressed in days to weeks. The software code reviews involved allowed correcting other errors and providing various enhancements which often made up at least in part for the the cost of correcting the date bug.<br />
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It is unclear whether the 2038 problem will be addressed as effectively in time, but documented experience with the Y2K bug and increased software modularity and access to source code has allowed many otherwise vulnerable systems to already upgrade to wider timestamp and date formats, so there is reason to believe that it may be even less consequential and expensive. The 2038 problem has been previously mentioned in [[607: 2038]] and [[887: Future Timeline]].<br />
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This comic assumes that the 38 years between Y2K and Y2038 should (or must) be split evenly between recovering from Y2K and preparing for Y2038. That would put the split point in 2019 (specifically, January 10, 2019). The caption points out that it's now (2022) well past that demarcation line, so everyone should have completed their "Y2K recovery" and begun preparing for Y2038. It is highly unlikely that there are more than a very few consequential older systems that still suffer from this bug, while systems built to operate only since the millenium can already handle years after 1999 correctly, though not ''necessarily'' those after 2099, 2255 or some other notable problematic date. There's also no reason any developer should have waited until 2019 to start preparing for 2038.<br />
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The title text refers to replacing the 32-bit signed Unix time format with a hypothetical new 33-bit signed {{w|Integer (computer science)|integer}} time and date format, which is very unlikely as almost all contemporary computer data structure formats are allocated no more finely than in 8-bit bytes. Taking 20 years to develop and implement such a format is not entirely counterproductive, as it would add another 68 years of capability, but it is far more counterproductive than upgrading to the widely available and supported 64-bit Unix time replacement format and software compatibility libraries.<br />
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==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
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[A timeline rectangle with 37 short dividing lines between the two ends, defining it into 38 minor sections, with the label "2000" above, associated with the leftmost edge, "2038" associated with the rightmost edge and "2019" directly over the centermost division that starts the section which covers that year, which is also extended to form a dotted line divided the whole height of the timeline into two equal 19-section halves. The left half has the label "Recovering from the Y2K bug" and the right half is labeled "Preparing for the 2038 bug". A triangular arrowhead labeled "Now" is also above indicating a rough position most of the way through the section that would represent the year 2022.]<br />
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[Caption:] Reminder: By now you should have finished your Y2K recovery and be several years into 2038 preparation.<br />
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{{comic discussion}}<br />
[[Category:Calendar]]<br />
[[Category:Computers]]<br />
[[Category:Programming]]<br />
[[Category:Timelines]]</div>172.70.86.12https://www.explainxkcd.com/wiki/index.php?title=Talk:2180:_Spreadsheets&diff=298629Talk:2180: Spreadsheets2022-11-12T13:23:50Z<p>172.70.86.12: </p>
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<div><!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--><br />
I really hope Randall shares this formula he made. It sounds incredible. [[Special:Contributions/162.158.126.34|162.158.126.34]] 21:15, 24 July 2019 (UTC)<br />
: Seems to me to perhaps be a bit of nerdsniping (a la XKCD 356) bait...<br />
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My unofficial job title is the Head of the Department for Extreme Spreadsheeting. There are multiple reasons for this, including that we need to share info easily across different offices, I'm very familiar with spreadsheet formulas, and I have no f***ing clue how to get a SQL database functioning properly. [[User:Misterblu28|Misterblu28]] ([[User talk:Misterblu28|talk]]) 21:48, 24 July 2019 (UTC)misterblue28<br />
: It involves chickens, black candles, a full moon, and one of those fancy space-age pens that can write on any surface.<br />
:: I think that traditionally, one only needs the blood of the chicken unless you're making a chicken salad sandwich for afterwards. [[User:Mootstrap|Mootstrap]] ([[User talk:Mootstrap|talk]]) 12:05, 26 July 2019 (UTC)<br />
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The "devil" is clearly a reference to the FreeBSD daemon mascot. [[Special:Contributions/172.68.38.64|172.68.38.64]] 04:42, 25 July 2019 (UTC)<br />
: The devil is clearly a devil.[[Special:Contributions/141.101.98.148|141.101.98.148]] 08:48, 25 July 2019 (UTC)<br />
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The devil is clearly the strong one for everyone working in my company. A list used by ~50 people, 3 times a day? lets just put an excel sheet on sharepoint.... A complex design tool? Give me 2 days and a lot of hidden sheets in the back of the file and do it in excel - everything is excel. --[[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 06:04, 25 July 2019 (UTC)<br />
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Anybody remember Oracle’s SQL*Calc spreadsheet application? Individual cells could not only contain select queries but also insert, update, and delete, all using variable data from the spreadsheet. So you could select data from tables into a multidimensional array of cells in s spreadsheet, manipulate the data in the cells, then insert in back into the same (or different!) tables. Powerful but dangerous![[Special:Contributions/172.68.46.167|172.68.46.167]] 06:15, 25 July 2019 (UTC)<br />
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Remember all the TV Tropes links? We could totally put “Good Angel, Bad Angel” here. [[Special:Contributions/172.68.141.148|172.68.141.148]] 10:41, 25 July 2019 (UTC)<br />
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I refuse to accept this as complete until somebody can get the original script out of Randall or somebody here manages to make something that does the same job, or better.<br />
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Here's a start to the formula; it doesn't use REGEXMATCH() however. Uses a named range 'DatesList' which has the list of dates. Generates a calendar with Sunday in the first column where the only dates showing are those in the list -- wasn't sure what sort of output to target. =ARRAYFORMULA(IF(ISERROR(MATCH(ARRAYFORMULA(SEQUENCE((MAX(DatesList)-MIN(DatesList)-WEEKDAY(MIN(DatesList))+1)/7+1,7,MIN(DatesList)-WEEKDAY(MIN(DatesList)),1)),DatesList,0)),"",ARRAYFORMULA(SEQUENCE((MAX(DatesList)-MIN(DatesList)-WEEKDAY(MIN(DatesList))+1)/7+1,7,MIN(DatesList)-WEEKDAY(MIN(DatesList)),1))))<br />
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Relevant other comics about Excel (from a developer's perspective): http://www.commitstrip.com/en/2014/07/23/excel-the-poor-mans-ideexcel-lide-du-pauvre/ and /2014/12/19/the-coder-and-the-beast/ [[Special:Contributions/108.162.229.136|108.162.229.136]] 19:57, 25 July 2019 (UTC)<br />
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My goto functions tend to be LOOKUP() (or HLOOOKUP() and VLOOKUP() for various subtelties like matching unsorted arrays), LEFT(), RIGHT(), MIDDLE(), COUNTA(), COUNTIF() (especially for range A$1:A''current_or_preceding_row_number_for_this_cell'' to establish "this is the ''n''th example of some quality in this column", usually for firstness), FIND(), ISERR(), ISNUMBER(), SUBSTITUTE(), and of course loads and loads of IF()s, ...usually heavily nested. And at least these days Open/LibreOffice accept comma seperation of function params, 'cos forgwtting I'm not in Excel and not using semicolons in such a scratch-built monstrosity leading to an error that ''wasn't'' bad logic or nesting was a bummer, until I realised... [[Special:Contributions/141.101.98.148|141.101.98.148]] 20:56, 25 July 2019 (UTC)<br />
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I was hoping the explanation would say what those named functions do, LOL! Never used Google Sheets. But I've used the hell out of Excel. Can't imagine how a single cell could display a calendar, but I've often done a quick on-the-fly calendar where each cell is a day... Usually to check what weekdays certain days are. Like "What weekday was I born?". Often I designate one cell as a starting date, the first row uses the WEEKDAY function to check "Is that this weekday, an earlier weekday or a later weekday?". A later weekday, leave it blank. An earlier weekday, take yesterday and add one. This weekday, show it. Then Week 2, Sunday is Saturday + 1, Monday is Sunday + 1, etc. Copy / Paste to finish the week, Copy / Paste the week to finish the calendar. I change the cell formatting to show only the Day of the date, but each cell stores an entire date. And the 8th column shows the month every time the month changes (usually a VLOOKUP on a reference table I make with Fill Series). I can then just change the master cell to change what date range the calendar shows. I might use Excel the most for mass renaming files though. :) [[User:NiceGuy1|NiceGuy1]] ([[User talk:NiceGuy1|talk]]) 04:24, 26 July 2019 (UTC)<br />
::excel to rename files? How very Rube Goldberg. Windows still includes shell batch commands (.bat files) for that kind of functionality.[[Special:Contributions/162.158.246.82|162.158.246.82]] 14:44, 27 July 2019 (UTC)<br />
:::Yes, I use Excel to make the contents of the batch file, a list of REN commands instead of typing them individually, then copy and paste to a Notepad file, save it as "Go.bat", then type Go in a DOS command window. :) I use Excel to construct all the individual filenames, then compile the old names with the new names into "ren [old name] [new name]". If there's more than like 5 files, programming the Excel is faster and less work than naming each file individually. [[User:NiceGuy1|NiceGuy1]] ([[User talk:NiceGuy1|talk]]) 06:43, 12 November 2022 (UTC)<br />
::::"Go.bat"? How uninformative! – I, on the other hand tend to use "do.bat" for all my "preautomate a single task" needs... Much more descriptive, I'm sure everyone will agree. ;)<br />
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Something about the display is bugged out. [[Special:Contributions/162.158.107.67|162.158.107.67]] 05:43, 26 July 2019 (UTC)<br />
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QUERY() is overrated. FILTER() is more advanced and usable in other formulas.<br />
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I find this comic to be an accurate reflection of part of my job. I am the IT guy for our company. Which means that I'm also in charge of taking the basic reports that came with our point of sale program and editing the data into reports that are custom designed to answer the question that the manager asks. And the question is often different every day. So dropping the 10 page report into a spreadsheet to massage the data into 5 lines of 'boss answer' makes sense. But sometimes the question is a repeat. And after the 10th time the manager asked the question, I added a procedure into the database. So now every time I get a 'boss question', I have to decide if I'm going to make a procedure for it or a spreadsheet. The comic gets amusingly ridiculous for me on the 3rd panel, because running a query in the spreadsheet has pushed the complexity of my work up to the point where it's just as easy to make the procedure in the database. [[Special:Contributions/172.68.90.76|172.68.90.76]] 19:45, 29 July 2019 (UTC)SiliconWolf<br />
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For days after this comic was uploaded I was afraid to visit explain-xkcd as I was certain that the formula mentioned in the title text would be recreated already. Call me nerd-sniped, but I could not resist giving it a try. So here it is: https://docs.google.com/spreadsheets/d/1Q5GOo6x49HkyDsDGmr61za4S5GWCuXQkd-tX9zN4Zwo/edit?usp=sharing The calendar generates entirely from cell D4. Only input is start date in A1 and end date in A2. I don't know if Randall seriously developed the formula he described, but mine differs somewhat from his description. It does make heavy use of SEQUENCE, but uses only one ARRAYFORMULA (why would you double-nest it anyway?) and does not use REGEXMATCH as I could not find any use for it. Of course, there's also a hodgepodge of functions SWITCH, IF, some operators and a bunch of functions related to date calculations. It freezes the browser for some 15 seconds just as Randall promised. Output is a calendar displaying all the months from start to end date, containing name of the month, year, weekdays and every individual day. Feel free to copy the formula from D4 into your own Google Sheets spreadsheet and add any dates you like in cells A1 and A2 (they must be in those two cells in your sheet, too) using the function =DATE(yyyy,mm,dd). For me it works easily even for dates decades apart. If you see a random N/A error in one or two cells (though I haven't spotted any), let me know, it's easily correctable. If you see a REF error, you probably inserted dates decades apart, in which case you just need to hold on and Google will add more rows automatically. Be patient with it. [[User:Ipez|Ipez]] ([[User talk:Ipez|talk]]) 15:03, 3 August 2019 (UTC)</div>172.70.86.12https://www.explainxkcd.com/wiki/index.php?title=Talk:2696:_Precision_vs_Accuracy&diff=298496Talk:2696: Precision vs Accuracy2022-11-09T22:19:29Z<p>172.70.86.12: </p>
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<div><!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--><br />
87.532% of all statistics are just made up. [[Special:Contributions/172.70.178.220|172.70.178.220]] 11:10, 9 November 2022 (UTC)<br />
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Why is 'Barack Obama is 6'1"' and 'Barack Obama has 4 legs' medium precision? It seems to give exact value, so high precision. [[User:Tkopec|Tkopec]] ([[User talk:Tkopec|talk]]) 11:44, 9 November 2022 (UTC)<br />
: OK, I get it. 6'1" means something between 6'0.50" and 6'1.49". For height it's OK, but when counting legs, it seems like a stretch. [[User:Tkopec|Tkopec]] ([[User talk:Tkopec|talk]]) 12:30, 9 November 2022 (UTC)<br />
:: The four legs are probably considered to be only medium precise, not because of the number but because of the imprecise term "leg". While humans can walk on all four extremities, thereby using them as legs, the upper two are commonly referred to as arms. [[User:Bischoff|Bischoff]] ([[User talk:Bischoff|talk]]) 14:54, 9 November 2022 (UTC)<br />
:: (ECed by Bischoff) Plus a person's height (excluding differences to footwear and perhaps hairstyle) varies by an inch or so over the course of a day, as the spine compresses whilst mostly upright (would depend a bit upon your daily activities, but "an inch" or 2-3cm is the typical quoted value, with all the questions about precision ''as well as'' accuracy). Within an inch of such a foot-and-inch value is basically between slightly over a percentage point of drift across a continuum of ultimately non-integer values.<br />
:: The number of legs is ''generally'' a whole number (perhaps lower-limb amputees could claim "half a leg", but is that for above the knee or below or... that's beyond my wish to define, I would leave it up to the individual amputee to finesse to their own liking) and assigning decimals, even .000(recurring), would be ''over-''precise. A definite plain figure (however inaccurate) being the happy and acceptable medium between that and the vague imprecision (never mind inaccuracy) of the kind in the cell below. [[Special:Contributions/172.71.178.137|172.71.178.137]] 15:00, 9 November 2022 (UTC)<br />
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Someone should add an explanation of the difference between precision and accuracy. [[User:Nutster|Nutster]] ([[User talk:Nutster|talk]]) 13:13, 9 November 2022 (UTC)<br />
:Tried it myself. Maybe made it too compact, but I often go on too long so I tried made it as brief and snappy as I felt I could. Over to other editors to rewrite or replace. [[Special:Contributions/172.71.178.137|172.71.178.137]] 15:00, 9 November 2022 (UTC)<br />
::That there is confusion over this was a bit of a surprise to me, about 20 years ago, when I worked (as I did for many years) in the outdoor pursuits trade. GPS units would give a 12-character grid reference (1m<sup>2</sup>), but couldn't be relied upon to that level. I would tell people they're more precise than they are accurate, until it became apparent that they were waiting for me to complete the joke they thought I'd begun, as I was so clearly contradicting myself, what with the two words meaning identical things. {{unsigned|Yorkshire Pudding|20:18, 9 November 2022}}<br />
:::I deal with OS Grid References a lot, in a similar context, and a number of people who give 10-digits or more (2x5, for 1m res) from devices that typically don't ever settle down to less than 3m, and provably can be tens of metres off if there happens to be a small tree or shrub nearby.<br />
:::(In fact, the other day I was geohashing myself, and my device was insisting I was in a totally different bit of the open field, 50m or so, no matter how much I sat it down at the provably correct point and wandered away so that even ''I'' wasn't obscuring its view of the sky. But it was good enough for me, which was all I do it for, so after giving it 5 minutes I counted it as done.)<br />
:::And, in yet another activity, the publicised information for an event included a 12ish-DP reference for the starting area (vaguer than that), but just the ''postcode'' for the HQ (a very definite building that you could bullseye on a map), in a rural area where it covered half the valley! [[Special:Contributions/172.70.86.12|172.70.86.12]] 22:19, 9 November 2022 (UTC)<br />
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::Having gone on to explain the difference between the words, the neat brevity I'd sought was lost. <br />
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::Obviously they can be used sort of interchangeably in casual conversation, but I thought the difference was well enough known that, when talking about a navigational instrument, it would be obvious what was meant.<br />
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::Nope.<br />
[[User:Yorkshire Pudding|Yorkshire Pudding]] ([[User talk:Yorkshire Pudding|talk]]) 20:18, 9 November 2022 (UTC)<br />
How is 17.082 palindromic? [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 14:54, 9 November 2022 (UTC)<br />
:My error, I meant an anagram! (Was going for "anagramic", and my brain clearly rebelled.) [[Special:Contributions/172.71.178.137|172.71.178.137]] 15:00, 9 November 2022 (UTC)<br />
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High Precision High accuracy, Randal Munroe misses when Obama was president. Low precision Medium-rare accuracy, so do we, Randal, so do we.</div>172.70.86.12https://www.explainxkcd.com/wiki/index.php?title=2696:_Precision_vs_Accuracy&diff=2984892696: Precision vs Accuracy2022-11-09T19:05:49Z<p>172.70.86.12: /* Explanation */ Better grammar, better formatting. (?)</p>
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<div>{{comic<br />
| number = 2696<br />
| date = November 9, 2022<br />
| title = Precision vs Accuracy<br />
| image = precision_vs_accuracy_2x.png<br />
| imagesize = 501x462px<br />
| noexpand = true<br />
| titletext = 'Barack Obama is much less likely than the average cat to jump in and out of cardboard boxes for fun' is low precision, but I'm not sure about the accuracy.<br />
}}<br />
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==Explanation==<br />
{{incomplete|Created by BARACK OBAMA IN A CARDBOARD BOX. Further detail, sortable table? - Please change this comment when editing this page. Do NOT delete this tag too soon.}}<br />
This comic parodies the difference between 'accuracy' and 'precision' with a table. {{w|Accuracy and precision}} are common concepts to be encountered in the scientific field and often students have issues with the differences between them. Accuracy concerns whether a statement is true, while precision concerns how detailed it is; it is possible for a statement to be one but not the other. The comic explores this concept by comparing {{w|Barack Obama}}, former President of the United States, with {{w|cat}}s. Confusingly, he measures different statistics of both Barack Obama and cats (sometimes measuring them in terms of cats) leaving the unwary reader just as confused as before.<br />
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Being precise is typical of calculations that roll out an excess of significant digits, often in the form of trailing decimals. Precision is lowered by using more rounded figures, or merely being comparative, but largely unaffected by whether the original values used were accurate or even correct. Accuracy is a cumulative function of the accuracy given to the intermediate values used for any calculation, and can be degraded by using figures that are themselves in some way inaccurate or imprecise. One part of confusion between the two is because being too precise usually decreases accuracy.<br />
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The numbers mentioned in the top row (high precision) of the table all use exactly the same digits, dictating that a full five digits of ''precision'' are used in them all. The most "valid" or correct value is a number that's very accurate and precise (see table). For the medium accuracy the number is an anagram of the 1st entry, giving a value that is reasonable but would be overly exact, whilst the low accuracy number is just a repeat of the first entry's digits with a shifted decimal but clearly at the wrong scale. For the latter, he replaces the thousands separator with the decimal point, perhaps as a visual pun.<br />
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The title text compares Obama's and cats' enjoyment of playing with cardboard boxes. While cats are known to do this,{{citation needed}} we don't know whether Obama does.<br />
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The day prior to the publication of this comic (November 8, 2022) was election day in the United States, so Randall may have been remembering Barack Obama's presidency at this time.<br />
<br />
{| class="wikitable"<br />
!Precision<br />
!Accuracy<br />
!Statement<br />
!Explanation<br />
|-<br />
|High<br />
|High<br />
|Barack Obama was president for 70,128 hours<br />
|This is the official length in hours of {{w|Barack Obama}}'s 8-year presidency, including 2 {{w|leap year|leap days}}. Obama served from January 20, 2009 through January 20, 2017, and his term officially began and ended at noon on those days. (There were three {{w|leap second|leap seconds}} during his presidency, though.)<br />
|-<br />
|High<br />
|Medium<br />
|Barack Obama weighs as much as 17.082 cats<br />
|The accuracy would depend on the mass of the cats in question. Also a human's mass can vary by a few pounds in a small amount of time as meals are consumed, resources are used in metabolism and wastes are eliminated, and thus this may be overly precise due the margin of error in both the mass of cats and the mass of Mr. Obama. In 2016, Obama was [https://www.cnn.com/2016/03/08/politics/obama-medical-exam-loses-weight officially reported] to weigh 175 lb (79.3787 kg). [https://www.google.com/search?q=how+heavy+is+an+average+cat Google claims that an average cat weighs between 8.8 and 11 lbs], so this statement may be close to accurate.<br />
|-<br />
|High<br />
|Low<br />
|Barack Obama is 70.128 feet tall<br />
|A highly precise (5 significant digits) measurement, but far from his actual height, published as 6'1".<br />
The given value is more than an order of magnitude different from both him and {{w|Robert Wadlow|almost}} any other known human, whilst one of 7.0128 would ''only'' be about 15% off – still a low accuracy, but not outside the realms of possibility for an otherwise unknown person.<br />
|-<br />
|Medium<br />
|High<br />
|Most cats have 4 legs<br />
|Like many mammals, cats are quadrupeds, which means "four feet". Unless there is a genetic or other developmental issue, or an an injury that causes the loss of a limb, then cats generally have 4 legs.<br />
|-<br />
|Medium<br />
|Medium<br />
|Barack Obama is 6'1"<br />
|While only as precise as the nearest inch, a common degree of rounding in that scale of measurement, that is the former president's published height.<br />
[https://www.cnn.com/2016/03/08/politics/obama-medical-exam-loses-weight In 2016], Obama was said to have "grown" 0.5 inches in height, so there is a definite lack of consistency of exactly how tall he is. The examinations may have been made at different times of their respective days, with some spinal compression occuring all the time not laid in bed, and his current height is also not publically recorded; several years of gradual aging could also reduce his posture slightly, or sustaining his fitness (since experiencing the travailles of office) may counteract this to a greater or lesser effect.<br />
|-<br />
|Medium<br />
|Low<br />
|Barack Obama has 4 legs<br />
|Barack Obama, being a mammal, does qualify as a tetra-pod, but as a primate, his two forelimbs have been modified into arms and hands, and like other humans, he does not generally use them for locomotion, but to manipulate his environment, thus this is highly ''in''accurate.<br />
<br />
|-<br />
|Low<br />
|High<br />
|Most cats have legs<br />
|A true (high accuracy) statement without much information (low precision).<br />
|-<br />
|Low<br />
|Medium<br />
|Barack Obama has fewer legs than your cat<br />
|Again, this will depend on the cat, but in general, true.<br />
|-<br />
|Low<br />
|Low<br />
|Barack Obama's cat has hundreds of legs<br />
|This statement has low accuracy, as Barack Obama owns a four-legged dog named Sunny, but is not known to have owned a cat, much less one with more legs than normal. It also has low precision, as "hundreds" could reasonably range from 200 to 900.<br />
|-<br />
|Low<br />
|Unsure<br />
|Barack Obama is much less likely than the average cat to jump in and out of cardboard boxes for fun<br />
|Barack Obama has never publicly jumped in and out of cardboard boxes for fun,{{citation needed}} but the possibility that he does in private exists.<br />
|}<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
<br />
:[A table with 3 rows and 3 columns]<br />
<br />
{| class="wikitable"<br />
|-<br />
! !! High accuracy !! Medium accuracy !! Low accuracy<br />
|-<br />
! High precision<br />
|Barack Obama was president for 70,128 hours||Barack Obama weighs as much as 17.082 cats||Barack Obama is 70.128 feet tall<br />
|-<br />
! Medium precision<br />
|Most cats have 4 legs||Barack Obama is 6'1"||Barack Obama has 4 legs<br />
|-<br />
! Low precision<br />
|Most cats have legs||Barack Obama has fewer legs than your cat||Barack Obama's cat has hundreds of legs<br />
|}<br />
<br />
{{comic discussion}}<br />
[[Category:Statistics]]<br />
[[Category:Comics featuring real people]]<br />
[[Category:Cats]]</div>172.70.86.12https://www.explainxkcd.com/wiki/index.php?title=Talk:1624:_2016&diff=298228Talk:1624: 20162022-11-05T14:46:54Z<p>172.70.86.12: </p>
<hr />
<div>This guy looks more like white hat, you can see it hanging off one of the bedposts {{unsigned ip|173.245.54.58}}<br />
:True, I have corrected this, mentioned it in explanation and transcript and also made a note in the wiki code so people who do not read the explanation won't change it without learning of their mistake ;-) --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 16:12, 1 January 2016 (UTC)<br />
<br />
Isn't Wonderwall already 20 years old? [[User:Mudri|Mudri]] ([[User talk:Mudri|talk]]) 11:28, 1 January 2016 (UTC)<br />
:Yes it was from 1995 a mistake by Randall. It was probably first big in the US in 1996 though? If the unpluged MTV version was more famous (?) then it was recorded in 1996. Mentioned now in the explanation. And happy new year to all on explain xkcd --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 16:12, 1 January 2016 (UTC)<br />
<br />
I feel old because all of those things mentioned (even the 20-year ones) are so much more recent than my own personal milestones and I know that the unsaid 30-year set, at least, would be even better.<br />
<br />
Let's see, a sample list for 30 years could include, as one per month: The ''Challenger'' disaster; Halley's Comet; Microsoft's IPO; Chernobyl; ''Short Circuit''; Mexico hosts the World Cup; Prince Andrew marries Sarah Ferguson; ''Castle In The Sky'' from Studio Gibhli; Desmond Tutu is a Bishop; Reagan and Gorbachev meet (unsuccessfully) in Reykjavík; Iran-Contra; Rutan Voyager's non-stop non-refuelled circumnavigation of the Earth; and, precise date unknown... The Simpsons created!<br />
<br />
And 40 years has its interesting points: the Cray-1 created; Apple Computers formed; Concorde flies; as does the (shuttle prototype) Enterprise; Vikings 1 and 2 land; Jimmy Carter nominated; Bob Marley killed; the Sex Pistols swear; the first Laser Printer; ''The Selfish Gene''...<br />
<br />
Anyway... Happy New Year, to all. Young ''and'' old. [[Special:Contributions/162.158.152.227|162.158.152.227]] 20:10, 1 January 2016 (UTC)<br />
<br />
Simpsons became it's own show on the 17th December 1989. Prior, it was featured on The Tracey Ulman show. The first Tracey Ulman short aired on April 19th 1987. It may have been CREATED in 1986, however.[[Special:Contributions/162.158.152.119|162.158.152.119]] 01:50, 3 January 2016 (UTC)<br />
<br />
I think Mr. Ford and others would dispute that Cars are only 10 years old. While _I_ may have walked to school (in the snow) (uphill (both ways)), I knew others driving back then. :p [[Special:Contributions/108.162.221.33|108.162.221.33]] 04:41, 3 January 2016 (UTC)<br />
:The Cars may be 40 years old, but even if the FX are lousy by todays standard, "You Might Think" is brilliant as ever. :P [[Special:Contributions/162.158.90.211|162.158.90.211]] 13:02, 6 January 2016 (UTC)<br />
<br />
Oh man, this was a year ago already! Time really is passing quickly. {{unsigned|LuigiBrick}}<br />
<br />
(This comment thanks to the highlighting of a typographical error, in the main page, by another user. A pity I couldn't wait another four years to make this addition...)<br />
The (valid) speculation that Mission: Impossible inspired the wire-dangling entrance is tarnished by it being smashed through the ceiling and otherwise unsubtle. I'd have said it was more inspired by Minority Report, as the first example of a rope-descent intrusion that comes to mind, but that was 2002 (wow... 20 years ago... not actually sure if that feels longer ago or less so, the last couple of years may have done funny things to my sense of time passing... or that might just be me and my own advancing years). No doubt this otherwise fairly standard action-trope existed in the more violent form in plenty of other films from other years ending in a 6, and probably multiple notable instances. (However, the most obvious {{w|You Only Live Twice (film)|James Bond example}}, the earliest I could definitively recall myself, was released in 196'''''7'''''. Darnit.) Still, an interesting idea. 14:46, 5 November 2022 (UTC)</div>172.70.86.12https://www.explainxkcd.com/wiki/index.php?title=Talk:2694:_K%C3%B6nigsberg&diff=298197Talk:2694: Königsberg2022-11-05T05:38:17Z<p>172.70.86.12: </p>
<hr />
<div><!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--><br />
<br />
; Aluminum foil<br />
Why would aluminum foil be valuable? I can see how it would be hard to produce at the time. But how would it be used and why would people of the time see a lot of value in it? [[Special:Contributions/172.71.146.65|172.71.146.65]] 03:42, 5 November 2022 (UTC)<br />
:Good question, but I'm persuaded the novelty and scarcity of metallic aluminium would have made it plenty valuable among those already wealthy enough to recognize what it was. Prussia was wealthy and Königsberg was its largest port city back then, so probably the mayor would have been able. [[Special:Contributions/172.70.206.205|172.70.206.205]] 03:49, 5 November 2022 (UTC)<br />
::Aluminium was very valuable - methods for its extraction from ore didn't exist in any useful form until much later. [[Special:Contributions/172.68.146.80|172.68.146.80]] 03:55, 5 November 2022 (UTC)<br />
::: Would scarcity be enough to make it valuable? Since nobody had this material back then, there wouldn't be any known applications for it. Compared to bringing e.g. a simple pocket calculator, a flashlight, a solar-powered e-book reader, etc. If an alien landed in my house and brought me some weird, shiny material that would be unable to build on earth, I wouldn't be too interested. But if they had some cool gadget or books full of alien information, I would immediately see its value. [[Special:Contributions/172.71.142.88|172.71.142.88]] 04:05, 5 November 2022 (UTC)<br />
:::: At the time, there were few chemists who could have recognized what it was, but the Mayor of Königsberg would plausibly have been able to commission one. It likely would have taken months if not years, though. I guess if you have a time machine such details don't matter. [[Special:Contributions/162.158.166.173|162.158.166.173]] 04:11, 5 November 2022 (UTC)<br />
::::: Bear in mind that platinum was once 'an inferior substance that got in the way of accumulating silver', and cobalt was the stuff that the underground spirits mischievously put in the way of those seeking copper. To different degrees, their attractiveness has increased since those times they were considered less than desirable.<br />
::::: But, for aliminum foil, I suspect it would have been like pineapples in English(/European?) stately circles... Not to be used for anything practical, but shown off (as long as it did not deteriote beyond a certain point), possibly there'd be money to be made in 'hiring it out' to decorate tables at fancy dinners (in carefully handled fragments, after the first few tearing incidents). L<br />
::::: No doubt a natural philosopher or somesuch would give his eyeteeth to analyse the substance, but being so far beyond the ability to recreate (assuming they discovered what they might even need to do) it would take the bankrolling of an extremely rich patron to obtain permanent posession of some without obligation to return it to the social circuit situations. So easily destructed (I wonder if they'd discover thermite a hundred and more years early, before they ran out of potentially finely shredded aluminium?) or at least aesthetically denatured.<br />
:::::I suppose a screwed up ball of foil (carefully glued together internally, of all fragments still reobtainable) could be the end-game for the original roll, and a wonder it could still be (again, taking the "pineapple place" on the tables of the high and mighty, relatively untarnishing as it would be and gingerly some lucky few would be allowed to hold it and marvel at its sharp fragility and metallic lightness.<br />
:::::...or, in another destiny, perhaps it would be given to a master tailor, in order to (try to?) create some sartorial masterpiece for one or other monarch of the age. Not that I'm sure they'd be able to accomplish that properly (limited pre-offcut trials on how to attach it to underfelts/whatever and to somehow exploit its flexibility without exceeding its very low tolerance for shear-force damage). It'd be a story and a half, whatever happened to it! [[Special:Contributions/172.70.86.12|172.70.86.12]] 05:38, 5 November 2022 (UTC)</div>172.70.86.12https://www.explainxkcd.com/wiki/index.php?title=2694:_K%C3%B6nigsberg&diff=2981812694: Königsberg2022-11-05T04:57:00Z<p>172.70.86.12: Readding something that was accidentally squished by Conflict handling (it seems). Or was it a slip of the cursor? Either way, mea culpa.</p>
<hr />
<div>{{comic<br />
| number = 2694<br />
| date = November 4, 2022<br />
| title = Königsberg<br />
| image = konigsberg_2x.png<br />
| imagesize = 448x343px<br />
| noexpand = true<br />
| titletext = At first I thought I would need some gold or something to pay him, but then I realized that it was the 18th century and I could just bring a roll of aluminum foil.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a FOX, TWO CHICKENS, AND THREE BAGS OF GRAIN. Do NOT delete this tag too soon.}}<br />
<br />
[[File:Konigsberg bridges.png|frame|right|{{w|Königsberg}} in Euler's time, showing the river Pregel and its seven bridges]]<br />
<br />
This comic is about the {{w|Seven Bridges of Königsberg}}, a seminal {{w|graph theory}} problem addressed by the famous mathematician {{w|Leonhard Euler}}. A popular pursuit, beforehand, was to attempt to devise a path through the city that would cross each of the seven bridges exactly once, without crossing the river forks any other way. In 1736, Euler proved that there was no actual solution possible. This result is considered to be the first theorem of graph theory and the first proof in the theory of networks[http://www-personal.umich.edu/~mejn/courses/2004/cscs535/review.pdf] — a subject now generally regarded as a branch of {{w|combinatorics}} — and presaged the development of {{w|topology}}. Combinatorial problems of other types had been considered since antiquity. <br />
<br />
[[Cueball]] attempts to cheat on the final exam in his algorithms class by traveling back in time to commission the construction of an eighth bridge before Euler could learn of the problem, granting it a trivial solution that would remove all impetous for any intellectual analysis. With the addition of the eighth bridge, it becomes possible to create a path that crosses each bridge exactly once, starting at the north bank and ending on the eastern island (or vice-versa). He hopes that this would alter his present-day timeline in such a way that the test becomes easier because graph theory might never have been developed. However, there would remain no way to traverse each bridge exactly once and return to your starting point. (In the standard vocabulary of graph theory, the altered graph would have an Euler trail but not an Euler cycle.) Thus, the problem might still have been sufficiently interesting to spark Euler's curiosity. (Adding a ninth bridge connecting the north bank to the east island would render the problem relatively trivial.)<br />
<br />
The title text alludes to the fact that ordinary {{w|aluminum foil}}, which was not commercially available until 1911, would have been a tremendously valuable curiosity in the 18th century, which didn't even have {{w|tin foil}}. Aluminium itself was a highly priced metal before the 1880s, when methods were developed to cheaply refine it. Famously, the {{w|Washington Monument}} was constructed with a tip made of pure aluminum due to its great value and conductive capacity. Aluminum had not even been extracted in its pure form at the time of Euler, and was only known in compounds such as {{w|alum}}, so it would have been rare and exotic indeed.<br />
<br />
{{clear}}<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
:[Cueball, standing next to two men wearing wigs, pointing with a pointer at a map showing the 7 bridges problem, with an extra bridge added in dashed lines]<br />
:Cueball: Lord mayor of Königsberg, I will reward you handsomely if you construct this bridge before my friend Leonhard arrives.<br />
<br />
:[Caption below the panel]<br />
:I tried to use a time machine to cheat on my algorithms final by preventing graph theory from being invented.<br />
<br />
{{comic discussion}}<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Comics featuring real people]]<br />
[[Category:Math]]<br />
[[Category:Programming]]</div>172.70.86.12https://www.explainxkcd.com/wiki/index.php?title=Talk:2693:_Wirecutter_Recommendation&diff=298011Talk:2693: Wirecutter Recommendation2022-11-02T18:42:51Z<p>172.70.86.12: </p>
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<div><!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--><br />
<br />
I'm glad the explanation (as if reading, at least) lept straight into reminding me about the website. I initially read the first panel as Cueball looking for a {{w|Diagonal pliers|specific item}} recomendation... [[Special:Contributions/172.70.86.12|172.70.86.12]] 18:42, 2 November 2022 (UTC)</div>172.70.86.12https://www.explainxkcd.com/wiki/index.php?title=2554:_Gift_Exchange&diff=2225452554: Gift Exchange2021-12-13T15:40:10Z<p>172.70.86.12: /* Explanation */</p>
<hr />
<div>{{comic<br />
| number = 2554<br />
| date = December 13, 2021<br />
| title = Gift Exchange<br />
| image = gift_exchange.png<br />
| titletext = In addition to having all their budgets in a spreadsheet with consistent formatting, they just love expressing preferences on a well-calibrated numerical scale.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a SURVEY - Please rank this comment on a scale of <thunderstruck frowny face> to <maniacally grinny face> when editing this page. Do NOT delete this tag too soon.}}<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
{{comic discussion}}</div>172.70.86.12https://www.explainxkcd.com/wiki/index.php?title=1185:_Ineffective_Sorts&diff=2225241185: Ineffective Sorts2021-12-13T01:53:19Z<p>172.70.86.12: /* Explanation */</p>
<hr />
<div>{{comic<br />
| number = 1185<br />
| date = March 13, 2013<br />
| title = Ineffective Sorts<br />
| image = ineffective_sorts.png<br />
| titletext = StackSort connects to StackOverflow, searches for 'sort a list', and downloads and runs code snippets until the list is sorted.<br />
}}<br />
<br />
==Explanation==<br />
The comic gives examples of four non-functional {{w|sorting algorithm}}s written in {{w|Pseudocode|pseudo}}-{{w|Python (programming language)|Python}}.<br />
<br />
The first sort is an unfinished {{w|merge sort}}. The merge sort works recursively by dividing a list in half and performing a merge sort to each half. After the two halves are sorted, they are merged, taking advantage of the fact that the two halves are now in correct order and thus the merge can be done efficiently. The author of the merge sort in the comic appears to have given up on writing the sorted-merge part of the sort, which is why it's a ''{{Wiktionary|half-hearted}}'' merge sort, but instead concatenates the halves without sorting. In its current state, the sort would divide the list into elements of size one, then recombine them in their original unsorted order, but in nested lists - making the original data more difficult to work with. The author acknowledges this failing with the comment "Ummmmm... Here. Sorry."<br />
<br />
The second sort is an "optimized" variant of {{w|bogosort}}. A standard bogosort works by randomly shuffling the elements in the list until they are sorted. In a comment, the author points out that this variant of bogosort runs in O(n log(n)), whereas standard bogosorts actually have an expected runtime of O(n·n!) but may never finish. This variant of bogosort finishes so much faster because in most cases it does not actually sort the list, instead reporting a fictitious error in the operating system (a "kernel page fault") if the list isn't ordered after shuffling log(n) times. The bogosort is "optimized" because no comparison sort algorithm can possibly do better than O(n log(n)) in the worst case.<br />
<br />
The third sort parodies a programmer explaining a {{w|quicksort}} during a job interview. The quicksort works by choosing an index as a pivot value and sorting all elements less than the pivot before the pivot and all the elements greater than the pivot after the pivot. It then does a quicksort to the section less than the pivot and the section greater than the pivot until the whole list is sorted. The interviewee flounders for a little while, then asks whether they can use the standard libraries to call a quicksort. The joke being, the standard library contains a quicksort, and the programmer would rather rely on that (possibly even pass it off as his own work) than his own example of quicksort. While it's commonly a good idea in real projects, this would surely count as a failure on interview.<br />
<br />
The final sort is just a mess. First it checks to see if the list is sorted, and exits if it is. Then it rotates the list by a random amount 10,000 times (as if cutting a deck of cards) and exits if the list is ever sorted. Next, in desperation, it checks if the list is sorted three times. Finally, realizing that they have no chance of success, the author performs the computer equivalent of a {{tvtropes|RageQuit|Rage Quit}} and attempts to destroy the computer rather than admit defeat. First, the program attempts to schedule a shutdown of the computer in five seconds, then attempts to delete the current directory, then attempts to delete the user's home directory (presumably the grader's files), and finally all the files on the computer. {{w|rm (Unix)|rm}} is a POSIX command; the -r and -f flags mean that the remove command will remove all contents of the specified directories and will not prompt the user beforehand. Under the guise of "{{w|Software portability|portability}}", the program runs the equivalent Windows {{w|rmdir|rd}} command with switches to delete all files from the "C:" drive without prompting. Finally, the program returns a list containing the numbers one through five in order.<br />
<br />
In the title text, {{w|StackOverflow}} ([https://stackoverflow.com/ link]) is a question-and-answer site where programmers can ask and answer questions on programming. The author of this code takes advantage of the hopes that someone on StackOverflow knows what they are doing and has posted code to sort a list... ''and somebody [https://github.com/gkoberger/stacksort/ implemented stacksort]; well, sort of.''<br />
<br />
==Transcript==<br />
:'''Ineffective sorts'''<br />
define HalfheartedMergeSort(list):<br />
if length(list)<2:<br />
return list<br />
pivot=int(length(list)/2)<br />
a=HalfheartedMergeSort(list[:pivot])<br />
b=HalfheartedMergeSort(list[pivot:])<br />
// ummmmm<br />
return [a,b] // Here. Sorry.<br />
<br />
define FastBogoSort(list):<br />
// An optimized BogoSort<br />
// Runs in O(n log n)<br />
for n from 1 to log(length(list)):<br />
shuffle(list):<br />
if isSorted(list):<br />
return list<br />
return "Kernel Page Fault (Error code: 2)"<br />
<br />
define JobInterviewQuicksort(list):<br />
Ok so you choose a pivot<br />
Then divide the list in half<br />
for each half:<br />
check to see if it's sorted<br />
no, wait, it doesn't matter<br />
compare each element to the pivot<br />
the bigger ones go in a new list<br />
the equal ones go into, uh<br />
the second list from before<br />
hang on, let me name the lists<br />
this is list A<br />
the new one is list B<br />
put the big ones into list B<br />
now take the second list<br />
call it list, uh, A2<br />
which one was the pivot in?<br />
scratch all that<br />
it just recursively calls itself<br />
until both lists are empty<br />
right?<br />
not empty, but you know what I mean<br />
am I allowed to use the standard libraries?<br />
<br />
define PanicSort(list):<br />
if isSorted(list):<br />
return list<br />
for n from 1 to 10000:<br />
pivot=random(0,length(list))<br />
list=list[pivot:]+list[:pivot]<br />
if isSorted(list):<br />
return list<br />
if isSorted(list):<br />
return list:<br />
if isSorted(list): //this can't be happening<br />
return list<br />
if isSorted(list): //come on come on<br />
return list<br />
// oh jeez<br />
// i'm gonna be in so much trouble<br />
list=[]<br />
system("shutdown -h +5")<br />
system("rm -rf ./")<br />
system("rm -rf ~/*")<br />
system("rm -rf /")<br />
system("rd /s /q C:\*") //portability<br />
return [1,2,3,4,5]<br />
<br />
== Trivia ==<br />
<br />
* [https://xkcd.com/about/ xkcd's ''about'' section] has an FAQ about sorting algorithms. It mentions both quicksort and job interviews.<br />
<br />
{{comic discussion}}<br />
[[Category:Programming]]</div>172.70.86.12https://www.explainxkcd.com/wiki/index.php?title=Talk:2552:_The_Last_Molecule&diff=222329Talk:2552: The Last Molecule2021-12-09T16:02:42Z<p>172.70.86.12: </p>
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<div><!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--><br />
<br />
Unsuccessfully tried to search for a match to the image of the chemical compound. Did find this, which is difficult to use on a cellphone: OSRA: Optical Structure Recognition: https://cactus.nci.nih.gov/cgi-bin/osra/index.cgi [[Special:Contributions/172.70.211.172|172.70.211.172]] 07:43, 9 December 2021 (UTC)<br />
:I've tried to search for SMILES of the molecule, but also got nothing: https://pubchem.ncbi.nlm.nih.gov/#query=C1(C2CC(CCC)C(CC)C2(CCCC))C%3DCC(C(%3DCCC(%3DC)CC)C(C)C)%3DC1 [[Special:Contributions/162.158.222.137|162.158.222.137]]<br />
<br />
I truly don't understand the God part of the current explanation. [[Special:Contributions/172.68.110.121|172.68.110.121]] 07:55, 9 December 2021 (UTC)<br />
:There is an article at [https://www.smithsonianmag.com/smart-news/humans-make-110000th-earths-biomass-180969141/ Smithonian Magazine] that sums it up quite nicely: Of the 550 gigatons of biomass carbon on Earth, animals make up about 2 gigatons, with insects comprising half of that and fish taking up another 0.7 gigatons. Everything else, including mammals, birds, nematodes and mollusks are roughly 0.3 gigatons, with humans weighing in at 0.06 gigatons.<br />
::About half of all known living species on earth are insects. Therefore if there was a god who created all life, it would be reasonable to assume he likes them. [[User:Bischoff|Bischoff]] ([[User talk:Bischoff|talk]]) 08:26, 9 December 2021 (UTC)<br />
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Chemistry. I love chemistry :-) There is a concept called "Chemical Space" that I learned about in school. https://en.wikipedia.org/wiki/Chemical_space may help, in short: Chemical space is a huge but finite space of all possible atom arrangements in molecules. [[Special:Contributions/162.158.91.106|162.158.91.106]] 07:59, 9 December 2021 (UTC)<br />
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I've heard the claim, that we know less about our own ocean floor than we do about the surface of Mars several times before. Is there actually a credible source for this and how do we even quantify how much we know about either area? [[User:Bischoff|Bischoff]] ([[User talk:Bischoff|talk]]) 08:26, 9 December 2021 (UTC)<br />
:This essay might shed some light on the question. [[https://www.scientificamerican.com/article/just-how-little-do-we-know-about-the-ocean-floor/ Just How Little Do We Know about the Ocean Floor?]] From a geographical perspective, our maps of the ocean floor are much less detailed than those covering Mars. (5km resolution for ocean floor, 100m resolution for Mars - radar doesn't work underwater). [[Special:Contributions/162.158.107.18|162.158.107.18]] 09:25, 9 December 2021 (UTC)<br />
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The current explanation says that there are an infinite number of chemicals. Is that true? Source? Explanation how that is possible? <br />
Obviously the number of possible molecules is huge, but is it actually a literal, mathematical infinite? Given a finite observable universe, with presumably a finite number of atoms in it. There appear to be a finite number of elements which are stable for any appreciable amount of time and capable of forming molecules.<br />
It seems like there might be practical limitations to the size of a molecule, so that you can't keep making bigger and bigger ones just by adding more atoms/subunits? <br />
If you just keep adding carbon atoms to a diamond will you eventually reach a point where forces such as gravitation become a factor and the molecular bonds fail? I can imagine that long chain molecules light years long might reach point where other forces overwhelm the bond strength? [[Special:Contributions/108.162.246.76|108.162.246.76]] 09:10, 9 December 2021 (UTC)<br />
:For obvious reasons, as long as you limit the number of atoms involved the number of possible "molecules" is - in a mathematical sense - finite. (As there is only a finite number of reasonable stable elements.) But already simple things like polymers can bind millions of atoms in a single molecule. Together with the possible variations intrinsic to such polymers a simple "material" like phenolic resin [[https://en.wikipedia.org/wiki/Phenol_formaldehyde_resin]] is a mixture of more different chemical compounds (in a strict sense) than mankind can ever describe. For all practical application this compexity is not relevant, so no one really cares about.<br />
Additionally there is no clear boundary between typical molecules and other types of condensed matter, like crystals. Same applies to biochemistry. Does chemistry include bio-molecules? If yes, the chemistry guy have to include all the gene sequencing in their to-do list.<br />
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"how fast does light travel in one direction?" is not a good example for incompleteness in physics, because this question was settled by Michelson and Morley in the 19th century (answer: it travels with the speed of light)<br />
: It's not clear to me either what was meant here - seems out of place.<br />
:We know how fast light travels when it goes somewhere and comes back – that's ''c'' – but we don't know how fast it goes when only traveling in one direction. For example, light going at ''c''/2 in one direction and returning instantaneously in the other would still match our observations. We also can't reliably synchronize clocks over a distance because we'd either have to do it with a speed-of-light delay, or separate two clocks and find that relativity changed the timings. Of course, Occam's razor indicates that a consistent speed is more likely, but that's not proof. [[Special:Contributions/172.70.126.87|172.70.126.87]] 12:42, 9 December 2021 (UTC)<br />
:Observing two points (nominal source and nominal destination) from a third point perpendicularly off the mid-point between thoss two points, at an arbitrary distance, you ought to see if there's slowness or instaneity involved (at least make a comparison between bidirectional traversal). This does not remove a response bias in the signal from either end as sent towards the recorder at the observation point, but as the stand-off is increased it makes both observation paths nearer and nearer to parallel and so significantly removes the quantifiable initial 'sideways bias' that may exist.<br />
:I leave it as an excercise to the reader to produce the reasons why this might not practically work to quash all such 'inbuilt universal asymmetry', but it's a good start! [[Special:Contributions/172.70.90.141|172.70.90.141]] 13:21, 9 December 2021 (UTC)<br />
I genuinely don't understand the confusion being proposed here; in practice it's trivial to synchronize a single photon emitter with a single photon detector (such as a PMT) and confirm the speed of light across a single path, with no return trip involved. As far as I know there is know precidence in QM to suspect bidirectional travel could be a special case.<br />
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To quote Randall Munroe in https://what-if.xkcd.com/114/, "The whole universe is matter, as far as we can tell. No one is sure why there is more matter than antimatter, since the laws of physics are pretty symmetrical, and there's no reason to expect there to be more of one than the other. Although when it comes down to it, there's no reason to expect anything at all." Antimatter aside, this shows that the laws of the universe are sometimes asymmetrical. I also like the point that "when it comes down to it, there's no reason to expect anything." Why should we expect the speed of light to be symmetrical? There's no real reason to. [[User:Beret|Beret]] ([[User talk:Beret|talk]]) 14:53, 9 December 2021 (UTC)<br />
:On the contrary, without any such thing as the æther (the fundament through which we would be passing) there is no reason to expect the speed of light (in any given frame of reference) to be asymmetrical. Relativistic frame-dragging and other distortions due to (or resulting in!) accelerative forces will act accordingly, but not change ''c'' itself, in proper calculations, as a function to direction. [[Special:Contributions/172.70.86.12|172.70.86.12]] 16:02, 9 December 2021 (UTC)<br />
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Maybe we can cite one of some famous declarations of physicist saying the physics is almost done [https://nautil.us/blog/the-comforting-certainty-of-unanswered-questions (taken from this site)] :<br />
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:The British scientist William Cecil Dampier recalled his apprenticeship at Cambridge in the 1890s: “It seemed as though the main framework had been put together once for all, and that little remained to be done but to measure physical constants to the increased accuracy represented by another decimal place.” British physicist J. J. Thomson: “All that was left was to alter a decimal or two in some physical constant.” American physicist Albert A. Michelson: “Our future discoveries must be looked for in the sixth place of decimals.”<br />
--[[User:Marceluda|Marceluda]] ([[User talk:Marceluda|talk]]) 15:32, 9 December 2021 (UTC)</div>172.70.86.12https://www.explainxkcd.com/wiki/index.php?title=Talk:2549:_Edge_Cake&diff=222324Talk:2549: Edge Cake2021-12-09T15:33:07Z<p>172.70.86.12: </p>
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The cake being all edges is a reference to everything about her birth being an edge case.<br />
[[Special:Contributions/172.70.110.227|172.70.110.227]] 03:41, 2 December 2021 (UTC)<br />
: It seems likely that the title of the comic is a related pun: her birthday is an edge case, and so she has an edge cake.[[Special:Contributions/162.158.106.221|162.158.106.221]] 04:22, 2 December 2021 (UTC)<br />
So is Hairbun officially named Emily now, sort of like how all instances of Megan are Megan even though she's only called that once? I know all the names here are just placeholders of convenience, but even then I've never know what the rules for naming are. [[User:Captain Video|Captain Video]] ([[User talk:Captain Video|talk]]) 06:11, 2 December 2021 (UTC)<br />
: Well, Megan is referred to multiple times in the xkcds as "Megan", while the one time Hairbun was called Emily, it referred to the real{{citation needed}} Emily Dickinson. So, probably not. <span style="font-family:serif">[[User:Bubblegum|<span style="color:#00BFFF">bubblegum</span>]]-[[User_talk:Bubblegum|<span style="color:#BF7FFF">talk</span>]]|[[Special:Contributions/Bubblegum|<span style="color:#FF7FFF">contribs</span>]]</span> <span style="font-family:serif">02:44, 3 December 2021 (UTC)</span><br />
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Edge pieces on cake are often sought after because they hold more frosting, for cakes which are frosted while out of the pan. [[Special:Contributions/172.70.134.23|172.70.134.23]] 06:37, 2 December 2021 (UTC)<br />
: I have an impression that Cueball is delighted by having only edge pieces, however some cakes edge pieces may be either sought for or avoided, depending on one's tastes. E.g. tarts have more crispy base cake content and less filling at the edges. One person may go for the filling, another for the crispy base. -- [[Special:Contributions/162.158.102.11|162.158.102.11]] 09:50, 2 December 2021 (UTC)<br />
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So it seems the events in the comic happened on Apr 1., as the "last month" birthday could be either Feb 28. or 29. -- [[Special:Contributions/162.158.102.11|162.158.102.11]] 09:50, 2 December 2021 (UTC)<br />
:Not necessarily. Remember, Emily can have her birthday ''whenever she wants'', so the date this comic is set as is entirely arbitrary. [[Special:Contributions/172.70.178.51|172.70.178.51]] 12:26, 2 December 2021 (UTC)<br />
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Are there any particular existing arctic international flights that could have been the one Emily was born on? -- [[Special:Contributions/256.256.256.256|256.256.256.256]] 15:51, 2 December 2021 (UTC)<br />
:There are a few possibities (at least pre-COVID, and obviously we'd be looking historically in this case anyway) as [https://interestingengineering.com/polar-routes-flights-that-go-over-earths-poles might be shown here]. There's two possible (but neither definite) International Datelines on the comic diagram, in case they help orient which from/to directions might have been diverted further in or out of their own kinks in the flightpath to coincide with 90°N. [[Special:Contributions/172.70.162.77|172.70.162.77]] 16:21, 2 December 2021 (UTC)<br />
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Expanded copies of this comic have been appearing on other comics, so large that it fills the whole screen for me. Is anyone else having this problem? [[User:Sarah the Pie(yes, the food)|Sarah the Pie(yes, the food)]] ([[User talk:Sarah the Pie(yes, the food)|talk]]) 22:24, 2 December 2021 (UTC)<br />
:Someone (check the [[Special:RecentChanges|Recent Changes]] page, if you want) has been vandalising a lot of things. Currently I see a picture of an amphibious avian creature on this article's top (if I still need to revert it myself, I will do, but I've seen others have already been reverting other recent vandalism, so I may not need to by the time I've checked again). This very clever individual is obiviously mentally superior to us all(!) the way they can edit wiki pages seemingly at will... Impressive, eh? At some point I'm sure we'll get back to normlal, however boring that may be. [[Special:Contributions/172.70.90.67|172.70.90.67]] 23:33, 2 December 2021 (UTC)<br />
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Not to be too pedantic but isn't rotation a FREQUENCY, not a SPEED? [[User:Skulker|Skulker]] ([[User talk:Skulker|talk]]) 03:19, 3 December 2021 (UTC)<br />
:Depends on the context (and scale). The convention is usually speed for rotation (surface(distance/time) when it's relevant, angular(revolutions/time) otherwise) to avoid conflicts with wave frequency (which is independent of speed). Also they can be freely converted, though converting to and from surface speed requires an additional radius term. The exception is, if comparing periodicity, sometimes frequency is used when it has special relevance (Ex: resonance) -- [[Special:Contributions/172.69.68.200|172.69.68.200]] 02:59, 4 December 2021 (UTC)<br />
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Tempted to add a link in the Trivia section to the [https://en.wikipedia.org/wiki/SS_Warrimoo Wikipedia] or [https://www.snopes.com/fact-check/ss-warrimoo/ Snopes] pages on the SS Warrimoo, a ship that (reportedly) was on the intersection of the Equator and the International Date Line at the stroke of midnight on January 1, 1900, with a number of interesting implications that follow. There's no way to prove that it actually happened, but it's fun to imagine and is somewhat similar to the premise of the comic. --mezimm [[Special:Contributions/108.162.221.15|108.162.221.15]] 14:33, 3 December 2021 (UTC)<br />
:What convinces me that it's a post-constructed yarn, rather than a legitimate account of a plausible event, is that the 1899-1900 'specialness' is (numerically aside) significant only from a more modern viewpoint. The dominant view at the alleged time of the incident, was the 1-rooted changeover between Centuries (1801 through to the end of 1900, then 1901-2000 to follow), and only changed as the more classical form of education/opinion phased out of common use. It was either later contrived from whole cloth as a tall-tale (if done at the time, it would have been given a 1900/1901 timestamp) or gradually embroidered with all the extra coincidental boundary-crossings (spatial and temporal) well after the actual inspirational seed incident in order to make a better anecdote/shaggy-dog-story.... [[Special:Contributions/172.70.86.12|172.70.86.12]] 15:33, 9 December 2021 (UTC)<br />
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Many airplanes actually have limitations written into their operating manuals that prohibit flying north of 89 deg. N or south of 89 deg. S, mostly just so that the navigation software doesn't have to deal with the singularity. [[Special:Contributions/172.69.71.187|172.69.71.187]] 23:48, 3 December 2021 (UTC)<br />
:bloody lazy engineers! [[Special:Contributions/108.162.219.107|108.162.219.107]] 12:19, 5 December 2021 (UTC) <br />
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Is it not possible that Emily's birth happened to occur at the same moment that the contract specified transfer of ownership? Additionally, is it not possible that the airplane took off from within UTC+13:00 or UTC+14:00 and that the moment of Emily's birth happened to occur in the brief one-or-two hour period in which it was March 1st at that airport, but February 28th in UTC-12:00? UTC-11:00 is inhabited, so it would be possible that ownership of an airplane that took off from within UTC+14:00 was transferred to a company based out of UTC-11:00 during the one-hour period that it was February 28th in UTC-11:00 and March 1st in UTC+14:00 and that, at that exact moment, it was passing over the North Pole. [[User:DL Draco Rex|DL Draco Rex]] ([[User talk:DL Draco Rex|talk]])<br />
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Am I alone in thinking that babies don't get born instantaneously? I've never given birth myself but i'd always got the impression that it's a process and any attempt to pick a precise 'instant' is going to be somewhat arbitrary. This means that the plane will very probably have travelled through a variety of time zones any of which could be the 'real' time of birth. [[Special:Contributions/172.70.85.155|172.70.85.155]] 05:29, 4 December 2021 (UTC)<br />
:Time of birth is an arbitrary decision made by the midwives filling out forms in a hospital. The more unlikely point about that is that she'd be able to correlate the precise position of the plane at the exact time listed. [[Special:Contributions/108.162.219.187|108.162.219.187]] 12:37, 5 December 2021 (UTC)<br />
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Dickenson looks like a typo. Dickinson? [[Special:Contributions/172.70.162.77|172.70.162.77]] 08:44, 4 December 2021 (UTC)<br />
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Isn't an "all edge pieces cake" just a plate of cupcakes lol? [[User:Zman350x|Zman350x]] ([[User talk:Zman350x|talk]]) 06:46, 5 December 2021 (UTC)<br />
:Only if you frosted all sides of it.[[Special:Contributions/172.70.114.3|172.70.114.3]] 12:25, 5 December 2021 (UTC)<br />
:Alton Brown made a similar argument, but after experimenting, I strongly disagree. As with brownies, the cooking pattern is slightly different between having more edges and having a cupcake shape. In an edge piece, the edges and the corners are crisp while the center is gooey. Meanwhile, if cooked in a cupcake tin, while there might be more crispness, there is significantly less gooeyness. [[User:Cwallenpoole|Cwallenpoole]] ([[User talk:Cwallenpoole|talk]]) 14:23, 6 December 2021 (UTC)<br />
:If you cut the sheet into quarters or if the whole was round and cut with radial slices there won't be any center piece(s). And there are more, unusual cuts that could result in all edge pieces...[[Special:Contributions/172.70.34.165|172.70.34.165]] 14:40, 6 December 2021 (UTC)<br />
:My take was that a normal cake was baked, frosted and cut (with both edge and center pieces), and only the edge pieces were delivered to Emily.<br />
::Only a cake baked in a fractal pan would be good enough for her!</div>172.70.86.12https://www.explainxkcd.com/wiki/index.php?title=2551:_Debunking&diff=2221832551: Debunking2021-12-07T11:10:34Z<p>172.70.86.12: /* Explanation */ wrong word</p>
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<div>{{comic<br />
| number = 2551<br />
| date = December 6, 2021<br />
| title = Debunking<br />
| image = debunking.png<br />
| titletext = Mark Zuckerberg has only neutral feelings toward Peppa Pig, who he understands is a fictional character, and he blames the coronavirus pandemic on other factors.<br />
}}<br />
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==Explanation==<br />
{{incomplete|Created by a WEIGHTLESS CHIP DUST - Please change this comment when editing this page. Do NOT delete this tag too soon.}}<br />
<br />
When writing a news article that "debunks" a claim (shows why it is false), writing its headline in the form "X is false" is [https://www.psychologytoday.com/us/blog/words-matter/201807/when-correcting-lie-dont-repeat-it-do-instead-2 discouraged]. The reason is that just repeatedly seeing "X", even if negated or followed by "is false", can make readers subconciously believe it.<br />
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To avoid this, Journalist Randall has worded his debunking articles in a positive sense. This makes for a confusing read if the reader has not heard of the original claim. The "original claims" allegedly being debunked here don't actually appear to have been made anywhere, and can only be inferred from the debunking. <br />
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Much of the debunking relies on setting simple facts straight, making for bizarrely banal headlines. <br />
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===Table===<br />
{| class="wikitable" <br />
!Article Headline<br />
!Possible claim being debunked <br />
|-<br />
| AP Photos show that Dr. Fauci's office contains a normal amount of microwaves<br />
| That {{w|Anthony Fauci}}'s office contains an unusual number of microwaves. Whether this refers to microwave ovens or microwave radiation, most offices don't have any of either, so "a normal amount" is an odd thing to say. Fauci is the head of the {{w| National Institute of Allergy and Infectious Diseases}} in the US and is seen as the public face to the COVID-19 response.<br />
|-<br />
| Singer Billie Eilish was born years after the TWA Flight 800 Explosion.<br />
| A conspiracy theory linking {{w|Billie Eilish}} (born December 2001) with the {{w|TWA Flight 800}} crash in July 1996. <br />
|-<br />
| Vaccinated people can remove their hats without trouble by tugging upward, say doctors.<br />
| That vaccination causes one's head to swell, making hats become tight.<br />
|-<br />
| Physicists say Dorito powder is affected by gravity.<br />
| A claim that {{w|Doritos}} powder is not affected by gravity. <br />
|-<br />
| Steering wheels will work normally on Dec 12th<br />
| Faults (perhaps due to failures in the power steering system, triggered for example by solar storms) will cause cars to steer erratically on that date<br />
|-<br />
| Santa's skin is dry and healthy this year, with the same amount of oil as before.<br />
| Santa is suffering from oily skin, which can cause acne.<br />
|-<br />
| ''(Title Text)'' Mark Zuckerberg has only neutral feelings toward Peppa Pig...<br />
| That the founder of Facebook ({{w|Mark Zuckerberg}}) has paranoia concerning the character {{w|Peppa Pig}}, believing her to be a real talking pig and the cause of the COVID-19 pandemic. May be a reference to a [https://www.reuters.com/world/uk/uk-pm-johnson-briefly-lost-words-speech-business-2021-11-22 recent speech] by UK Prime Minister Boris Johnson in which he expressed admiration for Peppa, much to the bewilderment of journalists.<br />
|}<br />
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==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
:[Several news headlines shown in boxes]<br />
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:[Box 1] AP photos show Dr. Fauci's office contains a normal number of microwaves.<br />
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:[Box 2] Fact check: singer Billie Eilish was born years after the TWA Flight 800 explosion.<br />
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:[Box 3] Vaccinated people can remove their hats without trouble by tugging upward, say doctors.<br />
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:[Box 4] Physicists say Dorito powder is affected by gravity.<br />
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:[Box 5] Steering wheels will work normally on Dec 12th; make left and right turns as usual.<br />
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:[Box 6] CNN investigation; Santa's skin is dry and healthy this year, with the same amount of oil as before.<br />
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:[Caption below the panel:]<br />
:I don't know whether the "Don't repeat the claim in the headline debunking it" thing works or not, but it definitely makes reading the news weird.<br />
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{{comic discussion}}<br />
[[Category:COVID-19]]<br />
[[Category:Comics featuring real people]]<br />
[[Category:Biology]]<br />
[[Category:Physics]]<br />
[[Category:Conspiracy theory]]</div>172.70.86.12https://www.explainxkcd.com/wiki/index.php?title=User_talk:Natg19&diff=221887User talk:Natg192021-12-03T00:05:57Z<p>172.70.86.12: /* Amphibious avian vandal */ new section</p>
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<div>==[[2185: Cumulonimbus]]==<br />
Hi Natg19.<br> I removed the categories you added. <br>Science, because I do not think naming of clouds to be science. <br>But the other one, Weather, I removed because that category does not exist. <br>But I'm not against creating such a category. But then you should put in the work, finding a list of other comics (and other categories) that would go into this category, and also create the category page with the usual minor details that is in such a page. <br>See for instance [[:Category:Tornadoes]]. That would go into a weather category. But should it just be called Weather? Or should it be Weather phenomenon or something else? If you are interested I'm willing to help with the details of the category page, if you are willing to find at least 10 other weather comics, that are not already in a category like Tornadoes or [[:Category:Hurricanes]] --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 07:19, 7 August 2019 (UTC)<br />
:Weather (or meteorology?) could be a usefull category, with the subcategories of e.g. Hurricanes/Tornadoes. Other canidates for comics include obviously [[1324: Weather]] and [[2185: Cumulonimbus]] but also [[831: Weather Radar]], [[1245: 10-Day Forecast]], [[1434: Where Do Birds Go]], [[260: The Glass Necklace]], [[1321: Cold]], [[1119: Undoing]]. There should either be a direct connection to [[:Category:Climate change]] or it should be somehow merged to a category for climate. my 2 cents. --[[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 07:56, 7 August 2019 (UTC)<br />
::I like the idea of a category called meteorology. Which could include anything with weather with subcategories for storms of any kind... Complicated with climate change category. Weather is not climate change. That is one of the problems with climate change deniers, that they look at the weather not the climate! (PS added a ":" before the category in the climate change link, else it will not be a link but will add this page to the category! ;-) --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 13:43, 7 August 2019 (UTC)<br />
::: I would also add [[511: Sleet]], [[748: Worst-Case Scenario]], [[1026: Compare and Contrast]], [[1304: Glass Trolling]], [[1606: Five-Day Forecast]], [[2026: Heat Index]] to this meteorology category. I agree that the Hurricanes and Tornadoes page could be subcategories of this category. [[User:Natg19|Natg19]] ([[User talk:Natg19|talk]]) 17:23, 7 August 2019 (UTC)<br />
:::I'm unable to create the details of the category, I do not have permissions to create the page. [[User:Natg19|Natg19]] ([[User talk:Natg19|talk]]) 17:24, 7 August 2019 (UTC)<br />
::::I think we should make such a category. I will do it if we can find a good name. I think Weather is maybe a bit too weak a name. But maybe Meteorology is too much? --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 12:47, 8 August 2019 (UTC)<br />
:::::[https://www.thesaurus.com/browse/weather The saurus] doesn't give other good ideas on this one. I'd vote for weather, as with meteorology typos will be common, and also it will always be discussed, wether or not the comic tackles the topic scientific enough. --[[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 13:04, 8 August 2019 (UTC)<br />
::::::I tend to agree. I will create the [[:Category:Weather]] then, and add a few. I hope you two will add those you have suggested. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 07:11, 9 August 2019 (UTC)<br />
::::::PS Should Climate change be a part of this, or is this precisely not Weather? --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 07:24, 9 August 2019 (UTC)<br />
:::::::I can see Lupo added his comics to the category. I added also those not yet on the list from Natg19. Except the one about worst-case scenarios, that one I added to the hurricane category. comics belonging to a sub category should only be listed under the other if other particular weather phenomenon is also part of that comic. I have also added a paragraph under both the Weather and Climate change categories, stating that they are not related. Weather is what you see outside right now, Climate is what happens over years. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 11:39, 9 August 2019 (UTC)<br />
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== Amphibious avian vandal ==<br />
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Looks like you've gone some way to sort out QQQ's vandalism. What worries me is that https://www.explainxkcd.com/wiki/index.php/File:edge_cake.png currently shows (as most recent image, in the history table) your reuoad/reversion to what it should be, yet at the top of the page it still gives me the offending photo. Also at the top of the Edge Case page, at the very least. (It's not local-caching, I tested in another browser that shouldn't be awkward that way.)<br />
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Also trying to work out why the Pages With This Image include two others, one of which clearly has no recent edits (from which perhaps the Wiki could be slow to forget a reversion) so... Look, I'm no expert on this stuff, I'm not even a named account. Just saying that you ''may'' need to prod the server with logged-in powers I don't have (clearly you are at least at Upload privelidge-level, which I understand aren't immediately available upon registration) and check if you finished your repairs.<br />
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You're doing a good job (and others, I note), and maybe I'll register properly for more official future help from my end. Until then, I'm just an IP of long standing. Wwo - checking my 'own' recent contributions - seems to be dynamically upon a shared address, so no good point in replying. It might be best to edit this scrawl of mine away once you've absorbed my message, whatever you think you can/ought to do about it. ;) [[Special:Contributions/172.70.86.12|172.70.86.12]] 00:05, 3 December 2021 (UTC)</div>172.70.86.12https://www.explainxkcd.com/wiki/index.php?title=Talk:1532:_New_Horizons&diff=221616Talk:1532: New Horizons2021-11-30T13:36:18Z<p>172.70.86.12: </p>
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<div>Anyone know why the text on the comic was heavily aliased (pixelated edges), although it's since been fixed on the xkcd website? [[User:Keavon|Keavon]] ([[User talk:Keavon|talk]]) 07:45, 1 June 2015 (UTC)<br />
:Probably a bad setting on the PNG compression by Randall when saving. Maybe he's trying to optimize file size (although in this case, the quality suffered). --BigMal // [[Special:Contributions/108.162.238.192|108.162.238.192]] 11:53, 1 June 2015 (UTC)<br />
:Did the quality of the comic improve over time? Might have been a reference to the images provided by new horizons becoming more clear as it approached[[Special:Contributions/108.162.215.113|108.162.215.113]] 12:51, 5 June 2015 (UTC)<br />
:There's some weirdness in the earth images, too. You can see it if you bump the contrast and brightness a bunch -- there's a rectangular box around Earth, which it sits at the right end of. There's also a slight gradient in the box that's brighter at the right side, a couple of meandering green lines in the brightest part of the gradient, a series of green X shapes at lower left, and a repeating pattern of green, blue and pure black at top left. Curious, could be intentional or simply an artifact of how Randall made the image. [[Special:Contributions/108.162.217.167|108.162.217.167]] 21:21, 22 June 2015 (UTC)<br />
<br />
According to Wikipedia, "in August 2014, astronomers made high-precision measurements of Pluto's location and orbit around the Sun using the Atacama Large Millimeter/submillimeter Array to help NASA's New Horizons spacecraft accurately home in on Pluto." Was Steve involved in these measurements too? (And any of the numerous ways by which it can be determined how far away NH is and which way it is travelling!)--[[User:Laverock|Laverock]] ([[User talk:Laverock|talk]]) 12:43, 1 June 2015 (UTC)<br />
<br />
This joke appears to be aimed at the implausibility of the Horizon Mission’s concept art, which looks suspiciously like earth. The image shows deserts, mountains and oceans which appear to be “riffs off” of a satellite image of the Horn of Africa, western Asia, and the Indian Ocean. <br />
Examples: <br />
Artist's conception of New Horizons at Pluto. Image Credit: NASA<br />
http://www.nasa.gov/sites/default/files/15-011a.jpg<br />
Image usage:<br />
http://www.spaceflightinsider.com/missions/solar-system/new-horizons-starts-first-phase-pluto-encounter/<br />
:I think that -is- Earth, a view of the probe right after it was launched. Then again... Classic Star Trek episode "Miri" is set on a distant planet with identical continents to Earth for no reason except to get you interested quickly. It was made before "Planet of the Apes" by the way (spoiler). An unsatisfactory novel called "Preserver" revisits it and proposes there are super-powered aliens just messing with us. Actually in Star Trek there are super-powered aliens just messing with us about every third week and they usually constructed their own gonzo planet just for that purpose, so the assumption that these are new, unknown super-powered aliens is unjustified, but of course true (The Preservers), unless they are really Organians or Q but they just don't say so. And if the Planet Copiers are abroad, who's to say that Earth is the original. Outside Trek, it's also even odds that a fictional Counter-Earth planet on the other side of the sun - there have been several although it's physically impossible - has identical continents to Earth. And in "D.R. and Quinch Have Fun On Earth", our continents are alien graffiti, unfortunately leading to cleanup. Love, Robert Carnegie rja.carnegie@excite.com [[Special:Contributions/141.101.99.123|141.101.99.123]] 11:17, 12 June 2015 (UTC)<br />
<br />
I do not know if the image is concept art for the New Horizon mission from back in 2006; or if it is a more generic space exploration art work. It is hard to imagine that it is specific to the New Horizon’s Mission.<br />
One should ask New Horizons mission members to comment. There must be an interesting inside story. [[User:Dfh42|Dfh42]] ([[User talk:Dfh42|talk]]) 15:49, 1 June 2015 (UTC)<br />
<br />
This earlier mission art is probably closer to what Randall would consider plausible:<br />
http://www.nasa.gov/multimedia/imagegallery/image_feature_267.html [[User:Dfh42|Dfh42]] ([[User talk:Dfh42|talk]]) 16:29, 1 June 2015 (UTC)<br />
<br />
Waitasec, wouldn't the people on the ground know pretty much the exact position of this probe at all times? If nothing else they know its direction and distance from earth just by monitoring their communications with it. [[User:Odysseus654|Odysseus654]] ([[User talk:Odysseus654|talk]]) 17:45, 1 June 2015 (UTC)<br />
:Yes, that is the joke.[[User:Zeimusu|Zeimusu]] ([[User talk:Zeimusu|talk]]) 21:18, 3 June 2015 (UTC)<br />
<br />
;Slingshot maneuver<br />
<br />
It uses the gravity of a planet to alter the path and speed of a spacecraft. [http://en.wikipedia.org/wiki/Gravity_assist Reference] I guess Steve miscalculated the maneuver. --[[User:Arturotena|Arturotena]] ([[User talk:Arturotena|talk]]) 06:41, 1 June 2015 (UTC)<br />
<br />
I believe this really requires three bodies to work. The close passage by the small object slightly alters the orbital elements of the larger body (around the largest body, in this case, the sun), while also changing the orbit of the small body, both direction and speed.--DrMath 06:44, 27 May 2018 (UTC)<br />
<br />
;References<br />
<br />
# Related tweet: [https://twitter.com/NASANewHorizons/status/603652798622920704 As @NASANewHorizons gets closer, our view of #Pluto gets better and better!].<br />
# Related link: [http://www.nasa.gov/feature/nasa-s-new-horizons-sees-more-detail-as-it-draws-closer-to-pluto NASA’s New Horizons Sees More Detail as It Draws Closer to Pluto].<br />
# [http://dawn.jpl.nasa.gov/team/ NASA Dawn Team]<br />
--[[User:Arturotena|Arturotena]] ([[User talk:Arturotena|talk]]) 06:34, 1 June 2015 (UTC)<br />
<br />
;Distance?<br />
<br />
If Pluto is 39.26 AU from the Sun, how can New Horizons be 0.34 AU from Pluto and 32.55 AU from the Sun? [[Special:Contributions/141.101.64.35|141.101.64.35]] 20:54, 1 June 2015 (UTC)<br />
:I reinserted the sentence semi-major axis, and I added a Wikipedia link: {{w|semi-major axis}}. [[Special:Contributions/108.162.238.144|108.162.238.144]] 21:47, 1 June 2015 (UTC)<br />
<br />
Why is the distance even in the explanation ? -- I move to strike and delete [[User:Spongebog|Spongebog]] ([[User talk:Spongebog|talk]]) 15:02, 2 June 2015 (UTC)<br />
<br />
;No rotation and an imminent impact?<br />
<br />
Most likely it's just a concession to making the cartoon easier to draw, but I'd note that between the third and fifth frames, Earth appears not to rotate noticeably. That implies either extreme speed, or less likely, slow enough speed that Earth is conveniently managing one or more complete rotations between frames. Since the conversation is implied to continue throughout, we can safely presume the former. That suggests an imminent collision somewhere on (or near) the southern coast of Yemen. [[Special:Contributions/108.162.217.167|108.162.217.167]] 21:21, 22 June 2015 (UTC)<br />
<br />
;Steve?<br />
<br />
So is Steve a character now? What about a dwarf character? [[User:Z|Z]] ([[User talk:Z|talk]]) 20:22, 2 June 2015 (UTC)<br />
<br />
: There must be other people named "Steve" ! [[User:Spongebog|Spongebog]] ([[User talk:Spongebog|talk]]) 06:35, 3 June 2015 (UTC)<br />
<br />
:: No, Steve was an {{w|only child}} . . . . [[User:Spongebog|BingoBash]] ([[User talk:Spongebog|talk]]) 06:45, 3 June 2015 (UTC)<br />
<br />
Btw, Steve was also mentioned in comic 228. [[User:TronX7|TronX7]] ([[User talk:TronX7|talk]]) 06:59, 5 June 2015 (UTC)<br />
<br />
I didn't even see this as a representation of Earth. As I looked at each image, I thought I was seeing an image of Goofy (rather than Pluto) as seen through a glass orb. [[Special:Contributions/108.162.237.165|108.162.237.165]] 20:26, 9 June 2015 (UTC)<br />
<br />
I've fixed the three opaque links. I'll remove the incomplete tag in the next few days, unless anybody objects. [[User:Cosmogoblin|Cosmogoblin]] ([[User talk:Cosmogoblin|talk]]) 14:10, 24 June 2015 (UTC)<br />
<br />
108.162.215.26 (why are all the anonymous contributors on this page Californian? You're the other side of the country, you don't need to worry about NASA missions exploding!) added a link about the worst-case scenario in the event of a launch disaster, but just copied it from Wikipedia without checking - it was broken, so I searched for the source and fixed it. In doing so, I had a look at what the report says, and I'm not convinced the text from Wikipedia (sourced originally from "The Cosmic Compendium", ISBN 978-1329022027) is correct. The report indicates on page 4-30 that the scenario mentioned would result in "0.4 mean health effects", whereas a less likely scenario mentioned directly below that would result in "102 mean health effects", about 250 times worse. Still, it's from a cited, published source, and if anybody's wrong, it's Rupert W Anderson. [[User:Cosmogoblin|Cosmogoblin]] ([[User talk:Cosmogoblin|talk]]) 15:32, 26 June 2015 (UTC)<br />
<br />
Cosmogoblin, the entirety of the text from "The Cosmic Compendium" by Rupert W Anderson is taken word for word straight from Wikipedia. So you didn't really chase your source far enough, I don't think. "Rupert" goes so far as to actually cite every single one of his sources as Wikipedia along with relevant licenses (public domain or creative commons) so I'm guessing that book is scamming people who don't realize what they're buying. {{unsigned ip|173.245.55.66}}<br />
<br />
From one IP to another: [https://www.explainxkcd.com/wiki/index.php?title=1532:_New_Horizons&curid=16349&diff=221594&oldid=200453 this was probably ''not'' a typo] - 'pane', as in '{{w|Windowpane|window pane}}', was valid. As 'panel' is, so no skin off my nose, and I (probably?) didn't write the original. But it's not a necessary edit so I'm hoping no-one goes off to do a mass-replacemenf. (And this comment is the best/only way to possibly get the attention of the unnamed editor concerned, or anyone else lurking on Recent Changes or otherwise randomly landing here.) [[Special:Contributions/172.70.86.12|172.70.86.12]] 13:36, 30 November 2021 (UTC)</div>172.70.86.12https://www.explainxkcd.com/wiki/index.php?title=explain_xkcd_talk:Editor_FAQ&diff=221492explain xkcd talk:Editor FAQ2021-11-28T04:00:10Z<p>172.70.86.12: /* Duplicating the hover text/title in the transcript section? */</p>
<hr />
<div>Feel free to enter any question about editing this Wiki and don't forget to sign you comment. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 21:18, 31 May 2018 (UTC)<br />
<br />
== Formatting of explanations ==<br />
<br />
Many pages contain tables where a definition list would be 1) easier to read 2) mobile friendly, for example: [https://www.explainxkcd.com/wiki/index.php?title=1957:_2018_CVE_List&oldid=160469 1957]. <br />
<br />
I was also involved in rewriting the transcript for [[1963]], where the discussion came up about how those should be styled. ("as if you were reading the comic to someone")<br />
<br />
I think we should have a small style guide to encourage sane formatting. What else should such guidelines contain? <br />
<br />
Edit: One more thing I'd love to see: semantic headlines (i.e. < h3> headlines for explanation subchapters instead of < h2> which is the same level as the explanation itself)<br />
<br />
<small>(Sidenote: I've been active on explainxkcd for quite some time, but only now got around making an account.)</small> [[User:Gir|//gir.st/]] ([[User talk:Gir|talk]]) 15:01, 19 August 2018 (UTC)<br />
<br />
:Thanks for your remarks. First: There is no need to start every new sentence at a new line. Tables are meant for small content in all other cases it's bad layout. I recently changed this [[2034: Equations]] to a proper floating text. At the transcript tables should never be used, even when there is a table in the comic image it should be described by text. The guide here was mainly written by me because there was nothing like this here before. Some people already helped and I'm happy for any further remarks to enhance it. And this table issue is definitely one; I just not wanted to be the only (arrogant) layout master. Your help is welcome to write something, otherwise I will do so soon.<br />
:For headlines we don't use HTML-code but WIKI-code. The main headlines are written like this: <nowiki>==Explanation==</nowiki>, <nowiki>==Transcript==</nowiki>, and (optional) <nowiki>==Trivia==</nowiki>. Headlines inside that chapters should be done in this way: <nowiki>;Subtitle</nowiki>. The preceding semicolon causes the entire line to be rendered in bold. Only when the explanation really needs sub-chapters it can be done by this: <nowiki>===Sub header===</nowiki> (three equal signs before and after the text). I will put this also into the FAQ.<br />
:Welcome and thanks for helping. PROTIP: Always use the preview button to check the layout before saving. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 13:39, 20 August 2018 (UTC)<br />
::hi, I'm aware about the headlines and stuff, it was just shorter to write it this way in the comment. I see you started a bit with a styleguide already; I hope I can contribute to it next week, when things cool down at work a bit. //gir.st/, who is to lazy to log in [[Special:Contributions/172.68.51.190|172.68.51.190]] 06:51, 24 August 2018 (UTC)<br />
<br />
So, one more thing, regarding 'What is the proper layout for headers?'. I think we should better use small <code><nowiki>====headings====</nowiki></code> instead of just description titles (<code><nowiki>;bold text</nowiki></code>), since it makes the intent clearer. what is your reasoning behind suggesting it the other way round? greetings, [[User:Gir|//gir.st/]] ([[User talk:Gir|talk]]) 14:49, 25 August 2018 (UTC)<br />
:Thanks for your input and of course Wiki markup headers should be valid. I just believe that the simplest way should also be valid for less experienced writers. When a new explanation starts it's often awful and chaotic; giving a simple but effective structure at the beginning helps against this chaos. So, I'm thinking about dividing the section "What is the proper layout for headers?" (it's a question because it's a FAQ) into two subsections:<br />
:*easy: a semicolon, the colon at the following paragraph may be mentioned - but I'm not sure about the colon because it should be ''easy''<br />
:*advanced: <code><nowiki>===headings===</nowiki></code> if the comic really can be divided into chapters; <code><nowiki>====headings====</nowiki></code> as a replacement for the semicolon; and <code><nowiki>==headings==</nowiki></code> is forbidden because it belongs to expl, trnsc, trivia. The semicolon, colon issue should be mentioned here.<br />
:Please consider that there was many chaos in the past and many writers will do their edits without reading this FAQ. So keeping this simple as possible seems to me to be inevitable. And dividing sections by using the semicolon for a header is still much better than many of those tables. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 17:41, 25 August 2018 (UTC)<br />
::Based on this discussion I edited the current comic here: [http://www.explainxkcd.com/wiki/index.php?title=2037%3A_Supreme_Court_Bracket&type=revision&diff=161880&oldid=161841] and compare it to this former version [http://www.explainxkcd.com/wiki/index.php?title=2037:_Supreme_Court_Bracket&diff=prev&oldid=161841]. Do not focus on the edits, just scroll down to the resulting page.<br />
::This brought me to another important issue: NO links in a header. At Wikipedia this is also not welcome. This site isn't Wikipedia but in this case I feel this is a good rule. But the TOC (Table of content) is shown in the preview while it's not at the resulting page. The result is preferred but the TOC in the preview may confuse editors here.<br />
::So, I'm still looking for simple instructions, layouts which advanced people always can enhance.<br />
::And consider that some editors are probably younger than xkcd is. Not sure about this but there are definitely young people here and I welcome them all. And I'm NOT getting old like Randall sometimes feel, I like to support every editor despite any other background. And this has to be simple on the first place. STOP(I could talk much more) --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 20:49, 25 August 2018 (UTC)<br />
:::Sorry, I missed this. I'd personally go with the "advanced" option, but mentioning both is fine too. Nice work on 2037! Really enjoying our conversations about this, I hope i'm not a bother ;-) [[User:Gir|//gir.st/]] ([[User talk:Gir|talk]]) 11:20, 28 August 2018 (UTC)<br />
OK, after a few days and some more edits (for example see here: [[2035: Dark Matter Candidates]]) I believe this would be the best guide:<br />
*<code><nowiki>====headings====</nowiki></code> should be preferred because the advantage is that each header has it's own edit button. One other advantage is that the header text will be shown at the summary in the history.<br />
*The semicolon may be used as a preliminary layout for new comics until it's clear of what content the explanation is composed of.<br />
*On more rare circumstances the <code><nowiki>===headings===</nowiki></code> may divide the explanation into different larger chapters.<br />
*<code><nowiki>==headings==</nowiki></code> is reserved to the general layout and has not to be used.<br />
And I still oppose to the colon at the beginning of any paragraph at all. Any thoughts? --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 13:17, 29 August 2018 (UTC)<br />
<br />
== Please '''''do not''''' use semicolon-lines as "headings" ==<br />
<br />
Hi, sorry to butt in, but I was going to mention this here anyway after I saw it in the FAQ. Please ''don't'' continue to give this advice to editors:<br />
<blockquote>For headlines you have to use Wiki-style code. The simplest way is a preceding semicolon at the beginning of the line which causes the entire line to be rendered in bold.<ref>§ [[explain xkcd:Editor FAQ#What_is_the_proper_layout_for_headers.3F|What is the proper layout for headers?]] of the [[explain xkcd:Editor FAQ|Editor FAQ]]</ref><br />
<br />
====References====<br />
<references/><br />
</blockquote><br />
<br />
The [[explain xkcd:Editor FAQ#In_which_case_tables_are_meaningful_and_when_not.3F|previous Editor FAQ section]] has it right: in wikicode, the semicolon opens a ''description list'', and will be translated into equivalent HTML. In other words, the wikicode is processed as follows:<br />
{| class="wikitable"<br />
|-<br />
! Wikicode !! HTML<br />
|-<br />
| style="vertical-align:top;" |<pre>; xkcd<br />
: a popular webcomic</pre><br />
|<pre>&lt;dl&gt;<br />
&lt;dt&gt;xkcd&lt;/dt&gt;<br />
&lt;dd&gt;a popular webcomic&lt;/dd&gt;<br />
&lt;/dl&gt;</pre><br />
|}<br />
<br />
One or more lines started with a semicolon ''must'' be followed by at least one line that starts with a colon, to provide the <code>&lt;dd&gt;...&lt;/dd&gt;</code> part of the description list block.<br />
<br />
It is a {{w|Help:List#Common_mistakes|common mistake}} to use semicolon-lines as "headings". Unfortunately the result is '''invalid HTML''', since the HTML spec requires that a <code>&lt;dl&gt;</code> block contain:<br />
<blockquote>Zero or more groups each consisting of one or more dt elements followed by one or more dd elements</blockquote><br />
It's fine to have multiple semicolon-lines in a row (as the HTML standard allows for groups of several <code>&lt;dt&gt;...&lt;/dt&gt;</code> blocks in sequence), but they must '''always''' be followed by at least one <code>&lt;dd&gt;...&lt;/dd&gt;</code> block, created in wikicode by following a line started with a semicolon with another line that starts with a colon. <br />
<br />
Just like lines started with <code>*</code> or <code>#</code>, a line started with a <code>;</code> creates a list element, and has syntactic requirements that must be followed. Abusing the description-term wikicode for purposes other than description-list creation not only breaks the HTML on the resulting page, but it makes the content much harder for screen readers and other assistive technologies to parse and accurately reproduce. <br />
<br />
(And, yes, technically Mediawiki's use of <code>:</code>-lines for indenting, as on talk pages, is also invalid since it creates a <code>&lt;dl&gt;&lt;dd&gt;...&lt;/dd&gt;&lt;/dl&gt;</code> block with no <code>&lt;dt&gt;</code> element. So it's bad enough on talk pages, it's 100x worse to encourage doing it on '''article''' pages.) Please consider removing this bad advice from the Editor FAQ. Thanks. -- [[User:FeRDNYC|FeRDNYC]] ([[User talk:FeRDNYC|talk]]) 05:48, 5 September 2018 (UTC)<br />
<br />
:Thanks for your remarks, that's why I started this FAQ and the discussion about it. Especially the header section is still preliminary, just check the section above here at the talk page.<br />
:My first purpose is to keep it as simple as possible for writers having not much or no knowledge about wiki code or HTML. After that an advanced section should follow and define the rules for a complete article.<br />
:Please check my summary from 29 August 2018 just above here. You're right the semicolon isn't a header, that's why I'm saying it should be used only temporary. And after reading your remarks here I would propose a single line with bold text and a following empty line instead of that semicolon thing.<br />
:Keep it simple for people who just want to write something here; advanced users will change it to an appropriate layout later. Consider: When a new comic is out the explanation often starts in chaos. And for now I'm really happy that the overwhelming usage of tables is stopped.<br />
:Let me know what you do think about the bold text line (not by semicolon) and the more sophisticated header guidance for the final layout as I've mentioned on 29 August 2018. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 12:45, 5 September 2018 (UTC)<br />
::And of course the usage of a semicolon should also be mentioned together with the colon because it's a list. An entire paragraph "How do I format lists?" has still to be written yet. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 12:51, 5 September 2018 (UTC)<br />
::One more: I've checked the definition for <code>dd/dt/dl</code> and it's clear the <code>dd</code> tag must be followed by at least one (either <code>dt</code> or <code>dl</code>) child. This tells me that the indent done by a colon is proper HTML. This is very important because every transcript since the first comic uses this indentation. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 13:20, 5 September 2018 (UTC)<br />
<br />
==Incomplete tags==<br />
The FAQ says to use <code><nowiki>{{incomplete transcript|YOUR REASON}}</nowiki></code> but instead of rendering like this (like with the incomplete template):<br />
<br />
{{notice|'''This transcript is incomplete:''' ''YOUR REASON'' <br/>If you can address this issue, please '''[{{fullurl:{{{target|{{FULLPAGENAME}}}}}|action=edit}} edit the page]!''' Thanks.}}<br />
<br />
It renders like this:<br />
<br />
{{notice|'''This transcript is incomplete.''' Please help [{{fullurl:{{{target|{{FULLPAGENAME}}}}}|action=edit}} editing] it! Thanks.}}<br />
<br />
Can someone please change this? [[Special:Contributions/172.68.133.180|172.68.133.180]] 02:55, 13 October 2018 (UTC)<br />
:The FAQ also says: "The reason at the transcript is not shown to the viewer." You can see it when you edit the transcript. And because the reason for the comic is also often not given this should be enough for the transcript. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 16:49, 15 October 2018 (UTC)<br />
<br />
== math markup ==<br />
<br />
Just to note - I was curious about the "math markup" message at the top of each page, and duly followed the link to the Editor FAQ as instructed, but ther--e is no mention of why it shouldn't be used... (no account yet, as I've not made any edits - yet! and i use google data saver, so this is not my ip -->) --[[Special:Contributions/162.158.34.22|162.158.34.22]] 23:49, 11 December 2018 (UTC)<br />
<br />
:damn, I'm tired - just re-read the section titles, and there it is. It's late, so sorry! --[[Special:Contributions/162.158.34.22|162.158.34.22]] 23:54, 11 December 2018 (UTC)<br />
<br />
::I think the reason given is incomplete, but wanted to check here before I amended it. Transcripts are for the benefit of visually-challenged visitors, so using math markup, and thus rendering the text as images, is counterproductive. Right? -- [[User:Dtgriscom|Dtgriscom]] ([[User talk:Dtgriscom|talk]]) 15:06, 20 March 2019 (UTC)<br />
<br />
:::The explanation is (in my opinion) somewhat silly, as the image generated by MathML has an alt tag for text browsers/accessible use. Further, if this wiki's settings were chosen correctly, the image would be output with MathML alongside, which is the ''actual'' (non-plaintext) accessible solution for displaying mathematical formulas on the web. See also: https://accessibility.princeton.edu/about/blog/mathml-accessible-math-markup [[User:DimeCadmium|DimeCadmium]] ([[User talk:DimeCadmium|talk]]) 02:20, 12 October 2019 (UTC)<br />
<br />
== Create page for new comic ==<br />
<br />
Should there be a paragraph about this?<br />
Since the bot is not working anymore, people need to do this. I know I have seen isntructions somewhere on this wiki, but cannot find them... [btw: there is a new comic up, right now, as I post this line, which is not yet in the wiki. SO if you know how to do it, do it before explaining it on the FAQ :)] --[[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 13:27, 3 January 2020 (UTC)<br />
<br />
== Page targeted by Spam ==<br />
<br />
The page is currently targeted heavily by Spambots. I am not sure why they target this specific page. It might be, because it is linked in the header? Since Admins (who could protect the FAQ) seem to be currently absent from the page, anyone got any ideas what to do about it? leave it to spam and create a seperate FAQ with the same content? --[[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 10:08, 26 February 2020 (UTC)<br />
<br />
== Spaces ==<br />
<br />
Seriously, why oh why is [[1285:_Third_Way|1285]] not linked into the statement about the one space / two space [[1285:_Third_Way | controversy]]? This feels like an inexplicable gap. Is there a policy insisting the FAQ remain fastidiously humorless in all ways? [[Special:Contributions/162.158.107.231|162.158.107.231]] 02:10, 29 January 2021 (UTC)<br />
<br />
== Duplicating the hover text/title in the transcript section? ==<br />
<br />
Is there a reason not to duplicate the title/hovertext in the transcript section, so a screenreader user can be sent there and not have to page back up for that bit (besides "one or more editors would need to check all entries and edit it in where missing")? [[Special:Contributions/141.101.68.43|141.101.68.43]] 00:11, 28 November 2021 (UTC)<br />
:For my two (or three) cents:<br />
:1) You'd be duplicating it, so you ought to lose the sub-image record if you do that or you could get silly with all kinds of repeating of everything..<br />
:2) It's a Transcript to try to record/present the text (and imagery) you cannot already screen-read.<br />
:3) It doesn't need manual editing (and manual editing is more likely to have mistakes, anyway).<br />
:...Perhaps some Template(-pair?) could be developed to sit post-template to "display:screenreader-only" (or whatever the markup format would be) the upper-templated titletext field? [[Special:Contributions/172.70.86.12|172.70.86.12]] 04:00, 28 November 2021 (UTC)</div>172.70.86.12https://www.explainxkcd.com/wiki/index.php?title=Megan&diff=221285Megan2021-11-24T16:15:35Z<p>172.70.86.12: /* Characteristics */ Presuming it was 'either' when just two datum points were quoted, but not updated when it was no longer.</p>
<hr />
<div>{{Infobox character<br />
| image = Megan.png<br />
| imagesize = 150px<br />
| caption = Megan<br />
| first_appearance = [[15: Just Alerting You]]<br />
}}<br />
'''Megan''' is a [[stick figure]] character in [[xkcd]]. She is the second-most frequently appearing character, after [[Cueball]], and the most frequently appearing female character. She does not necessarily always represent the same character from comic to comic. She is essentially the female equivalent of Cueball, representing the every-woman to his {{w|everyman}}. This is less clear than for Cueball as there are several comics, where there are [[:Category:Multiple Cueballs|multiple Cueball-like figures]], any of whom could be called Cueball.<br />
<br />
There are very few comics where this happens with Megan-like characters, with the few including [[139: I Have Owned Two Electric Skateboards]], [[173: Movie Seating]], [[1409: Query]], [[1496: Art Project]], [[430: Every Damn Morning]], [[2040: Sibling-in-Law]], and in [[1951: Super Bowl Watch Party]].<br />
<br />
Of course she also appears several times in some of the comics with [[:Category:Large drawings|large drawings]], like [[1110: Click and Drag]]. Often this should be seen as different small comics, where there is just one Megan in each story. In [[1608: Hoverboard]], however, there are two identical Megans at the bottom rear end of the Destroyer, where one is talking to the other. As opposed to with Cueball, an example where this is a serious problem for Megan has yet to be found.<br />
<br />
Megan does sometimes appear to have slightly specific personality traits; she has quite odd habits, and is sometimes shown to be very focused and intent on a goal. However, as explained above this is not a general rule for a given Megan character.<br />
<br />
==Name==<br />
''Explain xkcd'' originally referred to this character as "Cutie" (complementing "Cueball" with a matching first syllable). But then a "Cutie" was given a specific name, Megan, in [[159: Boombox]] and later in for instance [[215: Letting Go]], [[420: Jealousy]], [[478: The Staple Madness]], and [[654: Nachos]]. The name was also used without displaying a drawing of Megan in [[596: Latitude]] and in the title text of [[627: Tech Support Cheat Sheet]]. <br />
<br />
The name Cutie was then changed to Megan. If this rule should be followed generally, then Cueball should be re-named Rob after [[276: Fixed Width]] (and the [[:Category:Comics featuring Rob|other 8 times]] a Cueball has been named Rob in total). But as mentioned above this was not to be. <br />
<br />
She can also be drawn under a different name as in [[672: Suggestions]], where a sexy image of her, hair hanging loose over her face, is called Susie. And in [[1221: Nomenclature]] Megan is called Mrs. Whatsit in the transcript provided in the comic source. In [[734: Outbreak]] Cueball and Megan are named Ryan and Laura, but that is a movie, so they could be actors called Cueball and Megan in real life...<br />
<br />
A character that looked a lot like Megan, but with somewhat longer hair and a much meaner attitude, was distinguished from her as [[Black Hat]]'s girlfriend [[Danish]]. A similar long-haired version of Megan also appeared in [[1730: Starshade]], although without the attitude.<br />
<br />
==History==<br />
Early comics often feature Megan-style characters who may or may not be identified as Megan. [[Randall]] appears not to have standardized his character lineup early in the comic's run, and as a result, certain early female characters sometimes have similar hair to Megan, but some different features.<br />
<br />
The name (or even pseudonym) "Megan" may be reference to a lost love of Randall's, given that he wrote a passive-aggressive toast for Megan's wedding in [[420: Jealousy]] about how he was madly still in love with her, put across in a way that would generally ruin the day for everyone involved. We also see this earlier in [[215: Letting Go]].<br />
<br />
Several of the [[:Category:Cancer|comics about cancer]] have Megan representing Randall's fiancée (later wife).<br />
<br />
==Characteristics==<br />
Megan is distinguished by her black shoulder-length hair which generally appears to be parted in the middle in front, and is draped behind what are presumably her (undrawn) ears.<br />
<br />
In [[1409: Query]], we learn that she is 30 or younger, implying that she was born in 1984 or later (this comic appeared in 2014); that her annual income is less than or equal to $100,000; and that she is afraid of flying. In [[630: Time Travel]], we learn she was born in 1983. In [[2178: Expiration Date High Score]], we can calculate that she is 37, and since this comic appeared in 2019, it implies she was born in 1982 or earlier. Randall is probably not concerned about chronological consistency for his characters, although another explanation is that since the figure is not explicitly named "Megan" in any of these comics, these are three different characters.<br />
<br />
Although she is a stick figure this does not mean she cannot be drawn topless: [[864: Flying Cars]].<br />
She is also shown explicitly dressed in [[1492: Dress Color]]. <br />
In [[631: Anatomy Text]] a naturalistic drawing of (undressed) Megan is found.<br />
<br />
She is implied to, if not be bisexual, then at least experience same-sex attraction: while she has often been shown to be in a relationship with Cueball, [[267: Choices: Part 4]] mentions that, though she doesn't remember it, she's made out with an alternate version of herself (who is obviously female), and in [[305: Rule 34]], she reacts quite enthusiastically to her idea for porn centered around women playing electric guitar in the shower.<br />
<br />
According to [[1521: Sword in the Stone]], Megan is canonically the Queen of England.<br />
<br />
==See also==<br />
*[[:Category:Comics featuring Megan|Comics featuring Megan]].<br />
*It was at some point suggested that Megan and Cutie should be un-merged? In relation to a similar suggestion that Cueball and Rob should be merged. But nothing came of the [http://www.explainxkcd.com/wiki/index.php/explain_xkcd:Community_portal/Proposals#Merge_Cueball_.26_Rob discussion.]<br />
<br />
{{navbox-characters}}<br />
<br />
[[Category:Characters]]</div>172.70.86.12https://www.explainxkcd.com/wiki/index.php?title=2545:_Bayes%27_Theorem&diff=2212252545: Bayes' Theorem2021-11-23T08:14:42Z<p>172.70.86.12: </p>
<hr />
<div>{{comic<br />
| number = 2545<br />
| date = November 22, 2021<br />
| title = Bayes' Theorem<br />
| image = bayes_theorem.png<br />
| titletext = <nowiki>P((B|A)|(A|B)) represents the probability that you'll mix up the order of the terms when using Bayesian notation.</nowiki><br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by <nowiki> P(d/dx x^x | d/dx x^(1/x)) </nowiki> - Please change this comment when editing this page. Do NOT delete this tag too soon.}}<br />
<br />
{{w|Bayes' theorem}} describes the probability of an event, given knowledge of conditions related to the event. It is typically used to update the probability that a starting condition occurred, given an outcome. This can reveal unintuitive results when the probability involved is very small. For example, when testing a large number of people for a rare disease, even a fairly accurate test will produce more false positives than the number of people actually afflicted with the disease, and hence a positive result is more likely to be false than true.<br />
{| class="wikitable"<br />
|| || Tested positive || Tested negative || Total<br />
|-<br />
|| Infected || 0.1% || 0.0% || 0.1%<br />
|-<br />
|| Uninfected || 0.9% || 99% || 99.9%<br />
|-<br />
|| Total || 1% || 99% || 100%<br />
|}<br />
For example, if a test has a 100% sensitivity (all infected are tested positive) and a 1% specificity (1% of uninfected nevertheless are tested positive), the interpretation of a positive test depends on the prevalence (percentage of infected). In the example case, the prevalence is 0.1%, so that when the test result is positive (left column) the subject is uninfected nine time out of ten. Although this would be a very performant test, given the prevalence, chances are in fact that the test is a false positive.<br />
<br />
Bypassing the graphical display, the bayesian formula would give : p( Infected | Positive ) = p( Positive | Infected )*p( Inflfected )/p( Positive ) = 100% * 0.1% / 1% = 10% <br />
<br />
In this comic, a teacher is presenting a problem which the students are supposed to use Bayes' theorem to solve. However, the off-panel student knows that they are studying Bayes' theorem, so they use that prior knowledge to guess the usual answer to such problems. The punch line is the caption - if you know Bayes' theorem well enough, you don't need to actually calculate the probabilities.<br />
<br />
The title text refers to the mathematical definition of Bayes' theorem: P(A | B) = P(B|A) * P(A) / P(B). Here, P(A|B) represents the probability of some event A occurring, given that B has occurred. This is often referred to as "the probability of A given B". It can be hard to remember if P(A|B) means probability of A given B, or if it's B given A, especially when talking about the probability of an earlier cause given a later effect. Randall's joke is based on this difficulty. Here P((B|A)|(A|B)) is the probability that you ''write'' (B|A) given that the correct expression is (A|B), which makes it the probability that you got the order of the notation mixed up.<br />
<br />
==Trivia==<br />
When this comic came out, the title text was only "P((B", the comic itself linked to [https://xkcd.com/2545/A) A)] or [https://xkcd.com/A) A)] (depending on where the comic was viewed from), and the "Black Lives Matter" image in the header was replaced by "(A", but this was quickly corrected. ([https://web.archive.org/web/20211122212442/https://xkcd.com/2545/ archive])<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
:[Miss Lenhart using a pointer and pointing to a white-board with statistical formulae]<br />
:Miss Lenhart: Given these prevalences, is it likely that the test result is a false positive?<br />
:(off-panel voice): Well, this chapter is on Bayes' Theorem, so yes.<br />
<br />
:[Caption below the panel]:<br />
:Sometimes, if you understand Bayes' Theorem well enough, you don't need it.<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Comics featuring Miss Lenhart]]<br />
[[Category:Statistics]]</div>172.70.86.12https://www.explainxkcd.com/wiki/index.php?title=2542:_Daylight_Calendar&diff=2209352542: Daylight Calendar2021-11-17T17:11:07Z<p>172.70.86.12: /* Explanation */ added note on number of days in a year</p>
<hr />
<div>{{comic<br />
| number = 2542<br />
| date = November 15, 2021<br />
| title = Daylight Calendar<br />
| image = daylight_calendar.png<br />
| titletext = Could be worse. In some towns north of here, it's already December, and the 21st will last for nearly a week.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created at CINNAMON O'CLOCK - No comment yet on Cueball's delight in the extra dead line time. No direct explanation on how the 21 december for a week comes about in the title text. Only indirect from other parts of explanation. Please change this comment when editing this page. Do NOT delete this tag too soon.}}<br />
<br />
At the time of this posting, the United States had ended {{w|daylight saving time}} (DST) recently, on November 7, and returned to standard time. Daylight saving time is a practice of setting clocks ahead by 1 hour during warmer months to effectively 'borrow' some of the typically unused early morning light and pass it down to the late evening where more people can make use of it. In the United States, daylight saving time starts on the second Sunday in March and ends on the first Sunday in November. <br />
<br />
A result of ending of daylight saving time is the sun setting earlier than people are used to, as people have become acclimatised to the shifted clocks &mdash; though it does mean an 'extra' hour of light has returned to the seasonally redarkening mornings. The first sentence of the comic may be the start of a typical comment about how the sun seems to set earlier than usual in November; which it does anyway (north of the equator) but the clock-shift makes it even more obvious. <br />
<br />
In this comic, however, Randall turns the normal talk about DST on its head by devising a [[:Category:Calendar|calendar system]] where the dates "change" based on 12 hours of daylight. This causes shorter "days" in the summer months, which may get more than 12 hours of daylight in a "solar day" and longer "days" in the winter months which would have fewer hours of daylight in a "solar day". As mentioned in the title text, this change would be very pronounced near the poles, which may only get a few hours of daylight per 24 hours in the winter, but conversely may get 20 or more hours of daylight per 24 hours in the summer.<br />
<br />
At temperate latitudes and above, as the calendar goes towards winter (for your hemisphere) the length of daylight per daily cycle shortens. Instead of having "long summer days" (i.e. periods of daylight) and shorter ones in the winter, but still the artificial pressures of a regulated 24-hour cycle to adhere to, the proposal seems to be that the date gets incremented whenever (and ''only'' when) twelve hours of daylight have passed.<br />
<br />
In the summer, a day-count starting at sunrise could require a late-afternoon switch to 'tomorrow', which would in turn be switched earlier still the next day as it was already partly used up, with possibly two date-changes per astronomical day (early morning and mid-evening, for example). As winter draws on, not enough daylight will pass to guarantee a date-change in any single period. On the day of this comic's release - November 15, 2021 - Massachusetts, where Randall lives, gets ten hours and forty five minutes between {{w|civil twilight}}s. It is possible that the last day-mark was late during the previous daylight cycle and the next one won't be until early in the following one.<br />
<br />
Depending on how exactly daylight is measured, we may have more "days" in a year than the usual 365, since refraction of light near the horizon means that the sun is visible slightly more than 50% of the year on average. This effect is strongest near the poles, since the sun spends more time near the horizon. In addition, due the Earth's elliptical orbit, more northerly parts of the Earth receive more sunlight than southerly parts. Combined, these effects mean that a year at the north pole is 381 "days", compared to 369 at the Equator.<br />
<br />
Exactly how the time is marked is not fully explained. Starting each day-period at 00:00 would be easiest, but could be a psychological step too far. One possibility is to set a nominal 00:00 six hours before a day-change, in line with an 'idealised' twelve-hours-of-daylight day, but disregard hours 'belonging' to a prior daylight period. Then keep the clock running (throughout any intervening nights and into the next daylight as necessary) until the date clicks over and realigns as necessary. Clock times would not reach 23:59 for most of the summer, and could far exceed that in the winter. Megan's clock has reached 26:15, by this sunset, and may well be due to be far into the 30-hours range before more daylight and the moving on to the new date and reset time, if not beyond.<br />
<br />
Beyond the arctic (and antarctic) circle, twelve hours of daylight would be accumulated up twice per traditional day, at times, while being effectively on hold for much of the other six months, depending upon actual latitude.<br />
<br />
==Transcript==<br />
:[Megan is looking down at her phone which she holds up in her hand, while Cueball stands next to her]:<br />
:Megan: Ugh, I hate November. It's 26:15 and the sun is setting ''again!''<br />
:Megan: 3-day days are the worst.<br />
:Cueball: I like it. I know it's dark, but it's nice to have the extra time on deadlines.<br />
<br />
:[Caption below the panel]:<br />
:In our new calendar system, the date changes after every 12 hours of daylight, regardless of how long that takes.<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Comics featuring Megan]]<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Calendar]]<br />
[[Category:Daylight saving time]]</div>172.70.86.12https://www.explainxkcd.com/wiki/index.php?title=Talk:2541:_Occam&diff=220759Talk:2541: Occam2021-11-13T04:55:15Z<p>172.70.86.12: </p>
<hr />
<div><!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--><br />
<br />
The minimalist nature of the cartoon seems appropriate to the subject.<br />
I think keeping the explanation simple would also be appropriate.<br />
My attempt was:<br />
<br />
Combines {{w| Occam's razor}} with the {{w| barber paradox}}. <br />
The title text refers to {{w| Murphy's law}}.<br />
<br />
Which promptly was greatly expanded. [[Special:Contributions/162.158.106.131|162.158.106.131]] 20:28, 12 November 2021 (UTC)<br />
<br />
:Aye, sorry about that. I also thought I was minimalist (except for the different Incomplete-BOT-thing submitted, probably) and consciously overwrote you by my own 'from scratch' one after I got the inevitable edit-conflict. I might not have done, but I believe your explanation would have suffered later hyperverbiation by others, anyway, but mine covered at least one extra issue (the continuity of the razor throughout it all) that could postpone this. [[Special:Contributions/172.70.162.57|172.70.162.57]] 20:36, 12 November 2021 (UTC)<br />
<br />
::No worries. "Simplify, simplify, simplify!" - Thoreau<br />
::"Why didn't he just say Simplify" - One of the panelists on Says You [[Special:Contributions/162.158.106.131|162.158.106.131]] 20:46, 12 November 2021 (UTC)<br />
<br />
Shouldn't the name of the comic be "Razor", since that's the common concept? [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 22:50, 12 November 2021 (UTC)<br />
<br />
The highest likelihood (and funnier line) is that Peter (referring to The Peter Principle) grabs the razor.{{unsigned}}<br />
<br />
Benford may have something to say about the number of injuries he subsequently observes needing treatment, on any given day... [[Special:Contributions/172.70.86.12|172.70.86.12]] 04:55, 13 November 2021 (UTC)</div>172.70.86.12https://www.explainxkcd.com/wiki/index.php?title=2541:_Occam&diff=2207502541: Occam2021-11-12T20:46:52Z<p>172.70.86.12: /* Explanation */ Tweak for better reading. Minimal expansion.</p>
<hr />
<div>{{comic<br />
| number = 2541<br />
| date = November 12, 2021<br />
| title = Occam<br />
| image = occam.png<br />
| titletext = Oh no, Murphy just picked up the razor.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a BOT THAT ONLY CREATES ALL PAGES NOT MENTIONING ITSELF - Please change this comment when editing this page. Do NOT delete this tag too soon.}}<br />
<br />
This comic conflates three conceptual approaches. {{w|Occam's Razor}}, the {{w|Barber Paradox}} and {{w|Murphy's Law}}.<br />
<br />
Occam suggests that explanations should not add unnecessary entities (but be the 'simplest'). The '{{w|Philosophical razor|razor}}' is a principal that conceptually cuts away alternative explanations.<br />
<br />
The Barber Paradox is a puzzle, derived from {{w|Russell's paradox}}, in which a barber is expected to shave (with an in-universe razor) all men in his town who do not shave themselves. The question is whether he must/must not thus shave himself.<br />
<br />
In the titletext, Murphy is invoked with the expectation that if anything can go wrong it will. Shaving with a {{w|Straight razor|cut-throat razor}} has failure modes including one explained by this name.<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
[One panel. Megan and Cueball walking.]<br />
<br />
Megan: The simplest explanation is that Occam shaves the barber.<br />
<br />
{{comic discussion}}</div>172.70.86.12https://www.explainxkcd.com/wiki/index.php?title=Talk:2541:_Occam&diff=220745Talk:2541: Occam2021-11-12T20:37:54Z<p>172.70.86.12: </p>
<hr />
<div><!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--><br />
<br />
The minimalist nature of the cartoon seems appropriate to the subject.<br />
I think keeping the explanation simple would also be appropriate.<br />
My attempt was:<br />
<br />
Combines {{w| Occam's razor}} with the {{w| barber paradox}}. <br />
<br />
The title text refers to {{w| Murphy's law}}.<br />
<br />
Which promptly was greatly expanded. [[Special:Contributions/162.158.106.131|162.158.106.131]] 20:28, 12 November 2021 (UTC)<br />
<br />
:Aye, sorry about that. I also thought I was minimalist (except for the different Incomplete-BOT-thing submitted, probably) and consciously overwrote you by my own 'from scratch' one after I got the inevitable edit-conflict. I might not have done, but I believe your explanation would have suffered later hyperverbiation by others, anyway, but mine covered at least one extra issue (the continuity of the razor throughout it all) that could postpone this. [[Special:Contributions/172.70.162.57|172.70.162.57]] 20:36, 12 November 2021 (UTC)</div>172.70.86.12https://www.explainxkcd.com/wiki/index.php?title=2540:_TTSLTSWBD&diff=2207172540: TTSLTSWBD2021-11-12T16:49:26Z<p>172.70.86.12: /* Explanation */ Nonwiki-type link correction (looks like it was tried to be hardcoded with a Ref# at some point). Wish I knew the Wikicommons tag-code off the top of my head, though.</p>
<hr />
<div>{{comic<br />
| number = 2540<br />
| date = November 10, 2021<br />
| title = TTSLTSWBD<br />
| image = ttsltswbd.png<br />
| titletext = Tomorrow's sessions will be entirely devoted to sewing machine rotary hooks.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by an EXCESSIVELY LONG ACRONYM THAT SEEMS LIKE IT SHOULD WORK BUT DOESN'T. Do NOT delete this tag too soon.}}<br />
<br />
[[Cueball]] is standing at a lectern on a [[1661: Podium|podium]], addressing a large crowd. He is describing the program of some event, listing the different topics that will be covered. These appear to be random, but the caption gives the punchline: it is a conference on things that seem like they shouldn't work but do.<br />
<br />
By "things that seem like they shouldn't work", it means things that the average person would have some intuitive sense that the function of thing was impossible, and yet ample real-world experience shows that they do, and may become a routine function that people depend upon. TTSLTSWBD in the title and the banner is the abbreviation for "Things That Seem Like They Shouldn't Work, But Do".<br />
<br />
{{w|Organ transplantation}}, where a functioning organ is cut out of one person (possibly a dead one) and put into another person where it will now operate for their benefit. Given the very complex and delicate nature of living tissue, it's rather surprising that this could work at all. In reality, it's not a simple process, and a lot of things could go wrong, but modern medicine is advanced enough that organ transplantation is widely accepted and regularly practiced, usually functioning well enough to extend life.<br />
<br />
{{w|Airship|Airships}}, or dirigibles, are [https://upload.wikimedia.org/wikipedia/commons/e/ee/Giant_Aircraft_Comparison.svg huge], rigid structures which are filled with bags of lighter-than-air gas, which causes the entire structure to float, and could carry both passengers and significant loads. The idea of such a huge vessel traveling, able to both move rapidly and float in place, would be hard to imagine if it didn't exist, yet zeppelins functioned and were a practical mode of transportation for a time. Unlike the other things mentioned, airships are largely obsolete (having lost favor due to {{w|Hindenburg_disaster|safety concerns}} and surpassed by other technologies)<br />
<br />
{{w|Lunch|Lunch}} is listed as if it was another topic of the TTSLTSWBD, but it actually just means that after discussing airships, the conference will take a break to eat lunch, as many [[1530:_Keyboard_Mash|humans]] usually do.<sup>&#91;[[285: Wikipedian Protester|''citation needed'']]&#93;</sup> Because lunch is a relatively modern construction, filling a niche that grew after dinner shifted later into the day, it may defy one's intuition. In this sense, a three-meal day may seem like it shouldn't work, but most who observe all three meals on schedule would likely argue that it does.<br />
<br />
{{w|Gyroscope|Gyroscopes}} are simple devices consisting of a spinning disc mounted inside three concentric {{w|Gimbal|gimbals}}. The rotational inertia of the disc resists change in orientation, and the gimbals allow it to remain in a single orientation, even when it's mounted to something that's moving. The notion that a disc can remain steady, even when everything around it is moving can be counterintuitive even to those who understand the physical principles. This weirdness has been previously referenced in [[332: Gyroscopes]]. <br />
<br />
{{w|Butterfly|Butterflies}} fly with an unusual fluttering pattern, which works in part due to the {{w|Ornithopter#Aerodynamics|notoriously complex principles of fluid dynamics}} that may look like uncontrolled fluttering but yet somehow allows the creature to land directly on specific flowerheads to feed. This is not as intuitively understandable as the flight of larger creatures such as birds.<br />
<br />
The title text refers to {{w|Rotary hook|rotary hooks}} on sewing machines, which are a complicated (and complicated looking) mechanism whose purpose is to feed one thread in a loop around a whole spool of another thread, and are apparently counterintuitive enough that the conference feels they need a whole day to cover them.<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
:[Cueball stands at a lectern gesturing with one hand held out, speaking to an audience. A banner hangs on the wall with the acronym "TTSLTSWBD" displayed in large text, with illegible smaller text under it.]<br />
:Cueball: Next we have a session on organ transplants and another on airships.<br />
:Cueball: Then lunch, then we'll have one on gyroscopes and one on butterflies.<br />
:[Caption below panel:]<br />
:The first annual conference on Things That Seem Like They Shouldn't Work But Do<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Animals]]</div>172.70.86.12