https://www.explainxkcd.com/wiki/api.php?action=feedcontributions&user=141.101.104.77&feedformat=atomexplain xkcd - User contributions [en]2024-03-19T03:06:16ZUser contributionsMediaWiki 1.30.0https://www.explainxkcd.com/wiki/index.php?title=Talk:2016:_OEIS_Submissions&diff=159786Talk:2016: OEIS Submissions2018-07-08T19:41:48Z<p>141.101.104.77: </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 />
"All integers which do not appear in the example terms of another OEIS sequence" there is no paradox: it's pecified *another* sequence<br />
[[Special:Contributions/162.158.154.133|162.158.154.133]] 17:52, 6 July 2018 (UTC)<br />
<br />
I am so sorry that this comment is not related to the strip, but is the scaling for the explanation way off? Previously the scaling of the whole website was stretched, but now it is a bit too cramped for me. It happens to the previous strips too.Boeing-787lover 18:10, 6 July 2018 (UTC)<br />
<br />
Is it too much of a stretch to mention that Chris Hemsworth stars in the movie ''Blackhat'', which is also a nickname for an XKCD character? [[User:John at work|John at work]] ([[User talk:John at work|talk]]) 19:31, 6 July 2018 (UTC)<br />
<br />
The Sub 59 one is also a paradox, it specifies that it should include all of the author's accepted submissions, so it would have to be on it's own list itself in order to be accurate? [[Special:Contributions/172.68.58.233|172.68.58.233]] 19:47, 6 July 2018 (UTC)<br />
:No, it would not be paradoxical. If it is accepted, then the sequence contains its identification number. If it is not accepted, that number is not in the sequence. The sequence changes depending on its own status, but there is no contradiction. This is different from e.g. the set of sets that don't contain themselves. If that set contained itself, it shouldn't contain itself, and if it didn't contain itself, it should contain itself. Both alternatives are logically impossible, so the set itself is impossible. There is nothing impossible about submission 59. [[User:Howtonotwin|Howtonotwin]] ([[User talk:Howtonotwin|talk]]) 20:15, 6 July 2018 (UTC)<br />
:If OEIS would bend their own rule and allow a sequence of one number, they could accept SUB[59] , and it will never be out of date as long as they never accept another RM submittal.[[User:GODZILLA|GODZILLA]] ([[User talk:GODZILLA|talk]]) 00:49, 8 July 2018 (UTC)<br />
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The Westside IRT stops sequence is a wonderful piece of trivia. I found [https://www.nytimes.com/1987/01/27/science/in-a-random-world-he-collects-patterns.html the NYT article], which gives as its reason that at that time only infinite sequences were included. I have failed to find the necessary third-party reference to the inclusion of the sequence in OEIS (this, being an open wiki, is unacceptable) to include the point in {{w|IRT Broadway–Seventh Avenue Line|the Wikipedia article on the West Side IRT}}. Can anybody supply one? [[User:Yngvadottir|Yngvadottir]] ([[User talk:Yngvadottir|talk]]) 20:35, 6 July 2018 (UTC)<br />
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I'm wondering about the comment "In UTF-16, a 9 takes up 2 bytes," about the 2 TB of 9s. Does OEIS store numbers in UTF-16 format? [[Special:Contributions/172.68.174.94|172.68.174.94]] 21:01, 6 July 2018 (UTC) nprz<br />
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<br />
Helvetica seems to be one of the fonts where all digits have the same width (so that columns of numbers line up). Strangely, there seems to be a kerning pair for "11" that some Software uses. "Helvetica Neue" does not seem to have that kerning pair. (Tested using the simple HTML page in https://gist.github.com/hn3000/bec217afe666b0ee0a0430e976df4d22#file-numbers-by-width-in-font-html ).<br />
[[User:Hn3000|Hn3000]] ([[User talk:Hn3000|talk]]) 11:04, 7 July 2018 (UTC)<br />
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Such a coincidence! I've been working on my first submission all week and wrote an Emacs Lisp program that discovered the third integer pair the day this came out! You get to see it now that I have a number allocated ([https://oeis.org/A316587 A316587]): 12, 34, 56, 78, 6162, 7879. Can you find the next number in the sequence? Hint: my sequence is a proper subset of A001704. Still editing before I submit for approval. ''&mdash; [[User:Tbc|tbc]] ([[User talk:Tbc|talk]]) 18:11, 7 July 2018 (UTC)''<br />
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Digits do not have the same width in Helvetica, at least not in the version of Helvetica I have. Using the PHP function [http://php.net/imagettfbbox imagettfbbox] (part of the GD library), here is the bounding box width of single digits in 12pt size:<br />
5 points: '1'. 8 points: '4', '7'. 9 points: '0', '2', '3', '5', '6', '8', '9'.<br />
With a very large size (480pt) the differences ar more notable:<br />
166 points: '1'. 302 points: '9'. 307 points: '6'. 308 points: '2', '8'. 309 points: '0', '5'. 311 points: '7'. 313 points: '3'. 318 points: '4'.<br />
<br />
For 2-digit numbers in 480pt size I find: 522 points: '11'. 559 points: '61', '71'. 560 points: '91'. 562 points: '21'. 563 points: '51', '81'. 566 points: '41'. 568 points: '31'. 620 points: '19'. 623 points: '13'. 624 points: '10', '15', '18'. 625 points: '12'. 626 points: '16'. 629 points: '14', '17'. The rest range from 657 to 675 points.<br />
<br />
In short, sub[44] makes sense, with all the caveats mentioned in the explanation. The phrases `1 to 9 in no particular order, 11, 10 and 12 to 19 in no particular order and so on' are exaggerated IMHO, the order within these subsets is not completely arbitrary.<br />
Zetfr 10:22, 8 July 2018 (UTC)<br />
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I think that all nines sequence can be reference to Dilbert strip about random number generator which always returns 9 http://dilbert.com/strip/2001-10-25<br />
[[Special:Contributions/141.101.104.77|141.101.104.77]] 19:41, 8 July 2018 (UTC)qbolec</div>141.101.104.77https://www.explainxkcd.com/wiki/index.php?title=1975:_Right_Click&diff=1552291975: Right Click2018-04-02T17:17:50Z<p>141.101.104.77: /* Explanation */</p>
<hr />
<div>{{comic<br />
| number = 1975<br />
| date = April 1, 2018<br />
| title = Right Click<br />
| image = right_click.png<br />
| titletext = "Right-click or long press (where supported) to save!"<br />
}}<br />
'''NOTE: The above is the first panel of an interactive comic.'''<br><br />
To experience the interactive content, click [https://www.xkcd.com/1975/ here] or this link for [https://m.xkcd.com/1975/ mobile devices].<br />
<br />
==Explanation==<br />
{{incomplete|Please add an explanation table of all functions This is an April Fools comic, so it'll take a while to get organised and much longer to fill out. Do NOT delete this tag too soon.}}<br />
<br />
This is an interactive comic which manipulates the context menu of the browser. This menu is typically accessible by a right-click or a long press on mobile devices without a mouse.<br />
<br />
The comic uses {{w|Javascript}} and {{w|HTML5}} to override the standard context menu. Since modern browsers use the same features to integrate Add-ons into that menu, the behaviour may be different depending on the browser environment.<br />
<br />
The manipulated context menu is described below:<br />
;Main Context Menu<br />
<br />
{| border =1 width=100% cellpadding=5 class="wikitable"<br />
! # !! Menu Item !! Explanation !! Sub-Menu Items<br />
|-<br />
!1<br />
| '''Save'''<br />
| Only appears after successfully completing the ADVENT.EXE game or getting the easter egg in mornington crescent.<br />
| Save image> Downloads this image. [https://xkcd.com/1975/v6xso1_right_click_save.png]<br />
<br />
|-<br />
! 2 <br />
| '''File''' <br />
| Normal submenu <br />
|Close> Closes menu, does nothing.<br />
Open: A:\, C:\, / (See more [[#Table - Filesystems Menu|below]])<br />
<br />
Find: Where, When, How, (not usable) What, Why<br />
<br />
|-<br />
! 3 <br />
| '''Edit''' <br />
| Enables a mode allowing the user to draw on the webpage. Pressing Esc asks "Aw, that looks nice though. Really delete?" and the page returns to normal if OK is clicked.<br />
| None<br />
|-<br />
! 4 <br />
| '''System''' <br />
| Normal submenu <br />
|Shut Down> Changes the only menu option to "Power on", then once that is used, system returns to normal.<br />
<br />
/ (See [[#Table - Filesystems Menu|below]])<br />
|-<br />
! 5 <br />
| '''View''' <br />
| Normal submenu <br />
|Cascade>Links to [http://wiki.xkcd.com/geohashing/Mt._St._Helens,_Washington]<br />
<br />
Tile> Links to [[245: Floor Tiles]]<br />
<br />
Minimize> Changes pointer to a smaller pointer.<br />
<br />
Full Screen> Enters full screen.<br />
|-<br />
! 6 <br />
| '''Utilities''' <br />
| Normal submenu <br />
|Park drives> Nothing.<br />
<br />
Check space usage> (cannot click) Space usage: -Dark matter -Hydrogen -Helium -Scattered clumps of heavier elements -Stars -Rocks -Some space probes -Earth<br />
<br />
Spell check> English (links to [[1069: Alphabet]]) and Colors (links to [https://blog.xkcd.com/2010/05/03/color-survey-results/])<br />
<br />
Train AI> links to [[1838: Machine Learning]]<br />
<br />
Identify song> opens a long word-by-word menu for song lyrics; it's actually a menu-ised version of [[851: Na]].<br />
<br />
Advanced> several Unix commands, all absurd (or dangerous) for some reason:<br />
* <code>apt-get install /dev/null</code>: <code>apt-get</code> is the standard package manager used in Debian-derived Linux distributions (including Ubuntu); it is normally used to install software; <code>/dev/null</code> is the "bit-bucket" device on any Unix system, which can be used as a dummy output file to discard output or as a dummy empty input file. This command would attempt to install <code>/dev/null</code> (which is a device, not a package!) or, more correctly, would try to install a package reading its data from <code>/dev/null</code> (if <code>apt-get</code> is given a file name it tries to interpret it as a .deb package), which is obviously impossible.<br />
* <code>brew install apt-get</code>: <code>brew</code> is a third-party package manager for macOS; it is generally used to install "missing" open-source utilities on a macOS system; the command is attempting to install the aforementioned <code>apt-get</code>, which is both impossible (<code>apt-get</code> doesn't run on macOS) and hilariously recursive (did you install a package manager - brew - to install another one?). Even if this were possible, the package would have been called "aptitude", as apt-get is only one of the commands in the package manager.<br />
* <code>/usr/local/bin/wine xen-hypervisor.exe</code>: <code>wine</code> is a compatibility layer used to run Windows executables on Linux (and on macOS); the fact that it is in <code>/usr/local</code> hints that it has been manually compiled on this machine; Xen is a Linux-based hypervisor, i.e. a software used to run and manage virtual machines over a Linux host, but the .exe suffix here hints that it is a Windows executable. The command would try to launch a Windows build of a Linux-based virtual machine manager on a Unix machine through a Windows emulation layer (wine).<br />
* <code>source .bash_history</code>: the <code>source</code> shell command reads the file that is given as argument and executes each of its rows as a command in the current shell, roughly as if you typed them in; <code>.bash_history</code> (located in the user home directory) is the file where the bash shell saves the history of the commands that have been run. This command would re-run all the command that have been typed in the shell.<br />
* <code>rm -rf $DIRECTROY/*</code>: <code>rm -rf</code> deletes recursively and forcefully the paths it is given as arguments; <code>$DIRECTROY</code> is a shell variable, probably containing some directory that whoever typed in this command wanted to clean; however, it is misspelled (it says <code>$DIRECTROY</code>, not <code>$DIRECTORY</code>), and, due to how POSIX shell work, it is thus expanded to an empty string; so, the command becomes <code>rm -rf /*</code>, which deletes all the files and directories in the root of the disk, effectively killing the system instead of just deleting the content of some directory. Notice that this particular misspell manages to circumvent the builtin protection of many <code>rm</code> versions, which refuse to do a plain <code>rm -rf /</code>, as <code>/*</code> gets expanded by the shell, so <code>rm</code> never has the chance to see explicitly that you are killing all the data in the root directory.<br />
* <code>:(){:|:&};:</code>: this is [https://askubuntu.com/q/159491/208527 a classic shell fork bomb], i.e. a small program that keeps launching copies of itself, until all resources have been exhausted or the user somehow manages to kill all its copies.<br />
* <code>echo "source .bashrc" >> .bashrc</code>: <code>.bashrc</code> is a file that gets executed whenever the <code>bash</code> shell is started in interactive mode; this command appends the string <code>source .bashrc</code> to it, which effectively executes it again recursively; this would pretty much make it impossible to open an interactive shell when launching it with the default parameters.<br />
* <code>alias gcc=php</code>: the <code>alias</code> shell builtin create an alias for another command; <code>gcc</code> is the GNU C compiler driver, which is used to compile programs written in the C language; <code>php</code> is the command-line interpreter for the PHP language. This line creates an alias such that when typing <code>gcc</code>, <code>php</code> is actually invoked, which would generate completely absurd error messages. This is doubly devious, as PHP isn't generally held in high esteem by large part of the programming community (especially by someone writing stuff in C).<br />
<br />
'); DROP TABLE Menus;-- links to [[327: Exploits of a Mom]]<br />
|-<br />
! 7 <br />
| '''Games''' <br />
| Normal submenu <br />
| Twenty Questions> A Twenty Questions interface that gets really confusing.<br />
<br />
Rock Paper Scissors> A Rock Paper Scissors game where the computer always matches your move.<br />
<br />
D&D> A complex Dungeons and Dragons interface. Allows you to cast various spells from D&D 5e which link to various pages, including xkcd comics (e.g. [[1331: Frequency]]), what-ifs (e.g. {{what if|144|Saliva Pool}}) and other external sites (e.g. [https://www.nasa.gov/sun The Sun | NASA]). <br />
<br />
ADVENT.EXE> A text-based game. If played correctly, you can win, unlocking 'Save'>'Save image' from the beginning menu, which links to [https://xkcd.com/1975/v6xso1_right_click_save.png]. 'ADVENT.EXE>Castle>Well>Wish for...' has links to comics [[572: Together]], [[1053: Ten Thousand]], [[152: Hamster Ball]], [[1196: Subways]], [[231: Cat Proximity]] and to what-if articles {{what if|111|All the Money}} and {{what if|9|Soul Mates}}.<br />
<br />
Hoverboard> Links to [[1608: Hoverboard]].<br />
<br />
Mornington Crescent> This is a simulation of the well-known game {{W|Mornington_Crescent_(game)|Mornington Crescent}}, which bears a surprising resemblance to {{W|London_Underground|London's Underground}} railway network. Players name a station, in turn, endeavouring to reach Mornington Crescent. The rules of play are very complicated and beyond the scope of this article; interested persons are referred to ''N. F. Stovold’s Mornington Crescent: Rules and Origins'' (sadly out of print). In this variation, one may reach 'Vauxhall'>'Easter basket'>'Take egg', also allowing you to save. <br />
|-<br />
! 8 <br />
| '''Help''' <br />
| Contains various submenus, all of which, barring Credits, loop back recursively to this menu:<br />
|Tutorial<br />
Support<br />
<br />
Manual<br />
<br />
Troubleshooting<br />
<br />
FAQ<br />
<br />
Guide<br />
<br />
Q&A<br />
<br />
User forums<br />
<br />
--------------<br />
<br />
Credits> 'Some people who helped with this comic: <br />
[http://chromakode.com/ @chromakode] <br />
[https://twitter.com/aiiane Amber] <br />
[https://twitter.com/fadinginterest @fadinginterest] <br />
[https://twitter.com/wirehead2501 Kat] <br />
[https://twitter.com/cotrone Kevin] <br />
[http://90d.ca/ Stereo]'<br />
|-<br />
! 9<br />
| '''Do Crimes'''<br />
| Contains several "crimes" that can be committed. This option is unlocked by File > Open > C:\ (or /home/user) > Bookmarks/ > Secret > Enable Dark Web.<br />
| Steal Bitcoins > Grayed out.<br />
Say swears > Several clean swears that all link to [[771: Period Speech]].<br />
<br />
Hack > Three sub-options that link to various related comics. (Gibson: Nothing. Election: [[1019: First Post]]. Planet: [[1337: Hack]].)<br />
<br />
Forge a Scrabble Tile > Several sub-options that don't do anything. (U, Z, <this menu option intentionally left blank>, and two special characters, one appearing like a reversed 'E' modelled on a 'C', or Russian 'Э', as low-pitched [eh], and the second being crossed swords)<br />
|}<br />
<br />
<br />
;Filesystems Menu<br />
<br />
{| border =1 width=100% cellpadding=5 class="wikitable"<br />
! Drive !! Menu Item !! Explanation !! Sub-Menu Items<br />
|-<br />
! A:\ <br />
| '''Insert''' <br />
| Only appears before inserting a floppy disk.<br />
|Floppy disk> Unlocks other options for drive A:\, which are identical to drive C:\<br />
Chip card> A long sequence of being told 'Please wait. Authorizing...' ending in 'Chip error! REMOVE CARD NOW!'<br />
|-<br />
! C:\ <br />
| '''Documents/'''<br />
| Nothing.<br />
| None.<br />
|-<br />
! C:\<br />
| '''Music/'''<br />
| Leads to a long string of prompts for song lyrics, same as 'Hey now / Hey now na now / Sing "This Corrosion" to me' inverts the webpage's color. It's actually the same menu that is shown under Utilities>Identify song (which itself is a menu-ised version of [[851: Na]]).<br />
|-<br />
! C:\<br />
| '''Bookmarks/'''<br />
| Similar to Music/, Bookmarks/> Comics leads to a chain from which many comics are titled and linked. Bookmarks/> Secret> Enable Dark Web adds the 'Dark Web' option to the initial menu.<br />
|-<br />
! C:\<br />
| '''Games/'''<br />
| Same as 'Games' from the initial menu.<br />
|-<br />
! C:\<br />
| '''Sequences/'''<br />
| The options are the lines from a ''Tim and Eric'' sketch [http://knowyourmeme.com/memes/celery-man Celery Man]; the final option links to a YouTube video of the sketch.<br />
| After several single-option menus, it links to this Youtube video. https://www.youtube.com/watch?v=MHWBEK8w_YY<br />
|-<br />
! /<br />
| '''home/'''<br />
| Nothing.<br />
| guest> links to [//uni.xkcd.com]<br />
<br />
user> Same files as C:\<br />
<br />
root> Displays 'You are not in the sudoers file. This incident will be reported.'<br />
|-<br />
! /<br />
| '''opt/'''<br />
| Does nothing.<br />
| None.<br />
|-<br />
! /<br />
| '''sbin/'''<br />
| Does nothing.<br />
| None.<br />
|-<br />
! /<br />
| '''usr/'''<br />
| Opens an infinite sequence of options, each similar to the last, but replacing the previous selection with another folder; probably a reference to the fact that [https://www.tldp.org/LDP/Linux-Filesystem-Hierarchy/html/usr.html the /usr hierarchy] does contain a list of subdirectories pretty much identical [https://www.tldp.org/LDP/Linux-Filesystem-Hierarchy/html/the-root-directory.html to those of the root directory].<br />
|-<br />
! /<br />
| '''dev/'''<br />
| Nothing.<br />
|random/> links to a random xkcd comic.<br />
urandom/> links to [[221: Random Number]]<br />
|}<br />
<br />
In an additional fool it introduces the [https://uni.xkcd.com/ Unix XKCD] as a reference to the {{W|Telenet}}. (More on UniXKCD commands can be found [[721:_Flatland#UniXKCD|here]].)<br />
<br />
==Transcript==<br />
:[Empty frame with Cueball slightly right of centre.]<br />
<br />
:[Caption below the frame:]<br />
:Editor's Note: Today's comic is optimized for local viewing. To see the full version, just save a copy of the image!<br />
<br />
{{comic discussion}}<br />
<br />
<!-- Include any categories below this line. --><br />
<br />
[[Category:Interactive comics]]<br />
[[Category:April fools' comics]]</div>141.101.104.77https://www.explainxkcd.com/wiki/index.php?title=1943:_Universal_Dreams&diff=1511631943: Universal Dreams2018-01-17T23:37:34Z<p>141.101.104.77: /* Explanation */ Added nightmare reference and edited incomplete tag</p>
<hr />
<div>{{comic<br />
| number = 1943<br />
| date = January 17, 2018<br />
| title = Universal Dreams<br />
| image = universal_dreams.png<br />
| titletext = "That's ... unsettling." "Yeah, those definitely don't sound like the normal drea– LATITUDE THREE FIVE POINT..." <br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Can someone check whether the clayton movie is actually a reference? Seems to me the nightmare explanation is more relevant.}}<br />
<br />
The first and second panel are a discussion between [[Megan]] and [[Ponytail]] about {{w|Dream|dreams}}. Megan mentions a dream or nightmare about failing to prepare for an exam despite not being a student for years. This is similar to the dream depicted in [[557: Students]]. Ponytail responds that certain dreams occur with surprising frequency among many people, dubbing them "Universal Dreams" (which is the title of the comic).<br />
<br />
In the third panel, [[Black Hat]] describes an avatar of misfortune in the form of a horse appearing on a hill. This may be a reference to [http://www.imdb.com/title/tt0465538/ 2007 film Michael Clayton], which features a dream like sequence where the title character stops his car, gets out and approaches 3 horses on a hillside just minutes before his car explodes. Alternatively, it could be a reference to the "nightmare", a horse that was said to give bad dreams, which is why they are called nightMARES. (Mare means female horse.)<br />
<br />
In the last panel, Black Hat describes having dreams where he receives specific information about the real-world, which seems closer to {{w|List_of_dreams#Prophetic_dreams|prophesying}} or {{w|Precognition#In_dreams|precognition}} than what would be considered a normal dream, as normal dreams do not tell the future. This may be a reference to the [http://www.imdb.com/title/tt0448011/ 2009 film ''Knowing''] where a child writes down the latitude and longitude of disasters (including earthquakes) that will occur 50 years in the future. Dreaming of latitude and longitude was also a topic of [[240: Dream Girl]], but in contrast the events in that dream did not come true.<br />
<br />
In the title text, either [[Megan]] or [[Ponytail]] is responding to black hat when she unexpectedly interrupts herself with the first part of geographic coordinates- Latitude 35, just as Black Hat described, implying the whole comic might be another of Black Hat's dreams. 35 degrees North would include 31 major cities around the world, including 11 in Japan and 8 in the USA; the only major city within 35 degrees South is Canberra, Australia. This suggest an earthquake would happen soon in one of those major cities. The second half of the coordinates are most likely cut off to add uncertainty to the situation.<br />
<br />
==Transcript==<br />
<br />
:[Megan, Ponytail, and Black Hat are standing around.]<br />
:Megan: I've been out of school for years, but I still get those dreams where I have an exam and I didn't prepare.<br />
<br />
:[Ponytail shrugs.]<br />
:Ponytail: I think that's one of those weird universal dreams— like forgetting your clothes or discovering rooms in your house you didn't know about.<br />
<br />
:[Zoom-in on Black Hat.]<br />
:Black Hat: Yeah! Or when you're having a normal dream, but then a horse appears on a distant hilltop, and it means that the dream is about to turn bad!<br />
:Ponytail or Megan (off-screen): I... What?<br />
:Black Hat: I have that one like every night.<br />
<br />
:[Megan and Ponytail look at Black Hat.]<br />
:Black Hat: Or those ones where you're talking to someone, and they start repeating a latitude and longitude over and over, and then you wake up that morning and there's an earthquake there. <br />
:Black Hat: Haha, dreams, right? So weird!<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Comics featuring Megan]]<br />
[[Category:Comics featuring Ponytail]]<br />
[[Category:Comics featuring Black Hat]]<br />
[[Category:Dreams]]</div>141.101.104.77https://www.explainxkcd.com/wiki/index.php?title=765:_Dilution&diff=104734765: Dilution2015-11-08T18:03:22Z<p>141.101.104.77: fixes</p>
<hr />
<div>{{comic<br />
| number = 765<br />
| date = July 12, 2010<br />
| title = Dilution<br />
| image = dilution.png<br />
| titletext = Dear editors of Homeopathy Monthly: I have two small corrections for your July issue. One, it's spelled "echinacea", and two, homeopathic medicines are no better than placebos and your entire magazine is a sham.<br />
}}<br />
<br />
==Explanation==<br />
{{w|Homeopathy}} is the belief that poisons, bacteria, and other harmful substances can actually cure the diseases they normally cause, if they are administered in sufficiently dilute form. The normal procedure is to prepare a solution, then successively dilute it with water or alcohol by multiple factors of 10. (There's also a "succussion" step between rounds, which basically consists of shaking or striking the mixture, but no serious mechanism for how this would affect anything has been provided.) In the medical world, it's widely believed to be total bunk, with countless scientific studies repeatedly showing it to have no more effectiveness than a {{w|placebo}}.<br />
<br />
Here we find [[Cueball]], a firm believer in homeopathy, applying the idea to fertility by diluting his semen. 30X means that the semen has been diluted with water at a 1:10 ratio 30 times, so the solution contains 1 part semen to one-nonillion parts water. Since the average ejaculation contains 200 to 500 million sperm cells, this means the solution Cueball is holding has a 3.5x10<sup>-20</sup>% chance of containing even a single sperm cell. Clearly, [[Megan]] will not be getting pregnant from this, so she and Cueball will not be passing on their genes, which is why the comic states that the belief in homeopathy is not selected for.<br />
<br />
{{w|Echinacea}} is a genus of flowers commonly used in herbal remedies to stimulate the immune system. Scientific studies have not shown that such an effect exists. The title text is intended to represent a letter to the editors of fictitious journal 'Homeopathy Monthly', starting with a minor complaint that they seem unable to perform the basic proof-reading and fact-checking necessary to correctly spell one of the most well-known herbal remedies. This is followed up by a complete dismissal of homeopathy as a whole and the magazine in particular.<br />
<br />
==Transcript==<br />
:[Cueball stands at a desk with a beaker in one hand and a turkey baster in the other. Danish lies in a bed in the same room.]<br />
<br />
:Cueball: Okay, this time I've diluted the semen 30x.<br />
:Danish: We'll be ''sure'' to get pregnant now!<br />
<br />
:Belief in homeopathy is not, evolutionarily, selected for.<br />
<br />
{{comic discussion}}<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Sex]]<br />
[[Category:Comics featuring Danish]]</div>141.101.104.77https://www.explainxkcd.com/wiki/index.php?title=765:_Dilution&diff=104733765: Dilution2015-11-08T18:01:46Z<p>141.101.104.77: /* Explanation */</p>
<hr />
<div>{{comic<br />
| number = 765<br />
| date = July 12, 2010<br />
| title = Dilution<br />
| image = dilution.png<br />
| titletext = Dear editors of Homeopathy Monthly: I have two small corrections for your July issue. One, it's spelled "echinacea", and two, homeopathic medicines are no better than placebos and your entire magazine is a sham.<br />
}}<br />
<br />
==Explanation==<br />
{{w|Homeopathy}} is the belief that poisons, bacteria, and other harmful substances can actually cure the diseases they normally cause, if they are administered in sufficiently dilute form. The normal procedure is to prepare a solution, then successively dilute it with water or alcohol by multiple factors of 10. (There's also a "succussion" step between rounds, which basically consists of shaking or striking the mixture, but no serious mechanism for how this would affect anything has been provided.) In the medical world, it's widely believed to be total bunk, with countless scientific studies repeatedly showing it to have no more effectiveness than a {{w|placebo}}.<br />
<br />
Here we find [[Cueball]], a firm believer in homeopathy, applying the idea to fertility by diluting his semen. 30X means that the semen has been diluted with water at a 1:10 ratio 30 times, so the solution contains 1 part semen to one-nonillion parts water. Since the average ejaculation contains 200 to 500 million sperm cells, this means the solution Cueball is holding has a 3.5x10<sup>-20</sup>% chance of containing even a single sperm cell. Clearly, [[Danish]] will not be getting pregnant from this, so she and Cueball will not be passing on their genes, which is why the comic states that the belief in homeopathy is not selected for.<br />
<br />
{{w|Echinacea}} is a genus of flowers commonly used in herbal remedies to stimulate the immune system. Scientific studies have not shown that such an effect exists. The title text is intended to represent a letter to the editors of fictitious journal 'Homeopathy Monthly', starting with a minor complaint that they seem unable to perform the basic proof-reading and fact-checking necessary to correctly spell one of the most well-known herbal remedies. This is followed up by a complete dismissal of homeopathy as a whole and the magazine in particular.<br />
<br />
==Transcript==<br />
:[Cueball stands at a desk with a beaker in one hand and a turkey baster in the other. Danish lies in a bed in the same room.]<br />
<br />
:Cueball: Okay, this time I've diluted the semen 30x.<br />
:Danish: We'll be ''sure'' to get pregnant now!<br />
<br />
:Belief in homeopathy is not, evolutionarily, selected for.<br />
<br />
{{comic discussion}}<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Sex]]<br />
[[Category:Comics featuring Danish]]</div>141.101.104.77https://www.explainxkcd.com/wiki/index.php?title=Talk:1555:_Exoplanet_Names_2&diff=98286Talk:1555: Exoplanet Names 22015-07-24T05:34:23Z<p>141.101.104.77: </p>
<hr />
<div>[https://www.youtube.com/watch?v=znxFrgql5dc "This Land"] is a ''Firefly'' reference. [[User:Keavon|Keavon]] ([[User talk:Keavon|talk]]) 05:11, 24 July 2015 (UTC)<br />
<br />
.. I almost feel like that titletext gives enough reason for there to be (some) pages about the [[what_if?|''What If?'']] series, but ehhhh... [[User:Pixali|<font color="008000">Pixali</font>]] ([[User talk:Pixali|<font color="004b00">talk</font>]]|[[Special:Contributions/Pixali|<font color="004b00">contribs</font>]]) 05:02, 24 July 2015 (UTC)<br />
<br />
What is with Kepler-283? [[Special:Contributions/108.162.214.137|108.162.214.137]] 05:09, 24 July 2015 (UTC)<br />
:283b is the phonetic spelling for Uranus (your-a-nus) and 283c is the phonetic spelling for Uranus (your-ay-nus) [[Special:Contributions/141.101.104.77|141.101.104.77]] 05:33, 24 July 2015 (UTC)<br />
<br />
== Novella ==<br />
<br />
I'm not 100% sure what "Novella" refers to, aside from the dictionary definition of the word (and if that's the case I'm unsure of the context), but in case it's not widely-known on this wiki, I want to suggest the possibility that it's a tribute to the Novella brothers, who are among the co-hosts of the popular science podcast The Skeptic's Guide to the Universe. - [[Special:Contributions/108.162.241.175|108.162.241.175]] 04:43, 24 July 2015 (UTC)</div>141.101.104.77https://www.explainxkcd.com/wiki/index.php?title=Talk:1555:_Exoplanet_Names_2&diff=98285Talk:1555: Exoplanet Names 22015-07-24T05:33:06Z<p>141.101.104.77: </p>
<hr />
<div>[https://www.youtube.com/watch?v=znxFrgql5dc "This Land"] is a ''Firefly'' reference. [[User:Keavon|Keavon]] ([[User talk:Keavon|talk]]) 05:11, 24 July 2015 (UTC)<br />
<br />
.. I almost feel like that titletext gives enough reason for there to be (some) pages about the [[what_if?|''What If?'']] series, but ehhhh... [[User:Pixali|<font color="008000">Pixali</font>]] ([[User talk:Pixali|<font color="004b00">talk</font>]]|[[Special:Contributions/Pixali|<font color="004b00">contribs</font>]]) 05:02, 24 July 2015 (UTC)<br />
<br />
What is with Kepler-283? [[Special:Contributions/108.162.214.137|108.162.214.137]] 05:09, 24 July 2015 (UTC)<br />
:283b is the phonetic spelling for Uranus (your-a-nus) and 283c is the phonetic spelling for Uranus (your-a-nus) [[Special:Contributions/141.101.104.77|141.101.104.77]] 05:33, 24 July 2015 (UTC)<br />
<br />
== Novella ==<br />
<br />
I'm not 100% sure what "Novella" refers to, aside from the dictionary definition of the word (and if that's the case I'm unsure of the context), but in case it's not widely-known on this wiki, I want to suggest the possibility that it's a tribute to the Novella brothers, who are among the co-hosts of the popular science podcast The Skeptic's Guide to the Universe. - [[Special:Contributions/108.162.241.175|108.162.241.175]] 04:43, 24 July 2015 (UTC)</div>141.101.104.77https://www.explainxkcd.com/wiki/index.php?title=Talk:1489:_Fundamental_Forces&diff=84841Talk:1489: Fundamental Forces2015-02-21T13:45:43Z<p>141.101.104.77: </p>
<hr />
<div><br />
«The off-panel audience, probably a student or class, is interested, but quickly begins to realize Cueball's lack of understanding. Instead of acknowledging the problem directly, Cueball simply blusters onwards.»<br />
<br />
My interpretation is rather different. It looks like Cueball is a physicist who knows that the distinction of "four fundamental forces" is basically wrong/obsolete (the term "force" is not even used anymore in theoretical physics), but since his audience are high school students, he can't go into the many complex details underlying the fundamental interactions, and therefore is forced to gloss over it. This is confirmed by the title text (if Cueball didn't understand the theory of fundamental interactions, he wouldn't give that answer). --[[Special:Contributions/188.114.101.78|188.114.101.78]] 10:31, 20 February 2015 (UTC)<br />
<br />
To me it appeared as a typical exam situation for Cueball with '''him''' being the pupil. And ironically that situation looks similar to the real scientific understanding of the topic. [[User:Renormalist|Renormalist]] ([[User talk:Renormalist|talk]]) 11:12, 20 February 2015 (UTC)<br />
: I could see that, to an extent - it doesn't jive with the title text IMO, and it's less funny that a student would be glossing over this stuff than a someone in an instructive role, but I could see it -- [[User:Brettpeirce|Brettpeirce]] ([[User talk:Brettpeirce|talk]]) 11:46, 20 February 2015 (UTC)<br />
<br />
Irony like this is not uncommon in physics. What was the first encounter with electric phenomena? Triboelectricity. What don't we understand at all? Right. Or take Zenos paradoxon. Or the divisibility paradoxon. The oldest nuts tend to be the toughest. [[Special:Contributions/108.162.230.221|108.162.230.221]] 12:26, 20 February 2015 (UTC)<br />
<br />
:I'm not sure about ''the'' first one, but one of first electromagnetic phenomenons we encountered was light. We first observed it about 200000 years ago. :P [[Special:Contributions/141.101.104.77|141.101.104.77]] 13:45, 21 February 2015 (UTC)<br />
<br />
I knew from the title, "Fundamental Horses", that this was going to be a great one. {{unsigned ip|199.27.128.200}}<br />
<br />
I prefer Chromatic Horse and Flavor Horse. Why use weak names when we have new strong ones? [[Special:Contributions/108.162.254.98|108.162.254.98]] 11:58, 20 February 2015 (UTC)<br />
<br />
In high school Physics, my class was taught that physicists had recently combined the Electromagnetic and Weak Nuclear forces into the Electro-Weak Force, so there were only three and if we were to find the Higgs Boson, there might be just two or one. [[Special:Contributions/108.162.241.11|108.162.241.11]] 21:55, 20 February 2015 (UTC)<br />
:Actually, it is the Higgs Boson, that combines the electromagnetic and the weak nuclear interaction into the electroweak interaction, so it's still 3. But actually, even if electromagnetism and the weak interaction can be described in one theory, they are still viewed as two different phenomena, so it actually will always be 4. (Unless we discover other interactions). --[[Special:Contributions/141.101.105.192|141.101.105.192]] 22:23, 20 February 2015 (UTC)</div>141.101.104.77https://www.explainxkcd.com/wiki/index.php?title=Talk:1486:_Vacuum&diff=84453Talk:1486: Vacuum2015-02-13T13:59:44Z<p>141.101.104.77: Unsigned comments...</p>
<hr />
<div>This is obviously a reference to [http://en.wikipedia.org/wiki/Vacuum_energy Vacuum Energy].<br />
The "Tremendous" part is because calculation based on quantum electrodynamics suggest it should be 100 order of magnitudes larger than measured (That is a "1" with 100 zeros after it). [[Special:Contributions/141.101.98.202|141.101.98.202]] 09:42, 13 February 2015 (UTC)<br />
:AKA a googolplex -- [[User:Brettpeirce|Brettpeirce]] ([[User talk:Brettpeirce|talk]]) 12:55, 13 February 2015 (UTC)<br />
::No, that's just a googol. [[Special:Contributions/141.101.104.77|141.101.104.77]] 13:55, 13 February 2015 (UTC)<br />
<br />
Wondering if this is a reference to Terramex [http://tvtropes.org/pmwiki/pmwiki.php/VideoGame/Terramex] {{unsigned|Stese}}<br />
<br />
:My antivirus says this link is [[609|not safe]]. [[Special:Contributions/141.101.104.77|141.101.104.77]] 10:50, 13 February 2015 (UTC)<br />
::can't speak to your antivirus, but I don't see any problem with the site (TVTropes) - it's a page about a video game called "Terramex" (which in summary is a game about adventurers finding a scientist that can prevent a meteor from hitting Earth) - no idea what that might have to do with vacuum energy, vacuum cleaners, living rooms, berets, or billiard balls, or even flying, but oh well -- [[User:Brettpeirce|Brettpeirce]] ([[User talk:Brettpeirce|talk]]) 12:55, 13 February 2015 (UTC)<br />
I tried to read this explanation, but couldn't because of xkcd 1240 [[Special:Contributions/141.101.98.63|141.101.98.63]] 10:23, 13 February 2015 (UTC)<br />
I was expecting something related to February 14. You know, something about YouTube, IBM, ENIAC, Pale Blue Dot, Shoemaker, Hilbert, Catalan, etc. [[Special:Contributions/141.101.104.77|141.101.104.77]] 10:39, 13 February 2015 (UTC)<br />
<br />
Isn't 'the universe is mine to command!' a quote from Aladdin?? {{unsigned|Atty70}}<br />
<br />
:Yes it is a quote from Aladdin (by Jafar when he becomes a genie) [http://www.imdb.com/title/tt0103639/quotes]. It is also a quote from "insert your bond/sci-movie here" as it is the usual goal for any scientist that creates a lot of energy or a new weapon (only exception to this is in the real world with Einstein and the atomic bomb). Maybe something to add to the description (looking at someone with better english and story telling skills than I got) [[User:Aquaplanet|Aquaplanet]] ([[User talk:Aquaplanet|talk]]) 12:44, 13 February 2015 (UTC)<br />
<br />
faced?[[Special:Contributions/108.162.249.157|108.162.249.157]] 12:53, 13 February 2015 (UTC)</div>141.101.104.77https://www.explainxkcd.com/wiki/index.php?title=Talk:1486:_Vacuum&diff=84452Talk:1486: Vacuum2015-02-13T13:55:31Z<p>141.101.104.77: </p>
<hr />
<div>This is obviously a reference to [http://en.wikipedia.org/wiki/Vacuum_energy Vacuum Energy].<br />
The "Tremendous" part is because calculation based on quantum electrodynamics suggest it should be 100 order of magnitudes larger than measured (That is a "1" with 100 zeros after it). [[Special:Contributions/141.101.98.202|141.101.98.202]] 09:42, 13 February 2015 (UTC)<br />
:AKA a googolplex -- [[User:Brettpeirce|Brettpeirce]] ([[User talk:Brettpeirce|talk]]) 12:55, 13 February 2015 (UTC)<br />
::No, that's just a googol. [[Special:Contributions/141.101.104.77|141.101.104.77]] 13:55, 13 February 2015 (UTC)<br />
<br />
Wondering if this is a reference to Terramex [http://tvtropes.org/pmwiki/pmwiki.php/VideoGame/Terramex]<br />
<br />
:My antivirus says this link is [[609|not safe]]. [[Special:Contributions/141.101.104.77|141.101.104.77]] 10:50, 13 February 2015 (UTC)<br />
::can't speak to your antivirus, but I don't see any problem with the site (TVTropes) - it's a page about a video game called "Terramex" (which in summary is a game about adventurers finding a scientist that can prevent a meteor from hitting Earth) - no idea what that might have to do with vacuum energy, vacuum cleaners, living rooms, berets, or billiard balls, or even flying, but oh well -- [[User:Brettpeirce|Brettpeirce]] ([[User talk:Brettpeirce|talk]]) 12:55, 13 February 2015 (UTC)<br />
I tried to read this explanation, but couldn't because of xkcd 1240 [[Special:Contributions/141.101.98.63|141.101.98.63]] 10:23, 13 February 2015 (UTC)<br />
I was expecting something related to February 14. You know, something about YouTube, IBM, ENIAC, Pale Blue Dot, Shoemaker, Hilbert, Catalan, etc. [[Special:Contributions/141.101.104.77|141.101.104.77]] 10:39, 13 February 2015 (UTC)<br />
<br />
Isn't 'the universe is mine to command!' a quote from Aladdin??<br />
<br />
:Yes it is a quote from Aladdin (by Jafar when he becomes a genie) [http://www.imdb.com/title/tt0103639/quotes]. It is also a quote from "insert your bond/sci-movie here" as it is the usual goal for any scientist that creates a lot of energy or a new weapon (only exception to this is in the real world with Einstein and the atomic bomb). Maybe something to add to the description (looking at someone with better english and story telling skills than I got) [[User:Aquaplanet|Aquaplanet]] ([[User talk:Aquaplanet|talk]]) 12:44, 13 February 2015 (UTC)<br />
<br />
faced?[[Special:Contributions/108.162.249.157|108.162.249.157]] 12:53, 13 February 2015 (UTC)</div>141.101.104.77https://www.explainxkcd.com/wiki/index.php?title=1486:_Vacuum&diff=844511486: Vacuum2015-02-13T13:53:53Z<p>141.101.104.77: /* Explanation */</p>
<hr />
<div>{{comic<br />
| number = 1486<br />
| date = February 13, 2015<br />
| title = Vacuum<br />
| image = vacuum.png<br />
| titletext = Do you think you could actually clean the living room at some point, though?<br />
}}<br />
<br />
==Explanation==<br />
<br />
According to quantum mechanics there is tremendous energy density in space-time itself: this is known as: {{w|vacuum energy}}, zero point energy, vacuum foam, etc. Of course, this energy is not literally available to be tapped although it does {{w|Hawking radiation|evaporate}} off {{w|black_hole}}s (see the “What If?” released the same week as this comic: [http://what-if.xkcd.com/129/ Black Hole Moon]).<br />
<br />
In the cartoon, [[Beret Guy]] appears to be making a silly mistake, confusing the metaphorical »vacuum« referred to in calculations of the theoretical energy density of space time{{Citation needed}} with the partial vacuum of a {{w|vacuum cleaner}} – a device commonly used to clean dust from households.<br />
<br />
[[Cueball]] tries to correct him, but it turns out that Beret Guy really is able to tap into this fundamental source of energy.<br />
<br />
But even though Beret Guy now claims the Universe is his to command, (a sentence used by the crazy villain in many movies), Cueball is not fazed by this and simply asks, in the title text, if Beret Guy ''could actually clean the living room at some point, though?''<br />
<br />
==Transcript==<br />
:[Beret guy is holding an upright vacuum cleaner upside-down by the handle, waving it around above his head]<br />
<br />
:[The vacuum cleaner is upright on the ground, and Beret guy is standing on its body, wiggling the handle]<br />
:Cueball: What are you doing?<br />
:Beret Guy: Trying to unlock the tremendous energy of the vacuum.<br />
<br />
:[Beret guy rides the vacuum cleaner as it begins to lift off, propelled upward by an unknown force]<br />
:Cueball: That's not what that -<br />
:Beret Guy: '''Ha ha! It works!'''<br />
<br />
:[Beret guy flies away on the vacuum cleaner]<br />
:Cueball: I '''said''', that's -<br />
:Beret Guy: The universe is mine to command!!<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Comics featuring Beret Guy]]<br />
[[Category:Comics featuring Cueball]]</div>141.101.104.77https://www.explainxkcd.com/wiki/index.php?title=1486:_Vacuum&diff=844501486: Vacuum2015-02-13T13:52:10Z<p>141.101.104.77: /* Explanation */</p>
<hr />
<div>{{comic<br />
| number = 1486<br />
| date = February 13, 2015<br />
| title = Vacuum<br />
| image = vacuum.png<br />
| titletext = Do you think you could actually clean the living room at some point, though?<br />
}}<br />
<br />
==Explanation==<br />
<br />
According to quantum mechanics there is tremendous energy density in space-time itself: this is known as: {{w|vacuum energy}}, zero point energy, vacuum foam, etc. Of course, this energy is not literally available to be tapped although it does {{w|Hawking radiation|evaporate}} off {{w|black_hole}}s (see the “What If?” released the same week as this comic: [http://what-if.xkcd.com/129/ Black Hole Moon]).<br />
<br />
In the cartoon, [[Beret Guy]] appears to be making a silly mistake, confusing the metaphorical »vacuum« referred to in calculations of the theoretical energy density of space time{{Citation needed}} with the partial vacuum of a {{w|vacuum cleaner}} – a device commonly used to clean dust from households.<br />
<br />
[[Cueball]] tries to correct him, but it turns out that Beret Guy really is able to tap into this fundamental source of energy.<br />
<br />
But even though Beret Guy now claims the Universe is his to command, (a sentence used by the crazy villain in many a movie), Cuball is not fazed by this and simply asks, in the title text, if Beret Guy ''could actually clean the living room at some point, though?''<br />
<br />
==Transcript==<br />
:[Beret guy is holding an upright vacuum cleaner upside-down by the handle, waving it around above his head]<br />
<br />
:[The vacuum cleaner is upright on the ground, and Beret guy is standing on its body, wiggling the handle]<br />
:Cueball: What are you doing?<br />
:Beret Guy: Trying to unlock the tremendous energy of the vacuum.<br />
<br />
:[Beret guy rides the vacuum cleaner as it begins to lift off, propelled upward by an unknown force]<br />
:Cueball: That's not what that -<br />
:Beret Guy: '''Ha ha! It works!'''<br />
<br />
:[Beret guy flies away on the vacuum cleaner]<br />
:Cueball: I '''said''', that's -<br />
:Beret Guy: The universe is mine to command!!<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Comics featuring Beret Guy]]<br />
[[Category:Comics featuring Cueball]]</div>141.101.104.77https://www.explainxkcd.com/wiki/index.php?title=1486:_Vacuum&diff=844491486: Vacuum2015-02-13T13:50:06Z<p>141.101.104.77: </p>
<hr />
<div>{{comic<br />
| number = 1486<br />
| date = February 13, 2015<br />
| title = Vacuum<br />
| image = vacuum.png<br />
| titletext = Do you think you could actually clean the living room at some point, though?<br />
}}<br />
<br />
==Explanation==<br />
<br />
According to quantum mechanics there is tremendous energy density in space-time itself: this is known as: {{w|vacuum energy}}, zero point energy, vacuum foam, etc. Of course, this energy is not literally available to be tapped although it does {{w|Hawking radiation|evaporate}} off {{w|black_hole}}s (see the “What If…” released the same week as this comic: [http://what-if.xkcd.com/129/ Black Hole Moon]).<br />
<br />
In the cartoon, [[Beret Guy]] appears to be making a silly mistake, confusing the metaphorical »vacuum« referred to in calculations of the theoretical energy density of space time{{Citation needed}} with the partial vacuum of a {{w|vacuum cleaner}} – a device commonly used to clean dust from households.<br />
<br />
[[Cueball]] tries to correct him, but it turns out that Beret Guy really is able to tap into this fundamental source of energy.<br />
<br />
But even though Beret Guy now claims the Universe is his to command, (a sentence used by the crazy villain in many a movie), Cuball is not fazed by this and simply asks, in the title text, if Beret Guy ''could actually clean the living room at some point, though?''<br />
<br />
==Transcript==<br />
:[Beret guy is holding an upright vacuum cleaner upside-down by the handle, waving it around above his head]<br />
<br />
:[The vacuum cleaner is upright on the ground, and Beret guy is standing on its body, wiggling the handle]<br />
:Cueball: What are you doing?<br />
:Beret Guy: Trying to unlock the tremendous energy of the vacuum.<br />
<br />
:[Beret guy rides the vacuum cleaner as it begins to lift off, propelled upward by an unknown force]<br />
:Cueball: That's not what that -<br />
:Beret Guy: '''Ha ha! It works!'''<br />
<br />
:[Beret guy flies away on the vacuum cleaner]<br />
:Cueball: I '''said''', that's -<br />
:Beret Guy: The universe is mine to command!!<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Comics featuring Beret Guy]]<br />
[[Category:Comics featuring Cueball]]</div>141.101.104.77https://www.explainxkcd.com/wiki/index.php?title=Talk:1486:_Vacuum&diff=84427Talk:1486: Vacuum2015-02-13T10:50:44Z<p>141.101.104.77: </p>
<hr />
<div>This is obviously a reference to [http://en.wikipedia.org/wiki/Vacuum_energy Vacuum Energy].<br />
The "Tremendous" part is because calculation based on quantum electrodynamics suggest it should be 100 order of magnitudes larger than measured (That is a "1" with 100 zeros after it). [[Special:Contributions/141.101.98.202|141.101.98.202]] 09:42, 13 February 2015 (UTC)<br />
<br />
Wondering if this is a reference to Terramex [http://tvtropes.org/pmwiki/pmwiki.php/VideoGame/Terramex]<br />
<br />
:My antivirus says this link is [[609|not safe]]. [[Special:Contributions/141.101.104.77|141.101.104.77]] 10:50, 13 February 2015 (UTC)<br />
<br />
I tried to read this explanation, but couldn't because of xkcd 1240 [[Special:Contributions/141.101.98.63|141.101.98.63]] 10:23, 13 February 2015 (UTC)<br />
I was expecting something related to February 14. You know, something about YouTube, IBM, ENIAC, Pale Blue Dot, Shoemaker, Hilbert, Catalan, etc. [[Special:Contributions/141.101.104.77|141.101.104.77]] 10:39, 13 February 2015 (UTC)</div>141.101.104.77https://www.explainxkcd.com/wiki/index.php?title=Talk:1486:_Vacuum&diff=84426Talk:1486: Vacuum2015-02-13T10:40:33Z<p>141.101.104.77: Fixed newlines</p>
<hr />
<div>This is obviously a reference to [http://en.wikipedia.org/wiki/Vacuum_energy Vacuum Energy].<br />
The "Tremendous" part is because calculation based on quantum electrodynamics suggest it should be 100 order of magnitudes larger than measured (That is a "1" with 100 zeros after it). [[Special:Contributions/141.101.98.202|141.101.98.202]] 09:42, 13 February 2015 (UTC)<br />
<br />
Wondering if this is a reference to Terramex [http://tvtropes.org/pmwiki/pmwiki.php/VideoGame/Terramex]<br />
<br />
I tried to read this explanation, but couldn't because of xkcd 1240 [[Special:Contributions/141.101.98.63|141.101.98.63]] 10:23, 13 February 2015 (UTC)<br />
I was expecting something related to February 14. You know, something about YouTube, IBM, ENIAC, Pale Blue Dot, Shoemaker, Hilbert, Catalan, etc. [[Special:Contributions/141.101.104.77|141.101.104.77]] 10:39, 13 February 2015 (UTC)</div>141.101.104.77https://www.explainxkcd.com/wiki/index.php?title=Talk:1486:_Vacuum&diff=84425Talk:1486: Vacuum2015-02-13T10:39:28Z<p>141.101.104.77: </p>
<hr />
<div>This is obviously a reference to [http://en.wikipedia.org/wiki/Vacuum_energy Vacuum Energy].<br />
The "Tremendous" part is because calculation based on quantum electrodynamics suggest it should be 100 order of magnitudes larger than measured (That is a "1" with 100 zeros after it). [[Special:Contributions/141.101.98.202|141.101.98.202]] 09:42, 13 February 2015 (UTC)<br />
Wondering if this is a reference to Terramex [http://tvtropes.org/pmwiki/pmwiki.php/VideoGame/Terramex]<br />
I tried to read this explanation, but couldn't because of xkcd 1240 [[Special:Contributions/141.101.98.63|141.101.98.63]] 10:23, 13 February 2015 (UTC)<br />
I was expecting something related to February 14. You know, something about YouTube, IBM, ENIAC, Pale Blue Dot, Shoemaker, Hilbert, Catalan, etc. [[Special:Contributions/141.101.104.77|141.101.104.77]] 10:39, 13 February 2015 (UTC)</div>141.101.104.77https://www.explainxkcd.com/wiki/index.php?title=397:_Unscientific&diff=84379397: Unscientific2015-02-11T22:22:14Z<p>141.101.104.77: /* Explanation */</p>
<hr />
<div>{{comic<br />
| number = 397<br />
| date = March 17, 2008<br />
| title = Unscientific<br />
| image = unscientific.png<br />
| titletext = Last week, we busted the myth that electroweak gauge symmetry is broken by the Higgs mechanism. We'll also examine the existence of God and whether true love exists.<br />
}}<br />
<br />
==Explanation==<br />
In the first and second frames, [[Megan]] can be seen accusing {{w|MythBusters}} of not actually "doing science" because of its lack of {{w|Rigour|rigor}} - a debate beyond the scope of this Wiki. The zombie of deceased physicist, {{w|Richard Feynman}}, comes to explain to [[Megan]] that she has failed to recognize the purpose of MythBusters. He explains that MythBusters is only meant to get people to accept and understand the basics of science, and that more complex lessons (such as on rigor) would be wasted on people who don't understand those basics.<br />
<br />
In the last frame, [[Cueball]] attempts to save himself and [[Megan]] from zombie Feynman by implying that physicists, being extremely intelligent, would have more desirable brains. Also, being a lab, the number of brains available would be higher than just two. Feynman's closing remark implies that {{w|String theory|string theorists}} are less intelligent than other types of physicists. This notion fits appropriately with Feynman's description of the core of science. Moreover, Feynman's own career involved applying physics to real world applications (such as for the Manhattan Project), whereas the work of string theorists is theoretical and untested.<br />
<br />
It is also a pun on {{w|Membrane_(M-theory)|M-theory}} (also called Brane theory), a part of string theory, which some argue is impossible to test scientifically.<br />
<br />
The title text starts by rebounding against the complaint of validity as science by purportedly tackling a ''really'' big scientific enquiry. Then veers away into two far more esoteric proposed fields of study, of which at least one is not even determinable by the scientific method{{Citation needed}}.<br />
<br />
==Transcript==<br />
:[Cueball and Megan are sitting on a coach, watching Mythbusters.]<br />
:TV: Can a ninja catch an arrow? On this episode, we'll find out!<br />
:Cueball: Mmm, science.<br />
:Megan: Hey, Mythbusters is entertaining, but it's not science.<br />
<br />
:Zombie Feynman: ''BRAAAAAIIINNS''...<br />
:Cueball: Zombie Feynman!<br />
:Zombie Feynman: You got a problem with Mythbusters?<br />
:Megan: They fail at basic rigor!<br />
<br />
:Zombie Feynman: "Ideas are tested by experiment." That is the <u>core</u> of science. Everything else is bookkeeping.<br />
<br />
:Zombie Feynman: By teaching people to hold their beliefs up to experiment, ''Mythbusters'' is doing more to drag humanity out of the unscientific darkness than a thousand lessons in rigor. Show them some love.<br />
<br />
:Zombie Feynman: Anyway, back to zombie stuff. I hunger for ''BRAAAAAIIINNS!''<br />
:Cueball: Uh, try the physics lab next door.<br />
:Zombie Feynman: I said <u>brains</u>. All they've got are string theorists.<br />
<br />
{{comic discussion}}<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Comics featuring Megan]]<br />
[[Category:Comics featuring real people]]<br />
[[Category:Physics]]<br />
[[Category:Science]]<br />
[[Category:Zombies]]</div>141.101.104.77https://www.explainxkcd.com/wiki/index.php?title=Talk:1481:_API&diff=83890Talk:1481: API2015-02-02T06:47:47Z<p>141.101.104.77: </p>
<hr />
<div>It seems like the current explanation is completely wrong. The XML file with data and information about it's layout is just /X?HTML/.[[Special:Contributions/141.101.104.77|141.101.104.77]] 06:45, 2 February 2015 (UTC)<br />
<br />
And title text is about leap seconds. Sorry, I don't have time to edit the explanation myself. [[Special:Contributions/141.101.104.77|141.101.104.77]] 06:47, 2 February 2015 (UTC)</div>141.101.104.77https://www.explainxkcd.com/wiki/index.php?title=Talk:1481:_API&diff=83889Talk:1481: API2015-02-02T06:45:47Z<p>141.101.104.77: Created page with "It seems like the current explanation is completely wrong. The XML file with data and information about it's layout is just /X?HTML/.~~~~"</p>
<hr />
<div>It seems like the current explanation is completely wrong. The XML file with data and information about it's layout is just /X?HTML/.[[Special:Contributions/141.101.104.77|141.101.104.77]] 06:45, 2 February 2015 (UTC)</div>141.101.104.77https://www.explainxkcd.com/wiki/index.php?title=1478:_P-Values&diff=834761478: P-Values2015-01-26T13:46:09Z<p>141.101.104.77: /* Explanation */ the "signifcant" error is no longer in the comic, so removed reference to it</p>
<hr />
<div>{{comic<br />
| number = 1478<br />
| date = January 26, 2015<br />
| title = P-Values<br />
| image = p_values.png<br />
| titletext = If all else fails, use "signifcant at a p>0.05 level" and hope no one notices.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Needs work to improve readability for non-statisticians.}}<br />
<br />
This comic plays on how the significance of scientific experiments is measured and interpreted. The {{w|P-value|p-value}} is a statistical measure of how well the results of an experiment fit with the results predicted by the hypothesis. Low ''p''-values occur when the results appear to reject the {{w|null hypothesis}}, whereas the high ''p''-values suggest no relation between the hypothesis and the real world.<br />
The ''p''-value calculated from the experiment data is used to interpret whether the experiment was significant and supports the hypothesis.<br />
<br />
The significance threshold (usually 0.05) should be set prior the experiment in order to avoid ex-post changes in order to get a better experiment report. A simple change of this threshold (e.g. from 0.05 to 0.1) can change the experiment result with ''p''-value=0.06 from "barely significant" to "significant".<br />
<br />
The highest ''p''-value at which most studies typically draw significance is ''p''<0.05, which is why all ''p''-values in the comic below that number are marked at least significant. 0.050 is labeled "Oh crap. Redo calculations," because the ''p''-value is very close to being considered significant, but isn't. Redoing the calculations may result in a different answer, but it is not guaranteed that it will be lower than 0.050. Values that are higher than 0.050 and lower than .1 are considered to be suggesting significance without actually supporting it, which will likely support additional trials.<br />
<br />
Values higher than .1 should be considered not significant at all, however the comic suggests taking a part of the sample (a "subgroup") and analyzing that subgroup without regard to the rest of the sample. For example, in a study trying to prove that people always sneeze when walking by a particular street lamp, someone would record the number of people who pass the lamp and the number of people who sneezes. If the results don't get the desired ''p''<0.1, then pick a subgroup (e.g. OK, not all people sneeze, but look! women sneeze more than men, so let's analyze only women). Of course, this is not accepted scientific procedure as it's very likely to add sampling bias to the result.<br />
<br />
The title text suggests that, if the results cannot be normally considered significant, to invert p<0.050, making it p>0.050. This is intended to fool casual readers, as the change is only to the inequality sign, which may go unnoticed.<br />
<br />
==Transcript==<br />
{{incomplete|First draft.}}<br />
<br />
There are two columns in a T-table labelled "p-value" and "interpretation". The interpretation column selects various areas of the P-value column.<br />
<br />
{| class="wikitable alternance"<br />
|+ P-values<br />
! P-value<br />
! Interpretation<br />
|-<br />
| 0.001<br />
| rowspan="4"| Highly significant<br />
|-<br />
| 0.01<br />
|-<br />
| 0.02<br />
|-<br />
| 0.03<br />
|-<br />
| 0.04<br />
| rowspan="2"| Significant<br />
|-<br />
| 0.049<br />
|-<br />
| 0.050<br />
| Oh crap. Redo calculations.<br />
|-<br />
| 0.051<br />
| rowspan="2"| On the edge of significance<br />
|-<br />
| 0.06<br />
|-<br />
| 0.07<br />
| rowspan="4"| Highly suggestive, relevant at the p<0.10 level<br />
|-<br />
| 0.08<br />
|-<br />
| 0.09<br />
|-<br />
| 0.099<br />
|-<br />
| ≥0.1<br />
| Hey, look at this interesting subgroup analysis<br />
|}<br />
<br />
{{comic discussion}}</div>141.101.104.77https://www.explainxkcd.com/wiki/index.php?title=1292:_Pi_vs._Tau&diff=731531292: Pi vs. Tau2014-08-07T20:41:37Z<p>141.101.104.77: /* Explanation */</p>
<hr />
<div>{{comic<br />
| number = 1292<br />
| date = November 18, 2013<br />
| title = Pi vs. Tau<br />
| image = pi vs tau.png<br />
| titletext = Conveniently approximated as e+2, Pau is commonly known as the Devil's Ratio (because in the octal expansion, '666' appears four times in the first 200 digits while no other run of 3+ digits appears more than once.)<br />
}}<br />
<br />
==Explanation==<br />
<br />
This is yet another of [[Randall]]'s [[:Category:Compromise|compromise comics]]. A few mathematicians argue as to whether to use pi, which is the ratio between a circle's circumference and its diameter, or tau, which is the ratio between a circle's circumference and its radius.<br />
<br />
Some consider pi to be the wrong convention and are in favor of using tau as ''the'' circle constant (see the [http://tauday.com/tau-manifesto Tau Manifesto], which was inspired by the article "[http://www.math.utah.edu/~palais/pi.html Pi is wrong!]" by mathematician Robert Palais). Others consider proponents of tau to be foolish and remain loyal to pi (see the [http://www.thepimanifesto.com Pi Manifesto]). Of course, regardless of which convention is used, the change is merely in notation — the underlying mathematics remains unaltered. Still, the choice of pi vs. tau can affect the clarity of equations, analogies between different equations, and how easy various subjects are to teach.<br />
<br />
Most people know π (pi) by the approximation 3.14, but do not know τ (tau) which, by definition, is twice as large as pi. Randall is suggesting using "pau", which is a portmanteau of "pi" and "tau", as a number situated, appropriately enough, halfway between pi and tau, i.e. 1.5 pi (or 0.75 tau). But of course his number would be inconvenient, as this value does not naturally turn up when working with circles or other mathematical constructs, so there are no commonly used formulas that would use pau.<br />
<br />
The title text claims that pau can be approximated by e+2, as both values are roughly 4.7 — a similarity that holds little since it requires another irrational constant, {{w|E_(mathematical_constant|e}}. It also attributes the nickname "Devil's Ratio" to pau, due to the sequence {{w|Number of the Beast|666}} supposedly appearing four times in the first 200 digits of pau when expressed in the {{w|octal}} base. However, this is not the case, and was likely due to an error in the computer system used by WolframAlpha; for more details see below.<br />
<br />
==Transcript==<br />
:[On the left is a "forbidden"-style slashed circle with the π symbol, captioned "Pi". On the right is a "forbidden"-style slashed circle with 2π, captioned "Tau". In the middle it reads 1.5π, captioned "Pau".]<br />
:A compromise solution to the Pi Tau dispute<br />
<br />
==Math details==<br />
Possibly, [[Randall]] used [http://www.wolframalpha.com/ Wolfram|Alpha] to calculate the result (he uses it a lot, for example [http://what-if.xkcd.com/70/ What-if 70: The Constant Groundskeeper] or [http://what-if.xkcd.com/62/ What-if 62: Falling With Helium]).<br />
However, when the comic was published, there was (and still is, as of April 29, 2014) a bug in Wolfram|Alpha so that, when getting 200 octal digits from "pau", it just calculates the decimal value rounded to 15 significant digits (this is 4.71238898038469) and expands that as octal digits as far as needed.<br />
<br />
This gives a periodically repeating number. In the first 200 digits of the octal expansion, the sequences 666 and 6666 do occur, but each only once. There are 4 occurrences, however, in the first 300 digits:<br />
<pre><br />
4.554574376314416445676661714336617116240444076666510533533077631151350452060436452476274022621206136310000177621674175071262255702044274154476005744176002676623042402346036604733130522524127534777714554305412763636566643022106616734723661726160312772574551366370203115523402704104015532221722772357666</pre><br />
Expansion that long indeed does contain 666 (the {{w|Number of the beast|number of the beast}}) four times (with one instance as 6666). It also contains 0000, 222, 444, and 7777, but they only appear once in a run.<br />
<br />
{{w|Mathematical coincidence|Coincidentally}}, e+2 is also very similar to 1.5 pi, although only to a few digits.<br />
<pre><br />
1.5π = 4.71238898038...<br />
e+2 = 4.71828182845...<br />
</pre><br />
<br />
==Trivia==<br />
*For Pi the sequence '666' occurs for the first time at position 2440. Many more occurrences can be found here: [http://www.angio.net/pi/ The Pi-Search Page].<br />
* Note that pau is Catalan for peace, which is a good solution for the pi/tau dispute.<br />
* In the discussion it has been theorized that Randall used [[356: Nerd Sniping|Nerd Sniping]]. In which case he was aware of the mistake in Wolfram!<br />
*For an entertaining introduction to the concept of tau, see this [https://www.khanacademy.org/math/recreational-math/vi-hart/pi-tau/v/pi-is--still--wrong Vi Hart video].<br />
<br />
{{comic discussion}}<br />
[[Category:Comics with color]]<br />
[[Category:Math]]<br />
[[Category:Compromise]]</div>141.101.104.77https://www.explainxkcd.com/wiki/index.php?title=1292:_Pi_vs._Tau&diff=731521292: Pi vs. Tau2014-08-07T20:40:52Z<p>141.101.104.77: </p>
<hr />
<div>{{comic<br />
| number = 1292<br />
| date = November 18, 2013<br />
| title = Pi vs. Tau<br />
| image = pi vs tau.png<br />
| titletext = Conveniently approximated as e+2, Pau is commonly known as the Devil's Ratio (because in the octal expansion, '666' appears four times in the first 200 digits while no other run of 3+ digits appears more than once.)<br />
}}<br />
<br />
==Explanation==<br />
<br />
This is yet another of [[Randall]]'s [[:Category:Compromise|compromise comics]]. A few mathematicians argue as to whether to use pi, which is the ratio between a circle's circumference and its diameter, or tau, which is the ratio between a circle's circumference and its radius.<br />
<br />
Some consider pi to be the wrong convention and are in favor of using tau as ''the'' circle constant (see the [http://tauday.com/tau-manifesto Tau Manifesto], which was inspired by the article "[http://www.math.utah.edu/~palais/pi.html Pi is wrong!]" by mathematician Robert Palais). Others consider proponents of tau to be foolish and remain loyal to pi (see the [http://www.thepimanifesto.com Pi Manifesto]). Of course, regardless of which convention is used, the change is merely in notation — the underlying mathematics remains unaltered. Still, the choice of pi vs. tau can affect the clarity of equations, analogies between different equations, and how easy various subjects are to teach.<br />
<br />
Most people know π (pi) by the approximation 3.14, but do not know τ (tau) which, by definition, is twice as large as pi. Randall is suggesting using "pau", which is a portmanteau of "pi" and "tau", as a number situated, appropriately enough, halfway between pi and tau, i.e. 1.5 pi (or 0.75 tau). But of course his number would be inconvenient, as this value does not naturally turn up when working with circles or other mathematical constructs, so there are no commonly used formulas that would use pau.<br />
<br />
The title text claims that pau can be approximated by e+2, as both values are roughly 4.7 — a similarity that holds little since it requires another irrational constant, {{w|E_(mathematical_constant)}}. It also attributes the nickname "Devil's Ratio" to pau, due to the sequence {{w|Number of the Beast|666}} supposedly appearing four times in the first 200 digits of pau when expressed in the {{w|octal}} base. However, this is not the case, and was likely due to an error in the computer system used by WolframAlpha; for more details see below.<br />
<br />
==Transcript==<br />
:[On the left is a "forbidden"-style slashed circle with the π symbol, captioned "Pi". On the right is a "forbidden"-style slashed circle with 2π, captioned "Tau". In the middle it reads 1.5π, captioned "Pau".]<br />
:A compromise solution to the Pi Tau dispute<br />
<br />
==Math details==<br />
Possibly, [[Randall]] used [http://www.wolframalpha.com/ Wolfram|Alpha] to calculate the result (he uses it a lot, for example [http://what-if.xkcd.com/70/ What-if 70: The Constant Groundskeeper] or [http://what-if.xkcd.com/62/ What-if 62: Falling With Helium]).<br />
However, when the comic was published, there was (and still is, as of April 29, 2014) a bug in Wolfram|Alpha so that, when getting 200 octal digits from "pau", it just calculates the decimal value rounded to 15 significant digits (this is 4.71238898038469) and expands that as octal digits as far as needed.<br />
<br />
This gives a periodically repeating number. In the first 200 digits of the octal expansion, the sequences 666 and 6666 do occur, but each only once. There are 4 occurrences, however, in the first 300 digits:<br />
<pre><br />
4.554574376314416445676661714336617116240444076666510533533077631151350452060436452476274022621206136310000177621674175071262255702044274154476005744176002676623042402346036604733130522524127534777714554305412763636566643022106616734723661726160312772574551366370203115523402704104015532221722772357666</pre><br />
Expansion that long indeed does contain 666 (the {{w|Number of the beast|number of the beast}}) four times (with one instance as 6666). It also contains 0000, 222, 444, and 7777, but they only appear once in a run.<br />
<br />
{{w|Mathematical coincidence|Coincidentally}}, e+2 is also very similar to 1.5 pi, although only to a few digits.<br />
<pre><br />
1.5π = 4.71238898038...<br />
e+2 = 4.71828182845...<br />
</pre><br />
<br />
==Trivia==<br />
*For Pi the sequence '666' occurs for the first time at position 2440. Many more occurrences can be found here: [http://www.angio.net/pi/ The Pi-Search Page].<br />
* Note that pau is Catalan for peace, which is a good solution for the pi/tau dispute.<br />
* In the discussion it has been theorized that Randall used [[356: Nerd Sniping|Nerd Sniping]]. In which case he was aware of the mistake in Wolfram!<br />
*For an entertaining introduction to the concept of tau, see this [https://www.khanacademy.org/math/recreational-math/vi-hart/pi-tau/v/pi-is--still--wrong Vi Hart video].<br />
<br />
{{comic discussion}}<br />
[[Category:Comics with color]]<br />
[[Category:Math]]<br />
[[Category:Compromise]]</div>141.101.104.77