explain xkcd - User contributions [en]

1115: Sky

2015-12-02T20:50:09Z

108.162.216.57: /* Explanation */

{{comic
| number = 1115
| date = October 1, 2012
| title = Sky
| image = sky.png
| titletext = I dropped a bird and I didn't hear it hit bottom.
}}

==Explanation==
This comic is about the fact that much of the way we see the world is subjective. From space the directions up and down appear subjective, as gravity can not be strongly felt. Also since the {{w|vestibular}} system (the balance glands in the ear) does not strongly impact {{w|equilibrioception}} (the sense of balance) and the sense of balances is often based on vision, which uses subjective clues to determine what is the up and down, up and down can seem arbitrary at times. For example people can convince them selves (accidentally or deliberately) that up is down and down is up or be confused about their orientation (dizzy). Forcing yourself to think in a different perspective changes a lot of things that are usually thought of as mundanities.

[[Beret Guy]] convinces himself that down is toward the sky. [[Megan]] witnesses and asks him why he is clinging to the ground. He responds that he is holding on to the ground so that he does not fall into the sky. Megan at first dismisses this but later looks up, gets scared and is found by [[Ponytail]], clinging to a mailbox afraid of falling up.

The title text continues this idea, where Megan "drops" a bird into the sky, and never hears it hit the "bottom". As birds can fly, and captured birds often fly away when released, its flight appeared to Megan as the bird falling upward.

==Transcript==
:[Megan approaches Beret Guy, who appears to be doing a handstand on the lawn.]
:Megan: What are you doing?
:Beret Guy: Clinging to the ceiling of a bottomless abyss.

:[Megan walks past him.]
:Megan: You are very odd.

:[Megan towards a mailbox.]

:[As she passes the mailbox, she looks up.]

:[This panel appears to be upside down. Megan is clinging to the mailbox, and Ponytail approaches her.]
:Ponytail: What's wrong?
:Megan: I looked down.

==Trivia==
*This comic's official transcript actually refers to [[Ponytail]] as Ponytail.
{{comic discussion}}
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring Beret Guy]]

1568: Synonym Movies 2

2015-08-24T12:25:02Z

108.162.216.57: /* Transcript */

{{comic
| number = 1568
| date = August 24, 2015
| title = Synonym Movies 2
| image = synonym_movies_2.png
| titletext = There's also the TV show based on the hit Hot and Cold Music books: Fun With Chairs, Royal Rumble, Knife Blizzard, Breakfast for Birds, and Samba Serpents.
}}

==Explanation==
[[File: Flipped.jpg|right|A flipped version of the comic]]

This comic is a continuation of [[1563: Synonym Movies]] with a new set of movie series. As with the previous comic, the titles aren't always synonymous with the original (''Indiana Jones as Professor Whip'').

This set includes ''Wandboy'' (''Harry Potter''), ''Puncher'' (''Rocky''), ''Tropical Boaters'' (''Pirates of the Caribbean''), and ''Professor Whip'' (''Indiana Jones'').

The ''is in Another Movie'' title in the ''Professor Whip'' series differs from the other titles in that it does not reference the plot of the movie. The more dismissive reference may be due to ''Indiana Jones and the Kingdom of the Crystal Skull'' being poorly received by fans of the series.

The title text is a reference to the TV series ''A Game of Thrones'', based on the book series ''A Song of Ice and Fire''.

==Table of the titles==
'''SPOILER ALERT!''' Many of these explanations contain information revealed during the movie.

{| class="wikitable"
|-
! width="12em" | Synonym
! width="13em" | Real Title
! Notes
|-
| ''Wandboy and the Magic Rock''
| ''{{w|Harry Potter and the Philosopher's Stone (film)|Harry Potter and the Philosopher's Stone}}''
| Also known as Harry Potter and the Sorcerer's Stone in the US.
|-
| ''Wandboy and the Hidden Room''
| ''{{w|Harry Potter and the Chamber of Secrets (film)|Harry Potter and the Chamber of Secrets}}''
|
|-
| ''Wandboy and the Fugitive''
| ''{{w|Harry Potter and the Prisoner of Azkaban (film)|Harry Potter and the Prisoner of Azkaban}}''
| A central character in Harry Potter and the Prisoner of Azkaban, Sirius Black, is a fugitive.
|-
| ''Wandboy and the Burning Cup''
| ''{{w|Harry Potter and the Goblet of Fire (film)|Harry Potter and the Goblet of Fire}}''
|
|-
| ''Wandboy and the Firebird Club''
| ''{{w|Harry Potter and the Order of the Phoenix (film)|Harry Potter and the Order of the Phoenix}}''
| The {{w|Phoenix}} is a bird that is strongly connected to fire. Dying phoenixes go up in flames, only to be reborn out of the ashes shortly afterwards. The Order of the Phoenix is an association of wizards founded by Albus Dumbledore, whose distinctive pet is a phoenix.
|-
| ''Wandboy and the Book Owner''
| ''{{w|Harry Potter and the Half-Blood Prince (film)|Harry Potter and the Half-Blood Prince}}''
| In ''Harry Potter and the Half-Blood Prince'', Harry's Potions textbook was previously owned by a "Half-Blood Prince." Therefore, "Half-Blood Prince" is replaced with "book owner."
|-
| ''Wandboy and the Magic Stuff (1/2)''
| ''{{w|Harry Potter and the Deathly Hallows – Part 1}}''
| rowspan="2" | The ''Deathly Hallows'' are three magical items that are believed to have once belonged to the Death himself. Someone in possession of all three items is thought to be master of death, which is widely interpreted as meaning able to defeat death. Near the end of the ''Harry Potter'' series, the protagonist is in possession of all items, but he destroys the ''Elder Wand'' (the most powerful wand of all times), loses the ''Stone of Resurrection'' on purpose (a stone capable of bringing people back to life) and only keeps the ''Invisibility Cloak'', which is a family heirloom. See also {{w|The Tales of Beedle the Bard#"The Tale of the Three Brothers"}}.
|-
| ''Wandboy and the Magic Stuff (2/2)''
| ''{{w|Harry Potter and the Deathly Hallows - Part 2}}''
|-
| ''Puncher''
| ''{{w|Rocky}}''
|
|-
| ''Puncher II''
| ''{{w|Rocky II}}''
|
|-
| ''Puncher III''
| ''{{w|Rocky III}}''
|
|-
| ''Puncher IV''
| ''{{w|Rocky IV}}''
|
|-
| ''Puncher V''
| ''{{w|Rocky V}}''
|
|-
| ''Puncher Lastname''
| ''{{w|Rocky Balboa (film)}}''
|
|-
| ''Tropical Boaters: Spooky Boat''
| ''{{w|Pirates of the Caribbean: The Curse of the Black Pearl}}''
| The Black Pearl is a ship crewed by "spooky" ghost pirates.
|-
| ''Tropical Boaters: Angry Wormface''
| ''{{w|Pirates of the Caribbean: Dead Man's Chest}}''
| This film's villain has (worm-like) octopus tentacles growing on his face.
|-
| ''Tropical Boaters: Boats Everywhere''
| ''{{w|Pirates of the Caribbean: At World's End}}''
| This film includes a huge fleet of ships.
|-
| ''Tropical Boaters: Vitamin Water''
| ''{{w|Pirates of the Caribbean: On Stranger Tides}}''
| "Vitamin Water" describes the Fountain of Youth.
|-
| ''Professor Whip and the Box of God''
| ''{{w|Raiders of the Lost Ark}}''
| Later marketed as Indiana Jones and the Raiders of the Lost Ark.
|-
| ''Professor Whip and the Scary Church''
| ''{{w|Indiana Jones and the Temple of Doom}}''
|
|-
| ''Professor Whip Looks for a Cup''
| ''{{w|Indiana Jones and the Last Crusade}}''
|
|-
| ''Professor Whip is in Another Movie''
| ''{{w|Indiana Jones and the Kingdom of the Crystal Skull}}''
| ''Indiana Jones and the Kingdom of the Crystal Skull'' is widely regarded as the worst in the series. Therefore, the "synonym" is simply called "another movie" to imply that it shouldn't have been made.
|-
| ''Fun With Chairs''
| ''{{w|A Game of Thrones}}''
|
|-
| ''Royal Rumble''
| ''{{w|A Clash of Kings}}''
|
|-
| ''Knife Blizzard''
| ''{{w|A Storm of Swords}}''
|
|-
| ''Breakfast for Birds''
| ''{{w|A Feast for Crows}}''
|
|-
| ''Samba Serpents''
| ''{{w|A Dance with Dragons}}''
|
|}

==Transcript==
:[22 DVDs on a shelf in four groups. All DVDs are labeled in black on light grey. Text written so it is supposed to be read when the DVD is lying down.]
:[First group of 8 DVDs. All standing straight]
:Wandboy and the Magic Rock
:Wandboy and the Hidden Room
:Wandboy and the Fugitive
:Wandboy and the Burning Cup
:Wandboy and the Firebird Club
:Wandboy and the Book Owner
:Wandboy and the Magic Stuff (1/2)
:Wandboy and the Magic Stuff (2/2)

:[Second group of six DVDs. Five standing straight, last on the right leaning against the rest]
:Puncher
:Puncher II
:Puncher III
:Puncher IV
:Puncher V
:Puncher Lastname

:[Third group of four DVDs. First and last standing straight, others leaning on first]
:Tropical Boaters: Spooky Boat
:Tropical Boaters: Angry Wormface
:Tropical Boaters: Boats Everywhere
:Tropical Boaters: Vitamin Water

:[Fourth group of four DVDs. Three standing straight, second from left leaning on first]
:Professor Whip and the Box of God
:Professor Whip and the Scary Church
:Professor Whip Looks for a Cup
:Professor Whip is in Another Movie

{{comic discussion}}

1416: Pixels

2014-09-04T02:30:26Z

108.162.216.57: m typos

{{comic
| number = 1416
| date = September 3, 2014
| title = Pixels
| image = pixels.png
| titletext = It's turtles all the way down.
}}
'''NOTE: The above is only a zoomed out version of the this interactive comic.''' For a collection of images that appear when zooming in on this comic, see [[1416: Pixels/Images]].

==Explanation==
{{incomplete|Individual panels need explanations}}
This interactive comic begins with a panel where [[Cueball]] is stacking turtles. This is a reference to the idiom "turtles all the way down," which refers to the problem of infinite regression: if everything in the universe is "on top of" something else, so to speak, there must be a "bottom." A joking solution to the paradoxical nature of such a bottom is the proposition that {{w|Turtles_all_the_way_down|the world rests on a semi-infinite stack of turtles}}.

As can be read you should "scroll to zoom". This can be done by placing the cursor inside the panel of the comic. When scrolling up (using the mouse wheel) the picture zooms in until the pixels are visible. When you continue to scroll on each pixel then resolves into another comic picture, with black-on-white comic panels making up the white pixels and white-on-black panels making up the black pixels. Scrolling on until you can see the pixels of the comic picture you are now zooming into the process is repeated again and will be so for all subsequent sets of comic panels. Not all white and all black panels are the same; some sets involve more than two different panels, but all involve repetitive tiling.

===Book Launch===
This comic was released on September 3rd, 2014, the day after Randall's book ''[http://www.amazon.com/What-If-Scientific-Hypothetical-Questions/dp/0544272994 What If]'' was launched. The book is shown and referred to in a number of frames, for example it is [[:File:pixels-upgoer.png|'''literally''' launched]] as a part of an <strike>rocket</strike> [[1133:_Up_Goer_Five|''up goer'']] built by Cueball.

The model ''up goer'' is [[:File:pixels-assembly-1.png|made of Rocket Parts from KSP]]. KSP is the {{w|Kerbal Space Program}}, a spaceflight simulator. Perhaps XKCD's 'parts' refers to KSP's large community of mod developers who contribute 'parts' to the game.

The frames showing the book launch use URIs that include the text "upgoer" in reference to the [[Up Goer Five]] comic.

===Needs More Struts===
{{w|Strut|Struts}} are structural members in engineering, and are are one of the components used in Kerbal Space Program to construct rockets. 'Needs More Struts' seems to be a meme amongst players of Kerbal Space Program, along the lines of 'When in doubt, overengineer'. Megan deems Cueball's rocket to be insufficiently structurally sound, and declares that it "[[:File:pixels-assembly-4.png|Needs More Struts]]"

===The Only Copy===
Cueball & Megan turn to each other having just launched the What-If book rocket into space (construction and launch are seen in other panels). perhaps Megan realises they may have misunderstood the term 'book launch' and that they may have just lost the only copy of the book.

===Holism, Reductionism, Mu===
These three words refer to "A MU offering", an essay by Douglas Hofstatder in his book [[24|Godel, Escher, Bach]]. It includes a similar multiple level drawing: {{w|Mu (negative)|the word MU}} is composed of copies of the words HOLISM and REDUCTIONISM, each of which are in turn made of smaller copies of the other, which are in turn made of [http://newtonexcelbach.wordpress.com/2011/02/16/two-more-letters/ tiny copies] of the word MU.

===Cantor Set===
[[:File:pixels-cantor.png|One panel]] contains a number of lines and dots, which are in fact a depiction of the first 5 steps of a {{w|Cantor set|Cantor Ternary Set}}, mirrored about the horizontal centreline. The Cantor ternary set is constructed by repeatedly deleting the open middle thirds of a set of line segments.

===Time Turners===
The time turner is a device from the Harry Potter series of novels by JK Rowling. It allows the user to re-live a period of time over again. In the third novel Hermione is given the time-turner to allow her to take extra classes, however it is eventually used to spare Buckbeak the hippogryph from execution. This prompted many questions regarding why time-turners weren’t used on other occasions to save people's lives (among other things).

While J.K Rowling has “[http://pottermore.wikia.com/wiki/Time-Turner solved the problem to her own satisfaction]” she admits that she entered into the subject of time-travel too lightly.
This panel jokes that if the real life JK Rowling had a fictional time-turner which worked, she would have gone back and removed the time-turner plotline from the book, saving her all the hassle of dealing with the resulting time-travel questions. This act would result in a time-travel paradox.

===Stockholm Syndrome===
{{w|Stockholm syndrome}} is the name for a psychological phenomenon, in which hostages develop sympathy, empathy and/or positive feelings towards their captors. These feelings are usually seen as irrational, seeing as the hostage is held against their wishes, usually with the threat of physical harm or death.

[[:File:pixels-stockholm.png|This panel]] asks "How do we know anyone really ''wants'' to live in Stockholm?", questioning whether everyone who lives in the city of Stockholm is in fact held hostage there and only stays because they have developed to like life there (due to Stockholm Syndrome).

===Shut Down the Server===
Cueball tells an offscreen character that he is going to shut down the server, while carrying a bucket of water.

Usually shutting down a server is done via the operating system or software, in this case it appears that cueball is simply going to douse it with water, likely resulting in serious water damage to the hardware.

=== du ===
`du` is a Linux command to indicate the "disk usage" of a file or directory.

~$ du -s video/
4170882256

This is a command that shows how large all the files are in this user's "video" directory - presumably where they store their personal videos. The units of the result is probably kilobytes (depending on settings)

This number is clearly large and difficult to parse, and the units are not clear. More appropriate units would be terabytes rather than bytes. The du command offers an option to display units in "human readable format", which will adapt to use kilobytes, megabytes, gigabytes, terabytes, etc. as appropriate. The next command purports to request the same result in more human-readable form.

~$ du -hs video/
A lot.
~$

It seems that the computer, rather than giving a specific answer, simply says that the size of the video directory is "A lot."

The final line indicates the computer is now ready to accept a new command.

===Fire Hydrant===
Black Hat is talking to a fireman, with a fire engine on fire in the background, he asks "To be fair, what else would you expect to come out of a 'Fire Hydrant'?"

Black Hat appears to have managed to replace the usual water supply to the hydrant with some sort of flammable liquid. Thus when the hydrant is used, the result is, quite literally, fire. In Black Hat's logic, a hydrant which delivers water should be called a water hydrant.

===Evolution===
The {{w|March of Progress}} image is a famous and instantly recognisable image showing the stages of human evolution by way of a series of primate figures as if marching in a line. The panel parodies the March of Progress image, with 5 ducklings following an adult duck. In this case they don’t actually ‘evolve’ into the adult duck however. The comic has some resemblance to [[537: Ducklings]].

==Transcript==
:[Cueball is stacking turtles, and is about to put the fourth turtle on his pile. At the bottom right there is a small panel. Inside this is written:]
:Scroll to zoom

:[When zooming in there will be several panels with text. The transcript of these may not be possible to complete - but add the transcript of these panels here: [[1416: Pixels/Transcript|interactive transcript]]]

==Bugs==
Doesn't seem to work properly in all browsers (e.g. Firefox and Safari on MacOSX), giving "TypeError: this.data is null" in line 173 of zoom.js: "var item = this.data.get(dims)"
Doesn't seem to work in IE8, comic is blank, but title text works.

Does not work on xkcd.org neither www.xkcd.org in Firefox and Chrome. Currently you should visit http://xkcd.com for this comic to work properly.

Also, it doesn't work on HTTPS.

==Gallery==
[[File:1416_Pixels_layout.png|thumb|Graph of links between the 79 individual images]]
[[1416: Pixels/Images|This gallery]] contains some of the 79 images<ref>http://azttm.wordpress.com/2014/09/03/xkcd-com-1416-pixels/</ref> used in this comic. The images are related in a [[:File:1416_Pixels_layout.png|directed graph]].

==Images Database==
This google sheet describes all possible images, their associated codes, and what possible images can be used as sub-images for each zoom level: https://docs.google.com/spreadsheets/d/1nldKAkeVcK606CY12KI9bah9rDmK9E7CZOyinsEj2Lo/edit?usp=sharing

==Image scraping script==
This gist recursively downloads all possible images:
https://gist.github.com/Aaron1011/d3b56325881cd639506a

==References==
<references/>

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

1405: Meteor

2014-08-08T21:42:52Z

108.162.216.57: /* Transcript */ capitalization

{{comic
| number = 1405
| date = August 8, 2014
| title = Meteor
| image = meteor.png
| titletext = No, only LAVA is called 'magma' while underground. Any other object underground is called 'lava'.
}}

==Explanation==
This is one of [[Randall]]'s comics on the topic of [[:Category:My Hobby|My Hobby]]. In this comic the author makes semantically incorrect statements to [[356: Nerd Sniping|frustrate nerds]] who know the correct word, and confuse people who don't know the precise word so they can go on to frustrate more nerds.

[[Cueball]] tells a witness (a fictional stand-in for the author Randall) that he found a piece of a {{w|meteor}}. Randall corrects Cueball, telling him that what he found is called {{w|magma}}, and that that the phrase "a piece of a meteor" would be correct if the object was in the air, once it hits the ground it called {{w|magma}}. In doing so Randall attempts to confuse or annoy Cueball. In truth, {{w|meteorite}} is the expression for a piece of a meteor that has landed just as {{w|lava}} is the expression for magma that has reached the surface.

The word "{{w|pedant|pedantic}}" means being overly concerned with being precise. It is usually a pejorative term used to refer to someone who is overly fussy and corrects someone's word choice even when the more ambiguous or slightly incorrect term they used was fine for informal communication.

The title text expands on the joke, as if the conversation had continued with a confused Cueball responding that he thought magma was underground. Randall attempts to confuse him further. Indeed lava is called magma while it is underground, but it's ridiculous to suggest all other things are called lava when underground.

===Meteor & Magma===
Here is a list the of terminology that is being muddled:
* Small metallic or rocky body from space is called:
** A {{w|meteoroid}} while it travels through space
** A {{w|meteor}} if it enters Earth's atmosphere and produces a streak of light.
** A {{w|meteorite}} if it lands on a planets surface.
* Molten rock is called:
** {{w|Magma}} if it is flowing underground
** {{w|Lava}} after it has been extruded to a planets surface, generally through volcanic eruption.

==Transcript==
:Cueball: Check it out -- I got a piece of a meteor!
:Friend: ''Actually'', it's only called that while falling. Once it lands, it's called ''magma''.

:My Hobby: Mixing pedantic terms

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

Talk:1375: Astronaut Vandalism

2014-06-02T18:22:23Z

108.162.216.57:

Is there an actual place that this is referencing? --[[Special:Contributions/108.162.222.41|108.162.222.41]] 05:14, 30 May 2014 (UTC)
:This seems to be Grenada, MS. {{unsigned ip|108.162.221.28}}

Grenada is possible - but given the NASA connection to Winona, and the fact that the numbers are exact (but reversed), I think it's a better candidate. {{unsigned|Thesetwoutes}}
:There is Camp McCain 17 miles north of Winona which would have the correct distances. [[User:Sten|'''STEN''']] ([[User talk:Sten|talk]]) 10:20, 30 May 2014 (UTC)

Space is usually indicated by pointing straight up. This sign points a little to one side as well though. Since these places the other pointers reference are in the northern hemisphere, and from the comic's point of view Memphis (North) is on the left and Jackson (south) is on the right, the 'Space' sign is pointing slightly south. Assuming the sign would point straight up at the equator, measuring the angle from the direction the sign is pointing to the vertical axis, and doing some math, would give the latitude of the sign and a better indication of its exact location. [[Special:Contributions/141.101.89.225|141.101.89.225]] 06:49, 30 May 2014 (UTC)

There doesn't seem to be anywhere named anything like "space" 53 miles from Jackson along this line. (Approximately Goodman, MS, birthplace of John Lomax.) Is the marker supposed to have been brought in specifically for this purpose? I thought it would make more sense if the arrow had just been turned up. (For the numbers reversed theory, 36 miles from Jackson appears to be completely rural, though features the site of Casey Jones' death.) [[Special:Contributions/108.162.216.35|108.162.216.35]] 12:00, 30 May 2014 (UTC)

My first thought that this was a reference to the blues musician Robert Johnson. According to legend, Johnson met the devil at a crossroads in Mississippi to exchange his soul for talent in blues music. There are a few different real crossroads that have been put forth as the legendary location. These include Dockery Plantation, Hazelhurst, Beauregard, Clarksdale, and Rosedale. None of these locations, though, match the distances shown in the comic (Dockery Plantation is probably the closest). {{unsigned ip|108.162.216.55}}

Here is a map showing the distances from each city (with sPace as Pace.) [http://maps.google.com/maps/api/staticmap?size=600x500&path=fillcolor:0x00FF00|weight:1|color:0xFFFFFF|enc:oevrE~hqiPrLeuMzg@}rM|bAknMp}AqgMzwBo~LlqCgsLljD{eLnbEovKtyEaeKtoFwqJtdGu|IfxGyeIpjHomHh{HqsGrjIixFfxI{{EfdJk~DlnJ}_DzvJu`Cn}Jy`BdbKo`A`eKy_@`fK?`eKx_@dbKn`An}Jx`BzvJt`ClnJ|_DfdJj~DfxIz{EpjIhxFj{HpsGpjHnmHfxGxeIrdGt|IvoFvqJtyE`eKnbEnvKljDzeLlqCfsLzwBn~Lp}ApgMzbAjnMzg@|rMtLduMuLfuM{g@|rM{bAjnMq}AngM{wBn~LmqCfsLmjD|eLobElvKuyEbeKwoFvqJsdGr|IgxGzeIqjHlmHk{HpsGqjIhxFgxI|{EgdJj~DmnJ|_D{vJt`Co}Jx`BebKn`AaeKx_@afK?aeKy_@ebKo`Ao}Jy`B{vJu`CmnJ}_DgdJk~DgxI}{EsjIixFi{HqsGqjHmmHgxG{eIudGs|IuoFwqJuyEceKobEmvKmjD}eLmqCgsL{wBo~Lq}AogM}bAknM{g@}rMsLguM&path=fillcolor:0x00FF00|weight:1|color:0xFFFFFF|enc:i{dnElemePhXixYxjAetY||BykYnnDm_Yb_F{nXtnGkzW||HabWriJ}eVptKefUn}L_cThdNq|RthO}rQrjPkfPviQgwN`fRseMh_SwqKpuS}{IphTkdHdxTokFjdUiqDfmUmvBnrUyz@ftU?nrUxz@dmUlvBldUhqDbxTnkFphTjdHpuS|{Ij_SvqK`fRreMviQfwNpjPjfPthO|rQhdNp|Rn}L~bTptKdfUtiJ|eV||H`bWtnGjzW`_FznXnnDl_Y||BxkYxjAdtYhXhxYiXjxYyjAdtY}|BxkYonDj_Ya_FznXunGlzW}|H~aWuiJ|eVqtKffUo}L~bTidNn|RuhO|rQqjPlfPwiQfwNafRpeMk_SvqKquS|{IqhTldHcxTlkFmdUjqDemUjvBorUzz@gtU?orU{z@gmUkvBkdUkqDexTmkFqhTmdHquS}{Ii_SwqKafRqeMwiQgwNsjPmfPuhO}rQidNo|Ro}L_cTqtKgfUsiJ}eV}|H_bWunGmzWc_F{nXonDk_Y}|BykYyjAetYiXkxY&path=fillcolor:0x00FF00|weight:1|color:0xFFFFFF|enc:_nc~EnfpdPpTmrVr_AunVhjBkgVptCm|U~}DymUnfF{{T~mGifT~sHsmSrxIsqRp{JsrQp|KupPr{LalOnxM{dN~rNi{LdkOooKv`P{aJrsPmrHxcQoaGbqQkoEp{Qc|C`cRehBrgRws@`iR?pgRvs@`cRdhBr{Qb|CbqQjoExcQnaGrsPlrHv`PzaJdkOnoK~rNh{LnxMzdNr{L`lOp|KtpPn{JrrQrxIrqR`tHrmS|mGhfTpfFz{T~}DxmUntCl|UjjBjgVp_AtnVpTlrVqTjrVq_AvnVkjBjgVotCj|U_~DzmUqfFx{T}mGjfTatHpmSsxIrqRo{JrrQq|KvpPs{L`lOoxMzdN_sNf{LekOpoKw`PxaJssPlrHycQpaGcqQhoEs{Qd|CacRdhBqgRts@aiR?sgRus@acRehBq{Qe|CcqQioEycQqaGssPmrHw`PyaJekOqoK_sNg{LoxM{dNs{LalOq|KwpPq{JsrQsxIsqR_tHqmS_nGkfTofFy{T_~D{mUqtCk|UijBkgVs_AwnVqTkrV&sensor=true] {{unsigned|Jdallman2570}}

So we can follow that sign, have a good day and go to space today? [[Special:Contributions/141.101.88.225|141.101.88.225]] 13:56, 30 May 2014 (UTC)

I think the point Randall is trying to make here (as he did repetitively in the past) is that space (100 km) is actually not that far away as it "seems", at least closer than the cities on the other two arrows. {{unsigned ip|173.245.52.158}}

He also rather neatly (with the help of the USAF) makes the point that there is no single hard line where space starts. [[User:Jim E|Jim E]] ([[User talk:Jim E|talk]]) 15:45, 30 May 2014 (UTC)

I'm wondering whether Jackson 115 might relate to the Jackson 5. --[[User:Dfeuer|Dfeuer]] ([[User talk:Dfeuer|talk]]) 15:05, 31 May 2014 (UTC)

The driving distance from Jackson, Mississippi to Memphis, Tennessee is 210 miles. I figure the extra three miles added was done so as to accommodate the disposal of the bodies in the trunk - or the children in the back - and/or purchase a gun.

Talk:1336: Transformers

2014-02-28T19:16:57Z

108.162.216.57:

Wow, this really is a departure from Randall's usual style. [[Special:Contributions/108.162.219.17|108.162.219.17]] 12:27, 28 February 2014 (UTC)
: I guess it would have been impossible to make robot as stick figures and make people recognize them as robots...., hence I think this is a one-off [[User:Spongebog|Spongebog]] ([[User talk:Spongebog|talk]]) 15:39, 28 February 2014 (UTC)
:: This '[[600:_Android_Boyfriend]]' is the only other "Robot" strip I can think off [[User:Spongebog|Spongebog]] ([[User talk:Spongebog|talk]]) 15:42, 28 February 2014 (UTC)

Is this a nod to Perry Bible Fellowship in some way? It seems more like a PBF strip. [[Special:Contributions/141.101.98.37|141.101.98.37]]

:Agree, I thought of PBF too. Is there a category here for "Comics with non-stick-figure characters"? - [[User:Frankie|Frankie]] ([[User talk:Frankie|talk]]) 14:29, 28 February 2014 (UTC)

I went to PBF to see if there was a cross-over, but I was disappointed.--[[Special:Contributions/108.162.210.135|108.162.210.135]] 18:24, 28 February 2014 (UTC)

Insecticons, maybe? [[Special:Contributions/108.162.216.57|108.162.216.57]] 19:16, 28 February 2014 (UTC)

102: Back to the Future

2014-02-01T00:12:02Z

108.162.216.57: /* Explanation */

{{comic
| number = 102
| date = May 15, 2006
| title = Back to the Future
| image = back_to_the_future.jpg
| titletext = He's kind of an asshole, when you think about it.
}}

==Explanation==
{{incomplete|Cueball is Hairy at the first two panels, it's not an inking error}}
This comic is a reference to the "{{w|Back to the Future}}" film series (specifically the first film) in which the protagonist, Marty McFly (played by {{w|Michael J. Fox}}) travels back from 1985 (present day for him) to 1955 and accidentally interferes with his own parents' first meeting. He must then arrange for them to fall in love before he ceases to exist from the paradox of his own parents never having children. An unintended side-effect of the way events occur is that his dad gains self-confidence in the past and becomes "less of a loser" in the present.

As noted in the comic, the time machine Marty uses is built by his professor friend, Doctor Emmett L. Brown ({{w|Christopher Lloyd}}) out of a {{w|DeLorean DMC-12}} (a 1980s-era sports car).

[[Cueball]] (who seems to have hair in the first two frames but perhaps that is just an inking error) has a very similar experience, and suggests that the aforementioned changes to history are what he really needed to do. After a frame of awkward silence, [[Megan]] reminds him that her father was in the {{w|World Trade Center}} North Tower – implying that he died (along with several thousand others) in 1 World Trade Center on {{w|September 11, 2001}} at the time the tower collapsed due to a terrorist-flown passenger jet crashing into the building. Megan is therefore implying that that saving her father's life (and perhaps the lives of the other 9/11 victims) might have been something else of importance he "needed" to do - perhaps something of significantly more importance. He seems oblivious to what she is trying to suggest, which as the title text notes, makes him kind of an asshole.

As a side note, for the comic to make sense, the events in the comic must take place after {{w|September 11, 2001}}, and not 1985 as it is in the movie. Since no dates are mentioned, Cueball probably went back by twenty years, because that's how far back Marty travels in the film.

==Transcript==
:[Megan and Cueball are standing, talking to one another.]
:Cueball: This weekend, my professor friend built a time machine out of a DeLorean and I went back in time! I helped make sure my parents got together and helped my dad to be less of a loser.

:Megan: Wow! Do you still have the time machine?
:Cueball: Nah. But I did what I really needed to do.
:Megan: Uh huh.

:[Neither says anything.]

:Megan: Okay, you remember that my father was in the WTC North Tower, right?
:Cueball: Yeah...why?
:Megan: I...nothing.

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

Talk:1318: Actually

2014-01-17T21:20:43Z

108.162.216.57:

I started reading the comic from the topmost line "Actually, measurements suggest it's flat." It seemed that he was talking about the planet, but it's also a response to the curved-space line from before. Upon further reading, I can't tell if the discussion is about a planet or a universe, and it looks like you can go around the circle twice and assume both. [[Special:Contributions/173.245.50.72|173.245.50.72]] 05:13, 17 January 2014 (UTC)

: It is about the shape of the Earth. The Earth exists in a curved universe. The alt text is referring to the fact that by being more and more specific you can always get the last word in but it may alienate you from your peers. [[Special:Contributions/108.162.246.117|108.162.246.117]] 05:14, 17 January 2014 (UTC)

The transcript needs some way to show that Cueball is talking to the second Hairy in the end. [[Special:Contributions/108.162.216.71|108.162.216.71]] 08:25, 17 January 2014 (UTC)

: "show that Cueball is talking to the second Hairy in the end" -> Do you consider it done ? [[User:MGitsfullofsheep|MGitsfullofsheep]] ([[User talk:MGitsfullofsheep|talk]]) 08:50, 17 January 2014 (UTC)

Fixed factual error about sum of angles of a triangle in a closed geometry. An example of closed geometry is spherical geometry, where sum of angles of a triangle is π < A + B + C<3π http://en.wikipedia.org/wiki/Spherical_trigonometry . Previous text wrongly stated that A+B+C would be smaller than π in closed geometry and greater in open geometry. [[User:MGitsfullofsheep|MGitsfullofsheep]] ([[User talk:MGitsfullofsheep|talk]]) 08:50, 17 January 2014 (UTC)

About the oblate configuration: why attribute it to centripetal force? Because centrifugal force is an "apparent" force? Well centripetal force from gravitational pull is actually balancing the centrifugal force caused by rotation of the earth. The whole "centrifugal force does not exist" thing is a misconception. It's an inertial force and writing the equilibrium equations for an object in the rotating reference frame (the one we experience everyday) at latitude phi you see: gravitational pull toward the center of the planet + centrifugal force away from the axis of rotation= mass*g(phi). This g(phi) is not the same in every spot of the earth, it changes in value and direction (does not always point exactly to the center of the earth) with latitude.{{unsigned ip|108.162.229.65}}
: I second this. The centripetal force would actually be the gravity of earth. Attributing the oblate shape of earth to this is just plain wrong, since it pulls inwards, not outwards. Actually all forces could be called "apparent" forces, since they're really just constructs to help you calculate the acceleration of a body. There's always a (local) reference frame where a particular force doesn't "exist". {{unsigned ip|173.245.53.131}}
:: Sure, there is always such frame, but gravitation is real force anyway because we can measure the higgs field by detecting higgs bosons. At least I think we can. Failing that, electromagnetic forces are real because we can measure electromagnetic field by detecting photons, this I'm sure of :-). -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 10:23, 17 January 2014 (UTC)
:::Come now. Do you really expect me to do coordinate substitution in my head while strapped to a centrifuge? [[User:Diszy|Diszy]] ([[User talk:Diszy|talk]]) 15:44, 17 January 2014 (UTC)
::::No, Mister Diszy, I expect you to die. [[Special:Contributions/108.162.238.117|108.162.238.117]] 20:14, 17 January 2014 (UTC)

I don't see why the explanation assumes the top claim is at the start and end. I think that part of the explanation is a stretch and that the "flat" claim is not meant to be given twice. [[Special:Contributions/108.162.246.117|108.162.246.117]] 17:38, 17 January 2014 (UTC)
:It's a loop. Technically there is no "start". Each line is a direct "more specific" response to the previous remark. [[Special:Contributions/108.162.238.117|108.162.238.117]] 20:17, 17 January 2014 (UTC)

I always suspected Freddie Mercury was a closet planetoligist. {{unsigned ip|127.0.0.1|20:26, 17 January 2014 (UTC)}}

I highly doubt this pun is intentional, but this could be seen as a case of circular logic. [[Special:Contributions/108.162.238.117|108.162.238.117]] 20:35, 17 January 2014 (UTC)

Any significance to where they are standing along the circle? If we start with flat, the first three are right in a row, but then the rest are spread out further.[[Special:Contributions/108.162.216.57|108.162.216.57]] 21:20, 17 January 2014 (UTC)

Talk:1317: Theft

2014-01-15T15:10:03Z

108.162.216.57: How many identities stolen @ once?

This comic seems to be about the idea that true identity theft would require the thief to take on the identity perfectly. The thief in the comic is Randall Munroe making fun of himself and how he is often existential and is excited about space... 1st post--[[Special:Contributions/173.245.55.78|173.245.55.78]] 05:19, 15 January 2014 (UTC)

Maybe it's a shared account, so it really is Megan's own existentialism & Randall's love of space -- a true crisis!
[[Special:Contributions/108.162.216.57|108.162.216.57]] 15:10, 15 January 2014 (UTC)

Talk:1316: Inexplicable

2014-01-13T23:36:13Z

108.162.216.57:

[http://xkcd.com/725/ Literally] haunted? [[Special:Contributions/173.245.53.152|173.245.53.152]] 08:22, 13 January 2014 (UTC)

I was wondering too if Randall was also taking a sideways swipe at the way many people today misuse the term "literally".[[Special:Contributions/108.162.216.30|108.162.216.30]] 22:42, 13 January 2014 (UTC)

I would say he trying to say that some errors that computers have are impossible to fathom. I've baffled our IT people on many an occasion and the solution is usual 'rebuild' which is the computer equivalent of an exorcism.[[Special:Contributions/108.162.231.228|108.162.231.228]] 10:18, 13 January 2014 (UTC)
:Definitely this. It is also much harder to figure out what the problem is with a computer when you weren't the one who has spent all their time using the computer. It is why I can't understand how IT people do their jobs. [[User:Daleb|Daleb]] ([[User talk:Daleb|talk]]) 13:14, 13 January 2014 (UTC)

Surprised nobody mentioned [https://en.wikipedia.org/wiki/Ghost_in_the_machine Ghost in the machine] yet... --[[User:Koveras|Koveras]] ([[User talk:Koveras|talk]]) 10:28, 13 January 2014 (UTC)

I find the current explanation entertaining but... raises questions.

Is "This comic is inexplicable and represents a self-referencing joke about explainxkcd.com." serious?
:I think it's not and I deleted the sentence. [[Special:Contributions/173.245.50.84|173.245.50.84]] 14:39, 13 January 2014 (UTC)

"While it might [be] a reasonable conclusion [i.e. that it is 'haunted'] for a human, demons can't possess a computer." - this reads like "demons exist, but are incapable of possessing computer equipment", rather than "demons cannot possess a computer, because they don't even exist", which would be my ''preference'' (under the standard rules of not being able to ''prove'' the non-existence of the supernatral... and, believe me, I've had my fair share of totally baffling computer problems, in my time, and often anthropomorphise equipment, somewhat, ''at least'' to explain it to non-tech users... but then end up adopting the same attitude myself, of course).

"The title text suggests that Megan insists that Cueball resume possession of his laptop, as she is unsettled by the ghost; Cueball simply refuses, seeing an opportunity to make his problem hers." - I see that as more akin to the "cursed gem" type of story. One simply cannot palm the gem off on somebody else, but it must have a legitimately willing recipient (including a thief stealing it, often) in order for the curse itself to transfer itself. Now that the 'status' of the laptop is known he's not going to accept it back and take the 'curse of errors' back upon himself. [[Special:Contributions/141.101.99.223|141.101.99.223]] 14:08, 13 January 2014 (UTC)

:I just removed the sentence "While it might [be] a reasonable conclusion for a human, demons can't possess a computer." In the real world ghosts (the comic does not mention demons) don't exist and can't possess either humans or computers; in a fictional world, they might be able to do either or both (a la King's "Trucks"). -- [[Special:Contributions/108.162.212.217|108.162.212.217]] 15:24, 13 January 2014 (UTC)

I think the joke is just that normally the smartass that knows more about computers than you is able to easilly fix it, but not in this case. [[User:Halfhat|Halfhat]] ([[User talk:Halfhat|talk]]) 16:13, 13 January 2014 (UTC)

So am I the only one who thinks that the caption(or whatever the hover over text is called) refers to Cueball trying to return the laptop to a retail store. I mean I can see a store like Best Buy refusing to take back a laptop because a customer insists that there is a ghost in it. [[Special:Contributions/108.162.216.83|108.162.216.83]] 18:25, 13 January 2014 (UTC)

Overthinking, maybe, but if the computer is haunted (read: possessed), then a valid solution IS to return (read: unpossess? dispossess?) it. [[Special:Contributions/108.162.216.57|108.162.216.57]] 23:36, 13 January 2014 (UTC)

Talk:1304: Glass Trolling

2013-12-16T13:37:54Z

108.162.216.57:

In google now, you can use "OK glass" instead of "OK google".--[[User:Mralext20|Mralext20]] ([[User talk:Mralext20|talk]]) 05:23, 16 December 2013 (UTC)

There are actually privacy activists who call for grabbing such gadgets and destroying them by stomping on them. Google for "#camover" in combination with "google glass" to find hints. --[[User:Kigana|Kigana]] ([[User talk:Kigana|talk]]) 08:58, 16 December 2013 (UTC)

I don't know, aren't dioptric glasses correcting more complicated problems like astigmatism also costly? -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 09:55, 16 December 2013 (UTC)
: Speaking in gross costs, yes. My new glasses cost well over $400 USD. Thankfully, due to decent vision insurance, I only paid $53 for exam ($10), frame/lenses ($20) and the upcharge (discounted) for polycarbonate lenses. Context: I have heavy astigmatism (especially my left eye) plus farsightedness. --BigMal // [[Special:Contributions/108.162.216.57|108.162.216.57]] 13:37, 16 December 2013 (UTC)

936: Password Strength

2013-12-03T18:20:24Z

108.162.216.57:

{{comic
| number = 936
| date = August 10, 2011
| title = Password Strength
| image = password strength.png
| titletext = To anyone who understands information theory and security and is in an infuriating argument with someone who does not (possibly involving mixed case), I sincerely apologize.
}}

==Explanation==
{{incomplete}}
Computer security consultant Mark Burnett has posted a [http://xato.net/passwords/analyzing-the-xkcd-comic/ good discussion and analysis] of this comic on his blog.

This comic is saying that the password in the top frames "Tr0ub4dor&3" is easier for password cracking software to guess because it's shorter in length than "correcthorsebatterystaple" and also more difficult for a human to remember, leading to insecure practices like writing the password down on a post-it attached to the monitor (Tr0ub4dor&3).

It is absolutely true that people make passwords hard to remember because they think they are "safer", and it is certainly true that length, all other things being equal, tends to make for very strong passwords and this can confirmed by using [http://rumkin.com/tools/password/passchk.php rumkin.com's password strength checker]. Even if the individual characters are all limited to [a-z], the exponent implied in "we added another lowercase character, so multiply by 26 again" tends to dominate the results.

In addition to being easier to remember, and long strings of lowercase characters are also easier to type on smartphones and {{w|Virtual keyboard|soft keyboards}}.

xkcd's entropy estimate of 11 bits per word assumes that the password is being brute-forced with a dictionary attack, and that the words are being chosen from a dictionary of 2000 words (log2(2000) ≈ 11). (For comparison, the [http://world.std.com/~reinhold/dicewarefaq.html#calculatingentropy entropy offered by Diceware's 7776 word dictionary is 13 bits per word].) If a dictionary attack were ''not'' used, the "common words" password would take even longer to crack than depicted. (25 ''random'' lowercase characters would have [http://www.wolframalpha.com/input/?i=log2%2826^25%29 117 bits of entropy], vs [http://www.wolframalpha.com/input/?i=log2%282000^4%29 44 bits] for the dictionary words.)

{{w|Steve Gibson (computer programmer)|Steve Gibson}} from the {{w|Security Now}} podcast did a lot of work in this arena and found that this password <code>D0g.....................</code> (24 characters long) is stronger than <code>PrXyc.N(n4k77#L!eVdAfp9</code> (23 characters long) because both have at least one uppercase letter, lowercase letter, number, and "special" character, so length trumps perceived complexity. Steve Gibson makes this very clear in his password haystack [https://www.grc.com/haystack.htm reference guide and tester]:
:"Once an exhaustive password search begins, '''the most important factor''' is password length!"

The important thing to take away from this comic is that longer passwords are better because each additional character adds much more time to the breaking of the password. That's what [[Randall]] is trying to get through here. Complexity does not matter unless you have length in passwords. Complexity is more difficult for humans to remember, but length is not.

==Transcript==
:The comic illustrates the relative strength of passwords assuming basic knowledge of the system used to generate them.
:A set of boxes is used to indicate how many bits of entropy a section of the password provides.
:The comic is laid out with 6 panels arranged in a 3x2 grid.
:On each row, the first panel explains the breakdown of a password, the second panel shows how long it would take for a computer to guess, and the third panel provides an example scene showing someone trying to remember the password.

:[The password "Tr0ub4dor&3" is shown in the center of the panel. A line from each annotation indicates the word section the comment applies to.]

:Uncommon (non-gibberish) base word
:[Highlighting the base word - 16 bits of entropy.]
:Caps?
:[Highlighting the first letter - 1 bit of entropy.]
:Common Substitutions
:[Highlighting the letters 'a' (substituted by '4') and both 'o's (the first of which is substituted by '0') - 3 bits of entropy.]
:Punctuation
:[Highlighting the symbol appended to the word - 4 bits of entropy.]
:Numeral
:[Highlighting the number appended to the word - 3 bits of entropy.]
:Order unknown
:[Highlighting the appended characters - 1 bit of entropy.]
:(You can add a few more bits to account for the fact that this is only one of a few common formats.)

:~28 bits of entropy
:228 = 3 days at 1000 guesses sec
:(Plausible attack on a weak remote web service. Yes, cracking a stolen hash is faster, but it's not what the average user should worry about.)
:Difficulty to guess: Easy.

:[Cueball stands scratching his head trying to remember the password.]
:Cueball: Was it trombone? No, Troubador. And one of the O's was a zero?
:Cueball: And there was some symbol...
:Difficulty to remember: Hard.

:[The passphrase "correct horse battery staple" is shown in the center of the panel.]
:Four random common words {Each word has 11 bits of entropy.}

:~44 bits of entropy
:244 = 550 years at 1000 guesses sec
:Difficulty to guess: Hard.

:[Cueball is thinking, in his thought bubble a horse is standing to one side talking to an off-screen observer. An arrow points to a staple attached to the side of a battery.]
:Horse: That's a battery staple.
:Observer: Correct!
:Difficulty to remember: You've already memorized it

:Through 20 years of effort, we've successfully trained everyone to use passwords that are hard for humans to remember, but easy for computers to guess.

==External links==
* Some info was used from the highest voted answer given to the question of "how accurate is this XKCD comic" at StackExchange [http://security.stackexchange.com/questions/6095/xkcd-936-short-complex-password-or-long-dictionary-passphrase].
* Similarly, a question of "how right this comic is" was made at AskMetaFilter [http://ask.metafilter.com/193052/Oh-Randall-you-do-confound-me-so] and [[Randall]] responded [http://ask.metafilter.com/193052/Oh-Randall-you-do-confound-me-so#2779020 there].
* Also the Wikipedia article on 'Passphrase' is useful [http://en.wikipedia.org/wiki/Passphrase].
* In case you missed it in the explanation, GRC's Steve Gibson has a fantastic page [https://www.grc.com/haystack.htm] about this (and may have prompted this comic, as his podcast [http://www.grc.com/sn/sn-303.htm] about this was posted the month before this comic).

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Math]]
[[Category:Computers]]