explain xkcd - User contributions [en]

2120: Brain Hemispheres

2020-05-11T19:51:42Z

108.162.219.44:

{{comic
| number = 2120
| date = March 6, 2019
| title = Brain Hemispheres
| image = brain_hemispheres.png
| titletext = Neurologically speaking, the LEFT hand is actually the one at the end of the RIGHT arm.
}}

==Explanation==
As a general rule, each cerebral hemisphere controls the opposite side of the body; things on the left half of the body are controlled by the right side of the brain and vice-versa. Biology is complicated, of course, so as with most biology "rules" there are exceptions, such as the {{w|cranial nerves}}, but it's true for most motor functions, and a relatively well-known factoid, if not strictly correct in all cases.

[[Randall]] spoofs this by saying that rather than controlling the left half of the body, the right brain controls the top. This leads to a Venn-diagram-like picture of the human body, with an overlap in the upper right, labelled "disputed," echoing maps that display a {{w|territorial dispute}}, suggesting that the halves of your brain fight for control of the region, or "{{w|dual control}}" like in an airplane, where the pilot and the copilot both can control the plane at any time. The reorganization also leaves a gap in the bottom left, implying that the left leg is not controlled by any part of the brain, and instead has a mind of its own.

The title text is another, separate joke about the same factoid. He proposes that the hands should be referred to not by their physical location, but by the hemisphere of the brain they're connected to. Of course, this is not only silly but inconsistent: if the hands were labelled by hemispheres of the brain, the same would presumably apply to the arms. Furthermore, there would be no reason to give left/right names to the hemispheres themselves, since their placement in the skull would be irrelevant.

==Transcript==
:[Cueball is shown with the right half of his brain (on the viewer's left) colored in orange and the left half (on the viewer's right) in iris blue. An iris blue box is overlaid over the right half of the body (on the viewer's left), and an orange box is overlaid over the top half. The boxes are overlapping in a greenish color on the upper right quarter of the body (on the viewer's left).]
:'''Neuroscience Fact:'''
:[An arrow pointing to the iris blue rectangle on top with the text above:]
:The ''left'' half of the brain actually controls the ''right'' half of the body...
:[An arrow pointing to the orange rectangle at the right, the text reads:]
:...while the ''right'' half of the brain actually controls the ''top'' half of the body.
:[An arrow pointing to the overlapping area (the top left body from the viewers perspective) with the text below:]
:Disputed/dual control
:[An arrow pointing to Cueball's left leg area (on the viewer's right), not highlighted by any color, and the text is:]
:This leg is fully autonomous

{{comic discussion}}

[[Category:Comics with color]]
[[Category:Comics featuring Cueball]]
[[Category:Biology]]

1074: Moon Landing

2015-08-04T03:43:59Z

108.162.219.44: /* Explanation */

{{Comic
| number = 1074
| date = June 27, 2012
| title = Moon Landing
| image = moon_landing.png
| titletext = Ok, so Spirit and Opportunity are pretty awesome. And Kepler. And New Horizons, Cassini, Curiosity, TiME, and Project M. But c'mon, if the Earth were a basketball, in 40 years no human's been more than half an inch from the surface.
}}

==Explanation==
The comment to which [[Cueball]] is referring is [https://twitter.com/neiltyson/status/73388356461019136 a tweet] by {{w|Neil deGrasse Tyson}}, an American astrophysicist and science communicator. As of this comic, Tyson is the "Frederick P. Rose Director" (a special honorary title) of the {{w|Hayden Planetarium}}. He has appeared on many different shows, ranging from The Discovery Channel to The Big Bang Theory.

There are a number of {{w|moon landing conspiracy theories|conspiracy theories}} claiming that the moon landing was a hoax. Tyson offers a pretty compelling argument against them, but [[Megan]] presents an even more convincing refutation, snarkily implying that NASA really hasn't done anything spectacular since 1969.

And Cueball responds with a pun on the word "burn". Burn can mean a particularly effective insult, or it can mean the consumption of fuel for propulsion. In this case, the "burn" was so effective it pushed the spaceship out of orbit (which usually takes a very large amount of burning, depending on the gravity of the planet or moon).

In the title text [[Randall]] mentions many successful {{w|NASA}} unmanned missions:
*The {{w|Mars Exploration Rover|Mars rovers}} Spirit and Opportunity, which landed in 2004. Opportunity has been working for over ten years on the surface of Mars; Spirit got stuck in 2009 and shut down for good in 2010. See this comic: [[695: Spirit]].
*{{w|Kepler (spacecraft)|Kepler}} found many {{w|exoplanets}}
*{{w|New Horizons}} is a mission to the dwarf planet {{w|Pluto}} and beyond. It's scheduled to arrive at Pluto by mid 2015.
*{{w|Cassini–Huygens|Cassini}} is a probe orbiting {{w|Saturn}} since 2004.
*{{w|Curiosity (rover)|Curiosity}} is another, larger Mars rover, exploring the Martian surface since August 2012.
*{{w|Titan Mare Explorer|TiME}} is a proposed mission to explore the oceans of Saturn's moon Titan.
*{{w|Project M (NASA)|Project M}} is an idea to send human-like robots to the Moon.
The final sentence of title text notes that all manned missions since the Moon landings have taken place in low-earth orbit, which is barely far off of the Earth's surface. If the Earth were scaled to the size of a regulation basketball, approximately 24 cm (9¼ inches) in diameter, those manned missions would have all taken place within 1.25 cm (½ inch) of the ball's surface. At this scale the Moon would be at a distance of 7.7 m (25.3 ft). Unmanned missions, such as those named above or the {{w|Voyager program|Voyager}} and {{w|Mariner program|Mariner}} probes of the 1960s and 1970s, have travelled much further.

==Transcript==
:[Cueball is sitting at a table with a laptop open. His hands are on the keys.]
:Cueball: Hah- Neil DeGrasse Tyson has a great reply to people who doubt astronauts went to the moon.
:Voice off-screen: Oh?
:Cueball: "Atop 3,000 tons of rocket fuel, where ''else'' do you think they were headed?"

:[The voice off screen turns out to be Megan. She is depicted, and now Cueball is off-screen.]
:Megan: Cute. But it overlooks an even simpler argument.
:Cueball: Which is?

:[Both Megan and Cueball are now visible. Cueball has turned his chair around to face her.]
:Megan: If NASA were willing to fake great accomplishments, they'd have a second one by now.
:Cueball: ''Ouch.''
:Megan: ...Too mean?
:Cueball: That burn was so harsh I think you deorbited.

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

1377: Fish

2014-06-04T06:53:18Z

108.162.219.44: /* Transcript */

{{comic
| number = 1377
| date = June 4, 2014
| title = Fish
| image = fish.png
| titletext = [Astronomer peers into telescope] [Jaws theme begins playing]
}}

==Explanation==
The Fermi Paradox is the contradiction that arises between the high likelihood of extraterrestrial life and the fact that no evidence for it has thus been found. Cueball and Megan are having a conversation regarding this, when Megan suggests that perhaps our search for extraterrestrial life is like looking at a patch of ocean floor looking for a fish. The diver knows that there must be a fish somewhere, but is unable to actually find it. She then goes on to ask why the fish would be hidden - i.e. camouflaged, and what it means about the remaining fish. The suggestion is that the fish would be hidden to avoid being eaten by predators, and perhaps the reason no extraterrestrial life is sending any sign of existence back is that they would be destroyed soon after they revealed their location. The final panels take the metaphor further, suggesting that there is literally a shark swimming through space eating all the aliens.

==Transcript==
{{incomplete transcript}}

[Cueball and Megan are walking down a hill]

Cueball: The Fermi paradox keeps getting worse. If planets are common, where '''is''' everybody?

Megan: Imagine you're a SCUBA diver looking at the ocean floor. You know there's a fish there, but you can't see it. Why?

Cueball: Maybe the fish looks like sand.

Megan: Yeah...

[Zoom out to the Earth from space]

Megan: ...and what would that tell you about the ecosystem?

[Pan to a shark swimming through space towards Earth]

{{comic discussion}}

1377: Fish

2014-06-04T06:48:50Z

108.162.219.44: /* Explanation */

1375: Astronaut Vandalism

2014-05-30T04:47:08Z

108.162.219.44: /* Explanation */ Fixed link

{{comic
| number = 1375
| date = May 30, 2014
| title = Astronaut Vandalism
| image = astronaut_vandalism.png
| titletext = That night, retired USAF pilots covertly replaced the '62' with '50'.
}}

==Explanation==
Signs like this normally show the distance to places on earth's surface. This sign also has an arrow pointing away from earth and towards "space", with a distance of 62 miles (100 km), due to "astronaut vandalism". The title text states that the distance to "space" was changed later from 62 miles (100 km) to 50 miles (80 km) by retired Air Force pilots. This indicates that the pilots wanted to reduce the altitude considered to be "space", so that their own high altitude flights to be considered space flights.

Additional background: The U.S. Air Force will award astronaut wings to rated officers who fly higher than 50 miles while the World Air Sports Federation (FAI) designated the 100-kilometer = 62 miles Karman Line in the mid 1950s. Useful summary: [http://www.slate.com/articles/news_and_politics/explainer/2004/09/where_does_space_begin.html Slate: Where does space begin?]

==Transcript==
A signpost with three arrows.
Arrow pointing up: Space 62.
Arrow pointing right: Jackson 115.
Arrow pointing left: Memphis 98.

{{comic discussion}}

Talk:Footnote

2014-05-29T02:06:18Z

108.162.219.44: Created page with "I remember the footnote originally being somewhat different (referring instead to a "formula"). Does anybody have that version? ~~~~"

I remember the footnote originally being somewhat different (referring instead to a "formula"). Does anybody have that version? [[Special:Contributions/108.162.219.44|108.162.219.44]] 02:06, 29 May 2014 (UTC)

Talk:1364: Like I'm Five

2014-05-05T05:58:04Z

108.162.219.44: Created page with "Almost certainly a reference to [http://www.locusmag.com/Perspectives/2014/05/cory-doctorow-how-to-talk-to-your-children-about-mass-surveillance/ this]. ~~~~"

Almost certainly a reference to [http://www.locusmag.com/Perspectives/2014/05/cory-doctorow-how-to-talk-to-your-children-about-mass-surveillance/ this]. [[Special:Contributions/108.162.219.44|108.162.219.44]] 05:58, 5 May 2014 (UTC)

1360: Old Files

2014-04-28T00:22:15Z

108.162.219.44: /* Explanation */

{{comic
| number = 1360
| date = April 25, 2014
| title = Old Files
| image = old_files.png
| titletext = Wow, ANIMORPHS-NOVEL.RTF? Just gonna, uh, go through and delete that from all my archives real quick.
}}

==Explanation==
{{incomplete|The file explains are better now, but still need work.}}
Cueball is digging through a pile of old files, which the comic represents as literally digging into the depths of his filesystem. The files are in concentric layers because each directory contains files moved over from an older system, so his "Documents" folder contains an "Old Desktop" folder from an older computer, the "Old Desktop" contains files recovered from the drive crash of the system before that, which had its own "My Documents" folder, which contained files saved from a [[wikipedia:Zip Disk|Zip Disk]] in high school. The result is that files from all the way back in high school have survived to his present-day machine. He discovers several files he is embarrassed about, including a poetry file that surprises him, since he does not remember writing poetry, and an "[[wikipedia:Animorphs|Animorphs]] Novel" mentioned in the title text, most likely a fan fiction of the Animorphs series, although possibly a copy of one of the original books.

This comic came out the day after [http://news.sky.com/story/1248397/andy-warhol-originals-found-on-floppy-disk Sky News published the story] of original {{w|Andy Warhol}} artwork, created in 1985 on an {{w|Amiga 1000}}, was recovered from recently found floppy disks.

The folders and files in detail:
*'''Documents''' (47 GB) - A large folder containing many of [[Cueball]]'s personal files.
**''misc.txt'' - A miscellaneous {{w|text file}} of unknown size. Quite likely, no one except Cueball will know what's in it.
**''Video projects'' - Video files can take up a lot of space, and likely make up a significant chunk of that 47 GB.
*'''Old desktop''' (12 GB) - A backup from a former computer.
**''Facebook pics'' - Because {{w|Facebook}} started in 2004, his old computer must have been functional by that time.
**''Pics from other camera'' - No mention about the content, only the creator will remember.
**''Temp'' - Old temporary files. Quite likely, even Cueball won't know what's in here.
**''Misc PDFs'' - {{w|Portable Document Format|PDF files}} are often used for documentation on programs, but this could be also a collection of digitized books or other scanned documents.
**''MP3'' - Probably mostly music. {{w|MP3}} is a widely-used format for digital audio files.
*'''Recovered from drive crash''' (4 GB) - When a {{w|Hard disk drive|hard drive crashes}}, sometimes part of that content can be recovered.
**''Temp'' - More old temporary files.
**''Work misc'' - Only the creator does maybe understand what's inside of this folder.
**''Audio books'' - {{w|Audiobook|Audio books}} are recordings of a text being read.
*'''My Documents''' (570 MB) - This is a typical {{w|Microsoft Windows}} for your own documents.
**''Downloads'' - A common default location for downloaded files. Its content can be anything.
**''Kazaa shared'' - {{w|Kazaa}} was a peer-to-peer file sharing program, defunct in August 2012. The "shared" folder was open to other people on the internet for downloading.
**''AYB'' - {{w|All your base are belong to us|All Your Base}} is an internet meme based on a famously bad translation of the video game ''{{w|Zero Wing}}''. Probably a reference to [[286: All Your Base]].
**''EV Override'' - {{w|Escape Velocity Override}} is an {{w|Apple Macintosh}} video game, released in 1998.
**''Angband'' - [http://rephial.org/ Angband] is a game named after a fictional iron prison created by {{w|J. R. R. Tolkien}}.
**''GIFs'' - {{w|GIF}} is an old image format widely used for small, animated images.
**''FIGHT CLUB.wmv'' - ''{{w|Fight Club}}'' is a movie from 1999. Nobody knows if this download was legal. As feature movies are typically compressed to 700 megabyte or more when shared over the Internet, it seems Cueball's file is either compressed in some obscure, irregular format or not the Brad Pitt movie - either way strongly in keeping with the original movie's themes of subversion.
**''Elasto Mania'' - {{w|Elasto Mania}} is a physics-simulation game released in 2000. It claims to show real physics on this game, but there is still a dispute on this.
**''AIM Direct Connect files'' - This may have to do with files transferred via {{w|AOL Instant Messenger}}.
**''4chan'' - {{w|4chan}} is web forum where users can upload content like pictures anonymously.
**''ICQ logs'' - {{w|ICQ}} is an instant messaging program introduced in 1996. It is no longer used much in North America.
*'''High school Zip disk''' (94 MB) - This refers to the {{w|Zip drive}}, the most popular form of {{w|superfloppy}}, introduced in 1994 with a capacity of 100 MB. These have long since given way to writable CDs/DVDs and {{w|USB flash drive}}s. These files are from when [[Cueball]] was in {{w|high school}} (i.e., a teenager) or earlier.
**''Korn MIDI'' - {{w|Korn}} is an American {{w|nu metal}} band formed in 1993. {{w|MIDI}} is a music format used by synthesizers and early computer games, which can not really produce the sound of that metal band very well.
**''Photos3'' - This is a folder of old photos from when Cueball was in high school.
***''Prom'' - A {{w|prom}} is a kind of semi-formal dance held every year by students at most US high schools. These photos were presumably taken at one.
**''lovenote.txt'' - An old text file of a {{w|love letter}}, probably to a classmate in high school.
**''Gorilla.bas'' - {{w|Gorillas (video game)|Gorillas}} is a video game first distributed with MS-DOS 5 and published in 1991 by IBM. The suffix "bas" indicates a {{w|BASIC}} program; the game was included with copies of QBasic (see below).
**''Dream.txt'' - Some private dreams.
**''James.txt'' - Who is James? Is our user addicted to him? Perhaps [[James]] is a friend of Randall, and the same as the one who came up with [http://explainxkcd.com/wiki/index.php/107 xkcd #107]?
**''AOL'' - {{w|AOL}} is an early online and internet service, founded in 1985 and popular in the 1990s.
***''Citadel'' - {{w|Citadel (software)|Citadel}} was a {{w|BBS}} and email platform that was widely used in the 1980s and early '90s.
**''QBasic'' - {{w|QBasic}} is an old MS-DOS program (an {{w|Integrated development environment|IDE}}), released by {{w|Microsoft}} in 1991, which was used to write and run computer programs in the BASIC language.
**''NYET'' - ''NYET'' was a {{w|Tetris}}-like game for MS-DOS, released in 1988.
**''Jokes.txt'' - An old text file of jokes.
*'''AAAFILES''' (9.4 MB) - some of [[Cueball]]'s oldest documents, likely prefixed with "AAA" to put the folder at the top of an alphabetically-sorted list.
*'''TXT''' (850 K) - old text files, which include the poetry he didn't remember writing.

==Transcript==

:Megan (on top of stack of files): You OK down there?

:'''Documents''' (47 GB)
::misc.txt
::Video projects
:'''Old desktop''' (12 GB)
::Facebook pics
::Pics from other camera
::Temp
::Misc PDFs
::MP3
:'''Recovered from drive crash''' (4 GB)
::Temp
::Work misc
::Audio books
:'''My Documents''' (570 MB)
::Downloads
::Kazaa shared
::AYB
::EV Override
::Angband
::GIFs
::FIGHT CLUB.wmv
::Elasto Mania
::AIM Direct Connect files
::4chan
::ICQ logs
:'''High school Zip disk''' (94 MB)
::Korn MIDI
::Photos3 (Prom)
::lovenote.txt
::Gorilla.bas
::Dream.txt
::James.txt
::AOL (Citadel)
::QBasic
::NYET
::Jokes.txt
:[Cueball deep inside]
::AAAFILES''' (9.4 MB)
::'''TXT''' (850 K)

:Cueball (deep inside): ''Oh my god. I wrote '''poetry'''.''
{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]

771: Period Speech

2014-04-22T07:06:26Z

108.162.219.44: /* Explanation */ Added a rough "translation" of the dialogue

{{comic
| number = 771
| date = July 26, 2010
| title = Period Speech
| image = period_speech.png
| titletext = The same people who spend their weekends at the Blogger Reenactment Festivals will whine about the anachronisms in historical movies, but no one else will care.
}}

==Explanation==
The actors on this stage are using language and technology from wildly differing time periods. For example, "Forsooth" is from Shakespearean times; "Grok" is a slang term used among programmers; "Jive" is African American slang from the 1940s to the 70s; "Me Hearties" is 17th century pirate speak; and "Ten-Four" was popular during the 1970s CB radio craze. (Put together, the exchange roughly translates to "Do you truly understand the bullshit I'm saying, my friends?"/"Understood!".) The characters also combine archaic weapons like a spear and a sword with a presumably modern handgun and a laptop, adding to the growing heap of anachronisms.

Randall's contention is that hundreds of years from now, people will make similar errors that we do today when depicting historical items and language. Modern movies, fiction and other forms of media that depict history often confuse terms, items and equipment that were in one place and time period and place them in another, but few people notice because to them, all of it fits under the very broad category of "old, historical things" - only those with an interest in history really notice or seem to care. Thus following this trend, in the future, things like laptop computers and "grok my jive" will seem just as historical and "old-timey" as a spear or the saying "Forsooth!", except to those who participate in such things like "Blogger Reenactment Faires", as mentioned in the title text.

For instance, take a suit of full plate armor. To most people, plate armor is a "Medieval thing". So thus, when depicting King Arthur, a figure from 500 to 800 AD (if he even existed at all), one would put him in a suit of full plate because he is "medieval" and that is the stereotypical equipment of a Medieval figure. In actual fact, plate armor only came about after 1350, quite literally centuries after any story about King Arthur is set, and it coexisted alongside firearms for a very long time. King Arthur would have worn chainmail, but all of this would be lost on an average person watching a movie about King Arthur, to whom chainmail and full plate are interchangeable under the label of "historical armor" in their minds. It is not much of a jump from a span of 500 to 800 years of equipment being considered interchangeable to 1500 years of equipment and language being interchangeable.

The title text likely refers to [[239: Blagofaire]], which features the said "Blogger Reenactment Festivals".

==Transcript==
:[A sword-wielding Cueball on a stage addresses three others; one has a spear, another a handgun and a knife, and the third a laptop.]
:Cueball: Forsooth, do you grok my jive, me hearties?
:Actors: Ten-four!
:A few centuries from now, all the English of the past 400 years will sound equally old-timey and interchangeable.

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

1114: Metallurgy

2014-04-17T04:53:47Z

108.162.219.44: /* Explanation */ More specific link

{{comic
| number = 1114
| date = September 28, 2012
| title = Metallurgy
| image = metallurgy.png
| titletext = This exotic blade was wrought from a different fallen star. The meteorite was a carbonaceous chondrite, so it's basically a lump of gravel glued into the shape of a sword. A SPACE sword!
| imagesize =
}}

==Explanation==
The comic explains how weapons would really behave if they were made out of unusual materials. In fantasy stories, using unusual materials for weapons traditionally makes the weapons more powerful and cooler despite limited explanation for exactly why materials of extraterrestrial origin are so superior to their earthen counterparts.

The first sword is made from an iron meteorite. The quality of such metal can be rather hit-and-miss. On one hand, iron from meteorites was often mixed with "terrestrial" iron in the early stages of human development to create relatively high quality steel for swords. Undeveloped metalworking techniques at the time meant that extraterrestrial metal was often more refined and plentiful than man-made metal ingots. With that in mind, however, [http://www.sciencedirect.com/science/article/pii/0016703767901408 research] has shown that meteorites have an abundance of the chemical element Antimony (Sb) which by itself is a very brittle metal and therefore swords forged from metals harvested from meteorites may not be as strong as lore would have one think.

The second panel is a reference to stories set in Middle Earth and the sword is Sting, which glows blue when Orcs are near. Sting used to belong to Bilbo Baggins; when he grew old he gave it to Frodo Baggins as a gift. The dagger in question, though, glows because of the radioactive properties of {{w|Actinium}} (Ac) which is also highly toxic. Definitely not a dagger you would want to carry around for your every day battles.

The word "Eldritch" in the third panel means sinister, ghostly, or magical.

The fourth panel mentions that the weapon gives a +2 to a player's attribute. This is a reference to role-playing games in which it is common to find items that are able to improve one's character by increasing desirable attributes. In this case, however, +2 to cancer risk would definitely not be considered a desirable attribute to increase.

In the title text, the salesman tries to sell [[Cueball]] another meteoric blade, this one made from a {{w|carbonaceous chondrite}}. Carbonaceous chondrites are rocky meteors that generally don't contain a lot of metallic iron. The salesman is either stating that the blade is simply a bunch of nonferrous meteor fragments glued together in the shape of a sword, or stating that the iron he got out of the meteor is so full of impurities that it may as well be gravel. However, because it's made of extraterrestrial material he seems confident he'll still be able to sell it on novelty value alone.

==Transcript==
:[Cueball and Megan are in a weapon store talking to a bearded salesman wearing a hat.]

:[Salesman holds up a sword.]
:Salesman: This sword was forged from a fallen star. Antimony impurities make the blade surpassingly ''brittle'' and ''weak''.

:[Salesman holds up a dagger.]
:Salesman: And this dagger is made of metal from a far-off kingdom. It glows blue.
:Off-panel: When orcs are near?

:Salesman: No, always. Radiation from the Actinium content.
:Megan: ...Does it have Eldritch powers?

:Salesman: It gives the wearer +2 to cancer risk.
:Cueball: I think we should find another shop.

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

1114: Metallurgy

2014-04-14T20:01:28Z

108.162.219.44: /* Explanation */ Much more plausible explanation

{{comic
| number = 1114
| date = September 28, 2012
| title = Metallurgy
| image = metallurgy.png
| titletext = This exotic blade was wrought from a different fallen star. The meteorite was a carbonaceous chondrite, so it's basically a lump of gravel glued into the shape of a sword. A SPACE sword!
| imagesize =
}}

==Explanation==
The comic explains how weapons would really behave if they were made out of unusual materials. In fantasy stories, using unusual materials for weapons traditionally makes the weapons more powerful and cooler despite limited explanation for exactly why materials of extraterrestrial origin are so superior to their earthen counterparts.

The first sword is made from an iron meteorite. The quality of such metal can be rather hit-and-miss. On one hand, iron from meteorites was often mixed with "terrestrial" iron in the early stages of human development to create relatively high quality steel for swords. Undeveloped metalworking techniques at the time meant that extraterrestrial metal was often more refined and plentiful than man-made metal ingots. With that in mind, however, [http://www.sciencedirect.com/science/article/pii/0016703767901408 research] has shown that meteorites have an abundance of the chemical element Antimony (Sb) which by itself is a very brittle metal and therefore swords forged from metals harvested from meteorites may not be as strong as lore would have one think.

The second panel is a reference to stories set in Middle Earth and the sword is Sting, which glows blue when Orcs are near. Sting used to belong to Bilbo Baggins; when he grew old he gave it to Frodo Baggins as a gift. The dagger in question, though, glows because of the radioactive properties of {{w|Actinium}} (Ac) which is also highly toxic. Definitely not a dagger you would want to carry around for your every day battles.

The word "Eldritch" in the third panel means sinister, ghostly, or magical.

The fourth panel mentions that the weapon gives a +2 to a player's attribute. This is a reference to role-playing games in which it is common to find items that are able to improve one's character by increasing desirable attributes. In this case, however, +2 to cancer risk would definitely not be considered a desirable attribute to increase.

In the title-text, the salesman tries to sell Cueball another meteoric blade, this one made from a carbonaceous chondrite. Carbonaceous chondrites are rocky meteors that generally don't contain a lot of metallic iron. The salesman is either stating that the blade is simply a bunch of nonferrous meteor fragments glued together in the shape of a sword, or stating that the iron he got out of the meteor is so full of impurities that it may as well be gravel. However, because it's made of extraterrestrial material he seems confident he'll still be able to sell it on novelty value alone.

==Transcript==
:[Cueball and Megan are in a weapon store talking to a bearded salesman wearing a hat.]

:[Salesman holds up a sword.]
:Salesman: This sword was forged from a fallen star. Antimony impurities make the blade surpassingly ''brittle'' and ''weak''.

:[Salesman holds up a dagger.]
:Salesman: And this dagger is made of metal from a far-off kingdom. It glows blue.
:Off-panel: When orcs are near?

:Salesman: No, always. Radiation from the Actinium content.
:Megan: ...Does it have Eldritch powers?

:Salesman: It gives the wearer +2 to cancer risk.
:Cueball: I think we should find another shop.

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

Talk:1351: Metamaterials

2014-04-07T05:35:56Z

108.162.219.44:

You should also note the reference to https://en.wikipedia.org/wiki/Roses_are_red - which should be quite obvious though.
--[[Special:Contributions/108.162.229.61|108.162.229.61]] 06:34, 4 April 2014 (UTC)
:See also http://en.m.wikipedia.org/wiki/Roses_are_red Sebastian :--[[Special:Contributions/173.245.53.194|173.245.53.194]] 06:28, 4 April 2014 (UTC)

Is there any guidelines for making a transcript? In my opinion any explanation of the comic should stop at a note of who deliver the line. Only when it is not clear in which order a text should be read or for special comics should there be anything else than written text from the comic. [[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 11:50, 4 April 2014 (UTC)
:Take a look [http://explainxkcd.com/wiki/index.php/explain_xkcd:Community_portal/Proposals#Transcripts here]. It was a (short) discussion about transcripts. {{User:Grep/signature|12:20, 04 April 2014}}
::Thanks - from that I would say loose the explanation of what is in each image, and just write Megan or Megan off screen. I will. Change to that.[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 10:13, 5 April 2014 (UTC)
If I'm not terrible mistaken, this is not how metamaterials work. Can anybody link me a work about wavelength-shifting metamaterials?
[[Special:Contributions/108.162.210.249|108.162.210.249]] 16:35, 4 April 2014 (UTC) <span style="font-size: 0.7em;">(whoever put this on grep's talk page... it's supposed to go here)</span>
:I have a feeling this cartoon would be funnier if it ''was'' how metamaterials work. But what do I know about metamaterials? The reference to Instagram was pretty funny, though. Why people want to wreck fine photos is beyond me. [[Special:Contributions/108.162.225.157|108.162.225.157]] 05:08, 5 April 2014 (UTC)

For red to turn into blue, you still need a nonlinear medium and a lot of red. Or maybe a temporally modulated medium with a modulation similiar to the frequency of visible light...?
(This needs to go in the discussion. Not the explanation. FTFY. You are welcome. ;) [[Special:Contributions/173.245.55.67|173.245.55.67]] 20:25, 4 April 2014 (UTC)BK201

;The title text
I understood it as a filter that go online into peoples instagram pictures and turning them back to the original version. That is also a kind of a meta material - ie. not a real material. Of course(?) Randall will not apply a filter in front of every users camera when the picture is taken and before people use a filter on this "meta filtered" picture when they post it on instagram...? The reason I wish someone else to make the change is that I do not use instagram or filters and hope someone else who can do this better than me now dare to change this wrong explanation :-) [[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 10:09, 5 April 2014 (UTC)

:I really think it's a sheet that Megan holds in front of the flowers, and not a box. And I think that Randall does indeed mean to hold a sheet in front of peoples cameras when they take a picture. The phrase photobombing is used for the act of intruding into the camera view when someone is taking a photo in order to disturb the picture (for example jumping out in front of a group photo, obscuring the group). {{unsigned ip|141.101.80.205}}

::Well good thing I didn't correct then :-) But then the explanation is not good enough for someone not using these things. Is it so that you apply the filter before you take the photo directly into instagram - so you never see the real photo. Then the title would make some sence! [[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 20:25, 5 April 2014 (UTC)

It's a box. If you look closely you can see the side in panel 3 and the bottom in panel 4. [[Special:Contributions/108.162.219.44|108.162.219.44]] 05:35, 7 April 2014 (UTC)

1351: Metamaterials

2014-04-07T05:35:15Z

108.162.219.44:

{{comic
| number = 1351
| date = April 4, 2014
| title = Metamaterials
| image = metamaterials.png
| titletext = If I developed a hue-shifting metamaterial, I would photobomb people's Instagram pics with a sheet of material that precisely undid the filter they were using.
}}

==Explanation==
{{w|Metamaterials}}, artificially-created structures typically made from several materials in a microscopic checkerboard pattern, are famous for allowing bizarre optical properties, such as {{w|Metamaterial_cloaking|invisibility cloaks}}. This comic imagines that metamaterials can change the color of light passing through them.

In the real world a metamaterial can alter the spatial distribution of light and also its frequency, like done in {{w|Fluorescent lamp}}s — but this would not resemble the entire picture in a different color. In photography many {{w|Photographic_filter#Color_conversion|filters}} are used to enhance the quality and appearance of the image. These filters do not alter colors but block some of them, so the result is shown in a different color than the original. Nevertheless no application like this is able to switch a single color to another as it can be done by most modern computer photo programs.

[[Megan]] uses a box made of her metamaterial to switch the colors of the cliché Valentine’s Day poem, “{{w|Roses are red}}, violets are blue, sugar is sweet and so are you.”

The title text references this with [[Randall]] pondering making a metamaterial that reverses the effect of {{w|instagram}} filters, likely by placing the material between the camera and the subject just before the picture is taken without the photographer noticing - a so-called {{W|photobombing}}. Instagram is a photo application that applies one of a variety of filters like {{w|Color theory|hue-shift}} or contrast adjustments meant to simulate the look of old photographs. These filters may be able to interchange blue and red - as they are not real material filters.

==Transcript==
:Megan (off-screen): Violets are red.
:Megan (off-screen): And roses are blue.
:Megan: When metamaterials
:Megan: Alter their hue.

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

1342: Ancient Stars

2014-03-14T07:38:47Z

108.162.219.44: /* Explanation */

{{comic
| number = 1342
| date = March 14, 2014
| title = Ancient Stars
| image = ancient_stars.png
| titletext = 'The light from those millions of stars you see is probably many thousands of years old' is a rare example of laypeople substantially OVERestimating astronomical numbers.
}}

==Explanation==
{{incomplete|Title-text could use some extra explanation.}}
Cueball is making a common observation; many of the visible stars in the sky are so distant that it takes thousands years for light from that star to reach Earth. Unfortunately, the brightest star, Sirius, also happens to be one of the nearest at a mere 8.6 light-years (in other words, the light that is currently arriving from Sirius was emitted some time around August 2005). The previous US president, George W. Bush, was in office from 2000 to 2008; as Megan notes, this isn't terribly impressive.

The title-text references the fact that most normal people have a hard time imagining the large scale of astronomical numbers (for example, the distance between astronomical bodies or the size of a sun); they typically imagine them as many orders of magnitude smaller than they actually are. In this case, however, they instead overestimate the distance by quite a bit.

==Transcript==
Cueball: Just think - the light from that star was emitted thousands of years ago. It could be long gone.
Megan: That's Sirius. It's eight lightyears away.
Cueball: Oh.
Cueball: Just think - the light from that star was emitted in the previous presidential administration.
Megan: Mmm, doesn't pack quite the punch.

{{comic discussion}}

1337: Hack

2014-03-03T08:40:23Z

108.162.219.44: /* Explanation */

<noinclude>:''"1337", this comic's number, redirects here. For the 2007 storyline of the same name, starting with [[341|comic 341]], see [[:Category:1337]].''</noinclude>

{{comic
| number = 1337
| date = March 3, 2014
| title = Hack
| image = hack.png
| titletext = HACK THE STARS
}}

==Explanation==
{{incomplete|Created by a BOT - Please change this comment when editing this page.}}

[[wikipedia:ISEE-3/ICE|ISEE-3/ICE]] is a spacecraft launched August 12, 1978. The original mission was to study the interaction between the Earth's magnetic field and the solar wind. It was later sent to visit Comet Giacobini-Zinner and became the first spacecraft to do so by flying through a comet's tail. It's trajectory will bring it close to Earth on August 2014. A status check of the spacecraft has revealed that many of it's instruments are still working and that it contains plenty of fuel. But the hardware to communicate with ISEE-3/ICE has been decommissioned adn it will be expensive to reestablish the communication needed to use the spacecraft for another mission. See also http://www.planetary.org/blogs/emily-lakdawalla/2014/02070836-isee-3.html

The characters Crash and Burn (and also Zero Cool, known for his catchphrase "Mess with the best, die like the rest") are an allusion to the 1995 movie [[wikipedia:Hackers (film)|Hackers]]. Since the movie predates the shutdown-signal (1997), the charakters should both posess the skills and 'outdated' equipment to understand and hack the signal to the probe.

==Transcript==
{{incomplete transcript}}

{{comic discussion}}

Talk:1328: Update

2014-02-12T07:09:08Z

108.162.219.44: /* Dubious statement in explanation */

Note that 1.) web browsers usually can remember opened tabs (and even scroll position) and reopen them automatically on start, and/or ask if reopen those tabs if browser was not closed cleanly 2.) MS Windows tries to reopen apps closed during "upgrade reboot" --[[User:JakubNarebski|JakubNarebski]] ([[User talk:JakubNarebski|talk]]) 07:48, 10 February 2014 (UTC)
:Yes, browsers can remember the last tabs you have open, but may require the user to enable that option as it's off by default (with Chrome anyway - as was my experience). I usually leave it off because I don't necessarily want the last 5 tabs I had open to open automatically the next time I want to start my browser to do something completely different. If (my) Chrome browser crashes however (or otherwise does not close cleanly), it will ask me if I want to restore my previous session, which may include multiple tabs and browsing positions. =8o) [[User:Jarod997|Jarod997]] ([[User talk:Jarod997|talk]]) 14:12, 10 February 2014 (UTC)
:Windows does not reopen apps that it closed before an upgrade (at best it has an option to reopen Explorer windows in the same state if the user enables it.) As for Chrome saving tabs, it can be often flaky especially when using multiple windows combined with multiple profiles. This is moot since in Real Life™ users generally don't trust these features, when they are even aware of them. [[User:Ralfoide|Ralfoide]] ([[User talk:Ralfoide|talk]]) 15:19, 10 February 2014 (UTC)
: While browsers remember opened tabs, it's flakey. Some browsers in the "now remembering tabs" era were sometimes inconsistent on whether they should remember tabs (Chrome), some didn't give an option to manually exit with/without remembering tabs (Firefox/Chrome), some didn't preserve form input (Opera), etc. It behaves more like a screwed-on hack rather than a fully functional feature. --[[Special:Contributions/108.162.240.6|108.162.240.6]] 14:36, 11 February 2014 (UTC)

@Jakub, thanks for bringing it up. I knew about it, but for the sake of brevity decided to leave it out. Hooray for my first explanation btw! --[[User:Akha|Akha]] ([[User talk:Akha|talk]]) 08:33, 10 February 2014 (UTC)

While one interpretation is that users would push back even a critical update, the cynical me read it the other way around: that most updates labelled as critical and notified with "!"s and yellow triangles are actually not that urgent and naturally the user desensibilizes. [[Special:Contributions/173.245.53.201|173.245.53.201]] 11:16, 10 February 2014 (UTC)

:Note also that browsers are ones of VERY FEW application who can reopen exactly what you had open before restart, and even them usually fail to preserve form content. Also, physical problem is not likely to occur just after the patch was created: only problem which would really need immediate patching would be security problem related to virus just spreading, in which case it would probably be too late when the window appear anyway. So, in all cases, pressing "remind me later" and finishing your work as soon as possible is the most logical course of action regarding critical update. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 11:18, 10 February 2014 (UTC)

It's a sad day when non-kernel updates require a reboot. [[User:Chrisp6825|Chrisp6825]] ([[User talk:Chrisp6825|talk]]) 13:13, 10 February 2014 (UTC)

I think the comic has less to do with the time a reboot takes, and more to do with losing the user's current state [[Special:Contributions/173.245.54.46|173.245.54.46]] 16:27, 10 February 2014 (UTC)

I agree with the last comment. It's not about the time it takes to reboot. It's about the current state of things. If you have a bunch of apps running in different virtual desktops, then a lot of these won't be configured exactly as they were before rebooting. By the way, updates for OS X are exactly the same, with the exception that they're not downloaded automatically. {{unsigned ip|108.162.219.57}}

My initial interpretation was that Cueball doesn't want to reboot his laptop because rebooting increases the risk of a random electrical fire. --[[User:Rael|Rael]] ([[User talk:Rael|talk]]) 21:58, 10 February 2014 (UTC)
:Well that's why we have this twiki.... 'cause you're dumb. [[Special:Contributions/108.162.229.74|108.162.229.74]] 02:18, 11 February 2014 (UTC)
:Actually, that's a pretty smart explanation. I couldn't have put it to better words. [[Special:Contributions/108.162.219.59|108.162.219.59]] 14:23, 11 February 2014 (UTC)

If I was faced with such an update notification, I would probably have it download and install itself, but not reboot until tonight when I'm going to shut down anyway. I find it really annoying when Windoze does things like complain about updates and run virus scans right after booting up, which just makes loading up whatever software I want to use (i.e. web browsers) take even longer. I would much rather have it use my CPU time while I was, say, Web browsing or maybe programming (but not compiling... hmm...), or, better yet, asleep. Also, Linux. --[[User:Someone Else 37|Someone Else 37]] ([[User talk:Someone Else 37|talk]]) 04:23, 11 February 2014 (UTC)

"Laptop fire" reminds me of that silly but popular phenomenon in space operas: in case the own ship is hit by some enemies "rays",
inevitably fire will spark from keybords and monitors in the command room. Georg [[Special:Contributions/173.245.53.171|173.245.53.171]] 09:59, 11 February 2014 (UTC)
: http://tvtropes.org/pmwiki/pmwiki.php/Main/ExplosiveInstrumentation [[User:Wwoods|Wwoods]] ([[User talk:Wwoods|talk]]) 20:17, 11 February 2014 (UTC)

The usual lot of nonsense in the comments. Why don't we talk about how to improve the explanation? Arguing that browsers remember open tabs, or advertising Linux, or going into excruciating detail how you would react in this situation, is ludicrously off the point. The following points are those by this comic:
* Windows is always banging on about something, usually incredibly unimportant.
* Even if it is important (as here) we may just skim the explanation (because of the first point) and not even realize what it is saying
* Even if we do understand it, we don't want to be interrupted during our work (or our not-work) as we hate being inconvenienced in any way
[[Special:Contributions/108.162.219.58|108.162.219.58]] 21:45, 11 February 2014 (UTC)

Possible reference to Microsoft's monthly security patch on the second Tuesday of each month, having been posted the day before the second Tuesday of February 2014. [[User:Quetzalcoatl|Quetzalcoatl]] ([[User talk:Quetzalcoatl|talk]]) 22:23, 11 February 2014 (UTC)

==Dubious statement in explanation==
"The joke goes further because a software update mostly can't prevent any hardware failures like burning laptop batteries. This specific update is just nonsense."

It's quite possible for software to put hardware into a state which damages it. In an ideal world hardware would have protection against this but sometimes the protection is either missing or incorrectly set. This sort of thing CAN be worked around in software, if you know what the bad states are you can avoid ever putting the hardware into them.

Burning laptop batteries are an extreme example but not completely implausible.

-- plugwash

:This actually happened a few years ago. A poorly-written driver (among other issues) caused some Nvidia laptop GPUs to get so hot that they'd cause the cases of some laptops to warp. [[Special:Contributions/108.162.219.44|108.162.219.44]] 07:09, 12 February 2014 (UTC)

1288: Substitutions

2013-11-09T05:32:54Z

108.162.219.44: /* Explanation */

{{comic
| number = 1288
| date = November 8, 2013
| title = Substitutions
| image = substitutions.png
| titletext = INSIDE ELON MUSK'S NEW ATOMIC CAT
}}

==Explanation==
{{incomplete}}
[[Randall|Randall Munroe]] is playing off of the fact that many readers of modern news articles quickly become bored with the legal and political jargon. He suggests that by substituting certain words for others can make reading the article more interesting, albeit less accurate. Although since Randall [[558: 1000 Times|doesn't think very]] highly [[932: CIA|of the news]], he's probably suggesting this chart wouldn't make them less accurate at all.

For example, a sentence that reads
:Witnesses reported that the suspect allegedly escaped unharmed.
would be changed to
:These dudes I know reported that the suspect kinda probably escaped unharmed.

This substitution does not change the meaning much, and the original sentence does not lose much of its accuracy. However, for substitutions later in the comic, a sentence may be changed as following
:A new study finds that senators and other congressional leaders are increasingly likely to view election results on their smartphone.
into
:A Tumblr post finds that elf-lords and other river spirits are increasingly likely to view eating contest results on their Pokédex.

Which is less meaningful, but more interesting.

A [https://chrome.google.com/webstore/detail/xkcd-substitutions/jkgogmboalmaijfgfhfepckdgjeopfhk?hl=en&gl=001 Chrome extension] is available for applying the substitutions on webpages.

'Spaaace' is likely a reference to the Space Core from {{w|Portal 2}}.

The {{w|Virtual Boy}} is a table-top video game console made by Nintendo released in 1995, and discontinued about the same year. It achieved true-3D graphics through the use of a large visor containing a pair of LED screens.

The Pokédex is a device in the {{w|Pokémon|Pokémon world}} that records the data of captured Pokémon.

{{w|Homestar Runner}} is the title character of a Flash-animated web cartoon series.

{{w|Elon Musk}}, in the title text, is the CEO of {{w|Tesla Motors}}, which produces electric cars.

==Transcript==
:'''Substitutions''' that make reading the news more fun:

:Witnesses → These dudes I know
:Allegedly → Kinda probably
:New study → Tumblr post
:Rebuild → Avenge
:Space → Spaaace
:Google Glass → Virtual Boy
:Smartphone → Pokedex
:Electric → Atomic
:Senator → Elf-lord
:Car → Cat
:Election → Eating contest
:Congressional leaders → River spirits
:Homeland security → Homestar Runner
:Could not be reached for comment → Is guilty and everyone knows it

{{comic discussion}}


[[Category:Language]]
[[Category:Video games]]
[[Category:Pokémon]]
[[Category:Politics]]