explain xkcd - User contributions [en]

1371: Brightness

2014-05-30T03:50:29Z

108.162.219.61: /* Explanation */

{{comic
| number = 1371
| date = May 21, 2014
| title = Brightness
| image = brightness.png
| titletext = Recently, some exoplanet astronomers have managed to use careful analysis of reflected light to discover Earth during the day.
}}

==Explanation==
{{w|Exoplanets}} are planets outside of our solar system, and exoplanet astronomers are astronomers who attempt to discover and study such planets.

[[Megan]] is using a common exoplanet {{w|Exoplanet#Indirect_methods|discovery technique}} to discover a planet around a nearby star. When a planet passes between an observing astronomer and a star, the planet will block some tiny part of the light coming from that star, causing it to appear dimmer for some amount of time. The {{w|Kepler (spacecraft)|Kepler telescope}} used this technique to find evidence for exoplanets.

But here Megan is standing on the surface of the Earth at night, looking at the ground, and therefore presumably looking in the direction of the sun. By observing that it is completely occluded at night, she correctly concludes that the Sun is orbited by at least one planet: the Earth.

The title text alludes to using more complicated techniques to observe light reflected by small planets like the Earth, for example by detecting {{w|Methods of detecting exoplanets#Polarimetry|polarized light}} reflected from the planet's atmosphere. In some sense, observing the light that reflects off of the Earth during the day is in fact how we see everything around us.

The title text may also be a reference to [[1231: Habitable Zone]] where an astronomer is messed up by someone who puts a mirror in front of the telescope.

More details at: {{w|Methods of detecting exoplanets}}

==Transcript==
:[Megan is standing on a black night-time background, staring at the ground.]
:Megan: Based on this decrease in the star's brightness, I believe it is orbited by at least one planet.

:Exoplanet astronomers at night

{{comic discussion}}
[[Category:Comics featuring Megan]]
[[Category:Astronomy]]
[[Category:Exoplanets]]

Talk:1037: Umwelt

2014-05-07T20:54:57Z

108.162.219.61:

Normally I understand xkcd. But this one hurts my head. [[User:Lcarsos|lcarsos]] ([[User talk:Lcarsos|talk]]) 20:35, 15 August 2012 (UTC)
: I sorted all of them out. Phew!!! That was some work. The ones at the end have no appropriate picture in the image part. Atleast the hurricane one should be added. Please do so. [[User:TheOriginalSoni|TheOriginalSoni]] ([[User talk:TheOriginalSoni|talk]]) 11:09, 8 September 2012 (UTC)
:: I live in one of Umwelt's "hurricane areas", and that's the one I see. How do we add it? [[User:Ekedolphin|Ekedolphin]] ([[User talk:Ekedolphin|talk]]) 06:06, 30 January 2013 (UTC)

There is a fixed image used if your browser does not support javascript, which is missing. Additionally, the alt text varies at times. [[User:Divad27182|Divad27182]] ([[User talk:Divad27182|talk]]) 20:16, 4 October 2012 (UTC)

I can't see any of them neither in Firefox nor in IE :( --[[User:Kronf|Kronf]] ([[User talk:Kronf|talk]]) 11:32, 13 October 2012 (UTC)

This has got to be one of my favourite xkcd's! That amount of ingenuity in one edition! [[User:D3KN0W|Dean]] ([[User talk:D3KN0W|talk]]) 22:33, 01 January 2013 (UTC)

There is now also a category page for Jurassic Park, but I'm not sure how to work that into the explanation. [[User:Kaa-ching|Kaa-ching]] ([[User talk:Kaa-ching|talk]]) 09:04, 28 January 2013 (UTC)

I can't resist noting that Chrome is sadly mistaken in thinking that its puzzle piece links up to a corner piece - it would have to be an edge piece to do that. Firefox would never have that kind of issue... [[User:Natf|Natf]] ([[User talk:Natf|talk]])
: Supposedly, if there were a puzzle with inner corners, such as one with a plus cut out of it, this could link up as shown. ... I wanna make a puzzle like that now. [[Special:Contributions/99.44.200.140|99.44.200.140]] 08:00, 1 June 2013 (UTC)

It would be difficult to compile, but I think this page would benefit from having the conditions along with the image (for instance, "Displays when running Netscape:") [[Special:Contributions/24.41.66.114|24.41.66.114]] 03:27, 6 September 2013 (UTC)

Hey, um, I think there is an Animaniacs reference. Namely, the question about hot dogs resembles Yakko's question to the Wally Llama except it dealt with packages of eight and packages of ten. (I forget which is which) {{unsigned ip|71.166.47.84}}

I came here to seek informartion about how each strip was seen. Disappointed... Especially after seeing there is a hebrew one!?!?!?!? (number 29) Is it real? Because I assume it should be visible from Israel and I can't see it [[Special:Contributions/141.101.99.228|141.101.99.228]] 22:26, 30 December 2013 (UTC)

Added two location references to the 2Fast2Furious and Snake comics, with browser references. Anyone know why I got those results? {{unsigned ip|173.245.50.77}}
: I don't, especially since I live in the UK (not Texas) and yet I see the Snake comic? [[User:Enchantedsleeper|Enchantedsleeper]] ([[User talk:Enchantedsleeper|talk]]) 14:14, 7 April 2014 (UTC)

I found a new one, it seems to display when using TOR. Should I add it? [[Special:Contributions/173.245.49.60|173.245.49.60]] 02:22, 7 May 2014 (UTC)
:Yes definitely. [[User:Chriswampler|Chriswampler]] ([[User talk:Chriswampler|talk]]) 16:07, 7 May 2014 (UTC)
::The Reviews comic just as appearing under TOR is actually comic #1036. Can you confirm that it is actually showing up under Umwelt? [[User:Chriswampler|Chriswampler]] ([[User talk:Chriswampler|talk]]) 20:34, 7 May 2014 (UTC)
:::Yes. I checked like ten times. I just did it again.[[Special:Contributions/173.245.53.153|173.245.53.153]] 20:40, 7 May 2014 (UTC)
:Honestly I can't do much explaining. Does anyone get it? [[Special:Contributions/108.162.219.61|108.162.219.61]] 20:54, 7 May 2014 (UTC)

1099: Tuesdays

2014-05-05T02:10:48Z

108.162.219.61: /* Explanation */ Added a sentence to the end. Even if the drink was "bottomless", you wouldn't be able to fall in (and fall forever) unless it was a very large diameter.

{{comic
| number = 1099
| date = August 24, 2012
| title = Tuesdays
| image = tuesdays.png
| titletext = Try our bottomless drinks and fall forever!
}}

==Explanation==
[[Beret Guy]] and at least one other person (which looks like it might be [[Megan]]) are sitting at a restaurant. The waitress, [[Ponytail]], tells Beret Guy there is a special on Tuesdays for "endless wings". Restaurants often have different daily discounts to encourage people to come in. In a normal restaurant, "endless wings" would presumably refer to "all-you-can-eat" chicken wings, meaning the customer can pay a flat price and continue ordering additional wings without paying any more money.

However, in this comic, Beret Guy tells the waitress that he already has "endless wings", which he means literally (a similar issue of wishes being taken literally is referenced in [[1086: Eyelash Wish Log]]) and Beret Guy begins growing wings which ultimately appear "endless" as they grow to a span of at least the circumference of the earth by the last panel (and presumably continue growing). The other characters scream in horror for obvious reasons.

The title text plays on another common restaurant offer of "bottomless drinks", meaning unlimited free refills of drinks. However, taken literally, falling into something bottomless (i.e. without a bottom) would result in falling forever. However, even this is unlikely unless the diameter of the cups that the drinks are served in are large enough to fit a whole person into.

==Transcript==
:[Ponytail begins to serve some customers at a table.]
:Ponytail: ...and on Tuesdays we offer endless wings.
:Beret Guy: Haha, cool. i have those.

:Ponytail: You what?

:[Beret Guy sprouts a pair of wings.]
:Ponytail: AAAAA!!

:[Beret Guy's wings start getting longer.]
:Everyone: AAAAAAA

:[Wings start to extend into space out from the earth.]
:''Really'' everyone: AAAAAAAA

==Trivia==
*This is one of the few comics since the ''xkcd'' lettering became inked and standardized as all-caps that lowercase lettering has been used (including the word "i" which would normally be capitalized). In this case, the usage may be to denote a whisper or soft voice.

{{comic discussion}}
[[Category:Comics featuring Beret Guy]]
[[Category:Comics featuring Ponytail]]

Talk:899: Number Line

2014-04-24T21:25:37Z

108.162.219.61:

Where does sqrt(-1) go? [[Special:Contributions/67.78.183.206|67.78.183.206]] 19:07, 2 January 2013 (UTC)

:It goes up (literally above 0). A number line can be extended to a complex plane with sqrt(-1) as the unit of measurement in the vertical direction. Or at least, that's where it actually goes. I don't know where Randall would put it. [[Special:Contributions/75.69.96.225|75.69.96.225]] 01:04, 5 March 2013 (UTC)

I'm sorry...are you indicating the ACTUAL location for an IMAGINARY number? {{unsigned|‎74.213.186.41}}

Yes, that's exactly where it is (up to switching clockwise for counterclockwise). There is nothing strange about providing a location for imaginary or complex numbers, the location described is logical, and the adjective 'imaginary' is an artifact of nomenclature and nothing more.[[Special:Contributions/173.48.140.216|173.48.140.216]] 20:40, 30 March 2013 (UTC)

In fact, complex numbers are nearly more real than real ones! Complex analysis really opened my eyes to how much "stepping out" can help in solving problems. The complex notion of analyticity yields fruit in real analysis. Extensions to hypercomplex numbers are weirder, however. --[[User:Quicksilver|Quicksilver]] ([[User talk:Quicksilver|talk]]) 20:27, 17 August 2013 (UTC)

Analyticity must be an imaginary word, and therefore would be found one unit directly above any dictionary. [[Special:Contributions/50.203.89.169|50.203.89.169]] 14:19, 9 October 2013 (UTC)
:Oh my god, I can't believe how hard I laughed at that. Would an imaginary friend actually be above you then? I'm going to use that sometime. [[Special:Contributions/108.162.219.61|108.162.219.61]] 21:25, 24 April 2014 (UTC)

Is unexplored a map reference? [[User:Halfhat|Halfhat]] ([[User talk:Halfhat|talk]]) 17:53, 13 January 2014 (UTC)