explain xkcd - User contributions [en]

Talk:2464: Muller's Ratchet

2021-05-18T19:45:57Z

172.69.22.132:

I do this frequently: Seeking out the best quality of two media I've seen put together, in an effort to improve the quality of the resultant combined media.

I had no idea, all this time I'd been creating recombinant PNG.
[[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 20:58, 17 May 2021 (UTC)

This is the first time I've encountered recombination, but I've seen the many versions of images scattered across the internet for sure --[[User:Char Latte49|Char Latte49]] ([[User talk:Char Latte49|talk]]) 21:33, 17 May 2021 (UTC)

On a number of occasions I've had to edit images given to me to submit to a resource. The original photographer ''insists'' on having a 'burnt-on' timestamp directly on the image (he's always done that, and won't accept metadata does the job); meanwhile, the resource's policies are heavily against such 'decoration' and moderators often reject such. When I can't easily clone a 'coverage' area from within the same image - and feather its edges to blend in - I sometimes find another original (but slightly different viewpoint) submitted image that has a sufficiently unsullied 'patch' to let it pass muster. That's a slightly meta-example, I suppose. [[Special:Contributions/141.101.99.161|141.101.99.161]] 23:17, 17 May 2021 (UTC)

Sexual reproduction pictures on teh Interwebz mkay, but I lament a certain underrepresentation of amoeba pr0n. [[Special:Contributions/141.101.105.134|141.101.105.134]] 08:33, 18 May 2021 (UTC)

im guessing this time traveller ^^ just came back from 2008. dont go to 2020. ever. just dont. [[Special:Contributions/162.158.79.59|162.158.79.59]] 14:36, 18 May 2021 (UTC)Bumpf

That's a squirrel?? Look at its tail - squirrels have thick fluffy tails, not that skinny one. And if it is a squirrel, it's by far the largest I've ever seen - unless Hairbun and Cueball are children. I was 100% certain when I saw it that it was a cat. --mezimm [[Special:Contributions/172.69.42.124|172.69.42.124]] 14:53, 18 May 2021 (UTC)
:: And we do know how Randall draws squirrels: [[1503]], [[1578]], [[776]], and [[1156]] all contain examples. I vote that this be changed. --mezimm [[Special:Contributions/172.69.42.21|172.69.42.21]] 14:58, 18 May 2021 (UTC)
:: I'm not sure that's a cat, the muzzle looks wrong to me. Some other feline, maybe. A 4-legged furry mammal with a tail, almost definitely. Could we ask Randall for clarification? [[Special:Contributions/172.69.22.132|172.69.22.132]] 19:45, 18 May 2021 (UTC)

2463: Astrophotography

2021-05-15T06:23:21Z

172.69.22.132: /* Explanation */

{{comic
| number = 2463
| date = May 15, 2021
| title = Astrophotography
| image = astrophotography.png
| titletext = [One hill over, a competing astrophotographer does a backflip over a commercial airliner while throwing a tray of plastic space stations into the air, through which a falcon swoops to 'grab' the real one.]
}}

==Explanation==
{{incomplete|Created by a BACKFLIPPING ASTROPHOTOGRAPHER. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}
Astrophotographers like to take photos of things transiting the Sun. Typical things include planes, the International Space Station, and the Moon (solar eclipses).

The practice of "one-upmanship" refers to the practice of achieving something superior to what another has achieved, or "getting one up on" them. The caption claims that the photo shown in the comic is the result of a continuous string of one-upmanship among astrophotographers in a community, each striving to one-up the other.

In this comic there seems to be an abundance of things:
* There is an ongoing {{w|partial solar eclipse}} so the view of the {{w|Sun}} is partially obscured by the {{w|Moon}} in the upper right quadrant. Although the Sun is much larger than the Moon, the Moon is able to block the Sun's light from reaching {{w|Earth}} (which happens during a {{w|partial solar eclipse|Total Solar Eclipse}}) because it so much closer to the Earth that they have the same apparent size when seen from the Earth.
* It's close to sunset, with a rocky hill blocking roughly as much light from the Sun as the Moon
* [[Megan]] is standing slightly below the peak of the hill and seems to be juggling, with five balls, which are also in front of the sun.
* [[Cueball]] is standing at the peak of the hill, firing an arrow from a bow, one arrow has pierced what at first appears to be one of the juggling balls, but may be a {{w|Transit of Venus}}. A simultaneous Eclipse and Transit of Venus is actually expected in the future, but not until April 5, 15232 (13211 years after the publishing of this comic). It would though likely be easier to make the arrow "hit" Venus than one of the joggled balls, as the planets position is constant at the time the photo is taken. The other four balls are too large that any of them could represent Mercury, the only other planet that can transit the Sun, when seen from Earth. But Megan has been careful to make one ball go so much higher than the middle two, that it seems to fit that Venus has been shot out from between them.
* Two airplanes flying above them are pulling signs with the words "NICE SHOT" on two banners (which could refer to either the archer or the photograph or both). The signs will have to be made with see through holes through the canvas letting sun through. As there is an O it cannot just be holes in the canvas!
* The The {{w|International Space Station}} (ISS) can be seen transiting in the upper center.

Taking the picture required precisely scheduling and arranging the relative positions of several of the various subjects (and photographer), to coincide with the predictable but rare conjunctions of the rest of the scene, as well as special equipment:
* A solar filter must be used to photograph the sun without overexposing the image or even damaging equipment.
* The photograph must be taken during a partial solar eclipse. These only happen a few times per year and are only visible in part of the world.
* Related to the last point, a nearby person appears larger than the moon. It is possible to photograph the silhouette of a person or a cityscape in front of a full moon, making the moon look comparatively larger or smaller by adjusting the distance to the closer subject, and then the lenses used by the photographer to make them both fill just the right amount of the frame. The photographer needed to carefully choose their position relative to the subjects to make this happen.
* The exposure time of the photograph had to be short enough to capture clear silhouettes of the ISS, the juggling balls and the arrow while these were in the air.
* The mountain had to be in a location that would happen to see the ISS passing in front of the sun at the same time.
* The subjects had to achieve a moment in which four juggling balls were in the air and an arrow had pierced the point where Venus where, while sideways relative to the sun's light, which was still near normal intensity and could have made the task harder.
* The planes also needed to be flying in the correct directions for the text of the signs to be visible, and very precise timing for them to be in the correct position to read Nice as coming before Shot.
* All this had to be timed very very precise as the flyby of the ISS only takes a second.

The title text describes a similarly outlandish photo.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

:[Cueball and Megan stand on a hill with the sun behind them. Cueball is at the top-left of the hill, holding a bow in his left arm, which has been recently shot, with the arrow to right. Megan is at the bottom-right of the hill, juggling some balls. There are two planes going in opposite directions with banners on them. Above the planes is the ISS. All these items are silhouetted against the sun partially eclipsed by the moon in the upper right.]

:[Banners]: Nice Shot

:[Caption beneath the panel]:
:Our astrophotography community's one-upmanship is getting out of hand.

==Trivia==
Randall has commented on in comics ([[1855:_Telephoto]], [[1719:_Superzoom]]) and the ''How To'' chapter "How to take a selfie".

{{comic discussion}}

[[Category:Comics with color]]
[[Category:Space]]

Talk:2457: After the Pandemic

2021-04-30T22:38:16Z

172.69.22.132: /* Enough with the COVID comics */ new section

Other benefits of normalizing wearing masks: keeping warmer in the winter; protecting face from sun; reducing breathing of smoke and fine particulates; potentially reduce value of facial matching in face of ubiquitous surveillance. [[Special:Contributions/141.101.105.124|141.101.105.124]] 18:04, 30 April 2021 (UTC)
:Between our rapidly deteriorating air quality (check out how much of the dust we breathe is from plastic clothing fibers); ubiquitous tracking by an increasing number of increasingly untrusted groups (not that we can evade that with masks, only make it more error prone); & just the fact that we still interact with thousands who then interact with ''other'' thousands on a scale impossible only two centuries ago, making transmissible disease spread almost a certainty; ... I'd strongly prefer that ''everyone'' who can, wear a mask in any shared public space.
:Awkward, uncomfortable, & socially inconvenient? Yes. ''Better than an endless procession of mid-level epidemics, & a population with initially minor but alarmingly widespread respiratory & cardiac issues which progressively worsen?'' (again, look at air quality since 1999) ''Also yes.''
:If we're entering a crowded space, please just ''wear the masks, people.'' Now & always.
:Might as well get used to it, because within this generation, we're all going to need masks to breathe normally, anyway; & I'm not exaggerating even a little.
:[[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 19:25, 30 April 2021 (UTC)
:Mask wearing was already super common in Asia before the pandemic because of this. I'm hoping it gets more common here in the US too [[User:Opalmagpie|Opalmagpie]] ([[User talk:Opalmagpie|talk]]) 20:53, 30 April 2021 (UTC)

@Randall, we get it, you worry about COVID. Really, we get it.
:Right? It's like the comedians who all went 99% political during the last few years: Even if I agree completely, it isn't as funny after the 24th time you make a joke about it.
:[[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 19:25, 30 April 2021 (UTC)

Maybe another thing that will become common is self-quarantining when you're sick. You don't need to wear a mask if you don't go out. And now that we've learned that it's possible to work from home in many professions, you don't need to go into the office when you're contagious. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 21:47, 30 April 2021 (UTC)

== Enough with the COVID comics ==

I mean, seriously, if this is all XKCD has become, then it's time to move on. To help emphasize that point, I feel a new topic is in order.

Please post all your COVID-comic-hating comments here.

1137: RTL

2021-04-30T04:17:00Z

172.69.22.132: Missing apostrophe in a possessive.

{{comic
| number = 1137
| date = November 21, 2012
| title = ‮LTR‬
| image = rtl.png
| titletext = Collaborative editing can quickly become a textual rap battle fought with increasingly convoluted invocations of U+202a to U+202e
}}

==Explanation==

U+202e is a {{w|unicode control characters|unicode control character}} that changes all subsequent text to right-to-left (RTL, as the title references). In the comic, [[Black Hat]] tires of [[Cueball]]'s complaining and inserts a U+202e character in the middle of Cueball's speech, turning his complaints into gibberish - sentences that must be read from right-to-left.

The title of the comic builds on this theme, with the title of the webpage it is hosted on being LTR in some browsers (see [[#Trivia|trivia]]), the reverse of the comic name.

What Cueball actually tries to say after Black Hat's change is:
:— They didn't even...
:...What the hell?
:How did you...
:...Asshole.

When multiple writers work on the same text, arguments can often arise with some writers resorting to vandalizing the works of other writers. The title text takes this up a level, suggesting the use of U+202e and other direction control characters in editor wars to disrupt other people's work. For reference for future wars U+202c returns text back to its normal direction.

==Transcript==
:[Cueball is standing behind Black Hat who is sitting down with a laptop on his lap.]
:Cueball: And that's not even the worst part! The ''worst'' part is that—
:Black Hat types a command on the PC: U+202e
:Cueball: ‮—They didn't even...
:Cueball: ‮...What the hell?
:Cueball: ‮How did you...
:Cueball: ‮...Asshole.

==Trivia==
*In the version originally published there was a typo in the reverse text ("ETH" instead of "EHT" for "THE"). This mistake was corrected within a couple of hours.
*The title given in the web browser, (for instance seen on the icon for the browser bar at the bottom of the screen), for the comic on the xkcd website actually has a U+202e character preceding it;
**The page title is "xkcd: [U+202e]LTR", which for instance causes {{w|Firefox}} to write the page title as "xkcd: xoferiF allizoM - RTL" as the window title. So xkcd and the comics title is correct (The LTR turns to RTL). But the browsers name is reversed.
**This may only affect some browsers; it is known to also occur in {{w|Internet Explorer}}, {{w|Microsoft Edge}}, {{w|Google Chrome}}, {{w|Chromium (web browser)|Chromium}}, {{w|Opera (web browser)|Opera}} and {{w|Maxthon}}.
*In some browsers (for instance Internet Explorer), this page's title damages the appearance of all older entries in the [http://xkcd.com/archive/ archive page] on xkcd.
**Here is a picture example for people without access to explorer: [[Media:Reverse archive.jpg|Reverse archive]].
*This is the second comic in a row with Cueball and Black Hat discussing. Both with Black Hat with his back turned to Cueball.
**In the previous comic Black Hat broke a mirror, and in this comic he then reverses Cueballs speak
**Not exactly a mirroring of his speak, but still related.
**In the broken archive mentioned above, [[1136: Broken Mirror]] is the first (or last) entry to be broken!

==Unicode Control Characters==
{| class="wikitable"
|-
! Unicode number !! Name !! Meaning
|-
| U+202a || LEFT-TO-RIGHT EMBEDDING || The following text will be left-to-right. This will not change directionality of characters, so for example Arabic letters will stay right-to-left. This character alone does nothing in an English text, since the text direction is left-to-right by default.
|-
| U+202b || RIGHT-TO-LEFT EMBEDDING || The following text will be right-to-left. This will not change directionality of characters, so Latin letters will stay left-to-right. Full stops, which don't have a directionality on their own, will be left of the sentence. Use this character for some little misplacings that cause big confusion.
|-
| U+202c || POP DIRECTIONAL FORMATTING || The following text is formatted like the text before the last U+202a, U+202b, U+202d or U+202e character.
|-
| U+202d || LEFT-TO-RIGHT OVERRIDE || The following text will be left-to-right. Additionally, the directionality of characters is changed to left-to-right. Used alone in an English text, this will only affect characters that are right-to-left by default, like Arabic letters.
|-
| U+202e || RIGHT-TO-LEFT OVERRIDE || The following text will be right-to-left. Additionally, the directionality of characters is changed to right-to-left. Use this character to completely screw up an English text.
|}

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Black Hat]]
[[Category:Computers]]
[[Category:Unicode]]