explain xkcd - User contributions [en]

1020: Orion Nebula

2024-11-15T18:40:08Z

172.69.33.210: /* Transcript */ orion

{{comic
| number = 1020
| date = February 22, 2012
| title = Orion Nebula
| image = orion_nebula.png
| titletext = Also on the agenda: what's with his hips?
}}

==Explanation==
[[File:Orion composite1.jpg|right|thumb|200px|Orion]]
The {{w|Orion nebula}} is a diffuse nebula situated south of the three stars that compose {{w|Orion's Belt}} in the {{w|Orion constellation}}. In terms of the comic, it is the middle "star" in the sword/dong of Orion. Dong is an American slang word for penis. The star appears fuzzy to sharp-eyed observers, and the nebulosity is obvious through binoculars or a small telescope.

When the speaker says "We are no strangers to controversy" he is probably referring to {{w|Pluto}}'s {{w|IAU definition of planet#Criticism|demotion}} from {{w|planet}} to a {{w|dwarf planet}}/{{w|Plutoid|plutoid}}.

The title text is a quip about how small and off-kilter the hips are in Orion the constellation compared to the rest of its body. Although this is not far off the modern comic-style [https://www.researchgate.net/publication/332519132_Captain_Dorito_and_the_Bombshell_Supernormal_Stimuli_in_Comics_and_Film "Captain Dorito" body type], with a degree of posing in partly side-on perspective.

==Transcript==
:[Cueball stands behind a lectern decorated with the initials of the International Astronomical Union. There is a banner above him that also says 'International Astronomical Union,' decorated with small stars.]
:Cueball: Welcome to IAU Symposium #279.

:[Side view of Cueball standing on a podium behind the lectern]
:Cueball: We are no strangers to controversy, and we will not shy away from the tough issues.
:Cueball: Which brings us to the subject at hand:

:[A projection of the Orion constellation appears behind Cueball with a white arrow superimposed on the image pointing at the area between Orion's legs. Symposium attendees are off-screen to the bottom and right of the panel.]
:Cueball: It's time to talk about the fact that Orion clearly has a dong.
:Attendee #1 (off-screen): It's hard to miss.
:Attendee #2 (off-screen): We could keep telling people it's a sword.
:Attendee #3 (off-screen): C'mon, no one's buying that anymore.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Public speaking]]
[[Category:Penis]]
[[Category:Astronomy]]

3011: Europa Clipper

2024-11-14T15:12:38Z

172.69.33.210: /* Explanation */ nobody, in fact, has made any such comparison

{{comic
| number = 3011
| date = November 13, 2024
| title = Europa Clipper
| image = europa_clipper_2x.png
| imagesize = 333x356px
| noexpand = true
| titletext = They had BETTER make this a sample return mission.
}}

==Explanation==
{{incomplete|Created by a JOVIAN DESSERT. Please consider deleting this tag too soon, but refrain from doing so.}}

[[File:Animation of Europa Clipper trajectory around Jupiter.gif|thumb|right|The ''Europa Clipper's'' projected course around {{w|Jupiter}}, represented as the stationary green dot. In gold is Jupiter's moon {{w|Callisto (moon)|Callisto}}, in cyan is the moon {{w|Europa (moon)|Europa}} — the primary target of the spacecraft's study — and in orange-red is the innermost of Jupiter's four {{w|Galilean moons|"Galilean"}} moons, {{w|Io (moon)|Io}}. The spacecraft's track is shown in magenta. Jupiter's largest moon {{w|Ganymede (moon)|Ganymede}} and its second largest moon {{w|Titan (moon)|Titan}} are not shown, but their gravitational pull affects the ''Clipper's'' trajectory. A mission goal is to achieve a 6:1 {{w|orbital resonance}} with Europa by September 2034.[https://www.researchgate.net/profile/Martin-Ozimek/publication/383115312_AAS_24-433_Europa_Clipper_Mission_Analysis_Pump_Down_Trajectory_Design/links/66bcd845311cbb094938dbd6/AAS-24-433-Europa-Clipper-Mission-Analysis-Pump-Down-Trajectory-Design.pdf] ]]

The ''{{w|Europa Clipper}}'' space probe was launched from the {{w|Kennedy Space Center}} in Florida on October 14, 2024. It is expected to arrive at Jupiter and begin exploration of Jupiter's moons, particularly {{w|Europa (moon)|Europa}}, in April of 2030.

Europa is an icy moon. Water ice covers its surface. Beneath the ice, there is expected to be liquid water, which might contain living microbes.[https://europa.nasa.gov/why-europa/ingredients-for-life/] To sample this liquid, its crust (water ice) would need to be broken.

Europa's icy surface may be compared to the caramelized crust on the popular dessert {{w|crème brûlée}}, which is traditionally cracked with a spoon before eating. The carmel cream dessert is believed to have been [https://archive.org/details/lagastronomieaug00sabb/page/272/mode/2up invented in Europe], after which the moon and the space probe were named. In {{w|Greek mythology}}, Europa was a {{w|Phoenician}} princess whom {{w|Zeus}}, the king of the gods, abducted after transforming himself into a bull. This mythological Europa is also the namesake of the continent Europe. Thus [[Randall]] suggests the spacecraft might encounter crème brûlée, and has therefore been equipped with a spoon for the purpose of collecting samples, as spoons are the traditional {{w|tableware}} provided for eating such desserts. Perhaps because the {{w|Cassini-Huygens}} probe, after landing on the surface of Saturn's moon Titan in January of 2005, found that its surface had what was described as [https://www.sciencenews.org/article/world-unveiled-cr%C3%A8me-br%C3%BBl%C3%A9e-titan a "crème brûlée" consistency].

No such spoon is present on the ''Europa Clipper.''{{cn}} Its course is designed to avoid contact with Europa so as to prevent {{w|Planetary protection|contamination by microorganisms from Earth}}. The spacecraft is, however, equipped with a magnetometer at the end of a 8.5 meter deployable boom. Deployable instruments on spacecraft have often failed to deploy correctly, so the successful deployment of any instrument is considered a cause for celebration.

The title text expands on the joke by stating that the spacecraft "had BETTER" return samples of Europa to Earth. However, the ''Europa Clipper'' is not a {{w|sample-return mission}}.

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

:[A space probe with two rectangular solar panels, a circular dish of the front, and a very large spoon extending beneath, longer than the span of both solar panels]

:[Below the panel:]
:Good news: NASA's '''''Europa Clipper''''' is en route to Europa and has successfully deployed its crème brûlée spoon.

==Trivia==
The Clipper spacecraft was at one point to be developed alongside a lander, which was later dropped from being part of the same (or very closely partnered) mission. The latest version of the {{w|Europa Lander}} proposal is far behind the Clipper in implementation, not yet even being guaranteed funding.

Any actual sample return mission is currently far into the future of {{w|Ocean Worlds Exploration Program|the related plans for exploration}}, along with the possibility of digging deep enough into the ice to finally confirm or dismiss some of the more interesting theories about the world concerned.

In Arthur C Clarke's novel '''2010''', the monolith aliens tell humanity ''"All these worlds are yours - except Europa. Attempt no landing there."'' Contrary to the suggestion of the comic, no landing or any other physical interaction beyond observation of the surface of Europa is planned.

{{comic discussion}}
[[Category:Space]]
[[Category:Space probes]]
[[Category:Food]]

Talk:2694: Königsberg

2022-11-05T06:33:30Z

172.69.33.210: reply

; Aluminum foil
Why would aluminum foil be valuable? I can see how it would be hard to produce at the time. But how would it be used and why would people of the time see a lot of value in it? [[Special:Contributions/172.71.146.65|172.71.146.65]] 03:42, 5 November 2022 (UTC)
:Good question, but I'm persuaded the novelty and scarcity of metallic aluminium would have made it plenty valuable among those already wealthy enough to recognize what it was. Prussia was wealthy and Königsberg was its largest port city back then, so probably the mayor would have been able. [[Special:Contributions/172.70.206.205|172.70.206.205]] 03:49, 5 November 2022 (UTC)
::Aluminium was very valuable - methods for its extraction from ore didn't exist in any useful form until much later. [[Special:Contributions/172.68.146.80|172.68.146.80]] 03:55, 5 November 2022 (UTC)
::: Would scarcity be enough to make it valuable? Since nobody had this material back then, there wouldn't be any known applications for it. Compared to bringing e.g. a simple pocket calculator, a flashlight, a solar-powered e-book reader, etc. If an alien landed in my house and brought me some weird, shiny material that would be unable to build on earth, I wouldn't be too interested. But if they had some cool gadget or books full of alien information, I would immediately see its value. [[Special:Contributions/172.71.142.88|172.71.142.88]] 04:05, 5 November 2022 (UTC)
:::: At the time, there were few chemists who could have recognized what it was, but the Mayor of Königsberg would plausibly have been able to commission one. It likely would have taken months if not years, though. I guess if you have a time machine such details don't matter. [[Special:Contributions/162.158.166.173|162.158.166.173]] 04:11, 5 November 2022 (UTC)
::::: Bear in mind that platinum was once 'an inferior substance that got in the way of accumulating silver', and cobalt was the stuff that the underground spirits mischievously put in the way of those seeking copper. To different degrees, their attractiveness has increased since those times they were considered less than desirable.
::::: But, for aluminium foil, I suspect it would have been like pineapples in English(/European?) stately circles... Not to be used for anything practical, but shown off (as long as it did not deteriote beyond a certain point), possibly there'd be money to be made in 'hiring it out' to decorate tables at fancy dinners (in carefully handled fragments, after the first few tearing incidents). L
::::: No doubt a natural philosopher or somesuch would give his eyeteeth to analyse the substance, but being so far beyond the ability to recreate (assuming they discovered what they might even need to do) it would take the bankrolling of an extremely rich patron to obtain permanent posession of some without obligation to return it to the social circuit situations. So easily destructed (I wonder if they'd discover thermite a hundred and more years early, before they ran out of potentially finely shredded aluminium?) or at least aesthetically denatured.
:::::I suppose a screwed up ball of foil (carefully glued together internally, of all fragments still reobtainable) could be the end-game for the original roll, and a wonder it could still be (again, taking the "pineapple place" on the tables of the high and mighty, relatively untarnishing as it would be and gingerly some lucky few would be allowed to hold it and marvel at its sharp fragility and metallic lightness.
:::::...or, in another destiny, perhaps it would be given to a master tailor, in order to (try to?) create some sartorial masterpiece for one or other monarch of the age. Not that I'm sure they'd be able to accomplish that properly (limited pre-offcut trials on how to attach it to underfelts/whatever and to somehow exploit its flexibility without exceeding its very low tolerance for shear-force damage). It'd be a story and a half, whatever happened to it! [[Special:Contributions/172.70.86.12|172.70.86.12]] 05:38, 5 November 2022 (UTC)
::::::"Aim for brevity while avoiding jargon." —Edsger Dijkstra [[Special:Contributions/172.69.33.210|172.69.33.210]] 06:33, 5 November 2022 (UTC)