explain xkcd - User contributions [en]

Talk:2709: Solar System Model

2022-12-12T14:30:10Z

172.70.179.30:

Like the [https://outerwilds.fandom.com/wiki/Quantum_Moon Quantum Moon] from Outer Wilds. [[User:DanielLC|DanielLC]] ([[User talk:DanielLC|talk]]) 06:30, 10 December 2022 (UTC)

The lead sentence needs correcting: ELECTRONS orbit the nucleus, not ATOMS orbit the nucleus
([[User talk:ArtK|talk]]) 08:54, 10 December 2022 (UTC)[[Special:Contributions/172.70.210.49|172.70.210.49]] 08:56, 10 December 2022 (UTC)
:Fixed. —[[User:While False|While False]] ([[User:While False/explain xkcd museum|'''museum''']] | [[User talk:While False|talk]] | [[special:Contributions/While_False|contributions]] | [[special:Log/While_False|logs]] | [[Special:UserRights/While_False|rights]] | [https://www.explainxkcd.com/wiki/index.php?title=User:While_False&printable=yes printable version] | [https://www.explainxkcd.com/wiki/index.php?title=User:While_False&action=info page information] | [https://www.explainxkcd.com/wiki/index.php/Special:WhatLinksHere/User:While_False what links there] | [https://www.explainxkcd.com/wiki/index.php?title=Special:RecentChangesLinked&days=30&from=&target=User%3AWhile_False related changes] | [https://www.google.com Google search] | current time: {{CURRENTTIME}}) 09:10, 10 December 2022 (UTC)

Also, the electrons ORBIT, not REVOLVE.
([[User talk:ArtK|talk]]) 09:01, 10 December 2022 (UTC)[[Special:Contributions/172.70.210.49|172.70.210.49]] 09:01, 10 December 2022 (UTC)
: You can fix that yourself? click the edit button and replace it. That's... the whole point of wikis i'm pretty sure. [[Special:Contributions/162.158.79.83|162.158.79.83]] 14:36, 10 December 2022 (UTC)Bumpf
:: Yes, That is what I was trying to do but was locked out. Leaving a message was the next best thing.[[Special:Contributions/172.69.33.232|172.69.33.232]] 08:36, 11 December 2022 (UTC)

When I first read the comic, I was confused about Randall (Ms. Lenhart) describing quantum orbitals correctly. See, I knew the real history of science, so my brain autocorrected it to read that we used to think ''electrons'' had elliptical orbits. I had to look three times before I even saw the inversion. [[User:Nitpicking|Nitpicking]] ([[User talk:Nitpicking|talk]]) 16:28, 10 December 2022 (UTC)

Someone should add something about [https://en.wikipedia.org/wiki/Lyapunov_time Lyapunov time], and how orbits are unpredictable on longer timescales.[[Special:Contributions/162.158.146.175|162.158.146.175]] 16:59, 10 December 2022 (UTC)

([[User:pinkdoesstuff|talk]]) 3:42, 10 December 11 (UTC)
Someone PLEASE explain this to me like I'm five? The explanation confused me :(
:In the early 20th century atoms was in some respects believed to behave similar to solar systems, in that electrons orbited around the core of the atom like planets orbit around their sun. Nowadays, it has been discovered that electrons do not orbit around the core of the atom in such a manner; rather, the position of electrons are described with a more complicated model involving so called orbitals and probabilities. However, planets are still considered to orbit around their sun. The joke in this comic is that it claims the opposite: that atoms are still imagined with electrons in simple orbits, while planets have turned out to move according to the more complicated model with orbitals and probabilities. If this is amusing, it is probably because it is an absurd thought that something as big as planets would move in such an unintuitive way, which can not be described with classical mechanics. It may also be amusing that the history writing in the comic is very similar but opposite to the accepted one.
:[[User:While False|While False]] ([[User:While False/explain xkcd museum|'''museum''']] | [[User talk:While False|talk]] | [[special:Contributions/While_False|contributions]] | [[special:Log/While_False|logs]] | [[Special:UserRights/While_False|rights]] | [https://www.explainxkcd.com/wiki/index.php?title=User:While_False&printable=yes printable version] | [https://www.explainxkcd.com/wiki/index.php?title=User:While_False&action=info page information] | [https://www.explainxkcd.com/wiki/index.php/Special:WhatLinksHere/User:While_False what links there] | [https://www.explainxkcd.com/wiki/index.php?title=Special:RecentChangesLinked&days=30&from=&target=User%3AWhile_False related changes] | [https://www.google.com Google search] | current time: {{CURRENTTIME}}) 05:29, 11 December 2022 (UTC)

It's not space weather which makes position of planets hard to predict. It's the fact that while we have exact equations for two bodies, {{w|Three-body problem}} has no closed-form solution and leads to chaotic behaviour ... and there is little more than three bodies in our solar system. Also note that it gets even more complicated when you add theory of relativity into the mix. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 07:42, 11 December 2022 (UTC)

Of course, we now know that the planets are actually styrofoam balls held up by bits of string. [[Special:Contributions/172.70.175.10|172.70.175.10]] 22:02, 11 December 2022 (UTC)

ChatGPT sez: "The comic is about a teacher teaching a class about astronomy and how the models of the solar system have changed over time. In the past, it was believed that planets circled the sun in precise paths, like electrons orbiting the nucleus of an atom. However, we now know that planets do not have a fixed location and instead occupy "probabilistic orbitals," which means that their position is not certain but can be predicted with a certain probability. The title text suggests that this probabilistic model of planetary orbits also applies to the Earth's position in the habitable zone, where conditions are suitable for life. This is why life exists on Earth but is also mortal."

Nope. [[Special:Contributions/172.71.158.217|172.71.158.217]] 23:55, 11 December 2022 (UTC)

I just want to say that "This proposal was not well received in academia" was very funny! Well done, whoever wrote that.

2707: Astronomy Numbers

2022-12-05T20:46:42Z

172.70.179.30: /* Explanation */ Added brief explanation of title text

{{comic
| number = 2707
| date = December 5, 2022
| title = Astronomy Numbers
| image = astronomy_numbers_2x.png
| imagesize = 593x315px
| noexpand = true
| titletext = I adopted a cat that weighs 12 solar masses. Laser pointers love chasing it.
}}

==Explanation==
{{incomplete|Created by a CAT-LOVING LASER POINTER - Please change this comment when editing this page. Do NOT delete this tag too soon.}}
Scientists are used to working with extremely large scales, so seeing planets move at “normal” numbers (ones that don’t require scientific notation) is surprising to them. Ponytail remarks that she finds normal numbers “suspicious.” She then extends this paranoia to things that should be measured in regular numbers, such as the weight of cats. The vet (Megan) is seemingly used to this problem (perhaps she gets a lot of physicists) so gives the weight of Ponytail’s cat in solar masses, which sounds more correct to the Astrologist.

The title text suggests that laser pointers "love chasing" a new cat with a weight of 12 solar masses. This is presumably due to the effects of gravity, which would cause an ordinary object such as a laser pointer to be irresistibly pulled towards the hypothetical cat... along with everything else, up to and including the sun, because said cat would be the most massive object in the solar system by an order of magnitude.

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

Ponytail: "…And we need to correct for our elliptical orbit. On January 1st, Earth will be approaching the sun at a rate of…let's see…

65 miles per hour.

Weird. Okay."

Cueball: "Weird?"

Ponytail: "I get suspicious whenever I see a normal number in astronomy. We're not supposed to have those. Feels wrong.

Scales should all be incomprehensible."

Earlier, at the vet.

Megan in coat: "Your cat weighs 12 lbs."

Ponytail: "Ridiculous, nothing weighs '12'. You must mean 10-20? or 1040?"

Megan: "Fine. Your cat weighs 3x10-30 solar masses."

Ponytail: "Okay. Better."

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Ponytail]]
[[Category:Astronomy]]
[[Category:Comics featuring Megan]]

Talk:2689: Fermat's First Theorem

2022-10-24T18:57:24Z

172.70.179.30: comment

but it ''does'' spell ant bacon [[User:JLZ0kTC5|JLZ0kTC5]] ([[User talk:JLZ0kTC5|talk]]) 18:35, 24 October 2022 (UTC)

Possible reference to Fermat's Last Theorem.
*Make that ''certain'' reference to Fermat's Last Theorem. --[[Special:Contributions/172.70.179.30|172.70.179.30]] 18:57, 24 October 2022 (UTC)

2615: Welcome Back

2022-10-01T18:50:04Z

172.70.179.30: /* Explanation */

{{comic
| number = 2615
| date = May 4, 2022
| title = Welcome Back
| image = welcome_back.png
| titletext = 'We're shocked by the Notre Dame fire. Click for our tribute to--' [okay] 'Now that we're all staying at home these past few weeks thanks to this new coronavirus, we--' [okay]
}}

==Explanation==
[[Cueball]] is opening an app called TornadoGuard, a reference to comic [[937: TornadoGuard]]. In that comic the app is described to have a function so it "plays a loud alert sound when there is a tornado warning for your area". {{w|Tornado|Tornadoes}} are a [[:Category:Tornadoes|recurring theme]] on xkcd.

In the background, a tornado is approaching, so presumably a loud alert sound has just played and Cueball has opened the app. It is also possible that the app didn't play any alert (see reviews of the app in [[937]]), but Cueball saw the tornado and thus opened the app to check whether it had any news.

However, before he can interact with the app and learn more about the tornado, he has to click through various old messages from the app, since he hasn't opened the app in a while. This is feasible because May, which is the month in which this comic was published and typically the most active month for tornadoes, had seen fewer-than-average tornadoes in the previous two years but not during this year – see this [https://weather.com/storms/tornado/news/2022-05-02-may-tornadoes-2020-2021-recent-luck Tornado Central story]. So Cueball would have been more likely to have to worry about tornadoes this year than in the previous two years.

The comic is poking fun at the obtrusiveness of these kind of messages by presenting a scenario where they cause a significant delay before Cueball would be able to read the very urgent information about current tornadoes.

The messages include a description of a big update, a response to user feedback about one specific feature, and a social post seemingly unrelated to the app.

This continues in the title text where there are two more messages that refer to specific world events and can therefore be dated: The fire that {{w|Notre-Dame_de_Paris_fire|damaged the church of Notre Dame}} in Paris April 15th 2019; and the early attempts to limit the spread of Covid-19 disease, which was {{w|COVID-19_pandemic|declared a pandemic}} on March 11th 2020. It has been a while since the last [[:Category:COVID-19|reference to the pandemic]], actually the previous comic about this, [[2563: Throat and Nasal Passages]], was released almost exactly 4 months prior to this one.

The two mentioned news stories were relevant about three and two years before this comic was published, respectively. Neither of these are important to know right now, whereas an announcement about an [[2224: Software Updates|update]] that [[1172: Workflow|changes its functionality]] could be [[1328: Update|important to know about]].

Although it is possible that there are no more messages to click through if nothing of significance has happened [[2459: March 2020|subsequent to the title text ones]], the reader can easily imagine that the development team has posted further 'real time' messages that Cueball will still have to scroll through and/or dismiss, with very little immediate importance compared with the imminent proximity of an actual funnel-cloud.

==Transcript==
:[A large cloud fills the upper 3/4 of the panel. That it is a cloud is indicated by curved lines at the bottom of the cloud. Below the cloud lines is a tornado in the right part of the background. It is throwing up dust on or near the mid-distance horizon and creating an active debris cloud. In the foreground Cueball is standing holding his phone up in one hand, looking at the screen, which is on as indicated by five "light lines" coming of his display. Three paragraphs of text fills most of the white cloud space above Cueball, they are connected by lines, with the last leading down to the top of Cueball's phone. There are two rounded boxes to the right and below the first two paragraphs with text. They represents buttons Cueball presses on the screen to get to the next text message.]
:Hi! The TornadoGuard™ team is proud to announce a big update! We've added-
:''Okay''

:Note to users of sentinel mode: We've heard your feedback, and the controls are now-
:''Got it''

:The TornadoGuard™ team saw this cool leaf shaped like a spider; do you want to see...

:[Caption below the panel:]
:When you open an app for the first time in a while, you have to wait around while it tells you about all the cool adventures it's had.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Tornadoes]]
[[Category:Spiders]]
[[Category:COVID-19]]