this post was submitted on 26 Dec 2025
24 points (96.2% liked)

No Stupid Questions

45077 readers
1126 users here now

No such thing. Ask away!

!nostupidquestions is a community dedicated to being helpful and answering each others' questions on various topics.

The rules for posting and commenting, besides the rules defined here for lemmy.world, are as follows:

Rules (interactive)

Rule 1- All posts must be legitimate questions. All post titles must include a question.

All posts must be legitimate questions, and all post titles must include a question. Questions that are joke or trolling questions, memes, song lyrics as title, etc. are not allowed here. See Rule 6 for all exceptions.

Rule 2- Your question subject cannot be illegal or NSFW material.

Your question subject cannot be illegal or NSFW material. You will be warned first, banned second.

Rule 3- Do not seek mental, medical and professional help here.

Do not seek mental, medical and professional help here. Breaking this rule will not get you or your post removed, but it will put you at risk, and possibly in danger.

Rule 4- No self promotion or upvote-farming of any kind.

That's it.

Rule 5- No baiting or sealioning or promoting an agenda.

Questions which, instead of being of an innocuous nature, are specifically intended (based on reports and in the opinion of our crack moderation team) to bait users into ideological wars on charged political topics will be removed and the authors warned - or banned - depending on severity.

Rule 6- Regarding META posts and joke questions.

Provided it is about the community itself, you may post non-question posts using the [META] tag on your post title.

On fridays, you are allowed to post meme and troll questions, on the condition that it's in text format only, and conforms with our other rules. These posts MUST include the [NSQ Friday] tag in their title.

If you post a serious question on friday and are looking only for legitimate answers, then please include the [Serious] tag on your post. Irrelevant replies will then be removed by moderators.

Rule 7- You can't intentionally annoy, mock, or harass other members.

If you intentionally annoy, mock, harass, or discriminate against any individual member, you will be removed.

Likewise, if you are a member, sympathiser or a resemblant of a movement that is known to largely hate, mock, discriminate against, and/or want to take lives of a group of people, and you were provably vocal about your hate, then you will be banned on sight.

Rule 8- All comments should try to stay relevant to their parent content.

Rule 9- Reposts from other platforms are not allowed.

Let everyone have their own content.

Rule 10- Majority of bots aren't allowed to participate here. This includes using AI responses and summaries.

Credits

Our breathtaking icon was bestowed upon us by @Cevilia!

The greatest banner of all time: by @TheOneWithTheHair!

founded 2 years ago
MODERATORS
L3s@lemmy.world
technopagan@lemmy.world
jeffw@lemmy.world
L3s@hackingne.ws
L4s@lemmy.world
24
How much earth would compress and expand if all of it went from 0°C to 50°C (lemmy.blahaj.zone)
submitted 1 week ago* (last edited 1 week ago) by Clear@lemmy.blahaj.zone to c/nostupidquestions@lemmy.world
4 comments fedilink hide all child comments
 

I was wandering how much thermal expansion would be on earth if all of it started at like 0°C and went to 50°C

top 4 comments
sorted by: hot top controversial new old
[–] SkyNTP@lemmy.ml 11 points 1 week ago* (last edited 1 week ago)

The earth's core is about 5500C and is mostly composed of iron and nickel, probably. Presumably, it would shrink tremendously going from 5500C to 0C so in theory you could calculate the rate of shrinkage using iron's rate of thermal expansion. However the core is also under immense pressure which makes iron much denser (smaller) than on the surface of the earth. The immense temperature and pressure is a result of the action of gravity pulling the core onto itself.

The short answer I think is the earth cannot exist as we know it at anything below its core temp of 5500. Suppose we waved a magical wand that set it's temperature to 0, it would implode on itself (along with the rest of the planet) and heat right back up to its current core temp of 5500 before you could measure the effects of thermal expansion.

[–] XeroxCool@lemmy.world 6 points 1 week ago* (last edited 6 days ago) (1 children)

67% of the Earth's mass is comprised of silicates in the mantle. Solid silicates have very low thermal coefficients of expansion, meaning they change volume very little in comparison to other compounds. So if the mantle was cooled and solidified to 0, then heated to 50, it'd have very little effect. It'd grow something like 0.02% in volume.

Being that the mantle is generally liquid, you'll see a much larger effect from the initial cooling. But how much? I don't know. Liquid rock isn't present in mere mortal online calculators and my ability to dive into the material properties and manually calculate it is long gone from my head.

But "much" larger may not be significant to the human experience, given that 0.02% would be imperceptible as a baseline. If you had a 1km long solid silicon ruler, heating it from 0 to 50C would make it just (edit) 0.2m longer. A circumferential ruler reaching around the Earth along the equator would go from ~40,000km to 40,008km.

Edit: corrected 20m to 0.2m. Flubbed the percentage in the calculator as 0.02 (2%) instead of 0.0002 (0.02%). So really, really imperceptible to a human walking 1km

[–] GreyEyedGhost@piefed.ca 1 points 1 week ago (1 children)

Given the quaint physics of circles, the expansion of a ring of silicate around the earth would be quite noticeable. C = 2×pi×r, which can be converted to r = C/(2×pi). Plugging in those two values gives us

40000/(2×pi) = 6366.1977 km

40008/(2×pi) = 6367.4710 km

So, taking this ring from 0° to 50° would cause it to rise 1.2 km into the air, assuming it kept its integrity.

A simpler way to write this is

(40008 - 40000)/(2×pi) or 4×pi.

A tiny difference, relatively speaking, but a quite notable difference given the context.

[–] XeroxCool@lemmy.world 1 points 6 days ago

Yes, that would be one way to make it noticeable. If all land/sea floor lifted, gradually, 1.2km into the air, we wouldn't see it. I also Flubbed the per-km increase of the ruler and edited it to correct the increase down to 20cm per km. So as far as our ability to tell things are 0.02% further, no mere mortal would recognize it. But with a lap band around the Earth, we'd definitely notice the new halo floating above us instead of being a tripping hazard.

That reminds me of a fun fact about how the increase in circumference does not care what your starting values are. If you wanted to wrap a rope around a soccer ball, then make the rope lift 1m above the surface of the ball all around, you'd do probably do the pid math like (pid2)-(pi*d1) :

3.140.022m=0.069m of rope around the ball
3.14(0.022+1+1)=6.349m of rope to float 1m above the ball
6.349-0.069=6.28m of extra rope

Then do it for the planet.

3.1440,000,000m=125,600,000. 00m of rope around the planet
3.14(40,000,000+1+1)=125,600,006.28m of rope to float 1m above the ground 125,600,006.28-125, 600,000= 6.28m of extra rope.

1m above, or 2m greater diameter, can just be fed directly into pid as derived from pi(d2-d1) since we know it's a basic request to lift it 1m