this post was submitted on 19 Nov 2024
440 points (86.3% liked)
memes
10388 readers
2271 users here now
Community rules
1. Be civil
No trolling, bigotry or other insulting / annoying behaviour
2. No politics
This is non-politics community. For political memes please go to !politicalmemes@lemmy.world
3. No recent reposts
Check for reposts when posting a meme, you can only repost after 1 month
4. No bots
No bots without the express approval of the mods or the admins
5. No Spam/Ads
No advertisements or spam. This is an instance rule and the only way to live.
Sister communities
- !tenforward@lemmy.world : Star Trek memes, chat and shitposts
- !lemmyshitpost@lemmy.world : Lemmy Shitposts, anything and everything goes.
- !linuxmemes@lemmy.world : Linux themed memes
- !comicstrips@lemmy.world : for those who love comic stories.
founded 1 year ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
Hydrostatic equilibrium yes, but equal? No. We agree that centrifugal force is a factor. Now ask yourself, why would gravity suddenly strengthen at the equator to get the surface acceleration to stay equal to that of the poles?
It doesn't. As a result the Earth seeks a new hydrostatic equilibrium, bulging out at the equator. This in turn strengthens the centrifugal force a bit while also slightly diminishing the force of gravity (because more of the planet's mass is farther away). So the same effect is taken even further. Local differences add a layer of noise on top of this, but the end result is that the net surface acceleration is measured to average slightly less at equatorial regions than at the poles, with for example Singapore getting 9.7639 m/s2 of downward acceleration, while Helsinki gets 9.825 m/s2.
You're right, I had it backwards. Hydrostatic equilibrium makes it that the combined force vector of gravity and the centrifugal force is perpendicular to the planet surface everywhere.