/sci/ - Science & Math

>>8164923
The same as any other object. The shape is irrelevant

>>8164923
why does it need to be huge? It would have a better chance of not collapsing if it was small.
their orbits would be exactly the same as those of a sphere with the same center of gravity.
They could be spinning like mad doe.

>>8164926
Not if the orbits are close to the surface

This video deals with an interesting shape in the very first minutes

https://www.youtube.com/watch?v=VNqNnUJVcVs

>>8164938
No, the shape doesn't matter. Look at the equation for gravitational attraction.

I'm pretty sure sharp corners and edges would bend space quite interestingly for those having a fly-by. Or not. I don't know.

>>8164960
>brainlet

>>8164942
Fuck you

>>8164957
Look at the equations, solve them for a large slab, and note that the result very much depends on the fact that you have q slab instead of a sphere.

>>8164957
>distance from an object without any radial symmetry will be constant

Are you even fucking trying, failtard?

Borg cubes aren't nearly massive enough to be rounded by their own gravity, but yeah, there's a theroretical upper limit on mass before your spacecraft turns into a sphere of molten materials

>>8165003
Distance from center of mass, not from the object you fucking retard.

>>8164926
>>8164957

>>8166287
That's only true for spheres.

Imagine a very long, thin, dense cylinder. You could stand up and walk around on the ends of the cylinder, because there's a significant amount of mass directly below your feet. But if you were the same distance away for the COM but 90 degrees off the axis, you won't experience much gravitational attraction at all as all of the cylinders mass would be far away from you.

>>8164923
If it is too large it will collapse into a more spherical shape. That is why the largest volcano in the solar system isn't a gargantuan point and instead just a shield.

So, what you do is have them slightly below the collapse limit for their mass density-gravity.

>>8166326
They were talking about orbits, not surface gravity.

>>8166321
From a far enough distance, it really doesn't matter. Sure, if you fly a fucking spaceship near the surface shit will be weird, but OP asked about a fucking orbit, if you're far away enough that an orbit is stable it gets closer and closer to the same as a spherical object.

>>8166391
The two are strongly connected.

>>8166506
No. An orbit around object of some specific mass will be exactly the same no matter the shape of the object. Standing on that object is not an orbit at all.

>>8164923

Ask ur mom

>>8166945
Take a sphere and a given orbit of radius r. Now enlongate that sphere into ovoid, without changing its mass. Keep elongating it, until the length of the object is > 2r.

Problem with your orbit?

>>8167011
doesn't exist, doesn't matter.
Orbit my testicles and see what happens.

could there, on a planet sized cube shaped object made of some imaginary indestructible material (so it could keep its shape), be an atmosphere small enough that it couldn't form a regular atomphere around the cube but rather a small bubble on each side? there could be 6 different civilizations on each side, thinking they're the only civilization in a flat world

>>8164923
Am I really on sci? what the fucks with this thread?

here OP, for a cube.
http://arxiv.org/pdf/1206.3857.pdf

it shows how lakes would look, as well as orbits.

>>8166407
>From a far enough distance, it really doesn't matter.
well, yeah thats true. If you are far enough you can even orbit 2 object as if they are one.

That doesnt mean the orbit wouldnt be weird in a low orbit. Even the very small gravitiy deviations on earth make measureable changes to orbits

>>8167043
I guess so. The corners of the cube are basically huge mountains

>>8167024
>I don't want to be wrong: the post

>>8164976
> having no clue this is a legitimate pop sci video

to everyone else
please stop feeding the troll who pretends to not know what an orbit is.

>>8164923

While this is more about realistic shapes, I think this is a nice little paper related to this interesting question:
https://www.terrapub.co.jp/journals/EPS/pdf/5111/51111173.pdf
>Orbital evolution around irregular bodies

>>8167011
The orbit doesn't change, retard. You're being pedantic.

>>8167050
it's like seeing a glittering coin in a pile of moist pig shit.

fucking hate this board

So just to be sure.

You guys are saying, that an orbit around a very irregular "planet" would still be pretty much perfectly elliptical?

>>8164923
all mass exhibits gravity, dood.

>>8167683
>Im not wrong you are just pedantic
>retard

>>8167702
No it won't. Free falling bodies travel along spacetime geodesics. Sufficiently far from any body, these are conical sections. But that's just an approximation. In reality the gravitational field of a bumpy body has "bumps" too, therefore the geodesics are not those mathematically perfect conical sections. However since heavenly bodies are typically multiple magnitudes farther away from each other compared to their geometry, their orbits would be approximately elliptical.

>>8167812
ah ok.

So my pic would be a fair representation of an orbit around this body?

>>8167831
Nope. On your pic the orbiting body is too close compared to the bumpiness of the other body. Consider this: if you zoomed out enough, the body would look like a point, therefore the gravitational field would be approximately spherical at that distance and the orbit would be elliptical. However, if the distance is the same magnitude as the bumps on your body, then the gravitational field would be too irregular to be approximated spherically.

>>8167861
but I am specifically confused about close orbits. I know how this would play out, if you are far away.

>then the gravitational field would be too irregular to be approximated spherically.
yeah exactly. wouldnt this make a low orbit also very "bumby"?

How would we know when we have never observed/directly measured any such bodies/close orbits?
Isn't our current understanding of gravitation a formalized empirical statement based on the observation of only natural shapes?

How do we know how these bodies WOULD behave just with our math is my question. Wouldn't we need a QG theory for that?

>>8167683
it is one of many ways to illustrate that you can interfere with the orbit. just happens to be the most dramatic, but the point stands.

distance is EVERYTHING when it comes to this stuff. change the mass distribution, you change the distances to the infitesimal volume units.

You fuck tards think just because the total flux is constant, that a line integral is also going to be unchanged and that is preposterous on its face if you understand the slightest bit about geometry.

>>8167683
BUT IT DOES

>>8166363
volcano morphology is more of a result of the viscosity of the lava than anything else

>>8167050
10/10 ur my hero

Gravity is not real tho

>>8164957
The equations are derived with the asumption that the body considered is spherical.

It doesn't work the same way with any other different repartition of mass.

Also
>>8166363
>let's wave our wand and say these things are sturdy enough to not collapse in on themselves.
Can you read OP before -not- answering their question?

>>8167683
I think this retard here though the question was about the cube/egg shaped planet orbiting a star.

>>8164923

Watch the vsauce on a flat earth:

https://www.youtube.com/watch?v=VNqNnUJVcVs

On a cuboid, heading for the corners would feel increasingly tiring, as you headed "uphill" away from the cuboid's center of gravity, which would be neutral and normal at the center of each square face.

Worse still would be approaching the corners.

>>8170347
>tfw will never train in the corners of a square earth for maximum strength gains

>>8164923 (OP)

Watch the vsauce on a flat earth:

https://www.youtube.com/watch?v=VNqNnUJVcVs [Embed]

On a cuboid, heading for the edges would feel increasingly tiring, as you headed "uphill" away from the cuboid's center of gravity, which would be neutral and normal at the center of each square face.

Worse still would be approaching the corners.

>>8164923
This is kind of one of those "Godzilla Questions." Basically one can ask a question about the physique of Godzilla, but the question cannot be answered seriously as Godzillas body cannot exist. To put it really simply, you can't ask a question about an event that can't exist as if it existed. One can still geek out and fantasize about the event.

However, will try my best.
The best I can give you is that the gravitational affect would be more like a softened corner cut cube if the shape were say the aforementioned cube. The corners would have stronger gravitational pull than the center of an open face on the direct surface, but off of the surface would have the weakest point of gravity. Basically you'd feel like you're being pulled down on contact, but just by jumping you'd reach escape velocity (given that we're looking at an Earth-similar shape). As for at the center of a face surface, the gravity would be weaker directly on contact with the surface, but the initial gravity if disconnected or suspended above the surface would be much greater (as much as the gravity of the surface of the corners). Really weird to think about.

>>8170351
already posted.
do people actually read the thread they are posting in?