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/sci/ - Science & Math

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5068372 No.5068372 [Reply] [Original]

What would happen if two earth sized planets were to arrange in a stabilized position like shown in the picture ? Would the gravitational forces between the planets merge them together ? Would they disintegrate until there are nothing but little pieces ?

>> No.5068380

>>5068372

they would merge to form a spherical planet. it's how all planets were made.

>> No.5068388

>>5068372
It depends on the positioning of the north and south pole. If they're aligned, they'd repel each other at break-neck speeds into the depths of outer space.

>> No.5068394

>>5068388

i hope you are trolling. gravitational force is about a million times stronger than the earth's magnetic field.

drop a magnet on the north pole, either side up. in both cases it will fall straight down.

if you were correct we could launch rockets from the north pole with a big magnet instead of all that fuel.

>> No.5068396

>>5068394
those are 2 earth sized planets, not earth you fucktard. They could have insanely strong magnetic fields

>> No.5068401

>>5068394
Gravity is CAUSED by magnetic fields you retard. How the fuck do you think gravity works?

>> No.5068405

>>5068396

are they made of magnets? otherwise i am correct.

i studied physics in school.

>> No.5068415

>>5068401
Mars has pretty much no magnetic fields, so I guess you're telling me there's pretty much no gravity on Mars.

>> No.5068417

>Gravity is CAUSED by magnetic fields you retard.
Not the guy you're replying to, but I'm afraid you're a retard too.

Anyway, the magnetic force is a lot stronger than gravity, hence why a palm sized magnet can levitate another one against the entire gravitational pull of the earth.
However, planetary magnetic fields are weak as shit and woudl do nothing to prevent two planets such as those from grinding into each other.

To detail a bit more the OP scenario: if it was two small planetoids, like two pair of moons that were devoid of atmosphere with solid cores, then they could maintain such an orbit for prolonged periods. but with an atmosphere, they'd aerobreak and collide and it's all over. Even without the atmosphere pertubations from larger planets in the solar system or passing and impacting asteroids and other debries would mean they impact and merge.

>> No.5068418

>>5068401

1/10

made me reply

>> No.5068420

>>5068417
You need to learn some physics.

>> No.5068423

If they alone are heavy enough to collapse to sphere's then I'd guess the sum of them both will be heavy enough to collapse to a sphere

Anything living on those planets will be pretty fucked.

>> No.5068427

>>5068420
No source of legit education will ever say gravitation is caused by magnetic fields. Stop reading timecube, it will educate you stupid, though I guess that's already your irreversible state.

>> No.5068430

>>5068420

he sounds like middle-schooler who did a science project on this.

>> No.5068434

>>5068427
I'm saying that the aerobreaking stuff is bullshit. Even if they were orbiting each other that closely tidal forces would rip them apart.

>> No.5068438

>>5068434

what if they were dry and non-rotating? the immense pressure would melt the interface.

it's how all planets were formed; not necessarily from two big lumps, but the idea is the same.

>> No.5068443

The more you know.

>> No.5068449

There are three forces that I can think of in this system, so correct me if I miss anything:

1. Magnetic fields, but nobody here got it right so far. The orientation and magnitude of the resulting force depends on the orientation of the two fields (super approximation by two bar magnets), and this can be made extremely complex as planetary magnetic fields are extremely complex. Small magnetic fields are not insignificant.

2. Closely related to this is solar wind. If the net pressure of the particles deflected to the outside of the two planets is less than the pressure in between, the planets will be pushed apart (and vice versa).

3. Extremely powerful will be tidal forces. This not only affects the rotation of the planets (the Moon is tidally locked with Earth, in that only one side faces us) but also the distance (remaining tidal forces, such as the actual tides, take energy away from the gravitational interaction, causing the Moon to recede, which will continue until the moon reaches a geocentric orbit). Two bodies this close with masses this large will experience utterly enormous tidal forces.

Too lazy to do the full calculation for two Earths oriented (anti)parallel. Let me know if I missed any forces.

>> No.5068451

>>5068443

nobody said that.

>> No.5068452

>>5068438
They would rip each other apart as all of the material fell toward the barycenter. Doesn't matter if its dry (maybe you dont understand 'tidal') or rotating. If it's rotating some of the material could possibly form a ring.

>> No.5068454

>>5068438
And I guess that would create a planet of never-ending quakes and natural causes and an inhabitable surface like demolition debris all over.

>> No.5068453

>>5068434
>tidal forces
Fair point, but the tidal forces would be dependant on the size of the planet(oids). For a pair of ceres-sized planetoids it could work, guesstimated by gut feeling. If you care to dredge up tidal force equations and disprove me then feel welcome.

>> No.5068458

You do get contact binaries with asteroids but larger bodies would merge.

>> No.5068463

>>5068449
The tidal forces will be greater than the tensile strength of the rock the planets are made of. They will therefore tear each other apart.

http://en.wikipedia.org/wiki/Roche_limit

>> No.5068469

>>5068463

This. At that scale they're just balls of goop, not solid spheres. The crust is like what, a few kilometers thick, maybe like 25? That's less than 1% of the thickness of the planet. It would essentially have no effect in stopping the planets from fusing together.

>> No.5068472

>>5068463
I checked the Roche Limit for Phobos(having a radius of 11km), turns out it's 4000kms out so yeah I guess no body of significant size will ever be found in such an orbit.

>> No.5068477

>>5068472
The roche limit depends on the ratio of densities of the two objects, you can't just assume that knowing the limit of one system gives you the limit of another. The roche limit of two earth sized identical planets is about 8600 km, meaning that if the planet's surfaces were closer than 2200 km they would begin to break up.

>> No.5068479

There would also be a shit ton of lightning between the two planets as they approached and smooshed into each other. And fire.

>> No.5068485

Depends on the stability of the systems.

Really I doubt that, but we would have to making transportation tubes so we can colonize, transport, and meet expectations for ourselves.

>> No.5068501

What about the gravity between them ? Would the gravity between the two planets cancel each other out for the flying pieces of lands, rocks, sand, water and all that which float on the middle of the collision ?

>> No.5068505

>>5068501
Not unless there's magnets. I think that was established earlier in the thread.

>> No.5068538

>>5068401
>>5068388
2/10 for effort

>> No.5068554

>OP asks simple question
>first reply answers it straightforwardly
>second reply is an obvious joke
>aspies spend rest of thread debating joke post

>> No.5068558

>>5068554
Did you think there was real science on this board?

>> No.5068559

>>5068554
OP already got his answer, what else would we talk about in the thread?

>> No.5068560

>>5068554

lol more of those green arrows.

does that mean you are talking to yourself?

>> No.5068564
File: 50 KB, 256x256, 1341355557478.jpg [View same] [iqdb] [saucenao] [google]
5068564

>>5068401