What I was wondering is that, for example, toss a few balls into zero gravity space randomly, what would be the steady state motion? Would not all the balls go on weird directions and undergo irregular orbits due to the interacting and irregular gravitations. I imagine the largest or more dense planets to begin to influence the smaller and eventually it would stabalize. Is this what origin of the universe theories imagine, or am I totally missing something here? Would the smaller ones eventually all rotate around the largest? All in the same plane, more or less, and all in the same direction? It seems possible but I have no idea if this is mathematically derivable.

What are theories that explain chaotic motions into the present, same plane, same direction planetary orbits around the Sun?


Actually, the sun, planets and other small bodies are all created from the cloud of dust and gas that existed before the solar system. As the gas and dust collect towards the center, the mass rotates and soon an accretion disk forms (which is why the planets are nearly on the same plane).

So your notion of the beginning of the universe is incorrect. It did not start with a bunch of planets (or stars) randomly thrown into space. Also all the stars in a globular cluster are rotating in the same direction; the stars are in orbit in the cluster.

Yes, they did have irregular movements. It started with a large cloud of gas and dust, some from the big bang, mostly from exploded stars systems. The particles all had different directions and speed.

When gravity influenced enough particles to group and start accumulating is when the mass began to spin (conservation of momentum). The spinning mass flattens out to an accretion disk and planets can start to form (along with the sun).

  • $\begingroup$ This seems to partly answer my question +1. So are you saying the planets formed while already in their stabilized orbital motion. In other words maybe some dust and gas originally had chaotic motion but this all stabilized and 'then' formed planets. If this is what your saying then my question is just the same but we must replace 'balls', into gases and dust particles. Did they begin with irregular orbits until the accretion disk forms? $\endgroup$ – esé May 21 '14 at 4:33
  • $\begingroup$ Your answer is good by I followed what you said to this reference that explains it well. en.wikipedia.org/wiki/Circumstellar_disk $\endgroup$ – esé May 22 '14 at 11:02

That chaotic movements would make sens in a place, like a globullar cluster, with similarly-sized bodies. On the other hand, in a place like a planetary system where almost all mass belongs to a single body, you can be pretty certain taht you will have almost-independent orbits, like we have here.


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