Why do the planets orbit the Sun in the same plane?

I know they're not exactly on the same plane, but they only differ by a few degrees. What kept them from developing orbits like in the planetary model of the atom, with electrons orbiting the nucleus every which way?Why do the planets orbit the Sun in the same plane?They dont. Look at pluto. I'm sure that at some point they didnt but the millions of years and the constant tug of the planets on each other has coaxed them into the orbits we see todayWhy do the planets orbit the Sun in the same plane?Really good question.

Assume an isolated system of swarming particles. There would be a net, non-zero angular momentum and a center of mass.

the laws of collision dynamics, gravity would evolve it to a spinning disk. The math is beyond me but that is the general idea. all spinning suns have and axis of spin and therefore and equatorial plane for the planets, galaxies are mostly but not all disk shaped.Why do the planets orbit the Sun in the same plane?The planets formed within a rotating disc of gas and dust. Today's planets retain the same rotational characteristics.Why do the planets orbit the Sun in the same plane?
Conservation of momentum, relating to each ones gravity, and relating to the larger system.



But there are cluster galaxies... so anything may be possible.