13 replies to this topic

[narboza22]

Ok, this is something that I have not been able to figure out.

Provided that the universe is a 3 dimensional plane, why do all of the planets in our solar system for the most part orbit on the same 2 dimensional plane as seen here:

Why do the planets not orbit like electrons do around a nucleus on multiple planes:

[The Best Guest]

Maybe they really do but it is hard for us to get the right angle

[CodeCat]

First of all, electrons don't 'orbit' at all. And definitely they're not around the nucleus like that. It's more of a balloon-shaped cloud, where the cloud density signifies the probability of finding the electron there. Read up more on electron clouds and quantum mechanics if you want to know more.

Secondly, the reason why the planets are all aligned like that is because they were formed from a single rotating disc (called an 'accretion disc') of matter. As it rotated, matter began to collect into rings, much like Saturn's today. However, as the rings grew denser, they began to clutter up until eventually planets formed from them. Initially the planets must have been huge clumps, but over time their own gravity smeared them out into sphere-like shapes.

[Soul]

Cool, but how were the planets core made?

[CodeCat]

Well it's likely that the core was formed as it is because of its density. Iron is a very dense material, and since the accretion disc was likely originally formed from the depleted remains of a nova-ed star, there was lots of the stuff around. So what probably happened is that the iron simply 'sunk' into the core of the planets as they formed, just like heavy/dense things tend to sink into a bucket of water.

[Soul]

Oh I see.

[narboza22]

First of all, electrons don't 'orbit' at all. And definitely they're not around the nucleus like that. It's more of a balloon-shaped cloud, where the cloud density signifies the probability of finding the electron there. Read up more on electron clouds and quantum mechanics if you want to know more.

Secondly, the reason why the planets are all aligned like that is because they were formed from a single rotating disc (called an 'accretion disc') of matter. As it rotated, matter began to collect into rings, much like Saturn's today. However, as the rings grew denser, they began to clutter up until eventually planets formed from them. Initially the planets must have been huge clumps, but over time their own gravity smeared them out into sphere-like shapes.

I realize that there is a lot more to atomic structure that picture suggests, I was just using it as an example of what planets are not doing.

Assuming that the Sun and out solar system was formed from nebula or something, wouldn't there have been cosmic junk above and below the forming Sun as well as the current plane the planets are on? Where did all of that go? What kept planets from forming on another rotating disc? Is it just because the axis that the Sun rotates on(which is another question: does the Sun rotate on the same plane that the planets orbit on?).

[CodeCat]

I think it's more a matter of the impossibility of having several axes of rotation. Any dust that would have started orbiting the new sun in a different direction would have undoubtedly collided with dust orbiting in 'our' plane. And as a result it would have got dragged into that orbit or otherwise disrupted/thrown out of its own. I think the plane we are in just happened to have more matter in it, so everything got pulled in.

[Sûlherokhh]

Just think of how water 'drops' when it gets sucked into the drain. It starts circling motions. The same way the solar cloud collapsed into forming the sun's accretion disk. The reason the disc has exactly the plane it has now and not a plane in an angle to what we see today is because the original cloud was of course irregular, having most of the mass contained 'above' and 'below' the now apparent plane, making most of the matter fall from above and from below to the center, making a whirlpool motion parallel to the 'plane'.
Over time this cancelled out much of the angular swirling motion of matter coming from a different direction.
Does that answer the question better?

[Bart]

i always thought the planets do orbit like that atom image, and that the planar representation was just for illustration purposes

[CodeCat]

But think logically, if electrons were really small spheres rotating in orbits like that, wouldn't they eventually collide with each other?

[The Best Guest]

yes

[Sûlherokhh]

Quantum Mechanics best describe the behavior of 'objects' of this size.
As metioned above, unless a direct measurement is taken to determine (meant in the strictest sense) the location of such a small object, or the course of it's movements, the only thing you can do is calculate it's probability wave, which lets you know the probability of the electron going this way or that, being here or there, spinning on this axis or that.
Furthermore, once one of these things is determined, many other traits that electrons or other small particles possess become indeterminable.
This is phenomenon has become known as the 'Heisenberg uncertainty principle'.

As a matter of fact, Quantum Mechanical interpretations could actually be used to describe the planetary orbits, albeit the resulting probability wave could be best described as 'collapsed', stating the movements and locations of the planetary bodies as being a specific way almost 100%, instead of what you usually find when calculating the traits of subatomic particles.

But this is pretty deep stuff. If you are interested, you should go look for info on that on the net. There are good lectures and papers from universities about this at university-websites as well as commercially available. You could also try to get hold of some excellent audio books, or, like me, buy those books in a bookstore.

I am honored to call the place my home where this brilliant physicist (Heisenberg) along with Gauss made some of their most excellent advances in theoretical physics and mathematics. I guess i wouldn't be able to type this (on an internet forum) today if they hadn't, hehe.

Edited by Sûlherokhh, 27 August 2007 - 02:25 AM.

[CodeCat]

As a matter of fact, Quantum Mechanical interpretations could actually be used to describe the planetary orbits, albeit the resulting probability wave could be best described as 'collapsed', stating the movements and locations of the planetary bodies as being a specific way almost 100%, instead of what you usually find when calculating the traits of subatomic particles.

But you have to be careful, because quantum mechanics has yet to be unified with the theory of gravity/relativity. The most extreme cases where both theories are significant are as of yet a big mess in physics.