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Do the planets revolve on a 2d plane?

  1. Dec 8, 2007 #1
    (my first post) so i was watching a video on einstein's general theory of relativity when i realized that every solar system diagram shows the planets revolving around the sun on a two dimensional plane. do they really revolve at all the same level of say..a flat zero degrees, or do they actually orbit the sun like the electrons do in a typical picture of an atom? this may be an elementary concept, but i couldn't find the answer on google. thanks for any explanations.

    i do plan to take astronomy or astrophysics as a major in college next year. (:
  2. jcsd
  3. Dec 9, 2007 #2


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    In most systems we know of the planets orbit in a fairly narrow plane - within a few degrees. Most of our Solar System is within about 5-10 degrees though Pluto orbits 17 degrees off the plane.

    This is also what we expect to find to the other solar systems we will discover - it is a natural part of solar system formation. The gas and dust that proto-systems form from will tend to coalesce in a particular plane.

    BTW, the typical picture of an atom with electrons "orbiting" it is a false one. To understand how electrons are bound to the nucleus Google or Wiki "electron orbitals".
    Last edited: Dec 9, 2007
  4. Dec 9, 2007 #3


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    The eclipitc plane can wobble a great deal without creating newtonian problems. In our solar system it wobbles as much as 23 degrees.
  5. Dec 9, 2007 #4

    D H

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    The ecliptic plane is more-or-less fixed with respect to some inertial frame. It takes a lot of energy to change the orbital plane. What wobbles is not the orbital plane but the Earth itself. The Earth's rotation about its own axis precesses and nutates with respect to inertial. While the current obliquity of the ecliptic is about 23 degrees, it varies over a long period of time between 22 and 24.5 degrees.
  6. Dec 9, 2007 #5


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    Yes but let's not over-complicate the issue and drift from the OP's question. It seems to me he wants to know if we will find systems with planets orbiting perpendicularish to each other.

    The answer is: it can happen by certain rare events, but generally orbitral mechanics very strongly discourages it.
  7. Dec 9, 2007 #6
    thanks dave. that's the answer i wanted to hear. now i know the answer and then some more info.
    but yes, i know a little about quantum mechanics that electrons are measured by the probability they are in a certain area rather than the path they follow around the atom's nucleus.
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