Earth moving over the Sun instead of around Let's say you are observing the movement of the Sun and Earth from very far away. After year 1, the Earth creates an orbital plane around the Sun. Since the objects in the universe induce forces of different magnitudes on the Earth and Sun, you will observe the Sun and Earth moving differently, although the Earth will always orbit the Sun. My question is, what is the time frame under which the Earth moves out of the orbital plane it created after year 1. After how long does this orbital plane rotate? Will this change in orbital plane have any visual or physical effect for an observer on the Earth?
 A: The plane of the earth's orbit is extremely stable.  Of course, the earth's orbit is affected by the other planets, especially Jupiter, but all the planets orbit in approximately the same plane, so the forces pulling the earth's orbit out of its plane are small.  
We can see that the planes of the planets' orbit are stable, because all the planets are in roughly the same plane after 4.5 billion years, and it is approximately the same plane as the sun's rotation, so  it was determined by the angular momentum of the cloud from which the entire solar system formed.
A big change in the orbital plane of a planet could be caused by a close encounter with Jupiter.  This may have happened early on - indeed planets may have been ejected from the Solar system altogether.

Will this change in orbital plane have any visual or physical effect for an observer on the Earth?

Let's imagine that some slow and non-catastrophic process causes the earth's orbital plane to rotate by 90º.  We need to ask: what happens to the earth's rotation axis?  If it stays the same (and why would  it change?), then the effects would be dramatic, as the axis is now approximately in the plane of the orbit, pointing almost directly towards the sun twice a year.  The whole of northern hemisphere would be in daylight for several months in the "summer", then in darkness during the "winter".
