Are the planets in our solar system exhibiting perpetual motion or is it caused by the Sun's gravity?

Question

And if it is a form of perpetual motion, would a device exhibit perpetual motion if it were in space rather than on Earth which has more gravity and air friction?

For example, could you put a large wheel in space and initially spin it with rocket engines, have it create artificial gravity, and then because of Newton's law of motion "A body at rest remains at rest and a body remains in motion, unless acted on by another force" cause it to spin infinitely in a type of perpetual motion?

I suppose, it would have to be placed in a certain orbit where there would be little interference by gravitational pulls from either the other planets or by the large Sun.

Here is something similar to what I was asking about.

http://www.youtube.com/watch?v=NE_74gNzNP4

Answer 1

An interesting question.
Same as satellites in orbit around the Earth, and the moon. That does sound like perpetual motion, but actually it is like falling toward the gravity pull, but the forward speed of the object keeps it from ever getting nearer to the sun or the Earth that it would otherwise fall into.

Answer 2

No, it isn't a form of perpetual motion. There -is- a very small drag on the Earth as it orbits the Sun and (in another 100+ billion years) it will fall into what's left of the Sun (which will turn into a red giant and then shrink to a white dwarf in another 13 or 14 billion years)

Doug

Answer 3

There's no such thing as perpetual motion. It's just impercetably slowing. It's worse than watching paint dry. Or noting the metaphysical nature of a diamond. It'll take virtually forever.

Second part, no, but it does help a lot.

Answer 4

Planets are in perpetual motion, because god winds up the machine once a week.

http://www.cartoonstock.com/lowres/wda0171l.jpg