# Magnets and gravity

zelldot
is it posible to make a magnet rotate around a center point, with the use of other magnets?

## Answers and Replies

Mentor
Electric motors do that. Or do you mean fixed magnets? If you mean by fixing magnets to an apparatus at specific angles to make another magnet spin, no, it can't be done.

Theoretician
zelldot said:
is it posible to make a magnet rotate around a center point, with the use of other magnets?

Do you mean to ask if it is possible to have a magnet orbit another magnet as the Moon orbits the Earth?

If so, I don't think that it is possible without magnetic monopoles.

zelldot
you can place the magnets how you want, use anything you want, eg, string tieing up a magnet, whilt there is a magnet in the center, and yes i do want to make a magnet orbit anouther magnet or object... like the moon orbits the earth

The moon does not exactly orbit the earth, they orbit each other or I guess more properly, a common center of mass.

If you mean that you want to say balance the repulsive force of two magnets with some force or forces acting in the opposite direction, yes, you just have to engineer that situation.

But without some force other than their repulsive force (or attractive if you go the other way) you won't create an orbit, perhaps tying two magnets together on a stinger will create some straight line relationship but then an orbit requires more than that.

Gold Member
Isn't he askeing if the tangential force would cancel the attractive force, just like a gravitational orbit? Could you not set two magnets in "magnetic orbit" around each other?

Let's see, you would have to restrict their motion to a plane so that you could eliminate the dipole problem.

Now, magnets attract as the cube of their separation, right? And you'd have the poles acting at both ends (N-S on top and S-N on the bottom), so your force would be 2r^3.

Still, you should be able to (in theory) impart enough velocity upon them to cancel the attractive force, putting them in orbit about each other.

Of course, it would be much more unstable than a gravitational orbit, since any perturbations are cubed rather than squared.

zelldot
how could i make and object float and spin by them selves, using magnets, or even just float.

Staff Emeritus