# Magnetic Energy Reprise

Thetom
Inspired by this thread https://www.physicsforums.com/showthread.php?t=451674, I had an idea!
And it is just that: an idea. Can anyone tell me if it would work, in theory? And if not, why not?

So, passing a magnet through a coil of wire produces an electric current. But it will always take more energy to propel the magnet than is produced.

Would it be possible, in theory, to put a magnet into a low earth orbit and have it pass through a vast coil as it orbits the body? It would take no additional energy to keep the magnet moving, and it would constantly be producing current.

Well that was my idea. Could it work?

For the record, I had the idea on page one of that thread, before post 20 where Russ Watters states...

so obviously it is possible to set an object into essentially perpetual motion - it can be done with an orbit

Before.

By the by, I am currently accepting job offers from nasa, for more blue sky solutions.

Hope I didn't break any rules posting this. Not sure where to put it either.

## Answers and Replies

Staff Emeritus
Science Advisor
As the magnet passed through the coils its kinetic energy is converted into electrical energy, which causes it to lose velocity each time. This would cause it to fall from orbit.

JaredJames
As drakkith said, the magnets would slow it down until it eventually fell to Earth.

Even without the magnets though, orbits aren't permanent. Satellites and the space station need corrections every now and then to maintain their orbits.

Thetom
As the magnet passed through the coils its kinetic energy is converted into electrical energy, which causes it to lose velocity each time. This would cause it to fall from orbit.

Well that is such a shame. TBH i never thought about electric motors in the terms of converting kinetic energy into electrical energy (for some reason). But that makes so much sense and has given me a much more clearer (though still probably very simplified) idea of what is going on. Thanks.

Even without the magnets though, orbits aren't permanent. Satellites and the space station need corrections every now and then to maintain their orbits.

I had though about this and had just assumed some sort of on-board, attitude adjusting mechanism to keep the orbital path of the magnet true. Easier said than done i'm sure.

Thanks for the answers guys.

And NASA, obviously all my other ideas, the ones that actually work, are much better. I'll tell you about them on my first day..