Very basic question for discussion

Hi friends,

I could not come to the forum for quite some time but watching it. Now I have a basic question.

We know that when a conductor moves across a magnetic field, an e.m.f will induced in the conductor according to the theory of electricity.

We also know that the Earth will act as a huge permanent magnet and if we moves a conductor or coil of conductors across the Earth's magnetic field, theoretically the same thing should happen. If that is so, can this induced electricity be used for some practical purposes? Perhaps may be for powering satellites if the satellite is being put in the orbit perpendicular to the Earth's magnetic field?

In the US there is a saying that "there is no such thing as a free lunch." Generators operate in a magnetic field and as the output increases so does the torque on the shaft of the generator - as a result of the increased drag across the magnetic field. Unless there is something else at work it would seem that you could put enough kinetic energy (velocity) into a satellite however the most you'd ever get out is what you put in. You might "store" energy in the form of velocity and convert it to electrical energy as the satellite moves thru the field however the satellite would slow down in proportion to the energy that is converted. I think I have this right.

I guess the movement of the earth, gravitational pull from the moon and stuff like that does do some internal heating of the earth because of the iron core. If the earth's magnetic field were varying rapidly enough it would be useful however if that were the case then generators would produce electrity while standing still and within limits, we know that doesn't happen.

Interesting idea, I must admit.

Hi Ravi,

Here's a link that talks about tether generators:

**broken link removed**

Stevez - Many thanks for the valued information

Seeker- This is an interesting website. I learned a lot

Thanks again.