On Wed, 17 Oct 2007 11:34:16 -0600, "Bill" wrote:

The source of the field rotates with the earth. The field itself is
decoupled from the source once it leaves the source.

Sorry, but you are the only one who thinks that the earths magnetic
field doesn;t rotate with it.

Mason Peck of Cornell University in Ithaca, New York, US, has received
a grant to study the idea, which is based on the fact that magnetic
fields exert forces on electrically charged objects.
He says a satellite could charge itself up in one of two ways – either
by firing a beam of charged particles into space, or simply by
allowing a radioactive isotope to emit charged particles. The charged
satellite would then be gently pushed by Earth's rotating magnetic
field, enabling it to change orbit and even escape to interplanetary
space

Took all of two minutes with a search engine and 'earths rotating
magnetic field'. Got quite a few hits for something that doesn't
exist.

Casady