On Tue, 13 May 2008 00:19:50 -0400, "Jimmie D"
wrote:



Speaking of the trailing wire - I wonder if you could trail a loop - and
use it to generate electricity from cutting earth's magnetic lines of
force - (perhaps to power the aircraft after its up to speed. I think they
experimented with the idea on one of the shuttle's orbital missions, but
didn't hear much about the results.




I think I remember hearing the experiment worked too well and they had a lot
of uncontrolled arcing.
I wonder how much drag this would put on the shuttle.

Jimmie

The wire cutting through the magentic field will generate an EMF - a
potential difference between one end of the wire and the far end but
there is no complete circuit to tap it. If a return wire were
connected to the far end of the wire, it would generate the same value
and polarity giving no net emf (voltage) around the path. If one
could create a loop and rotate it in the field that would be a
different matter. The same concept applies to the voltage developed
between the wing tips of a (metal) aircraft.