🚀 go-pugleaf

Richard Schumacher writes:
: Bonus question: suppose that the tether were a coaxial cable, with shield
: and inner conductor shorted together at the far end. If the outer
: shield were superconducting, it would expel magnetic fields, yet the
: Earth's field would still induce a voltage in it (5 kV for a 20 km tether,
: more or less). Could the center conductor then be used as the return line,
: removing the need for plasma contacts at either end? Why or why not?

To save you from the wrath of the Ohm's Law Warriors (and snarfy in
particular :) I'd like to point out that the implication of the above 
is an infinite current in the superconducting outer sheath.
Quite apart from the physical limitations of critical current (whereat
the Meissner effect breaks down, as does superconductivity) there can
be no finite induced voltage by this mechanism, even for a perfect
superconductor.

Now I suppose I'll have to follow up with the appropriate Maxwell Equation.
Well, trust me on this. :-)
 --------------------------------------------------------------------------
| lord snooty @the giant | Would You Like Fries With That?                 |
| poisoned electric head |              andrew_-_palfreyman@cup.portal.com |
  --------------------------------------------------------------------------