In Reply to: Current flow in a vacuum vs. current flow in cryogenic material posted by Bob Reichenbach on 07/15/01 at 12:25 AM:
I know it is a little late to be responding to this query but I just came upon it and was considering the implications of your question. It is more a philosophical question than a Physics question. A little like the "sound of one hand clapping".
Since the "perfect" vacuum would contain nothing at all, there would be no such thing as temperature in that environment. Temperature is assumed to be the kinetic and other forms of energy which is contained in a particle or material. Hence no material or particle and there is no temperature. That is not to say zero temperature but "temperature" has no meaning without material of some sort.
Of course, you must know that current flow is the movement of electrons through a substance. "Perfect" vacuum would have no electrons or material hence no current flow.
This is all hypothetical since there is no such thing as "perfect" vacuum. Sub-atomic particles are constantly popping in and out of exsistence in the hardest vacuum. This is, I believe, called the "energy" or "energy state" of the vacuum. Scientists have speculated that should the "energy state" of the vacuum change (such as the energy of an atom can change), the entire universe would disappear.
Thanks for stimulating my few remaining brain cells.