Re: Faster than light?

James Rogers (
Thu, 19 Dec 1996 12:32:48 -0800

At 12:55 PM 12/18/96 -0800, you wrote:
>James Rogers writes:
>>The Casimir force is a manifestation of these electrons popping up and
>>disappearing momentarily in space. ... The net result is that the
>>concentration of electrons in the space between the plates is significantly
>>higher than the concentration on the outside of the plates, due to
>>significant overlap of the electron density curves. This generates a
>>repulsive force due to electron interaction between the plates that is
>>larger than the repulsive force generated on the outside of the plates where
>>the electron density is less.
>Um, isn't the Casimir force between conducting plates *attractive*,
>not repuslive? The usual explanation has you consider the zero point
>energy of the photons in the space between the plates, and notes that
>this (negative) energy gets larger as the plates get closer. Energy
>gradient gives a force.

You are correct. That's what I get for not checking my references. ;-|

-James Rogers