virtual particles preferred frame?

["Glenn A. Carlson" <gcarlson@MAIL.WIN.ORG>]

Though I disagree with the statement that the mass density of the
virtual particles is zero, I find the argument re the (infinite)
homogenous medium somewhate persuasive, i.e., it seems an infinite
homogeneous medium appears unchanged whether moving or not.

However, I was probably unclear about whether the distribution of
virtual particles was infinite or not.  I was considering the virtual
particle cloud surrounding, say, a real electron.  In this case the
virtural particle cloud is isotropic, but not infinite.

Glenn A. Carlson, P.E.
St. Charles County Community College
St. Peters, MO
gcarlson@mail.win.org

Subject:         <No subject given>
   Date:         Fri, 5 Nov 1999 16:16:45 -0800
   From:         Leigh Palmer <palmer@SFU.CA>

> Charge density zero?  Yes. Mass density zero?  No.  Particles and
> antiparticles have positive mass.

The mass density is indeed zero in a vacuum; that's the mass
density of virtual particles.

> A spherical (isotropic) distribution of *real* particles, as observed
> by one stationary with respect to the particles' center of mass, will
> be contracted (anisotropic) along the direction of relative motion, as
> observed by one moving with respect to the particles' center of mass.
> Why would it be different for a distribution of virtual particles?

Then you would claim that the mass density of a homogeneous
medium is anisotropic in the frame of someone moving with
respect to it. Please explain to me what observable quantity
is associated with an anisotropic mass density.

Leigh