I am still having trouble with this old thread now that I have read
about siphoning momentum from the vacuum. Would anyone like to comment
on my "Could redshifted virtual photons be used to detect universal
rest?" thread now in regard to this?

Basically are you people trying to tell me that there is no change
in
the attraction from the casimir force between 2 mirrors or a
paddle,
regardless of whether I am travelling at 50% c or stationary in
regard
to the Earth or the CMBR if you like?

[Moderator's note: yes. - jb]


If not at least tell me how a static vacuum or a moving/expanding
vacuum or us moving over either of these types of vacuums would affect
momentum at various speeds?


"Could redshifted virtual photons be used to detect universal rest?"

http://groups.google.com/groups?hl=e...ogle.com#link1

To siphon momentum from the vacuum

Or not to siphon momentum from the vacuum? that is the question:-)

Momentum From Nothing

http://focus.aps.org/story/v13/st3



Nothing will come of nothing, avers Shakespeare's King Lear, but don't
tell that to physicists. An object in strong electric and magnetic
fields can siphon momentum out of the vacuum of empty space and begin
to move, one researcher predicts in the 16 January PRL. The strange
effect should be observable in the laboratory with current
technologies.

The vacuum of empty space is a restless place. According to quantum
mechanics, particles pop in and out of existence, and those "virtual"
particles give the vacuum energy and can affect tiny objects. For
example, two parallel metal plates will feel a minute force, called
the Casimir effect, pulling them together. That's because virtual
photons with certain wavelengths cannot exist between them. The vacuum
outside the plates thus has more energy, so it squeezes the plates
together.

But the vacuum can also possess momentum, says Alexander Feigel of
Rockefeller University in New York, and it should be possible to
transfer some of that momentum to a material object. To reach that
conclusion, Feigel began by addressing a long-standing controversy in
electrodynamics: How should one define the momentum of an
electromagnetic field permeating matter? For nearly a century,
physicists have had two definitions, one proposed by German physicist
Max Abraham and another derived by Russian mathematician Hermann
Minkowski. According to Abraham's formulation, the momentum of the
electromagnetic field should be smaller in materials through which
light travels more slowly; Minkowski's formulation states that in such
materials the momentum should be bigger. Using relativity, Feigel
found that the Abraham definition accounts for the momentum of the
electric and magnetic fields alone, while the Minkowski definition
also takes into account the momentum of the material as well.

Feigel next used his theoretical tools to analyze the momentum inside
a material placed in strong, perpendicular electric and magnetic
fields. He found that virtual photons traveling through the material
would have a strange asymmetry. If the electric field pointed up and
the magnetic field pointed north, then virtual photons of a given
energy traveling east would have a different momentum from those
traveling west. That asymmetry would give the vacuum a net momentum in
one direction, and the material would have to gain momentum in the
opposite direction to compensate. In fields of 100,000 volts per meter
and 17 tesla--which can be created in the lab--the material should
move at a rate of 50 nanometers per second, Feigel says, which should
be measurable.

Others had reached similar conclusions about the meanings of the
Abraham and Minkowski definitions of momentum, but Feigel's analysis
is simpler, says Rodney Loudon of the University of Essex in
Colchester, United Kingdom. "He's done it in quite a nice, elegant
way," Loudon says. However, Ulf Leonhardt of the University of St.
Andrews in Scotland says Feigel's approach may be a little too simple,
as it treats the material as a macroscopic object and does not begin
with the forces on the individual atoms in it. "There are definitely
some subtleties that he's left out," Leonhardt says, though the
results may still be correct.

Both Leonhardt and Loudon warn that the predicted effect may be
difficult to spot. For example, Loudon says, if the material contains
a few freely moving electrical charges, they will experience larger
forces that may obscure the subtle quantum effect. Still, Leonhardt
says, "This is a smart idea."

--Adrian Cho
Adrian Cho is a freelance writer in Grosse Pointe Woods, Michigan.

Quantum Vacuum Contribution to the Momentum of Dielectric Media A.
Feigel Phys. Rev. Lett. 92, 020404

http://link.aps.org/abstract/PRL/v92/e020404

(issue of 16 January 2004)