The Polarized Vacuum
sanman
It has an interesting new article on the Polarized Vacuum, framed in
terms of the dielectric of space. Cool stuff.
Just as a personal speculation-- what if you could polarize the
vacuum? Could you create a "bubble" in the vacuum? Some sort of
discontinuity in spacetime?
Quantum Supercavitation -- an interesting fantasy, don't you think?
Just like how Russian engineers figured out how to make their Sqval
torpedo move underwater at speeds much faster than water would
ordinarily allow. The supercavitation approach has the bulk of the
torpedo fuselage surrounded by a vapor bubble having vapor pressure
greater than the surrounding water pressure.
Or here's another idea I just thought of a second ago. Consider
something like a ramjet. The ramjet takes in air at high speed,
resulting in a mach-wall or pressure wall that compresses injected
fuel to allow efficient combustion. How about an analagous situation
where the your fast-moving spacecraft then concentrates the oncoming
vacuum, so as to create a zone of elevated vacuum pressure which
facilitates muon-catalyzed fusion. In the "higher vacuum pressure"
zone, the muon would be sufficiently stabilized so as to be able to
catalyze the fusion of diatomic hydrogen.
galathaea
Sounds eerily related to Schwarz's formulation of sonoluminescence.
It all comes back to Casimir, where alot of beautiful-strange
possibilities arise. Particularly the "ramjet" idea. There was this
guy I read a few years back who worked on the concept of a "warp
drive" in terms of forming a negative energy density through casimir
effects...
Gordon D. Pusch
> It all comes back to Casimir, where alot of beautiful-strange
> possibilities arise. Particularly the "ramjet" idea. There was this guy
> I read a few years back who worked on the concept of a "warp drive" in
> terms of forming a negative energy density through casimir effects...
The "Casimir effect" is simply the macroscopic analog of the van der Waals
force between molecules; it is caused by the interaction between the
fluctuating net electric dipole moments of two macroscopic chunks of matter.
If one stops making the unphysical assumption of two perfectly conducting,
infinitely thin plates with no upper cutoff frequency to their coupling
to the electromagnetic field, and instead includes corrections for the
finite size of atoms and for a realistic dispersion relationship for
macroscopic matter, one finds that the maximum possible "Casimir energy
density" must be many orders of magnitude less than the mass-energy of the
matter generating the "Casimir effect;" hence, the total energy of the
matter must necessarily still be positive. Achieving "negative energy"
via the "Casimir effect" is not physically possible.
-- Gordon D. Pusch
perl -e '$_ = "gdpusch\@NO.xnet.SPAM.com\n"; s/NO\.//; s/SPAM\.//; print;'
galathaea
I should correct the attribution I made, which is of course
Schwinger's ideas on sonoluminescence.
Now, I am interested in such an analysis. I did not believe that such
an idea was technically feasible currently because of more mundane
issues (like the matter could not hold itself together under such
Casimir forces or the sizes required would make it impossible to use
effectively in the manner described). But I always figured that it
would still be possible to produce such an effect eventually in
different, laboratory circumstances.
Do you perhaps have a link to some sources showing such "no go "
calculations? The best source I have on Casimir and related is "The
Quantum Vacuum: An Introduction to Quantum Electrodynamics" by Peter
W. Milonni, which has a lot of nice historical information as well.
But it doesn't mention any sources that claim what you state (though
it doesn't really explore the possibility either).
FrediFizzx
news:b22ffac3.03060...@posting.google.com...
I think you need to read Milonni's book more thoroughly. I do seem to
recall Milonni describing something very similar to what Gordon is
describing. While Milonni is trying to make a convincing argument for the
existence of zero-point energy, etc., he does present the alternative
explanations.
FrediFizzx
sanman
> force between molecules; it is caused by the interaction between the
> fluctuating net electric dipole moments of two macroscopic chunks of matter.
> If one stops making the unphysical assumption of two perfectly conducting,
> infinitely thin plates with no upper cutoff frequency to their coupling
> to the electromagnetic field, and instead includes corrections for the
> finite size of atoms and for a realistic dispersion relationship for
> macroscopic matter, one finds that the maximum possible "Casimir energy
> density" must be many orders of magnitude less than the mass-energy of the
> matter generating the "Casimir effect;" hence, the total energy of the
> matter must necessarily still be positive. Achieving "negative energy"
> via the "Casimir effect" is not physically possible.
Hi Gordon,
To me, a negative energy density amounts to "stilling the vacuum" --
ie. calming the myriad fluctuations in it. I was just thinking about
the analogy of a Cold Gas gun, which allows a projectile to be
accelerated to a higher muzzle-velocity than otherwise possible,
because of its use of cold gas. I'm wondering how one might strive to
locally cancel out or suppress the vacuum fluctuations in a localized
region of space. According to Sakharov, the vacuum likely does not
interact with itself, only with matter. I'd wonder if superconductive
ultracold matter would be useful.
Sometime back, I was reading about the proposed upcoming generation of
muon-colliders, which would accelerate muons into high-velocity
collisions with each other. I wonder if those high-energy collision
experiments won't eventually reveal some underlying structure to
leptons, including the electron.
Somehow the electron seems like it's the next missing link in the
chain that leads us towards deciphering the vacuum.
galathaea
> "galathaea" <gala...@excite.com> wrote in message
> news:b22ffac3.03060...@posting.google.com...
> | gdp...@NO.xnet.SPAM.com (Gordon D. Pusch) wrote in message
> news:<gi3cin2...@pusch.xnet.com>...
> | > The "Casimir effect" is simply the macroscopic analog of the van der
> Waals
> | > force between molecules; it is caused by the interaction between the
> | > fluctuating net electric dipole moments of two macroscopic chunks of
> matter.
> | > If one stops making the unphysical assumption of two perfectly
> conducting,
> | > infinitely thin plates with no upper cutoff frequency to their coupling
> | > to the electromagnetic field, and instead includes corrections for the
> | > finite size of atoms and for a realistic dispersion relationship for
> | > macroscopic matter, one finds that the maximum possible "Casimir energy
> | > density" must be many orders of magnitude less than the mass-energy of
> the
> | > matter generating the "Casimir effect;" hence, the total energy of the
> | > matter must necessarily still be positive. Achieving "negative energy"
> | > via the "Casimir effect" is not physically possible.
> | Now, I am interested in such an analysis. I did not believe that such
> | an idea was technically feasible currently because of more mundane
> | issues (like the matter could not hold itself together under such
> | Casimir forces or the sizes required would make it impossible to use
> | effectively in the manner described). But I always figured that it
> | would still be possible to produce such an effect eventually in
> | different, laboratory circumstances.
> |
> | Do you perhaps have a link to some sources showing such "no go "
> | calculations? The best source I have on Casimir and related is "The
> | Quantum Vacuum: An Introduction to Quantum Electrodynamics" by Peter
> | W. Milonni, which has a lot of nice historical information as well.
> | But it doesn't mention any sources that claim what you state (though
> | it doesn't really explore the possibility either).
>
> I think you need to read Milonni's book more thoroughly. I do seem to
> recall Milonni describing something very similar to what Gordon is
> describing. While Milonni is trying to make a convincing argument for the
> existence of zero-point energy, etc., he does present the alternative
> explanations.
I've read Milonni through about 3 times now, and I have referred many
times to specific sections when I was getting more comfortable with
the calculations (this was maybe 8 years ago though). I just relooked
over the appropriate sections, and although I find the many
expositions concerning zero-point field and its relation to the
Casimir effect (and the many interpretations possible) I still fail to
find any exposition on a "no go" theorem for some of the exotic
effects predicted from naive use of the Casimir results (in
particular, a no negative energy density theorem, which is the topic
being discussed). If you could suggest a section where such results
are calculated, or perhaps a different referrence for such a
calculation, I would very much appreciate it. A good deal of my
research concerns exotic effects proposed in science and the analysis
of such results by the scientific community, and I was for some time
quite interested in the Casimir effect's many controversial
possibilities and the more in depth analyses of these possibilities,
and although I've always felt there were severe physical difficulties,
Mr. Pusch has suggested that there are results specifically indicating
a "no go" and those are what I would like to review.