On Oct 2, 2010, at 4:28 PM, james f woodward wrote:
Well, I'm not trying to pick a fight here, as the only thing that really
matters is if there is any way to make ABWs. But I should point out that
Thorne is the one who stipulates exotic rest mass.
So Kip made a minor mistake, i.e., a too restrictive premise. He did that back in 1986 before discovery of the accelerating universe.
Also near EM fields are macro-quantum coherent states of virtual photons including longitudinal polarizations, they have zero rest mass, but still have a Tuv that makes a Guv bending spacetime.
Furthermore, in a meta-material if both permittivity and permeability are negative, the near EM field energy density is negative - despite some people claiming otherwise, they are in error in my opinion.
The next hypothesis to be tested is that it is the actual speed of light in a material that determines the gravity coupling of that material i.e.
the coupling is (index of refraction)^4G/(vacuum speed of light)^4
this is Popper falsifiable.
That's why I quoted his appendix where he lays out the requirements of ABWs.
But let's assume that you are proposing something equivalent to rest mass
in the form of, say, a hypothetical structure that induces a state of
exoticity in its vacuum interstices. (Sounds like a metamaterial, eh?)
The problem here is that there is no latent state of exoticity in the
vacuum to be exposed by such a structure. Mean cosmic matter density is
on the order of 10^-27 gm/cm^3 (perhaps less), 70% of which is exotic
dark energy. The Jupiter mass of exotic matter you need for an ABW is on
the order of 10^22 gm/cm^3. That's nearly 50 orders of magnitude
difference. If that were in the form of virtual particles in the vacuum,
its mean energy density would not be zero pending exposure in a
metamaterial. It would turn the entire universe into a wormhole. What
you have is sort of the inverse of the "cosmological constant problem".
When you try to put stuff into the vacuum as virtual processes, there is
nothing else there to dress it to latency that can be manipulated to
expose the latent quantity.
While the vacuum is an unconvincing repository for humungous amounts of
latent exotic matter,
Actually this is probably not true at all. The evidence is that there is only tiny ambient virtual particle density ~ 10^-29 gm/cc and that the old Wheeler estimate of hc/Lp^4 is completely wrong! The hologram theory explains why that is the case i.e. hc/(area of future horizon)(Lp)^2
virtual particles or not, normal matter is a quite
reasonable repository. Indeed, even in the standard model bare masses
are idiotically large and negative. The standard model seems not to have
any reasonable process that might expose the latent exotic bare mass.
But the ADM model with Mach's principle does allow for such exposure.
So, arguably, there is no conceptual flaw. . . .
Paper is very useful in general and I will quote it in my book Star
On Oct 2, 2010, at 10:18 AM, JACK SARFATTI wrote:
"The problem with absurdly benign wormholes of traversable
dimensions is that they require „exotic‰ rest mass matter ˆ that is,
real stuff you can stop in the lab that has negative mass."
Not necessary. Virtual particles inside the vacuum directly bend
spacetime because of the equivalence principle. The premise you make
is sufficient, but not necessary.