Re: poly: faster than light in a super-vacuum

At 05:17 PM 9/07/00 +1000, I wrote:

>[in Wil McCarthy's] THE COLLAPSIUM (Del Rey), there's a
>detailed future technology based on Haisch's zero point energy EM theory of
>gravitation and other forces.

I've since discussed this a little with Wil, who allows me to cite the
following edited exchange (available to this list only, please):

=====================

WIL:

> the thing that startled me was yr hyper-c speculation.
>Quantum non-locality aside (as excluding transfer of useful information),
>it seems to stuff up temporal order so savagely that I can't take it
seriously.

Year by year, the evidence piles up for a non-local universe. You've been
following the FTL experiments of Gunter Nimtz and Lijun Wang? "Useful
information" is a surprisingly slippery term, but FWIW nonlocality does not
necessarily imply acausality, and FTL information transfer has arguably
been demonstrated in the lab already. Nimtz's opinion is that causality
violation is the Universe's only actual taboo, and even he is quick to
admit that causality is a (probably unprovable) postulate.

Regarding relativity, my strong suspicion is that Lorentz contraction et al
are pegged to local lightspeed, rather than to some universal "c".

============
ME:

I didn't mean to exclude or cast doubt on the *reality* of non-local
effects, rather to set them aside as irrelevant to this topic, since in my
understanding they cannot be used to convey informative messages except, as
it were, retrospectively, after a luminal message provides a key to unlock
the `instantaneous' correlations occurring superluminally but lost in
collateral noise.

>the FTL experiments of Gunter Nimtz and Lijun Wang?

I understood that these are group velocity effects. My sense of this is
that if you squeeze a horse through a narrow gate and infer from the
arrival of the tip of its nose that it's on its way, and even that it's a
horse, this knowledge can't be used either to accelerate or abrogate the
arrival of its tail.

>Nimtz's opinion is that causality violation is
>the Universe's only actual taboo

Self-evidently, I'd have thought, like dividing by zero or allowing
contradiction into a syllogism .

>my strong suspicion is that Lorentz contraction et al are pegged to local
>lightspeed, rather than to some universal "c".

Ack! But I doubt it, depending on how you define `local'. The local
lightspeed inside one of those nifty recent chilly condensates is a few
cms/sec, IIRC, but that entails no relativistic effects.

=======================

WIL:

Well, yes and no. The tip of the nose itself isn't detectable, although
it's generally not necessary to receive the tail for detection either. If
the horse's mass-energy is front-loaded, just the head may be enough to
trip your detector. And if the only possible messages are "one horse" and
"zero horses," then the arrival of the head does indeed carry a 1-bit
superluminal message. And a modulated stream of horses can carry, for
example, a Mozart concerto at 4c, which is exactly what Gunter Nimtz
demonstrated.

Now, some information theorists will argue that the bits, if transmitted
between relativistically approaching objects, could result in causality
violation and are therefore impossible to act on. IMO, these arguments are
specious, and supportable only because the experiment was performed on a
tabletop rather than between
planets. If the apparatus could be scaled up to, say, ping a responder on
the moon (admittedly difficult), it would require some sort of divine
intervention to hold the round-trip signal time to the luminal value.

> Self-evidently, I'd have thought, like dividing by zero or allowing
> contradiction into a syllogism .

In a four-dimensional universe where "matter" is composed of probability
density functions (i.e., waves), there is nothing logically impossible
about causality violation. It offends our sense of linear time, in the
same way that optical illusions offend our visual cortex. But regardless
of how we feel about them, they're just lines on the page. If "time" is an
arbitrary vector through a 4D space, then the question becomes: is that
space static or dynamic? If the former, then free will is an ugly lie. If
the latter, then 4D causality is the lie, and the only remaining question
becomes: how many dimensions must we invoke before it becomes static?

> The local lightspeed inside one of those nifty recent chilly
> condensates is a few cms/sec, IIRC, but that entails no
> relativistic effects.

Are you sure? (a) Photons traveling through high-index-of-refraction
materials retain their zero-rest-mass status, implying that they are fully
Lorentz-contracted when not directly interacting with the material (and,
obviously, non-Lorentz-contracted while absorbed in an atom). (b) Virtual
particles appear to be 100% real, physical manifestations of a zero-point
field. If "empty" space is genuinely filled with these, then photons
*will* interact with them, i.e., the refraction index of vacuum is not zero
at all, but some very high (albeit pervasive) value. Conclusion: the
Lorentz effects we observe in vacuum are the *statical average* of
supervacuum travel with frequent matter interactions. Modeling the
condensate atoms as Einsteinian projectiles in a very-low-c regime might
yield some surprisingly on-the-nose results!

================================

(I assume Wil means *statistical average*, immediately above, but in such
discourse statics are perhaps as likely as statistics. :)

Damien Broderick
Received on Tue Jul 11 20:15:57 2000