From: John Clark (jonkc@worldnet.att.net)
Date: Tue Mar 05 2002 - 10:02:43 MST
It's 6 years old but I still find this theory of sonoluminescence interesting.
I hope this new cold fusion thing turns out to be valid but I'd give you
4 to one odds it's another dud; at least they announced the results in a
peer reviewed journal not a press conference.
================================
PHYSICS NEWS UPDATE
The American Institute of Physics Bulletin of Physics News
Number 267 April 23, 1996 by Phillip F. Schewe and Ben Stein
A NEW THEORY OF SONOLUMINESCENCE.
Sound energy, in the form of a beam of ultrasonic waves, can be partly
converted into light energy by aiming the sound at an air bubble in a
sample of water. The sound causes the bubble to collapse and to emit
sharp (less than 12 picosecond) light pulses. The light's spectrum
implies that the source of the radiation is similar to a black-body
object at a temperature of tens of thousands of kelvins.
Theorists have tried to explain sonoluminescence by saying, for example,
that the radiation comes from a plasma formed by the collapse of the
bubble. But mostly the mechanism behind the production of the pulses
remains a mystery. Now Claudia Eberlein of Cambridge University
(cce20@phy.cam.ac.uk, 44-1223-337-458) offers a more daring explanation.
She believes the light is being emitted by the vacuum surrounding the bubble.
Modern quantum theory holds that unseeable virtual photons abound in
the vacuum. The behavior of these "zero-point fluctuations" is influenced
by the properties of the surrounding medium. The rapidly moving air-water
interface (where two media different indices of refraction come together)
may facilitate the conversion of virtual photons into real photons.
In fact, Eberlein says, sonoluminescence may represent the
first observable manifestation of quantum vacuum radiation.
This scenario can be compared to the "Unruh effect," a hypothetical
phenomenon in which photons are emitted by a mirror accelerating
through a vacuum. "Hawking radiation," the hypothetical emission
of particles from black holes, is yet another example of energy
seemingly coming out of nowhere; at the black hole's Schwarzschild radius
(inside of which, light cannot escape), space is so warped that energy
from the black hole can be converted into particle-antiparticle pairs;
one particle falls back into the hole while its partner escapes.
Eberlein asserts that researchers can put her theory to an experimental test
and compare the results to other models of sonoluminescence.
(Claudia Eberlein, upcoming article in Physical Review Letters.)
----- Original Message -----
From: jeff davis <jrd1415@yahoo.com>
To: <extropians@extropy.org>
Sent: Tuesday, March 05, 2002 3:25 AM
Subject: Re: Cold fusion redux
> Extropes,
>
> If you haven't already done so, do a google search on
> sonoluminescence. Then check it out. The first hit
> is as good a place as any to start:
>
> http://www-phys.llnl.gov/N_Div/sonolum/
>
> Here's a snippet:
>
> Sonoluminescence has created a stir in the physics
> community. The mystery of how a low-energy-density
> sound wave can concentrate enough energy in a small
> enough volume to cause the emission of light is still
> unsolved. It requires a concentration of energy by
> about a factor of one trillion. To make matters more
> complicated, the wavelength of the emitted light is
> very short - the spectrum extends well into the
> ultraviolet. Shorter wavelength light has higher
> energy, and the observed spectrum of emitted light
> seems to indicate a temperature in the bubble of at
> least 10,000 degrees Celsius, and possibly a
> temperature in excess of one million degrees Celsius.
>
> --------------------------------
>
> This is absolutely fascinating. I remembered reading
> the article on sonoluminescence that appeared in Sci
> Am in 1995. (But I haven't been able to access it
> again tonight on the web because Sci Am wants me to
> pony up some cash for the priviledge, and, well,
> that's not gonna happen.) The high temperatures
> suggested (required, proven(?)) by the production of
> light--in the uv no less-- would seem at least logical
> from conditions of spherical symmetry. The geometric
> and mathematical elegance of this phenomenon is
> breathtaking. A finite amount of energy is compressed
> into a volume which approaches a point--ie zero
> volume--which would result in an infinite energy
> density and an infinitely high temperature. Clearly,
> before such a "singular" point is reached, real world
> factors will intervene: absorbtion and reemission by
> the compressed medium, energy spread-out arising from
> a finite length spectrally-complex wave front, and
> imperfect focusing due to asphericity in the bubble,
> (others?).
>
> Whatever. Who can claim a sophisticated understanding
> of this phenomenon? Not me, certainly.
>
> What really makes this delicious for me is the cold
> fusion connection. When Ponds and Flieschman had
> their controversial moment, there was no plausible
> mechanism to support fusion in a flask. Now that there
> is, we can look back on the cold fusion controversy
> and see it in a whole new light (nice little pun,
> that).
>
> If one assumes that they actually did stumble on
> something, then it's clear that they did so by
> accident. They wanted to capitalize on it--patent
> it-- but couldn't, because frankly, they themselves
> didn't have a handle on it. And no one that followed
> up on F & P's work could get a handle on it either,
> despite tantalizing hints, fleeting and dubious, that
> there was something there. So, of course, with no
> plausible proof of a means to surmount the
> electrostatic repulsion energy barrier, and ever
> fearful of reputation damage, the scientific community
> retreated to the safety of life as it had been before
> the "irrational exhuberance", and cold fusion was
> relegated to the annals of crackpot science.
>
> It was clear to the respectable scientific community
> that cold fusion was not possible. The laws of
> physics made that quite clear.
>
> I remember, back then, looking for a "location" within
> the palladium where the fusion might take place.
> Seeking out the structure of the unit cell, looking at
> the shape of the spaces between palladium atoms where
> the absorbed deuterium might drift, its own electron
> indestinguishable from the sea of free palladium
> conduction band electrons. Wondering how this
> minds-eye scene, with its particular geometry and
> electronic environment, could promote the postulated
> event.
>
> My best guess was that the electrolysis power
> supplies, which were DC, but which provided that DC by
> conversion from 60 hz AC line voltage, retained a
> slight residual 60 hz and higher harmonics, AC signal,
> piggybacked on the DC. And that this caused the
> oscillation which accelerated the deuterium nuclei
> within the palladium matrix. That was my shot at an
> answer.
>
> Now we get to revist the Ponds and Fleischman
> experimental apparatus, with plausible mechanism in
> hand, and ask ourselves, "Is some previously unnoticed
> acoustic activity, some variant of the
> sonoluminescence mechanism, going on here?"
>
> Only time will tell what's really going on, and I'm
> looking forward to the adventure of discovery with
> pleasant anticipation. But what it really boils down
> to is that, as has so often been the case in the past,
> what was once obviously impossible, is now, well,
> maybe not.
>
> Or as my boy Ray says:
>
> "Everything's hard till you know how to do it."
>
> Best, Jeff Davis
>
>
>
>
>
>
>
>
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