Experts Say New Desktop Fusion Claims Seem More Credible

New York Times ^ | March 3, 2004 | KENNETH CHANG

[68skylark]

Scientists are again claiming they have made a Sun in a jar, offering perhaps a revolutionary energy source, and this time even some skeptics find the evidence intriguing enough to call for a closer look.

Using ultrasonic vibrations to shake a jar of liquid solvent the size of a large drink cup, the scientists say, they squeezed tiny gas bubbles in the liquid so quickly and violently that temperatures reached millions of degrees and some of the hydrogen atoms in the solvent molecules fused, producing a flash of light and energy.

"It can do some interesting science stuff as is," said Dr. Richard T. Lahey, a professor of engineering at Rensselaer Polytechnic Institute and an author of a paper describing the findings that will appear in the journal Physical Review E.

"Our interests are to see if we can't scale it up to something more exciting," he said.

The experiment could conceivably shrink the science of fusion — slamming hydrogen atoms together, producing heat and light — from giant, expensive reactors to the tabletop.

When this team of researchers made the same claim in an article in the journal Science two years ago, many scientists reacted with skepticism, even ridicule. But new experiments, using better detectors, offer more convincing data that the phenomenon is real.

"We've addressed all the issues and now they all speak for themselves with far greater intensity than they did before," said Dr. Rusi P. Taleyarkhan, the scientist who conducted the experiments at Oak Ridge National Laboratory in Tennessee and is a professor of nuclear engineering at Purdue University.

Skepticism remains, but Dr. Lawrence A. Crum, a professor of electrical engineering at the University of Washington who was highly critical of the Science paper, said the new work was "much better" and deserved attention to determine whether the effect could be reproduced.

"It's getting to the point where you can't ignore it," Dr. Crum said.

For decades, physicists have dreamed of harnessing the ferocious alchemy of the Sun as a clean, limitless energy source. Most experiments have been conducted in giant, expensive reactors using magnetic fields to confine the ultrahot gases.

In contrast, the new experiment, which cost less than $1 million, uses the power of sound to create energy comparable to the inside of stars.

To many scientists, however, the phenomenon, nicknamed sonofusion, bears uncomfortable similarities to "cold fusion," which has now been discredited.

Sonofusion has already achieved more scientific respectability than cold fusion ever did, with two articles published in major journals.

And unlike cold fusion, sonofusion is based on known science. Scientists have long observed a phenomenon known as sonoluminescence, in which a burst of ultrasound causes a bubble in a liquid to collapse and emit a flash of light; some have speculated that the gases trapped in the collapsing bubbles could be heated to temperatures hot enough for fusion to occur.

Still, controversy enveloped the Science paper two years ago. The new research by Dr. Taleyarkhan and Dr. Lahey provides a much clearer picture of neutrons that are ejected when fusion occurs.

Many scientists like Dr. Glenn Young, head of the physics division at Oak Ridge, said the experiment was solid, but still incomplete.

"Neutrons are slippery little rascals," he said. "They can fool you. They can bounce and show up around corners you don't expect."

[Physicist]

This would be hot fusion.

[PatrickHenry]

Iceberg, Goldberg ...

[Technogeeb]

Interesting. Has anyone else heard of this?

Yes; it is just sonoluminance, and it isn't fusion (unless you do something to lower the coulomb repulsion and catylize the reaction like injecting muons; otherwise it misses the required temperature / compression needed for fusion).

[mikegi]

I don't think anyone knows what's really going on in sonoluminescence. Everyone seems to attribute it to their favorite pet theory: ZPF people claim its a Casimir-like effect, etc. Anyway, here's a link to an experiment done at LLNL:

http://www-phys.llnl.gov/N_Div/sonolum/sonolum_paper.html

If I were to bet on a technology that will have a large influence on our future, I'd place it on THz pulses:

http://utol.ecen.ceat.okstate.edu/THz%20Interactive%20tour/impulse.htm

[azhenfud]

That's a BLENDER. Well, I guess tou could call it a fusion chamber....

[JerseyHighlander]

It's actually an age old communication tool used by shrimp...

exhibit A) http://www.sciencenews.org/scripts/printthis.asp?clip=%2Farticles%2F20011006%2Fclip%5Ffob3%2Easp

[RightWhale]

The science of acoustics is a valid branch of physics. It was amazing to me that one of my physics profs was studying acoustics in a candle flame in the 60s. One can actually do cutting edge physics, even lab physics on beer money.

[glasseye]

think 'coffie grinder'......

[azhenfud]

Remember the commercial with the "FUSED" chicken? That's cold fusion....

[Ichneumon]

It was amazing to me that one of my physics profs was studying acoustics in a candle flame in the 60s.

A decade or two ago some company actually made speakers for home stereos which produced sound by manipulating flames, although I don't remember the company or product name.

I couldn't find it Googling, but I did turn up this related project, which includes two different video clips of flame being used to reproduce audio: Voice of Fire project.

[RightWhale]

I'm not into the acoustics of candle flames, which is why I see these things as kind of amazing. Acoustics of the Saturn V main motors is [are?] more interesting.

[theFIRMbss]

>Unless there is a possibility of less than zero rating

Oh, be fair! It did co-star the always cuddly Rachel Weisz. Va-voom...

[edwin hubble]

Well.. What do we know for sure?
Acoustic Sonoluminescence has been studied and reported for decades.

http://www.physik.tu-darmstadt.de/~hofu/paper/boosting/main.html

What is interesting is the wavelength of light produced.
It is not emission spectrum light.
It is the wavelength (color) associated with a surface
temperature of more than 100,000 degrees.

The cavity (bubble) is created by the ultrasonic vibrations.

The bubble has a short life. It comes into existence in the low pressure component of the ultrasonic pressure wave. While in existence the bubble-cavity is a vacuum (low pressure) that has a small amount of water vapor in it.

The tiny bubbles (a brief nod here to Don Ho) then collapse quickly. There is almost no vapor pressure inside the bubble to keep from disappearing.

But think of the pressure as the bubble collapses to a diameter of zero. That's the key. Whatever vapor is inside the (vacuum) bubble cavity it is squeezed in an almost perfect isotropic (equally from all sides) collapse.

"The pressures are as high as 200Mbar (1Mbar = 1011 Pa) in the core of the imploding bubble. This pressure is equal to 1.974*108Pa or 19,743,336 atmospheres. The only state of matter which can exist under these conditions is plasma."

The emitted light is broad-spectrum. "Measurements of the spectrum of sonoluminescence (SL) indicate that it extends from above 700 nm to below 190 nm." ...corresponding to black-body emissions of more than 100,000K.
http://www.auditory.org/asamtgs/asa92nwo/5aPAa/5aPAa5.html

Note the spectrum goes "below 190nm" (UV). Scientists don't even know whether the bubbles emit X rays, a sign of very high temperatures. Water absorbs X rays, making it futile to try to detect them from outside the flask.

Conventional physics tries to explain SL as the adiabatic compression of the bubble which leads to very high interior temperatures. The issue is still hotly debated and possible explanations include shocks, plasmas, ionisation and photo-recombination, Bremsstrahlung radiation, and even fusion.
http://www.blazelabs.com/f-p-sono.asp

It remains difficult to explain the phenomena of sonoluminescence.

[ml/nj]

Has anyone else heard of this?

I just got notification of it from my Alumni email.

There may be additional information in the Press Release from RPI. I've always thought there was something to the Fleishman-Pons work, and I'm proud to see that my alma mater is helping to advance it.

ML/NJ (RPI '68)

[American_Centurion]

Grrrrrrrr.

Movie rating: phhhhhht!!

Rachel's rating: SCHWWIINNGGG!!!

Can I say that?

[hershey]

A little more tinkering with cold fusion and it's bye bye Middle East oil!

[Paul C. Jesup]

Using ultrasonic vibrations to shake a jar of liquid solvent the size of a large drink cup, the scientists say, they squeezed tiny gas bubbles in the liquid so quickly and violently that temperatures reached millions of degrees and some of the hydrogen atoms in the solvent molecules fused, producing a flash of light and energy.

Wasn't this is the plot for the movie Chain Reaction.

[Cold Heat]

Has anyone else heard of this?

No, but it is interesting?????

[js1138]

http://www.ionovac.com/

[js1138]