Fusion Power: Just Around the Corner

Controlled nuclear fusion as a power source is something which has been "just around the corner" for the last 50 years, but the inherent problems have been just too difficult to overcome. We had the hysteria about so-called "cold fusion" a decade ago (now completely discredited), but in general the approach has been to build really really big fusion reactors and make tiny incremental improvements over the course of decades. Now, a small-scale approach based on a phenomenon called sonoluminescence (meaning "light from sound") appears to be bearing fruit .

Sonoluminescence has been known for over 70 years, but the scientific community has never paid a whole lot of attention to it. If you take a flask of water (or some other liquids) and blast it with sound waves, under the right conditions a small spot in the center of the flask will start to glow very brightly. This was an interesting parlor trick, but didn't seem to have a whole lot of practical applications, nor did it seem to lead to any new physics. Combine that with the fact that sonoluminescence is hard to achieve (it only happens under exactly the right conditions), and most scientists ignored the phenomenon.

I first heard about sonoluminescence as a physics graduate student about ten years ago. I was reading some obscure articles about stupid physics tricks, and happened across a reference to it. Some casual research revealed the interesting fact that at least one researcher had measured the blackbody temperature of the light, and found that it was insanely hot.

"Hmm," I thought, "I wonder if this might be hot enough to induce nuclear fusion."

At the time, however, anything which smelled like cold fusion was career death to a graduate student in physics. Besides, nobody in the department knew anything about sonoluminescence, so I would have had to fly completely solo--not that I didn't consider it in passing, but I already had an interesting project, and I didn't want to go through the additional pain of convincing a thesis committee that my research wasn't a complete dead end.

As it happened, I dropped out of grad school a year or so later.

I'm glad to see, however, that I wasn't the only person to have that thought, and that this avenue might bear some serious scientific fruit. Even if sonoluminescence is never practical as a power source, if it does lead to nuclear fusion, it could greatly advance the state of the art in fusion research overall.