Monday, May 26, 2008

Cold fusion - same old same old.

Once again (and it seems like this happens every couple of years) someone is claiming "success" in a cold fusion experiment. Basically this fellow has made a cell containing some composite of ZrO2 and nanoscale Pd crystals. The claim is that when this cell is filled to moderate pressures (a few bar) with deuterium gas over a couple of days, the cell gets hot (compared to its surroundings) and stays hot for a while (tens of hours), and that 4He is detected afterward. Furthermore, the claim is that control experiments with ordinary hydrogen do not produce the long-term heating or helium, and that control experiments without the Pd/ZrO2 produce no heating at all. People who know next to nothing about nuclear physics argue that the lack of neutrons (from the D+D goes to 3He + n reaction pathway) or gamma rays is fine, since simple p and n counting lets you have D + D goes to 4He, despite the fact that the 3He reaction is vastly more favored in ordinary fusion. There continues to be no credible mechanism for getting the D nuclei close enough to each other to get fusion. Now, it's entirely possible that there is weird chemistry going on here, but how come in twenty years of people trying to do this stuff there has yet to be a clean, well-designed experiment done by physicists that is reproducible and actually shows anything interesting? It's grating on many levels that this, an anecdotal discussion of nonconclusive experiments, gets touted online through slashdot, gizmodo, digg, engadget, etc. Extraordinary claims require extraordinary evidence.

8 comments:

chad said...

*Sigh* I knew we'd be seeing more of this after Iron Man came out. Now people think you can build a tiny nuclear reactor out of palladium.

Aaron said...

Doug, we all know all scientific claims are automatically validated once a press conference is held to announce them (or to a lesser extent, when a press release is issued).

okham said...

Possibly the worst of all is that for all I know there may even be something there, but at this point the entire field is so discredited that it will take at least a generation before anyone decides to give any claim a fair chance. Of course, it's all a consequence of how this thing was handled from the very beginning (starting with the infamous press conference... Doug, did you really have to remind me that it was almost 20 years ago...)

CarlBrannen said...

Apparently they gave a public demonstration of anomalous heat and production of He4. The improvement over prior stuff is the "public demo" which is supposed to mean that they now have something reproducible.

I don't have much hopes for this either, but I do recall that in the early days of lasers, people had great difficulty reproducing other people's results. This is discussed at length in the book on the collapse of gravity wave measurements, Gravity's Shadow, I think by Collins.

The problem with duplicating laser results turned out to be details like how long the power wires were and minor stuff like that. It doesn't get into the lab report. The experience was that to duplicate the result, you had to have one of the folks who'd done it before come over and tweak your bench.

With the gravity wave experiments, Joseph Weber had seen results that were hard to believe. When others failed to reproduce he pointed out that their experiments were different from his. They never actually forced him to recant, but he did keep publishing weaker results. Finally they took funding away from him eventually, but never completely.

Anonymous said...

Arata (~ 85 yrs old, very careful experimenter, professor, many valid patents, careful with laws of physics and engineering) has been doing sequence of related D2/Pd experiments carefully for at least many (~10) years. Included were careful measurments of "heat" sources e.g. chemical reactions and thermal. The "error" was to assume that the public is an authority for anything, and that a press conference is valid for anything other than running for office.

papers are archived at http://www.lenr-canr.org/LibFrame1.html

See Iwamura recent data. Repeatable, careful, no press conferences. Discount LENR.org explanations of physics of why they see things. No one in the field yet knows.

Anonymous said...

It's not a nuclear reactor, Chad -- it's an arc reactor! Get it straight! It's Luddites like you who want to hold us back in the 20th century!

chad said...

Look, *I* know it's an arc reactor and *you* know it's an arc reactor, but does the average person make those distinctions?

Up Start Interactive said...

The problem with duplicating laser results turned out to be details like how long the power wires were and minor stuff like that.