Cold fusion

Incredibly, the cold fusion controversy is with us again. Physics World, normally a reputable source of news in physics, have a posting by Jon Cartwright on their weblog concerning claims that Japanese physicist Yoshiaki Arata of Osaka University may have demonstrated cold fusion.

To understand how startling – and controversial- such a claim is, you only have to call things by their proper names. ‘Cold fusion’ is media-speak for nuclear fusion at low energy, a process most physicists consider pretty much a contradiction in terms (it’s very difficult to achieve nuclear fusion even at extremely high temperatures and energies, with certain well-understood exceptions).

The dream of ‘cold fusion’ first hit the news in 1989, when chemists Fleischmann and Pons claimed to have observed a dramatic, unexplained heating effect in a chemical reaction, and attributed it to nuclear fusion processes ocurring at normal temperatures. The discovery made headlines around the world, because it offered the dream of a clean, cheap energy source on a small scale (nuclear fusion is a very different process from nuclear fission). However, the whole field was controversial from the very start.

Most physicists felt the jump from an unexplained heating effect to the assumption of nuclear fusion was highly speculative. Secondly, the effect was publicized (and funding received) long before the results were published in recognized journals, one of the first times this happened. Worst of all, when physics labs around the world rushed to reproduce the results, no discernible heating effect was found. The end result was a withdrawal of funding and a great career blow to the experimenters…and prompted a serious debate on the importance of peer review before going to the press!

Fusion in a beaker – the Fleischmann apparatus

It’s probably too early to say, but the current Japanese story bears many resemblances to the Fleischmann fiasco – a great deal of talk in the press (now web), a paucity of peer-reviewed results, and a great deal of copy written by non-physicists. In particular, I notice that most descriptions of the experiment focus once more on the benefits of ‘fusion energy’, (cheap, clean energy etc) with only a few lines concerning the skepticism of mainstream scientists.. (see this thread on the Richard Dawkins website for example)

There is also the question of biased opinion. For example, Cartwright’s article states ‘I also received a detailed account from Jed Rothwell, who is editor of the US site LENR (Low Energy Nuclear Reactions) and who has long thought that cold-fusion research shows promise’. Hmm. Not exactly an unbiased opinion, then. Indeed, a glance at the LENR website suggests that the above is not likely to represent the mainstream view…This is exactly the sort of press that caused such a problem the first time around…