Cold fusion is the general name given to processes that fuse atomic nuclei at or near room temperature. In theory these would provide useful energy without the complex apparatus required to emulate the nuclear fusion that powers the stars. The latter needs temperatures approaching 100 million degrees.
However, if you mention cold fusion to most scientists, they tend to back off. The subject has almost been relegated to pseudoscience since the controversy concerning the experiments by Stanley Pons and Martin Fleischman some 15 years ago. But recent events suggest the idea is gaining respectability once again. The US Department of Energy is to review the evidence from more recent research which claims to provide a theoretical basis for the idea. Some types of cold fusion are certainly known to be possible, such as the one formally called muon-catalysed cold fusion.
The situation is now complicated by a report by Rusi P Taleyarkhan of Purdue University in a journal of the American Physical Society, which is causing controversy among specialists. For several years, Dr Taleyarkhan has been working on experiments that combine bursts of high-frequency sound waves (ultrasound) with pulses of neutrons in a process that he describes as sonofusion or tabletop fusion. He claims to have detected fusion reactions taking place, though his results are disputed by other experimenters.
Nuclear engineer Rusi P. Taleyarkhan, of Purdue University, said his “sonofusion” device cost less than $1,000 and in the short-term could probably be engineered as a cheap source of neutron emissions for use in portable detection devices.
Washington Post, 8 Mar. 2004
The bigger issue is the knock-on effect Taleyarkhan’s ... paper could have for others in the field. If funding agencies start to think sonofusion is nonsense or simply being done badly, it could become as big a fiasco as cold fusion.
Guardian, 11 Mar. 2004