09:13 AM EDT on Monday, April 5, 2004

A big science story of 1989 was about fusion energy, allegedly created in a jar of water. Cold fusion promised to transform energy production, letting everyone supply his own energy needs from environmentally benign reactors in basements. Say goodbye to the fossil fuels that provide energy for the world economy, with all the pollution and greenhouse gases that they entail. The news caused a sensation, with many saying that it sounded too good to be true.

The process, discovered by two chemists at the University of Utah, B. Stanley Pons and Martin Fleischman, involved passing an electric current through deuterium oxide, or heavy water. Deuterium is an isotope of hydrogen with an atomic weight of two, because it has a proton and a neutron in its nucleus. The pair hypothesized that deuterium atoms were accumulating in the electrodes, made from a rare element called palladium, and that they were fusing to make heat.

Fusion, combining hydrogen atoms to produce energy, is the reaction that powers stars and the hydrogen bomb, and has occurred for brief instants in experimental reactors, in which gas plasmas are heated to millions of degrees, causing the momentary release of huge jolts of energy and radiation. The thought that such reactions could occur on a tame scale with equipment such as might be found in a high-school chemistry lab was breathtaking.

Unfortunately, the results achieved by Messrs. Pons and Fleischman couldn't be satisfactorily replicated. Indeed, the process was, and remains, inexplicable according to theories of physics. Cold fusion was quickly pronounced a hoax. The press and much of the scientific establishment piled on the unfortunate researchers.

Still, a few hardy souls have soldiered on, with hope kept alive by traces of tritium -- a hydrogen isotope with an atomic weight of three and so proof of fusion -- that have been discovered by some experimenters.

Now, with oil reserves looking less reliable, the U.S. Energy Department has decided to take a second look at cold fusion.

The experiments are, by all reports, tricky. The possibility of limitless supplies of energy produced in a controllable and environmentally benign way still sounds too good to be true. But who knows? The reaction that produces fire was probably not fully understood by its discoverers, but it certainly changed the course of human development. Perhaps the same is true of cold fusion.