Cold fusion, the supposed generation of thermonuclear energy using tabletop apparatus, was first reported in 1989 by electrochemists Martin Fleischmann and Stanley Pons. Then researchers at the University of Utah, they claimed they had fused the atomic nuclei of deuterium using routine electrochemical techniques. They reported they had integrated an isotope of hydrogen called "deuterium" into a palladium rod and, running electrical currents through it, produced nuclear fusion in a jar.

The excess heat measured in the experiment offered the promise of a new power source for the planet, not to mention huge financial rewards, prompting a global effort to develop the technology.

"Other experimenters failed to replicate their work, however, and most of the scientific community no longer considers cold fusion a real phenomenon," Scientific American explained a decade later.

Indeed, the world — particularly the science community at large — soon reacted with skepticism and, ultimately, derision. Following the failure to replicate the earlier results, the University of Utah discontinued cold-fusion research in 1991 and, in 1998, allowed its cold-fusion patents to lapse. After the University of Utah's lab was disbanded, work on cold fusion continued in several countries, notably Japan. In 1997, Japan's government finally gave up.

Nonetheless, research into the supposedly debunked field continued within a relatively small network of dedicated cold-fusionists.

"Normal fusion reactions, where hydrogen is fused into helium, occur at millions of degrees inside the Sun," EE Times explains. "If room temperature fusion reactions could be realized commercially, as Fleischmann and Pons claimed to have achieved inside an electrolytic cell, it promised to produce abundant nuclear energy from deuterium — heavy hydrogen — extracted from seawater."

The hope for low-energy nuclear reactions (LENR), the process once called "cold fusion," is to replicate the powerful energy generation that occurs in stars such as our sun, but to do so at a much cooler temperature. If successful, some researchers say, it has the potential to provide a nearly infinite supply of clean energy here on Earth.

Continued research now allegedly shows signs of paying off, as scientists last month described what they called the first clear visual evidence that LENR devices can produce neutrons, subatomic particles that scientists say are indicative of nuclear reactions.

At the March 2009 American Chemical Society (ACS) meeting in Salt Lake City, the site of the infamous presentation on cold fusion 20 years ago by Pons and his mentor Fleischmann, researchers announced a series of experimental results they argue confirm controversial claims of cold fusion.

"Our finding is very significant," study coauthor and analytical chemist Pamela Mosier-Boss, a scientist with the U.S. Navy's Space and Naval Warfare Systems Center (SPAWAR), said in a statement. "To our knowledge, this is the first scientific report of the production of highly energetic neutrons from an LENR device."

The new report was among 30 papers on the topic presented at the ACS meeting, injecting new life into this controversial field.

Among key findings was new evidence, presented by U.S. Navy researchers, of high-energy neutrons in what IEEE Spectrum describes as "a now-standard cold fusion experimental setup — electrodes connected to a power source, immersed in a solution containing both palladium and 'heavy water.'"

The Naval researchers claim that the earlier problem with cold fusion experimentation was instrumentation, which was not up to the task of detecting such small numbers of neutrons.

"By exposing a special kind of plastic to the reaction, patterns of minute dents (or 'triple tracks' that show three close nearby forms) were made by excited neutrons created from a nuclear reaction, they report," Scientific American says of Mosier-Boss and her team's work.

"If confirmed," IEEE Spectrum adds, "the result would add support to the idea that reactions like the nuclear fire that lights up the sun might somehow be tamed for the tabletop.

"But even cold fusion's proponents admit that they have no clear explanation why their nuclear infernos are so weak as to be scarcely noticeable in a beaker."

Moreover, a Rice University physicist who reviewed Mosier-Boss's published work said the study did not provide a plausible explanation of how cold fusion could take place in the conditions described.

"It fails to provide a theoretical rationale to explain how fusion could occur at room temperatures. And in its analysis, the research paper fails to exclude other sources for the production of neutrons," Paul Padley told the Houston Chronicle (via AFP).

The U.S. Department of Energy (DOE) is among the many skeptics. A DOE review, convened in 2004, reached similar conclusions to those of a review panel organized by the DOE in 1989: that evidence for the discovery of a new nuclear process was not persuasive.

The DOE recommended research continue, but even its tempered response and skepticism in the scientific community has done little to quell the enthusiasm of researchers.

Considering the latest claims, should the science community start warming to cold fusion as a limitless clean energy source for the 21st century? Or is it a fool's errand?

Resources

Whatever Happened to Cold Fusion?
by David Voss
Physics World, March 1, 1999

Electrochemically Induced Nuclear Fusion of Deuterium
by Martin Fleischmann and Stanley Pons
Journal of Electroanalytical Chemistry, March 1989

What is the Current Scientific Thinking on Cold Fusion? Is There Any Possible Validity to This Phenomenon?
by Peter N. Saeta, Michael J. Schaffer, Douglas R.O. Morrison and Robert F. Heeter
Scientific American, Oct. 21, 1999

Cold-Fusion Graybeards Keep the Research Coming
by Mark Anderson
Wired, Aug. 22, 2007

Cold Fusion Experimentally Confirmed
by R. Colin Johnson
EE Times, March 23, 2009

Cold Fusion Rebirth? New Evidence for Existence of Controversial Energy Source
American Chemical Society, March 23, 2009

New Cold Fusion Evidence Reignites Hot Debate
by Mark Anderson
IEEE Spectrum, March 2009

After 20 years: New Life for Cold Fusion?
by Katherine Harmon
60-Second Science (Scientific American), March 23, 2009

Cold Fusion 'Evidence' Unveiled
AFP, March 24, 2009

DOE Report on "Cold Fusion" Studies Recommends More Research
U.S. Department of Energy, Dec. 8, 2004