Disputes over scientific research methods, long ignored by an uninterested public, made headlines earlier this year when a pair of University of Utah researchers claimed they had discovered a reaction that could provide the world with a virtually unlimited source of energy.

On March 23, B. Stanley Pons and Martin Fleischmann announced that they achieved "cold fusion" in a flask, and scientists around the world quickly rushed to their labs to attempt to verify the researchers' claims.

Fusion, the process that powers the sun, has been pegged for years as a possible solution to the world's energy problems because the huge amount of energy it produces is fueled primarily by hydrogen, which exists abundantly in water.

Before the Utah announcement, fusion was thought possible only at high temperatures and pressures like those found at the center of the sun. Researchers had tried for years to create such conditions with million-dollar equipment.

While those tests have succeeded in producing fusion reactions, so-called "hot fusion" has no commercial applications because of the high equipment costs involved. Hot fusion also yields less energy than is required to start the process.

So when Pons and Fleischmann claimed that they had achieved fusion at room temperature with relatively inexpensive equipment, the two scientists were cast in an unfamiliar role--that of celebrities.

The fusion discovery made its way onto the covers of dozens of newspapers and tabloids, and Pons and Fleischmann became as close to house-hold names as two research chemists could ever hope to be. Some observers credited them with the greatest discovery since fire, and others said they would soon be on the way to Oslo for a Nobel prize.

But Pons and Fleischmann's fame soon turned to infamy, as other scientists began to question the pair's experimental method and results.

Critics quickly pointed out that Pons and Fleischmann never used a control experiment, although controls are standard scientific practices expected even of first-year chemistry students. Without a control experiment, it was impossible to tell for sure if the heat generated in the experiment came from fusion or from a previously unknown chemical reaction.

Adding to the confusion was the fact that Pons and Fleischmann made the announcement at a news conference rather than through the established route of publication in a scientific journal. Some accused the pair of publicity-mongering at a time when they should have been publishing an accurate paper on their findings for peer review.

When the pair finally produced a report a few weeks after the announcement, it contained a full page of mistakes. Specifically, one of Pons' graduate students who helped write the report had his name "inadvertantly" left off the report.

"Their experimental method was pretty sloppy," said Cabot Professor of the Natural Sciences Isaac F. Silvera, who is leading a Harvard team checking the fusion results. "And I don't like the idea of announcing in the press before publishing. It's not the way to do science."

Fusion occurs when two small atoms combine to form a larger atom, releasing energy. The Utah researchers reported that when they ran an electric current through a flask containing heavy water and palladium, a sharp increase in water temperature occurred. The pair claimed that atoms of deuterium (a form of hydrogen found in heavy water) entered the palladium and fused together into helium atoms.

Two Harvard teams joined scientists around the world in experiments designed to verify the claims of the Utah researchers.

Silvera leads a team in the Lyman Labs that is using a high-pressure diamond anvil to crush together a palladium and deuterium cell. Silvera says their first test, which failed to release heat or emit subatomic particles that are expected by-products of fusion, could have failed because of accidental leaking by the liquid deuterium.

"At this point I am a little bit pessimistic," Silvera says. "If we perform the experiment the way we want and we don't get results, then we're not going to pursue it."

Another Harvard team at the Advanced Physics Laboratory tried to duplicate the experiment procedure Pons and Fleischmann used, but gave up on its tests after they failed to produce either heat or neutrons.

Most cold fusion experiments around the world also yielded negative results, and the repeated reports of failure fueled speculation that Pons and Fleischmann's discovery was closer to science fiction than science.

The dissatisfaction with the Utah team's experimental technique came to a head at a convention of the American Physical Society on May 1, when several physicists charged that the claims of Pons and Fleischmann were unsubstantiated and that the two had used shoddy research methods.

Some observers called the accusations levelled against the pair by physicists "chemist-bashing."

"There have been many non-professional and emotional comments," said Dr. James Brophy, vice president for research at the University of Utah. "That is something that I have not seen before."

"They are two very respected scientists with worldwide reputations," Brophy continued. "They believe their work is correct."

Chemists one week later defended their colleagues and criticized the physicists for their attacks on Pons and Fleischmann. The resulting rift between physicists and chemists further clouded the cold fusion debate.

"Unfortunately there has been a polarization between the chemistry and physics community," Silvera says. "I don't think science needs that kind of confrontation."

At a conference in Los Alamos, N.M., two weeks ago, a group of scientists from both fields seemed to resolve the scientific schism, concluding that Pons and Fleischmann's research was flawed and that the heat they found was produced by a chemical reaction--not fusion.

"The whole thing is over," said prominent Yale physicist Moshe Gai, who attended the conference. "Pons and Fleischmann's experiment is clearly flawed."

But the scientists at the conference also supported the cold fusion findings of Brigham Young University professor Steven Jones, who detected neutron emission in small quantities. That discovery suggests that there are minute amounts of fusion occurring inside the palladium, a discovery which has few commercial applications but is of great scientific interest.

Jones, who initially worked with Pons and Fleischmann but was left out when the pair made their dramatic announcement in March, said he will be collaborating with Gai this summer. He emphasized that they will study his experiment, rather than the one conducted by Pons and Fleischmann.

"We'll be looking at the cold fusion reaction, in particular the Brigham Young phenomenon rather than that other one," Jones said. "That is, we'll be looking for neutrons rather than heat."

'I Dont Think the Story's Over'

Jones said that Gai has an extremely sensitive neutron detector which would help them better understand the way the neutrons are emitted from the reactions. The latest studies indicate that the neutrons are emitted in sharp bursts, a phenomenon for which there is yet no explanation.

"His detector will allow us to look at the bursts in much greater detail, so that we will be able to probe deeper [into] this phenomenon," Jones said. "We don't really understand how nature contrives to give us these neutrons, and that is the puzzle we have to unravel."

Meanwhile, Pons and Fleischmann, who declined invitations to the Los Alamos conference, remained in Utah to conduct additional tests. According to Brophy, they are attempting to clear up any mistakes they may have made in the first round of experiments and add additional data to the information they already have.

"They are aware of the appropriate criticisms of their experiments and are producing a report that will meet those criticisms," Brophy said. The report is expected to be out by mid-summer.

Brophy added that a second University of Utah team is conducting tests similar to the original Pons-Fleischmann experiment and so far has produced similar results.

The fusion confusion also continues outside of Utah. According to a Stanford University spokeperson, Stanford professor of Materials Science Robert A. Huggins insists that the heat energy released in his experiment could only be caused by fusion.

And in the past two weeks, separate teams in Sweden and Japan have announced they have reproduced the original Pons-Fleischmann experiment with the same results, leaving scientists as puzzled as they were when the controversy started.

As Silvera put it, "I don't think the story's over."