Fusion Claims Are at Odds With Basic Laws of Physics
Charles A. Barnes is a highly respected physicist at Caltech, and like others in his field, he believes that he understands the basic laws of physics that govern such fundamental reactions as the melding of two atoms into one through nuclear fusion.
Many of the best minds in science have studied that process extensively over the last four decades, and the laws that govern it are considered among the most elemental in science.
And that is why people such as Barnes are having trouble sleeping these days.
If two chemists really have produced fusion with a simple table-top apparatus, some of the fundamental laws of nuclear physics, based on years and years of research, are simply wrong.
It is as though a banker were suddenly told that two plus two no longer equals four.
For physicists, the world began to go a little crazy nearly three weeks ago when B. Stanley Pons of the University of Utah and Martin Fleischmann of the University of Southampton, England, announced that they had achieved nuclear fusion with a table-top apparatus. Furthermore, the two electrochemists claimed to have produced surplus energy, which would make them the first scientists in the world to produce more energy through fusion than it took to run their experiment.
But, as UCLA physicist Robert Conn noted a few days after the Utah announcement: “It doesn’t make any sense.”
Nonetheless, profound skepticism has given way slightly in the face of growing evidence that Pons and Fleischmann are on to something, although no one is sure what.
On Monday, two separate institutions reported confirming two different and critical parts of the Utah experiment. Texas A&M; claimed to have produced excess heat with a similar device, and the Georgia Institute of Technology reported that scientists there had detected neutrons emitted by another similar experiment, suggesting that nuclear fusion was indeed going on.
The problem is, none of the figures add up, according to the laws of physics. If the Utah experiment is valid, as suggested by Monday’s reports, then something quite extraordinary is happening.
‘All Bets Are Off’
And if that is the case, Barnes said Tuesday, “all bets are off.”
On the surface, fusion is a deceptively simple process, and the result should produce certain byproducts. In the Utah experiment, there are claims that some of those byproducts were produced, but not in the right numbers. If even a few were produced, it suggests strongly that nuclear fusion was going on, but if nuclear fusion was going on, the numbers should have been different.
It is as if two bicyclists collided head on with such force that their vehicles were left in a tangled mess. But when workers pulled the bikes apart, they could only find three wheels. The wreckage would suggest a fierce accident, but what happened to the other wheel?
And in Utah, what happened to the subatomic particles that should have subjected Drs. Pons and Fleischmann to a fatal dose of radiation if they were actually getting four watts of excess energy out of their device, as they claimed?
The Utah experiment purportedly fused the atomic nuclei of a heavy form of hydrogen, called deuterium. When two deuterium nuclei, called deuterons, fuse, “there are only three reactions possible,” Barnes said.
Possible Reactions
About half the time, two deuterons should produce one atom of helium-3, and one neutron, which should be fired out of the process with the energy of 2.45 million electron volts. Heat should also be released.
The other half of the time, the fusion should produce one proton and a radioactive form of hydrogen, called “tritium,” which should be easily detectable.
And then, about one time out of a million, the fusion should produce a rare type of helium-4 and release a highly energized gamma ray of 23.5 million electron volts.
All of those byproducts should be readily identifiable by experts with modern equipment, and the numbers should be so large that there would be no ambiguity. Neutrons released with helium-3, for example, should number at least 100 billion per second, all with the energy of 2.45 million electron volts. That is a “signature” that is difficult to mistake, and it would be a clear indication that nuclear fusion was taking place.
On that point, everybody agrees.
The problem is that Pons and Fleischmann, who have now been joined by scientists at Georgia Tech, claim that they did detect neutrons, but not nearly as many as they should have. The Georgia Tech scientists said they detected about 600 neutron counts per hour--far below the trillions of trillions that should have been expected, but 15 times higher than the natural background rate of 40 counts per hour. Pons and Fleischmann said they also detected neutrons, but only about three times the background rate.
But what happened to all the other neutrons?
“No one has as yet come up with a plausible explanation for the suppression of the neutron rate,” UCLA’s Conn said.
Pons has speculated that the neutron count is low because instead of releasing a neutron, the reaction is producing helium-4 instead of helium-3. Scientists, however, see no reason why that process should take place.
Others have suggested a wide range of possibilities ranging from tiny chemical “explosions” inside the apparatus to some combination of nuclear and chemical reactions. Peter Newmark, deputy editor of the British scientific journal Nature, said he has received many letters from other scientists suggesting alternative explanations for the heat released by the Utah experiment.
“They are from people who say, ‘This is what we think might be going on,’ ” he said in a telephone interview.
Waiting for Proof
No decision has been made on publishing the letters because, like many others, Newmark is waiting for someone to prove beyond reasonable doubt whether or not the Utah experiment was valid. Preferably, that proof will be accompanied by a reasonable explanation for the physics behind the process.
It all leaves experts such as Barnes very uneasy.
The low neutron count reported by Pons and Fleischmann has left him very “uncomfortable” because it could have resulted from a small error in the measurement.
The higher count reported by Georgia Tech is a little harder to dismiss, but it, too, is far below what it should be if fusion is taking place.
But if any neutrons, regardless of the number, are being emitted by the experiment, something very mysterious is going on.
“It would be very exciting for science,” Barnes said.
But physicists have been subjected to many claims of miracles through fusion in the past, only to see those claims disproved. The allure, noted Keith Thomassen of the Lawrence Livermore Laboratory, is undeniable.
Referring to the apparatus demonstrated by Pons and Fleischmann during their press conference of March 23, Thomassen fumed: “You see this stupidly simple little thing that can solve the world’s energy problems. It’s a nice dream, but there’s a long ways to go.”
James Mahaffey, who led the five-member Georgia Tech team, sees it a little differently:
“The scientific and engineering prospects are just limitless right now,” he said in the official announcement from Georgia Tech. “It’s like being there when fire was discovered.”
