In 1989, two physicists whose reputations had hitherto been impeccable made a startling claim: using a tabletop apparatus costing only a few thousand dollars, they had achieved nuclear fusion. "Cold fusion," as it is generally known, was not a new idea; the first claims had been made in the 1920s, and the phrase was coined in the 1950s. But it was a fringe, kooky idea until Martin Fleischman and Stanley Pons made their announcement. Their device consisted, essentially, of a cathode made of the rare metal Palladium, and an anode of nickel, immersed in heavy water, plus a calorimeter to measure the heat produced.
Fleischman and Pons made this assertion at a press conference, rather than in a scholarly paper, and they refused to disclose all the details of their apparatus because they had patent applications pending. This bad scientific form helps explain why the responses from other physicists were so nasty. When they attempted to replicate the Pons-Fleischman experiment and got no results, they dismissed cold fusion as "pathological science" and some accused Pons and Fleischman of fraud.
At that point most of the world lost interest in cold fusion, but not everyone. A few physicists who tried their own versions of the Pons-Fleischman experiment got "anomalous heat" from their devices, too. Some have reported detecting the radioactive isotope tritium, which would prove a nuclear reaction of some kind. So over the past 23 years there has been a steady trickle of claims, and enough interest by professional scientists to sustain regular conferences. Several governments have funded research, as have Toyota and a number of venture capitalists. The governments of India and Italy have made a particularly strong commitments. All told, well over $100 million has been spend on cold fusion research.
It is hard to know what to make of this. On the one hand, the claims of excess heat from these devices pile up, now in the thousands, and many scientists remain committed. On the other hand, the whole business has the feel of perpetual motion. This is from a nice article Charles Platt wrote for Wired:
Like Nigel Packham at Texas A&M, Claytor tested for tritium, partly because Los Alamos owns some of the most sensitive tritium detectors in the world. He found tritium sometimes at 100 times background levels. He also found neutrons. "We would see a burst," he recalls, "once in a while."Always the evasions, the excuses, the inability to produce these effects reliably, the secrecy necessary for commercial reasons or to avoid censorship. Palladium, cold fusion researchers say, is a "funny metal," and whether it works seems to depend very precisely on the kind and amount of impurities. Even the biggest enthusiasts report those "bursts," sometimes lasting for days but never indefinitely, and never predictably. One recent article by a cold fusion enthusiast puts it this way:
Since I'm still wondering if there's a hidden reason why I can't see his lab, I ask if his work is continuing. "To some extent," he says vaguely. "But it's not being funded anymore, because even though our results can't be explained by error, we can't produce them consistently. Therefore, we can't go to the program managers and ask them to give us money."
Whatever it is that makes LENR (cold fusion) work, the phenomenon seems to have a mind of its own, and decides when to turn itself on and off. The commercial work that seems closest to a resolution of these problems are holding their cards close to their chests, hoping to be first to enter a huge and lucrative market.Reliability is key to the definition of good science. Real scientific findings are replicable; they work the same way every time you try them, in every laboratory, or at least they work a statistically predictable percentage of the time. Physics has a bad history of alleged effects that appear sometimes but can't be repeated; "n-rays", for example, or esp, a whole garbage heap of discarded and disproved notions. So most physicists refuse to take cold fusion seriously on this basis alone.
Cold fusion also has a huge appeal for conspiracy theorists. People complain openly about government censorship, and the refusal of most countries to issue patents for cold fusion devices. On some web sites you can still find claims that cold fusion really does work, but this has been suppressed by a conspiracy in which the big oil companies figure prominently. Why governments would sign onto this conspiracy, especially those in oil-poor countries like India and Japan, is a mystery to me, but the vagueness and disinformation surrounding cold fusion certainly invites such speculations.
I remain intrigued, but I am skeptical of cold fusion. I can accept that weird things sometimes happen when you put a Palladium electrode in heavy water, but I don't see why that would have to be cold fusion. After all, cold fusion would violate a whole raft of our physical laws, so why not some other law instead? I don't have any problem with the funding of cold fusion research, since weird events continue to be detected around the world. But I doubt the answer to our energy needs is here.