杏吧原创

SCIENCE has had its share of embarrassing moments. Take Piltdown man, the missing link in human evolution exposed as a fraud after 40 years. Or the Allan Hills meteorite, hailed by US president Bill Clinton in a televised announcement in 1996 because it seemed to contain evidence of life on Mars 鈥� only it probably doesn鈥檛.

But few scientific embarrassments raised temperatures quite as much as cold fusion. In 1989, University of Utah chemists Stanley Pons and Martin Fleischmann announced that they had, at room temperature in the lab, tamed the process that powers the sun: nuclear fusion. This would have been an almost unimaginable technological leap. But no one could reproduce the result, at least not provably, reliably, or to general satisfaction. With no convincing theory to back up the observations either, Pons and Fleischmann were ostracised. Cold fusion 鈥� and anyone still willing to work on it 鈥� was frozen out.

Fast forward 25 years, and thaw is in the air. You won鈥檛 hear the words 鈥渃old fusion鈥�, but substantial sums of money are quietly pouring into a field now known as low-energy nuclear reactions, or LENRs. Earlier this year, the US House of Representatives Committee on Armed Services declared it was 鈥渁ware of recent positive developments鈥� in developing LENRs and noted their potential to 鈥減roduce ultra-clean, low-cost renewable energy鈥� and their 鈥渟trong national security implications鈥�. Highlighting too the interest of Russia, China, Israel and India, it suggested the US could not afford to be left behind, and requested that the Secretary of Defense . Cold fusion seems to be coming in from the cold 鈥� but why?

Mainstream physics has long had a simple answer for cold fusion believers: no-can-do. Nuclear fusion means overcoming the hugely powerful electrostatic repulsion between atomic nuclei and forcing them to merge into heavier nuclei. That needs humongous temperatures and pressures. The dream of hot fusion is being pursued with vigour by the scientific establishment: at the International Thermonuclear Experimental Reactor (ITER) in the south of France, for example, and in a host of smaller projects.

But a small band of believers has never lost faith in cold fusion. Researchers at the US Naval Research Lab (NRL) in Washington DC, have long put small budgets and spare time into seeing whether nuclear reactions really can happen at room temperature. Graham Hubler started there, and is now director of the Sidney Kimmel Institute for Nuclear Renaissance at the University of Missouri in Columbia, a cold-fusion lab established in 2012 with $5.5 million of philanthropic funding. 鈥淲e鈥檙e convinced there鈥檚 some sort of energy source here,鈥� he says. 鈥淚 wouldn鈥檛 have taken this job if I didn鈥檛 feel that way.鈥�

鈥淚n Japan, they want to develop the technique to clean up nuclear waste鈥�

That energy source lies in deuterium, a form of heavy hydrogen found naturally in seawater, with nuclei composed of a proton and a neutron. Most incarnations of cold fusion are some variant on Pons and Fleischmann鈥檚 original: you take a rod of palladium metal, dunk it into a beaker of water enriched in deuterium, and pass a low current through a platinum wire coil also held in the beaker. The idea is that somehow this current loads deuterium on to the lattice of palladium atoms so forcefully that the deuterium nuclei begin to fuse together, releasing energy. Do this right, and a cubic metre of seawater would release the energy of 10 barrels of crude oil.

Ask , another former NRL scientist, whether the sort of room-temperature 鈥渉eat anomalies鈥� that Pons, Fleishmann and others claim to have seen in experiments are real, and he doesn鈥檛 mince his words. 鈥淵es 鈥� as in hell, yes,鈥� he says. Nagel now works at George Washington University in Washington DC, and recently set up a non-profit LENR lobbying association, called . 鈥淚 wouldn鈥檛 have done that if I didn鈥檛 think this was both real and important,鈥� he says. 鈥淭he results are out there, and people are ignoring them.鈥�

Credibility and acrimony

A cynic might say they are all too easy to ignore. 鈥淎t NRL we did 120 experiments in the first two years and got absolutely nothing,鈥� says Hubler. In the past year, however, the NRL team has made some experimental changes and produced six anomalous heat events. The overall success rate of just 5 per cent might be seen as a 鈥渂lack eye鈥�, Hubler admits, but he insists he knows researchers with much better reproducibility rates.

Such claims are mostly unverifiable: perceived commercial sensitivity means most replication attempts take place behind closed doors. 鈥淢ost of the people working on this have dollar signs in their eyes,鈥� says Hubler.

That is not without consequence, and if acrimony is a measure of research credibility, there is something in cold fusion鈥檚 new wave. Take Italian LENR researcher Andrea Rossi and his . For some years, Rossi has been testing a device he calls the Energy Catalyzer or 鈥淓-Cat鈥�, latterly with heavyweight financial backing. , CEO of the $2.2 billion private equity fund Cherokee Investment Partners, put more than $10 million into Leonardo through a subsidiary, Industrial Heat, that .

In April this year, things turned sour. Rossi filed a lawsuit in a Florida court against Industrial Heat, complaining that Darden and various other business associates had 鈥溾�� him and his company in an effort to 鈥渕isappropriate鈥� his intellectual property rights. Industrial Heat has , alleging that one of Rossi鈥檚 E-cat tests had been a 鈥溾��. Both sides deny any wrongdoing.

The saga has given renewed ammunition to cold fusion鈥檚 critics in the US and Europe. In Japan, however, things have been proceeding more quietly 鈥� initially with a rather different end in mind than generating energy. In 2002, researchers from Japan鈥檚 multinational Mitsubishi Heavy Industries (MHI) claimed to have used LENR techniques to 鈥渢ransmute鈥� toxic, radioactive elements, such as those produced in conventional nuclear fission reactors, into other, less dangerous elements. That work is still going on. 鈥淢HI wants to develop the technique to clean up nuclear waste,鈥� says of Tohoku University鈥檚 Clean Energy Research Lab.

In 2013, researchers from Toyota Central Research and Development Laboratories reported successfully replicating the original experiment. In a technical review published in December last year, that 鈥渢ransmutation from cesium (Cs) to praseodymium (Pr), from barium (Ba) to samarium (Sm), from strontium (Sr) to molybdenum (Mo), etc., has been observed鈥�. The processes have, of course, been patented. The Japanese government, keen to decontaminate the site of the Fukushima nuclear reactor meltdown, is now providing some funding for academic LENR research.

A decade ago, researchers at the NRL tried to reproduce the Mitsubishi results, and sent a team to Japan to learn how to transmute elements first hand. NRL鈥檚 David Kidwell, who carried out tests on the Mitsubishi lab equipment, was not given permission to talk to New 杏吧原创 directly, but NRL documents authorised for public release suggest another explanation for the results: contamination. They declare that 鈥渆nvironmental surveys at MHI by NRL and MHI found praseodymium in key areas of laboratory鈥� and the 鈥減resence of praseodymium may have other explanations than transmutation of Cs鈥�. Yasuhiro Iwamura, who led the Mitsubishi team, rebuts the NRL explanation and .

Post-Fukushima, Japan has also seen a wave of interest in LENR for energy generation, with Mitsubishi, Toyota and Nissan all investing money. Last year, the Japanese government鈥檚 announced a programme called 鈥淓nergy and the Environment New Leading Technology鈥� that called, among other things, for research into technologies that induce heat reactions between metals and hydrogen. Hideki Yoshino, a language schools magnate, has set up a company called to research 鈥渃leaner, safer, and more abundant resources such as solar, geothermal, LENR (also known as cold fusion), and wind to supply our energy needs鈥�.

Clean Planet is the driving force behind the Tohuku Clean Energy Research Lab, where Kasagi works. Kasagi鈥檚 aim is to bring a device producing anomalous heat to market by the Tokyo Olympics in 2020. 鈥淓xpected heat output might be up to several tens of watts or more,鈥� he says. As yet, he doesn鈥檛 know how reliably this heat will be produced, but he is working on theories that might help improve reproducibility. 鈥淢y deep interest is to clarify how the nuclear reaction can occur,鈥� he says.

That remains perhaps the biggest stumbling block: explaining how LENR is supposed to work when physics says it can鈥檛. 鈥淚 dismiss most of the theories out of hand,鈥� Hubler says. Nagel feels similarly. 鈥淲hen it comes to the crunch, there鈥檚 no theory that overlaps sufficiently with experimental data,鈥� he says.

Some ideas have not been entirely quashed. of the Massachusetts Institute of Technology has suggested that a deuterium-loaded palladium lattice contains vacancies where two deuterium atoms can become squeezed together, sometimes resulting in fusion.

Another idea was the work of Allan Widom, a theoretical physicist at Northeastern University in Boston, and Lewis Larsen, a theoretical physicist and now CEO of Lattice Energy, a company aiming to create a functioning LENR device. Widom-Larsen theory, as it is known, makes an interesting statement about cold fusion: it isn鈥檛 fusion.

Instead, the anomalous heat generation comes about because, when infused with deuterium and possibly other contaminants, a palladium surface generates a varying electromagnetic field that shifts electrons about, in turn releasing neutrons. These are absorbed by other nearby atoms, transmuting them and causing them to release gamma-ray photons that are absorbed by other electrons, which radiate the extra energy as heat.

at NASA鈥檚 Langley Research Center in Virginia thinks the theory is a 鈥渞ich concept鈥� that could prove extremely fruitful. 鈥淟ENR is only one of its applications,鈥� he says. It doesn鈥檛 rely on new physics, and makes some very specific predictions 鈥� not that those predictions have been properly tested yet. Zawodny made his own attempts, but they were 鈥渂rief and low budget鈥�, he admits. The ongoing controversy surrounding Rossi鈥檚 E-Cat has made getting funding for further experiments difficult, he says.

Besides Zawodny鈥檚 inconclusive results, Widom and Larsen have graphs that purport to show a match between their theoretical predictions and experimental observations of how quickly various transmutation products are created. But this isn鈥檛 terribly convincing to critics, because it is 鈥渁fter-the-fact鈥� fitting to data from controversial experiments carried out years ago.

of the University of Illinois at Urbana-Champaign did those experiments. Now emeritus, he is still active. He had a patent granted in 2012 for a process called 鈥渄islocation site formation鈥�, which describes loading and unloading of isotopes of hydrogen into thin films in order to provide, among other things, 鈥渘uclear reaction processes鈥�. Miley claims to have a working LENR technology that produces hundreds of watts of energy, but doesn鈥檛 want to say any more than that. 鈥淚t is premature to discuss this new work in any detail,鈥� he says.

No risk, no reward

Such reluctance to share doesn鈥檛 help to dispel scepticism, Zawodny laments. 鈥淭he cold fusion stigma still remains, albeit in a weakened form,鈥� he says. 鈥淲e鈥檙e frustrated,鈥� says Hubler. 鈥淚f we had just one-thousandth of the money going into hot fusion鈥︹��

That comparison is somewhat problematic. It鈥檚 true that hot fusion isn鈥檛 going anywhere fast either. ITER is beset by delays and cost overruns, and won鈥檛 be working fully until the 2030s, while other projects are hardly out of the starting blocks. But at least we know why and how hot fusion works 鈥� it鈥檚 what powers the sun, after all. Making it work on Earth is simply a monumental engineering problem.

Hubler鈥檚 unspoken hope is for a funded fundamental physics programme that would methodically dissect cold fusion experiments to work out what is going on in the interesting 5 per cent. At the moment, he admits, there is too much trial-and-error experimentation coupled with wild speculation by theorists who often tend to ignore the details of experiments carried out so far 鈥� and indeed sometimes the known laws of physics.

Zawodny sees three vital tasks ahead. First, independent validation of existing methods for producing anomalous heat. Second, theoretical work to explain as much of the body of observations as is possible with one theory. Third, experimental testing of what a suitable theory predicts. 鈥淚 think you must have all three,鈥� he says. The sticking point, as he sees it, is that most people want hard, reproducible proof that the effect is real before they stump up any cash for research. 鈥淭here are few rewards without risk,鈥� he says.

鈥淥ne theory makes an interesting statement about cold fusion: it isn鈥檛 fusion鈥�

Some think it is worth a punt. Despite Cherokee鈥檚 aborted investment in Rossi鈥檚 technology, Woodford Investment Management in Oxford, UK, has recently funnelled 拢35 million into Industrial Heat. The company acknowledges that this is a 鈥渉igh risk area鈥�, but says it has done two years of due diligence and wants to build a suite of LENR technologies from what it sees as the most highly regarded people in the field. 鈥淲e analysed numerous reports from a variety of scientists as well as data on investigations that had been undertaken by several government departments around the world,鈥� a spokesman told New 杏吧原创.

Woodford鈥檚 strategy is to take candidates showing real evidence of success, develop and optimise them, and then gain independent third-party verification of their findings. 鈥淚t is an area that has been met with much scepticism and we are certainly not blind to this,鈥� the spokesman says. 鈥淗owever, the evidence we have seen to date, coupled with the potential market opportunity, suggests to us that it is an area that is worthy of further investigation.鈥�

Clearly, the House Committee on Armed Services feels the same way, but the latest signs are that the Secretary of Defense鈥檚 report is delayed and won鈥檛 now be presented next week as planned. We must wait a little longer to hear how warm his words will be.

This article appeared in print under the headline 鈥淚n from the cold鈥�