Introduction

The world community is truly at a crossroads like never before faced in the history of our civilization. If we continue business-as-usual with the consumption of fossil fuels, then, according to the 2014 edition of the Intergovernmental Panel on Climate Change (IPCC)'s climate change report, grave consequences will almost surely ensue, including rising sea levels, extreme temperatures, flooding, drought, agricultural losses and, quite likely, violent conflicts among human societies. Delays may have already cost the world society USD$8 trillion.

Some who distrust the scientific consensus on climate change have taken heart at an apparent leveling off of world temperatures in the past few years. But it is now clear that this respite is short-lived, since 2014 is on track to be the hottest year on record.

On 12 November 2014, China and the U.S. reached a historic agreement to limit greenhouse gases. Other nations will hopefully follow suit. But even these cuts may not be enough. So how are we going to meet these goals?

Substantial progress has been achieved in photovoltaic (solar panel) technology, and also in wind energy. But these sources cannot be the ultimate answer, since they depend on vagaries of weather and geography. Thus the world community badly needs some other industrial-scale green energy source that is relatively safe and clean.

Fusion energy

Nuclear fusion, the energy that powers the sun and stars, is certainly an attractive option, since the fuel (ordinary water) is free, and it produces neither greenhouse gases nor long-lived radioactive waste.

The problem is that nuclear fusion normally only occurs at extremely high temperatures (millions of degrees). Scientists have been working on taming fusion for decades. The two most common research approaches are tokamak reactors, in which the reaction chamber is shaped like a torus and the nuclear material is heated and confined by magnetic force; and inertial confinement reactors, in which an array of high-powered lasers aimed at a small pellet of hydrogen isotopes heats it, in a tiny fraction of a second, to millions of degrees and initiates nuclear reactions. Billions of dollars have been spent on developing both of these schemes, mostly by large government-funded laboratories, but even the leaders of these projects acknowledge that we are decades away from commercial realization.

In October 2014, U.S. aerospace company Lockheed Martin announced a "technological breakthrough" in developing power based on nuclear fusion, using a magnetic confinement device of a different design than the tokamak. The firm's current target is to build a 100-megawatt nuclear fusion reactor only about 2 meters by 3 meters (seven feet by 10 feet) in size, within five years. These dimensions are smaller by a factor of ten than the ITER prototype reactor under construction in France by an international government-funded collaboration. Sadly, few details are available, so experts in the field are generally very skeptical that it will work. See our earlier Huffington Post article for additional details.

Low energy nuclear reactions (LENR)

In March 1989, Martin Fleischmann and Stanley Pons of the University of Utah announced, in a hastily convened press conference, that they had achieved nuclear fusion (dubbed cold fusion) in a simple tabletop apparatus. But after numerous other research teams failed to replicate their experimental results, and after theoreticians argued that the claimed effects seemingly violated well-known principles of physical theory, Fleischmann and Pons were disgraced, and the episode became a textbook case of bad science. One scientist termed it the scientific fiasco of the [20th] century. Similarly, Time magazine listed "cold fusion" as one of the 100 worst ideas of the [20th] century.

But a funny thing happened on the way to the Fleischmann-Pons public hanging. Although the majority of researchers failed to reproduce the claimed anomalous heating effect, a few did observe this, at least in some experimental runs. A small community of researchers have pursued this research (now known as low-energy nuclear reactions or LENR) to the present day, with over 150 peer-reviewed papers reporting excess heating in similar experiments. At the request of some of these researchers, in 2004 the U.S. Department of Energy convened a review panel to consider the more recent evidence, but it concluded that LENR was not yet persuasive enough to initiate a new research program.

In the past few years, activity in the LENR arena has picked up considerably, with over 20 organizations involved, ranging from universities, national laboratories and NASA to corporations such as Mitsubishi and Toyota. Notables such as Bill Gates and former U.S. Secretary of Energy Steven Chu have expressed interest. Here are two particularly interesting developments:

Brillouin Energy

Researchers at Brillouin Energy Corp. of Berkeley, California are developing what they term a controlled electron capture reaction (CECR) process. In their experiments, ordinary hydrogen is loaded into a nickel lattice, and then an electronic pulse is passed through the system, using a proprietary control system. They claim that their device converts H-1 (ordinary hydrogen) to H-2 (deuterium), then to H-3 (tritium) and H-4 (quatrium), which then decays to He-4 and releases energy.

In one paper on their website, the Brillouin researchers found that "excess heat is always seen" when tuned pulses are present. They report being able to obtain excess heat using ordinary water with hydrided nickel, palladium or copper. In a second paper, the researchers assert that the excess heat is "measurable and repeatable."

Additional technical details are given in a Powerpoint presentation, a report summarizing their "quantum reaction hypothesis," and in a patent application. Their patent application reads, in part, "Embodiments generate thermal energy by neutron generation, neutron capture and subsequent transport of excess binding energy as useful heat for any application."

Andrea Rossi

In 2011, Andrea Rossi, an Italian entrepreneur with a somewhat checkered past, claimed that he and his research staff had developed a new LENR process, which they called the Energy Catalyzer or E-Cat for short. Their design consists of a ceramic or steel shell, to which a "fuel" consisting of hydrogen, lithium and nickel has been added to a sealed interior chamber. The apparatus is electrically heated from the outside to several hundred degrees Celsius. When this is done, according to Rossi and his research associates, the device produces significantly more heat energy than was input, much more than can be explained by ordinary chemical reactions, and, surprisingly, emits no significant radiation and produces no radioactive byproducts.

In May 2013, a team of Italian and Swedish scientists (not including Rossi) released a technical paper describing an experimental analysis of the E-Cat system. This attracted significant attention, although some criticism as well.

In October 2014, the same team of Italian and Swedish researchers released a new paper, entitled Observation of abundant heat production from a reactor device and of isotopic changes in the fuel. This paper describes a much more sophisticated experiment, with better equipment. It claims substantial power output, with a "coefficient of performance" (ratio of output heat to input power) of up to 3.6. The experiment was performed at an independent laboratory in Lugano, Switzerland.

As we mentioned in a previous

, the most intriguing results in the 2014

are the before-and-after analyses of the "fuel," which found an "isotopic shift" had occurred in this material. In particular, the team found that lithium-7 had changed into lithium-6, and that nickel-58 and nickel-60 had changed to nickel-62. Here, for example, are the results from the Secondary Ion Mass Spectrometry analysis:

Input "fuel" Output "ash" Lithium-6 8.6% 92.1% Lithium-7 91.4% 7.9% Nickel-58 67.0% 0.8% Nickel-60 26.3% 0.5% Nickel-61 1.9% 0.0% Nickel-62 3.9% 98.7%

Such isotopic changes can ONLY occur if real nuclear reactions are taking place -- they do not take place with any ordinary chemistry as we understand it.

A detailed critique of the Lugano report has been posted by Michael McKubre of SRI, a well qualified researcher who has also worked on LENR experiments. Another team of researchers is planning an independent test of some aspects of the experiment.

The latest development here is that a

, filed by Rossi and his industrial partner Industrial heat LLC in April 2014, has just been made public. No isotopic results are presented in this document, but it does include some rather startling heat output data, as shown in this table. Here "COP" means "coefficient of performance," namely the ratio of output heat to input energy.

Run no. Description COP 1 Single E-Cat (failed) 2 Single E-Cat 5.6 3 Single E-Cat 2.9 4 Array of 18 E-Cats 11.0

Needless to say, an eleven-to-one ratio of output power to input power, if it can be confirmed, is a remarkable advance. Some background on Rossi and his work is given in

by journalist Mats Lewan, and in

by Vessela Nikolova.

Experiment versus physics

In spite of the results above, how these phenomena can happen is a deep mystery (although possible theoretical explanations have been advanced for both the Brillouin and Rossi experiments). To begin with, the energy levels in the experimental apparatus used in these experiments seem nowhere near high enough to overcome the Coulomb barrier and trigger true fusion reactions as physicists have classically understood them. What's more, little or no radiation or has been observed, as would normally be expected if true nuclear reactions are taking place.

As the authors of the Lugano paper lamented, "It is certainly most unsatisfying that these results so far have no convincing theoretical explanation," although they argue that "the experimental results cannot be dismissed or ignored just because of lack of theoretical understanding."

Indeed, several physicists are skeptical of these results precisely because they appear to contravene physical law.

Reproducibility and the scientific process

The present authors are as intrigued about these results as anyone. If upheld, their significance can hardly be overstated, particularly if they can be parlayed into practical, safe, green energy solutions for the world's economy. What's more, many other researchers worldwide can and should participate in learning more about these remarkable phenomena. Clearly there are numerous aspects of these experiments that deserve significantly more study, whether or not true nuclear processes are occurring.

But, as scientists, we have to express strong words of caution. After all, the results mentioned above are, for the most part, still not published in respected, rigorously peer-reviewed journals. Furthermore, although many details are given in the reports and patent applications mentioned above, some key details are missing, making it still difficult to reproduce these results in separate experiments by completely independent research teams.

For example, Rossi and his team have still not stated the precise composition and construction of the "fuel" used in the E-Cat reactors. The Lugano report authors reported that they used a small envelope of fuel provided by Rossi; the report included mass spectrometer analyses of the fuel, but that is all. The same is true for the E-Cat cylinder used in the experiment -- this was provided by Rossi, and while some information has been given, there are doubtless details about its construction that remain hidden. Perhaps Rossi is trying to protect some proprietary secrets, but how can other teams hope to reproduce his team's claimed results without complete details (or at least enough to perform a completely independent experiment)?

Reproducibility is, after all, a key feature of scientific research, and many fields are currently experiencing difficulties in this arena. One issue is the increasingly pervasive practice, certainly present in LENR, of publishing results and theoretical analyses mainly on arxiv.org or other preprint servers, often without rigorous peer review. Another concern is reporting only successful experiments (although we are encouraged to see that in Rossi's patent application, he mentions that his first run failed). In the pharmaceutical world, these concerns have given rise to the all trials movement, which is encouraging the results of all trials to be publicly posted.

Along this line, even in the field of scientific computing, some are concerned that because of relatively lax standards in the field, large-scale computing experiments are not always reproducible. See our Huffington Post article and a technical paper for further details.

These are not just nit-picking concerns. It is precisely because the recent LENR developments are so potentially important that the well-established scientific protocol of fully-detailed experimental papers, reproducible by others (and successfully reproduced by others), accepted and published in respected peer-reviewed journals, should not be circumvented. As Carl Sagan reminded us in his book A Pale Blue Dot, "Extraordinary claims require extraordinary evidence."

Breakthroughs that failed

As one more possibly unwelcome bucket of cold water, we must point out that several very high-profile "breakthroughs" in recent years have at least partially evaporated. Here are three prominent examples:

In September 2011, an international team of researchers at the Gran Sasso Laboratory in Italy announced that neutrinos emanating from a particle accelerator at CERN (near Geneva, Switzerland) had arrived 60 nanoseconds sooner than if they had traveled at the speed of light, thus directly challenging Einstein's relativity, one of two cornerstones of modern physics. However, after months of careful checking, a subtle flaw was found in the measurement apparatus, and Einstein was vindicated. The episode was a major embarrassment for the research staff, and at least one resignation resulted.

In March 2013, researchers at CERN announced that they had confirmed that the particle discovered a few months earlier with the Large Hadron Collider was indeed the long-sought Higgs boson. This was hailed as a momentous discovery, decades in the making. But more recently, scientists have raised questions as to whether the particle discovered is really the Higgs -- it might be some other particle or particles masquerading as the Higgs; additional research studies are required.

In March 2014, researchers at the Harvard-Smithsonian Center for Astrophysics announced with considerable fanfare that they had detected the unmistakable fingerprint of the long-hypothesized inflationary epoch, a tiny fraction after the big bang. Sadly, within a few weeks these researchers acknowledged that their experimental results might possibly be due to dust in the Milky Way, pending better data.

So being careful is more than just a bucket of cold water. It is good common sense.