Tuesday, December 13, 2011

Extraordinary claims

What are we looking for in seeking to come to some kind of verdict on the claims that have been made over the past twenty years relating to purported LENR phenomena?  What are the nature and implications of such a verdict? And what do we mean by LENR, exactly?

Anyone who takes even a little interest in the field will no doubt have his or her own criteria and standards for adjudicating the claims.  A physicist or chemist will have a demanding set of requirements and will set a very a high bar before allowing something onto the record as evidence.  A child will ask his or her parents what they think about it.  And an adult who is not an expert in some relevant field will have yet another set of criteria, particular to him or her.  The requirements of the scientific community will obviously differ from those of the public.  As Charles Beaudette points out in his book Excess Heat, science is not a democratic endeavor, to be sorted out through a poll of various scientists, let alone of the general public.  Researchers try to remain aloof of fads, politics and public opinion and, to a certain extent, of the opinions of one another.  This kind of professional independence is crucial to the success of scientific activity.

But research is a profoundly human affair, as Kuhn and Feyerabend have shown.  It has its own fads and politics, and occasionally there is a shakeup, where something that was discounted or overlooked is seen in an entirely new light, and new luminaries arise.  Not only does the public have an interest in scientific activity, then, it also has its own side to its relationship with the scientific community. Ideally that relationship would not be allowed to devolve into a paternalistic one, like that of a parent to a child.  The public should not uncritically receive the criteria to be used in judging the merit of a claim, to be handed down to them from experts.  In allocating public money, members of funding institutions must arrive at criteria of their own, suitable to the purpose at hand, for determining whether a new area of research is promising and should receive money.  And while academics must remain free to pursue knowledge for its own sake, independent of whether it is encouraged by public institutions or not or shows much promise of yielding practical results in the near or medium term, public institutions in their turn should give the general welfare a central place in arriving at decisions.

A refrain sometimes heard among skeptics of the LENR research is that "extraordinary claims require extraordinary evidence," a phrase that goes back to Carl Sagan, and, before him, Marcello Truzzi.  What this seems to mean in such a context is that it doesn't matter how much incremental evidence has been gathered in support of the purported effects; in order for such individuals to be convinced, there must be evidence that is an order of magnitude or more above statistical error, something seen that is undeniable.  I take no position at this point as to whether such evidence has already been provided and is simply being ignored.  And perhaps we can allow that such a standard of evidence would be a proper one for researchers in many cases.  Although I must admit that the "extraordinary claims" phrase begins to take on the sound of a kind of dogma and its implications become less and less clear after hearing it several times, I can appreciate where the LENR skeptics are coming from and why they would be inclined to adopt such a standard for themselves.  There are many instances in the history of science where there has been a report of some remarkable breakthrough that attracted a lot of attention but which later turned out to be unfounded.

Be that as it may, the standard of evidence that I propose for the public and for funding agencies is a very different one.  Rather than requiring extraordinary, unimpeachable evidence, I propose that what is needed instead for evaluation of the LENR claims by the general public is a simple, straightforward, prima facie case for its existence in some form or another.  If, after looking at the evidence, one decides that there is good reason to believe that something unusual and promising is going on, then this should be quite sufficient as far as funding and related decisions are concerned.  And in the calculations that are used to build or undermine such a prima facie case, it will not be necessary to bring to bear the full arsenal of statistical analysis; well-conceived back-of-the envelope arithmetic will be fine.  Those among the public who did well in their college physics and math classes will be more than adequately prepared to assess whether such a prima facie case exists.

And what is it that we are looking for, precisely, when we talk about "low energy nuclear reactions"? How we answer this question is important.  Following are some possibilities:
  1. Significant levels of fusion, in which two atomic nuclei overcome the Coulomb barrier to fuse together to form a new element and release gamma rays, neutrons and helium -- sometimes called "nuclear ash."
  2. The formation of so-called heavy electrons, which give rise to inverse beta decay and then a cascade of unstable isotopes followed by their decay into stable isotopes.
  3. Energy emerging from the system above and beyond that put into it at levels that cannot be accounted for by a chemical reaction of some kind.
  4. A process that can be repeated and verified in other labs.
For which kind of evidence should we be looking in determining whether there is a prima facie case?  Items 1 through 4 are not necessarily mutually exclusive, and I think we should be looking for all four of them.  If for some reason we must choose between them, however, following Beaudette we should not hesitate to adopt item 3 as our fixed point.  In this regard, I argue that for our purposes it matters not in the slightest whether sufficient evidence is found in support of items 1, 2 or 4.  If we find enough promising evidence for item 3, we should be confident at that point that we will have established a prima facie case for LENR, against all claims not directly relating to item 3 to the contrary, even by those with far greater qualifications in physics or chemistry than us.  For even the most qualified of individuals can become fixated on a detail of derivative importance which he or she has mistaken for the primary touchstone when a phenomenon is poorly understood.  And we should be like the honey badger in approaching vocal criticisms of this methodological decision.  In insisting on item 3 like this, we are not doing anything particularly controversial or radical; we are simply keeping attention focused on the principle of conservation of energy.

Regardless of what we find in connection with item 3, it is possible that we will come across solid evidence of items 1, 2 and 4 as well.  Clear results supporting 1 and 2 would also be sufficient to establish a prima facie case.  (Item 4 isn't really of the same type as the others, but it seemed like a good detail to mention.)

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