The case against cold fusion experiments

The Fleischmann-Pons press conference was 30 years ago this month! I didn’t pay much attention to it at the time—I was, after all, in preschool—and then I heard hardly a word about cold fusion in college, or in physics grad school, or as a professional physicist. Finally, a few years ago, I was surprised to read that people were still researching cold fusion, now also known as LENR (Low Energy Nuclear Reactions). So I started reading about it. I immediately found sources making a strong-sounding argument based in theoretical physics that it cannot possibly exist, and other sources making a strong-sounding argument based in experiments that it does in fact exist. …Well, one of these two arguments is wrong!

This blog has been all about the theoretical physics case against cold fusion. The case is simple (…well, it’s simple if you have a strong background in theoretical physics!), but is it correct? Does it have any loopholes? Is the underlying theory uncertain? Nope! After countless hours of reading papers and doing calculations and writing blog posts, I find the theoretical case against cold fusion more convincing than ever. That leaves the other possibility: maybe the experiments purporting to see cold fusion are all wrong?! This is of course the mainstream scientific consensus on cold fusion, but the detailed story of exactly how and why the experiments are alleged to be wrong is a bit hard to find—mostly buried in obscure technical papers and websites. Here I’ll do my best to summarize and evaluate these arguments.

Continue reading

The dangerous dark side of cold fusion research

Maybe the previous post would have been a nice way to close out this blog, but I’ll do one last post, because I saw something that just really horrified me. In this otherwise nice and unremarkable article about the low proliferation risks of conventional (tokamak) nuclear fusion, a commenter bragged that cold fusion is awesome because it has such a low nuclear proliferation risk. And I was thinking: Are you kidding?? How on Earth could you possibly think that???

I do, in fact, think cold fusion has a low proliferation risk, for the simple reason that cold fusion doesn’t exist in the first place! But I don’t want to just shrug and leave it at that. For people like me interested in research ethics, I think the cold fusion community is an interesting case study, in that the community apparently has no culture of research ethics whatsoever, despite what I see as clear-cut reasons for extreme caution, up to and including terrified paralysis! So I wrote this post to quickly summarize why I feel that way.

Continue reading

Is there a plausible theory of cold fusion? NOPE.

Well, having spent a LOT of time looking into it, I feel comfortable saying: Nope! There is no plausible theory of how cold fusion could possibly work. Fitting cold fusion into the known laws of physics is like fitting a square peg into a round hole. Over the past 30 years, people have tried hammering that peg from every angle, some with incredible ingenuity and persistence. But none of the proposals to date can actually explain cold fusion, and there does not seem to be any way to fix any of them.

There is an elegant explanation here: Cold fusion cannot be explained by known laws of physics because there’s no such thing as cold fusion! Something is wrong with the experiments—more likely, many things, with different experiments having different problems.

[UPDATE—I just wrote a whole separate blog post making the case that a reasonable person can (and should) doubt the body of cold fusion experimental results, even ignoring the theoretical aspects: The case against cold fusion experiments]

Readers may object: Maybe cold fusion cannot be explained by known laws of physics because the known laws of physics are wrong? I can see the appeal of this argument, but there’s much less to it than meets the eye. I’ll copy some text from my first blog post:

[According to this argument], cold fusion is an experimental observation, and experiments are the ultimate arbiter of truth in physics, and if theorists cannot explain an experiment, then they should get to work finding a better theory.

This sounds very nice. It sounds like The Scientific Method like we all learned in school and read about in Karl Popper. Who could object to The Scientific Method?

It sounds nice, but it’s wrong! It is rational to give experiments a complete veto over theory only if experimental results are always correct. That’s not the case! Sensors can be calibrated incorrectly. Procedures can be followed incorrectly. Results can be described and interpreted incorrectly. Experiments can be wrong for reasons that are extraordinarily subtle, reasons that are not understood for months, or years, or ever. This is not a nitpicking hypothetical, it is one of the most basic facts of life for everyone in experimental science and engineering.

Therefore it is not only extremely common in practice, but also entirely correct, to use theoretical physics to inform our guesses about which experimental results are trustworthy. In other words, we are doing a Bayesian analysis of what to believe, and both theoretical and experimental knowledge are legitimate inputs into this analysis.

(Example: Here is a link to a meta-analysis in support of parapsychology. Oh, you still don’t believe in parapsychology? Did you meticulously read that article and judge its methodological soundness on its own merits? Or did you rule it out based on prior expectations derived from theoretical physics?)

We have a theory, let’s call it “Standard Model Quantum Field Theory With Perturbative Gravity” (I wish it was more widely known and had a catchier name), which, as far as we can tell, applies absolutely everywhere in the solar system. We have tested this theory an enormous amount, including in a wide variety of extremely specific and targeted ways, and it passes every test with extraordinary, ridiculous accuracy. The theory does not apply everywhere in the universe, because it cannot offer any predictions about certain exotic situations like microscopic exploding black holes or the Big Bang. That’s what’s spurring ongoing work in string theory and quantum gravity. I’m glad people are working on that stuff, but we shouldn’t lose sight of what we already have: a “theory of everything” sufficient to explain the microscopic goings-on in every laboratory experiment that we expect humans to ever be able to perform.

It’s not impossible that our current understanding of the fundamental laws of physics will be overturned by future experimental evidence. But that evidence needs to be exceptionally good and exceptionally specific, far beyond cold fusion experiments. Remember, the meta-analysis linked above shows that parapsychology is a reliably-reproducible experimental result. Experiments are hard.

Finally, you might say, maybe there’s a way to explain cold fusion in terms of the known laws of physics, and we just haven’t thought of it yet? Well, I sincerely tried over the past 4 years, and I failed. Julian Schwinger, one of the greatest nuclear physicists of the 20th century, tried and failed. Peter Hagelstein, a good enough physicist to get tenure at MIT, has been trying for 15 years, and failed. […in my opinion … I haven’t written it up, but I’ve grown much more confident in the criticisms hinted at here.] Notice any pattern?

And no, this isn’t like the mystery of high-temperature superconductivity, an example physics phenomenon which has legitimately taken decades to understand. In high-temperature superconductivity, physicists understood almost immediately why it can happen in broad outline, and we are just having endless trouble narrowing down the details of the “pairing mechanism” out of a few plausible candidates. Cold fusion is not like that at all. In fact it’s the opposite: We understand why cold fusion canNOT happen, in broad outline, and then all this theoretical work goes into fighting against that broad understanding, hunting for loopholes, or even just special pleading.

I can’t think of any analogous situation in modern physics, where an experimental result has turned out to be real, against such strong, longstanding, and carefully-considered theoretical reasons to disbelieve it. It’s easy enough to find a story of some well-regarded theoretical physicist claiming that, for example, lasers cannot work, days before they’re first demonstrated. Haha, stupid know-it-all theorists, you say. But there’s a world of difference between a theorist breezily dismissing something off-hand, and (say) this blog, where I am dismissing cold fusion after spending countless hours thinking about it and reading all the best ideas from decades of brainstorming by sympathetic proponents.

So, readers, if you want to keep hunting for theories of cold fusion, whatever, it’s your life, you can do what you like. Maybe I’ll even keep posting sporadically myself. But I feel totally satisfied that I got the right answer.

Numerical spin-boson model, part 1

As I mentioned in the last post, I have some concerns about the spin-boson model of cold fusion that are probably most easily settled via computer calculations. But before I jump into calculating something new, I want to make sure I understand the basics. So, in this post I am simply reproducing the computer calculations in Figs. 1-2 of the 2008 paper Models Relevant to Excess Heat Production in Fleischmann-Pons Experiments by Peter Hagelstein and Irfan Chaudhary. This was a fun and straightforward exercise in freshman quantum mechanics. I did not unearth any problem in the paper, nor did I expect to (at this stage). But now I have my first bit of working spin-boson code, and a bit more concrete understanding of the model. Time well spent! So without further ado…

Continue reading

Spin-boson model – quick update

This is a quick progress report on my studies of the “spin-boson” theory of cold fusion advocated by Peter Hagelstein at MIT. I happen to work 2 blocks away from Dr. Hagelstein’s office, so he’s been nice enough to meet with me a couple times over the years to discuss some of the technical details. Despite those meetings, and much time spent reading his papers, and many posts about the theory, there are still plenty of aspects of it that I haven’t yet tried to understand in detail.

That said, there are currently a number of aspects of the spin-boson model where I’m that seem implausible or wrong to me. I don’t think any of these complaints is fleshed-out and detailed enough that I could, say, write up an airtight disproof of the whole theoretical program tomorrow. But together, they make me pretty confident that this is not a path to a viable explanation of cold fusion. Let me list them:

Continue reading

Hydrino (Deep Dirac) Levels

In high school chemistry and 1st-semester quantum mechanics we all learn that “1s” is the ground state of a hydrogen atom. Wake up sheeple! A few brave souls have argued that hydrogen has a lower-energy state than 1s. According to some, it’s a whopping 500keV lower! These alleged lower-energy states are called “deep Dirac levels” or “hydrino” states.

My assessment? The ground state is 1s. The textbooks are correct. Boring but true.

This post, like the previous two posts, has nothing to teach us about cold fusion, except that this is a dead-end to avoid. But it’s still an interesting story about what can go wrong when solving differential equations.

Continue reading