Wednesday, November 21, 2012

Cold fusion and I

Some people seem to think that science is like this, but the everyday life of the researcher is nothing like Dr. Zarkow building a spaceship in his basement. In science, as in most tasks in life, there holds the rule "1% inspiration and 99% perspiration"

When I mention that I experimented with cold fusion, back in 1989, I find that many people are very interested. What I did is not especially relevant, but I thought I could tell that story here; if nothing else to show how easy it is to be overtaken by enthusiasm. But it may also be a way to show how the scientific method works.

Let me go back to 1989; when Fleischmann and Pons claimed that they could attain the fusion of deuterium nuclei in a test tube. I remember the feeling of elation of those months. It was such an incredible discovery: it was going to change everything in science. And not just that. I was thinking that also a lot of science fiction stories would have to be rewritten.

In July, I took a trip to Berkeley, to work at the Lawrence Berkeley Laboratory during the summer. There, they had one of the best labs of electrochemistry in the world. and if anyone was able to replicate the experiments made by Fleischmann and Pons, they were the right ones. So, when I arrived in Berkeley, one of the first things I discussed with my colleagues was cold fusion. I was surprised to discover that they were disappointed. They had tried to replicate the electrochemical cold fusion experiment almost immediately after the first announcement. But they were not getting any results and they had concluded that the whole story was a scam or a mistake. I distinctly remember overhearing my boss at the lab discussing about cold fusion on the phone with someone else, saying, "look, that was just a measurement error."

I spent that summer in Berkeley working on subjects unrelated to cold fusion, but I had not completely given up. You see, the claim by Fleischmann and Pons had unleashed a series of similar claims. Some people claimed that they could see fusion in gases emitted by volcanoes, and some that they could see fusion in metals other than palladium, just exposing them to gaseous deuterium. The overall atmosphere reminded the "Elvis sightings" story. Someone saw something, and immediately other people reported having seen something similar. So, maybe electrochemistry was not the only way to obtain cold fusion. Maybe there were other ways, even better ones! So, back in Italy, in September, I thought I could do something myself. I had a laboratory equipped with some instrumentation that could be used for that purpose; so, why not give it a try? At that time, I didn't have to teach, and I was free from the administrative tasks that take most of my time nowadays. So I could work in relative peace.

I won't bother you with the details of what I did (*). Let me just mention that my set-up was inspired by the work of Scaramuzzi and others in Frascati and that it was based on comparing tests made in vacuum with deuterium with tests done with ordinary hydrogen. I worked on that, I think, for two-three months. I tried several combinations of temperatures, pressures, and different kinds of palladium samples. But I couldn't see anything: no traces of cold fusion, no matter what I did. Eventually, I gave up.

I was not the only one to be disappointed. The excitement was gone and the cold fusion story was dying out. Nobody could obtain convincing results and several people started feeling ashamed for having been much too rash in publishing their results. The general conclusion was that the concept of "cold fusion" had been just a mistake; too much enthusiasm and not enough data.

That's the story, more or less. Now, can we learn something from it? Maybe so. For one thing, in science there is no such thing as a failed experiment as long as you do a correct analysis of the data. Of course, my experiments couldn't prove that cold fusion does not exist (**), just as no experiment can prove that unicorns do not exist. What my experiments could prove was that cold fusion was far from being so easy to obtain as it had appeared to be at that time (many other experiments were proving that). If there was any cold fusion in my set-up, it occurred on an extremely small scale, and it had to be very, very difficult to detect.

But I think there is more to be learned from this experience. One thing is how easy it is to be taken by the "Elvis sighting" atmosphere. In the beginning, people were telling me that I was a bad experimenter if I couldn't see any cold fusion. "Come on," they said, "everybody is seeing cold fusion. Why can't you manage to see anything?" And, you know, the Elvis sighting effect is strong: a number of times I thought I had really seen a helium signal that showed that, yes, there was cold fusion going on! But then I redid the experiment and the signal was gone. One of the characteristics of "pathological science", indeed, is that the results are always at the edge of the sensitivity of the instrumentation.

I was not the only one seeing ghosts of cold fusion. I remember discussing this matter with a colleague who told me he had the same problem with his setup. He was using a neutron detector, and he was seeing the same emission signal with deuterium and with hydrogen. His conclusion? Well, it was not that his neutron detector was a bit unreliable, but that he was seeing cold fusion also with hydrogen. I won't name this colleague, but let me just note that, fortunately for his reputation, it seems that he never published this idea of his.

In the end, however, I think the main point is that the scientific method works. Yes, scientists are human beings, and yes, they may be victims of their own expectations and of the "Elvis sighting" effect. They can make mistakes, even big ones but, on the whole, the system filters away the bad results. It is science, baby!

(*) Just in case you are interested in this kind of things, let me tell me something about the experimental setup I used. It is all from memory because the notes and the data from that time must be in some box, somewhere, but they would be very hard to find, now. I used a system that had been built for catalysis studies. It was made up of a reaction chamber connected with an ultra-high vacuum chamber equipped with a mass spectrometer. In the reaction chamber, I exposed a palladium sample to deuterium and hydrogen at different pressures and temperatures. My idea was that if cold fusion was occurring, then it would occur inside the palladium lattice and that would generate helium nuclei that would remain trapped there. So, after the reaction, I would pump out the deuterium, open the chamber and flash the sample at high temperature to release the helium into the mass spectrometer. Of course, there is a problem here: the deuterium molecule (D2) and helium have the same mass and can't be separated by an ordinary mass spectrometer. So, I had the gas passing through a trap made with freshly evaporated titanium that would adsorb the deuterium, leaving only helium. The trap could not eliminate all the deuterium, but I reasoned that, if the cold fusion effect was significant, I should see a difference by repeating the experiment using ordinary hydrogen. This detection setup was similar to the one used by Del Giudice, Di Ninno and others later, when they claimed to have detected cold fusion (link). The reactive system was also similar to the one used by Scaramuzzi and others in 1989, when they claimed they could see cold fusion by exposing titanium to deuterium gas (link). As I say in the main text, here, I never could see any significant effect. 

(**) You could say that I couldn't see cold fusion because I never could go to really high pressures with my setup. Yes but, later on, some people did something similar at pressures probably a hundred thousand times larger than what I could get. They didn't find anything, either (Silvera and Moshary, Physical Review B, 42, 14, 1990, p. 9143)


Ugo Bardi is a member of the Club of Rome, faculty member of the University of Florence, and the author of "Extracted" (Chelsea Green 2014), "The Seneca Effect" (Springer 2017), and Before the Collapse (Springer 2019)