A question that should be asked more often is, do scientists make mistakes? Of course they do. The good news, however, is that when it comes to measuring something, they tend to be meticulous, and published measurements are usually correct, or, if they matter, they are soon found out if they are wrong. There are a number of papers, of course, where the findings are complicated and not very important, and these could well go for a long time, be wrong, and nobody would know. The point is also, nobody would care.
On the other hand, are the interpretations of experimental work correct? History is littered with examples of where the interpretations that were popular at the time are now considered a little laughable. Once upon a time, and it really was a long time ago, I did a post doctoral fellowship at The University, Southampton, and towards the end of the year I was informed that I was required to write a light-hearted or amusing article for a journal that would come out next year. (I may have had one put over me in this respect because I did not see the other post docs doing much.) Anyway, I elected to comply, and wrote an article called Famous Fatuous Failures.
As it happened, this article hardly became famous, but it was something of a fatuous failure. The problem was, I finished writing it a little before I left the country, and an editor got hold of it. In those days you wrote with pen on paper, unless you owned a typewriter, but when you are travelling from country to country, you tend to travel light, and a typewriter is not light. Anyway, the editor decided my spelling of a two French scientists’ names (Berthollet and Berthelot) was terrible and it was “obviously” one scientist. The net result was there was a section where there was a bitter argument, with one of them arguing with himself. But leaving that aside, I had found that science was continually “correcting” itself, but not always correctly.
An example that many will have heard of is phlogiston. This was a weightless substance that metals and carbon gave off to air, and in one version, such phlogisticated air was attracted to and stuck to metals to form a calx. This theory got rubbished by Lavoisier, who showed that the so-called calxes were combinations of the metal with oxygen, which was part of the air. A great advance? That is debatable. The main contribution of Lavoisier was he invented the analytical balance, and he decided this was so accurate there would be nothing that was “weightless”. There was no weight for phlogiston therefore it did not exist. If you think of this, if you replace the word “phlogiston” with “electron” you have an essential description of the chemical ionic bond, and how do you weigh an electron? Of course there were other versions of the phlogiston theory, but getting rid of that version may we’ll have held chemistry back for quite some time.
Have we improved? I should add that many of my cited failures were in not recognizing, or even worse, not accepting truth when shown. There are numerous examples where past scientists almost got there, but then somehow found a reason to get it wrong. Does that happen now? Since 1970, apart from cosmic inflation, as far as I can tell there have been no substantially new theoretical advances, although of course there have been many extensions of previous work. However, that may merely mean that some new truths have been uncovered, but nobody believes them so we know nothing of them. However, there have been two serious bloopers.
The first was “cold fusion”. Martin Fleischmann, a world-leading electrochemist, and Stanley Pons decided that if deuterium was electrolyzed under appropriate conditions you could get nuclear fusion. They did a range of experiments with palladium electrodes, which would strongly adsorb the deuterium, and sometimes they got unexplained but significant temperature rises. Thus they claimed they got nuclear fusion at room temperature. They also claimed to get helium and neutrons. The problem with this experiment was that they themselves admitted that whatever it was only worked occasionally; at other times, the only heat generated corresponded to the electrical power input. Worse, even when it worked, it would be for only so long, and that electrode would never do it again, which is perhaps a sign that there was some sort of impurity in their palladium that gave the heat from some additional chemical reaction.
What happened next was nobody could repeat their results. The problem then was that being unable to repeat a result when it is erratic at best may mean very little, other than, perhaps, better electrodes did not have the impurity. Also, the heat they got raised the temperature of their solutions from thirty to fifty degrees Centigrade. That would mean that at best, very few actual nuclei fused. Eventually, it was decided that while something might have happened, it was not nuclear fusion because nobody could get the required neutrons. That in turn is not entirely logical. The problem is that fusion should not occur because there was no obvious way to overcome the Coulomb repulsion between nuclei, and it required palladium to do “something magic”. If in fact palladium could do that, it follows that the repulsion energy is not overcome by impact force. If there were some other way to overcome the repulsive force, there is no reason why the nuclei would not form 4He, because that is far more stable than 3He, and if so, there would be no neutrons. Of course I do not believe palladium would overcome that electrical repulsion, so there would be no fusion possible.
Interestingly, the chemists who did this experiment and believed it would work protected themselves with a safety shield of Perspex. The physicists decided it had no show, but they protected themselves with massive lead shielding. They knew what neutrons were. All in all, a rather sad ending to the career of a genuinely skillful electrochemist.
More to follow.