It should be common knowledge that it isn’t wise to accept, without air of caution, someone’s opinion on a matter as absolute fact, if that person is not an expert in the given field. Consider popular physics, for the moment. What field is it that a physicist (or, as will be the case in the blog post, a mathematician) is expert of? That’s one question. Another is: What does the composition of works in popular physics entail? If the answer to the former is not the answer to the latter, then there is something wrong. I believe something is. In my previous blog post, I highlighted how, even within the domain of expertise, physics, a physicist can have difficulty in understanding the meaning of what they derive, mathematically or in experiment, primarily, because being a good physicist means doing good physics, and not just sitting around thinking about —thinking about the thinking of the doing of physics, as it were; physicists have better things to do, and adherence to a large amount of dogma is required to be actively doing good physics. This causes problems when a physicist puts down the mathematics and methodology of his or her discipline, choosing to take up the pen for the sake of popular physics.
Back to the questions: The area of expertise of physicists is the highly technical logical systems (topos, for example, in cosmology, or group theory in particle physics) and collection of methods that are so complex and variegated in application that there is hardly a single (scientific) “method,” the old problem of Bacon and Descartes. The answer I propose for the latter of the above questions is that, when writing popular physics, there is often more history of science and philosophy of science —and if not these, then there is more actual scientific journalism— than actual physics and mathematics knowledge required. That they require varying degrees of competency of the technical disciplines is without doubt. If history and philosophy of science (HPS) are so much more relevant in the writing of popular science, and is even a natural extension of what historians and philosophers of science do on the scholarly, then why are scientists, especially physicists and mathematicians, writing these works? They are clearly out of their depth, in many cases, and the unfortunate thing is that most casual readers will not know that errors in history or philosophy (or both) have been made. In all fairness, physicists and other scientists tend to do rather well in their writing, but part of this is due to their consciousness expended toward avoiding philosophy; it is history that they will more often get themselves into trouble (I explain below).
My mark for this post is one of my favorite authors, Amir Aczel, author of Fermat’s Last Theorem; but we will look at Present at Creation (my review of it may be found by clicking HERE), in this blog post. It is worth noting that, while Aczel holds a PhD in Mathematics, he also has quite a bit of training in physics. I choose Aczel for this post, because there is no doubt that he is a scholar of high repute, and wholly capable in the art of writing as in mathematical thought. Therefore, I think Aczel’s error will do well in helping to prove my point. The error comes in Present at Creation, when he says, “Paul Dirac was the physicist who came up with the outrageous idea that nature must also contain antimatter: particles like the ones we observe, but with opposite electric charge” (2010, pg. 81). You wouldn’t know the error made, unless you were reasonably well versed in philosophy (and had a sufficiently technical knowledge of physics) or history of science. The problem is that Paul Dirac originally solved an equation (in suffusing and beginning to integrate quantum mechanics and relativity) which had a bizarre, unexpected second result; but he didn’t jump up for joy at some discovery, he actually pitched it in a state of bemusement. After Carl D. Anderson experimentally stumbled across the particle, Dirac is quoted in Nickolas Solomey’s fine work, The Elusive Neutrino: A Subatomic Detective Story, as saying, “‘It is very easy only to see what one is told to look for’” (1997, pg. 102). (note: I have come across this quotation in at least two other sources, one of which being The Strangest Man by Farmelo.) Solomey further this comment, with his observation, “Experimental physicists had been using cloud chambers [Anderson’s mode of discovery] for years by the time Anderson announced the positron’s discovery. They had simply missed the tracks of the positron because they hadn’t been looking for them” (1997, pg. 102-103). (Consider this with respect to Thomas Kuhn’s use of the Postman-Bruner experiments, in The Structure of Scientific Revolutions, or Jutta Schickore’s discussion of the microscope in chapter two of A History of Reflections.) Had Dirac known what the second solution meant and formally promulgated his prediction, it is not outside of reason that he would have been awarded a share in the 1936 Nobel Prize in physics to complement his 1933 award, if not for the prediction of the positron itself, then for the prediction of a matter/anti-matter symmetry. At any rate, Aczel’s error is not a one-and-done deal, it is systematic, and shaped his understanding of his subject. He continues on systematizing his error into his understanding on pages 85 through 87, and also incorporates the error into another discussion, later in the book. Aczel made a mistake, but I am inclined to think that it is not totally his fault, either.
I don’t think the error is completely Aczel’s fault (even if he would claim it for himself, as a respected academician does), because there is no citation in the above-cited text. This makes me think that Aczel acquired his historical information through discussion directly with physicists, either with colleagues or in a physics class —a wildly dubious source for acquiring history of physics and philosophy of physics. One learns as much physics mythology and lore in a technical physics classroom as one does actually sound HPS fact. One thing should be clear: Aczel stepped beyond his area of expertise, try as he might not to.
Now, we will consider what comes into play when an expert in HPS (historian of science or philosopher of science) is on the scene. The historian of science would not make the same mistake that Aczel did, because he or she would not have made the number one error in any historiographical study, namely, viewing history through a modern lens. Immediately, only given bits and pieces of the story, the historian would say something like: How did Dirac know what anti-matter was, before the instantiation of the concept? Looking back, as a physicist in the modern period, it is easy to erroneously say, “Ah! Dirac had a second solution to his equation, which means he predicted anti-matter.” No, that consequence does not necessarily follow, and this error is being made on the basis of taking the notion of anti-matter for granted. The philosopher of science might inquire in such a way say as examining what it was that possibly could have moved Dirac, in his time, toward the conclusion that a different kind of matter, a kind that annihilates normal matter, had been stumbled upon, just on the basis of the mathematical solution. Based on my personal knowledge, I am not even sure it was possible for Dirac to conclude that the second solution would imply annihilation between the particles, though I am certainly not studied on the subject enough to say with any real confidence. Nonetheless, my inclination is to think that Carl D. Anderson’s discovery of the positron was crucial and necessary for the understanding of that piece of mathematics, and it was welcoming that Dirac’s other solution should afford a place for its existence, making sense of it.
In conclusion, I think some amount of consideration should be given, reassessing who it is that should be writing popular physics and popular science. We would not expect most scientists to do all that well in doing their own journalism, and we see more and more scientists working with science-competent journalists to produce literature —and journalism is far less technical than HPS. Maybe the writing of popular science requires that scientists collaborate with historians and philosopher of science, and, if not, then leave it to HPS experts, altogether.