Physicists grapple with the challenges of philosophy far more often than you might think, as Robert P Crease reveals
When did philosophy first feature in Physics World? To answer that question, we need to go back to the June 1988 issue of Physics Bulletin, which preceded Physics World, with an article written by US plasma physicist Robert Jahn, who until two years previously had been at Princeton University. The feature described apparently positive results, found by both Jahn and others, based on experiments into “psychic” phenomena. Jahn claimed the work had implications for science, scientific method and humanity’s understanding of itself and its relation to the cosmos.
But the September 1988 issue of Physics Bulletin, the final of that publication, contained several letters denouncing Jahn’s work as unscientific. One respondent said it conflicted with “most of the physics confirmed daily in our laboratories” as well as with “elementary reasoning.” Another challenged Jahn’s claim that the results had been experimentally demonstrated, adding the evidence was not real and invoking Carl Sagan’s dictum that “extraordinary claims require extraordinary evidence”. That author said that the magazine’s “transition upmarket to Physics World” was not well served by Jahn’s article.
Turning to the launch issue of Physics World in October 1988, the first entry in its letters pages was a reply by Jahn. He attacked the “prejudicial rhetoric” of his critics and also defended the “extensive experimental data” and “hard analytical results” of his research. Jahn challenged sceptics to consult the technical literature, to visit psychic research laboratories to see for themselves, and to “conduct a few careful experiments of their own”.
The controversy did not end there. In the November 1988 issue, one of Jahn’s critics referenced painstaking experiments, the conclusions of which not only rebutted Jahn’s claims, but had also been repeatedly confirmed by laboratories worldwide for decades. That letter was followed by another reply from Jahn, who cited the “specific empirical facts” arising from his own careful “experimental protocols and results”.
The key is this: none involved in the debate called this argument philosophical, yet it was philosophical at its very core. The sign? Each antagonist thought that they were engaged in real research and that the other side was being unscientific. The dispute therefore turned, not on research findings, but on some differing understandings of what it means to conduct scientific inquiry. Finding a resolution would require enough critical reflection on how scientific inquiry should be carried out to achieve consensus. Such reflection is philosophy, whether done formally or informally.
Erecting a wall
Philosophers of science call this sort of issue the demarcation problem. It’s about how to distinguish between scientific activity and non-scientific activity that may look like scientific activity. Unfortunately it’s harder to solve than it looks. Not everything done in a lab, nor by accredited professors at prominent institutions, nor with expensive equipment is truly scientific. Attempts to demarcate the border between scientific and unscientific activity can put cases on the wrong side or leave the border permeable.
Physics World’s birth took place during an exciting time for demarcation, with several announcements on opposite sides of the wall. The discovery of high-temperature superconductors two years before the magazine’s launch turned out to be on the scientific side, despite Georg Bednorz’s doubts at the time that his results were real. He expressed these in an interview in the magazine’s first issue. The claimed discovery of cold fusion, which was announced in March 1989, turned out to be on the other side of the demarcation wall.
The demarcation problem was not the only philosophical issue broached in Physics World’s first year, though the word philosophy didn’t appear at all in the magazine’s first volume. The term first showed up in the second volume, and then only backhandedly, in a letter correcting a misuse of the term “natural philosophy”. But the magazine did cover what I would argue are philosophical matters, given that resolving any of them requires us to critically rethink our assumptions of what it means to do serious scientific research.
One such matter was touched on in an editorial in December 1988, on the limits of the ability of physics to shed light on consciousness, mentioning an article that Brian Pippard from the University of Cambridge had recently published elsewhere about the topic. Another perennial philosophical issue, linked to quantum mechanics, was raised by Alasdair Rae from the University of Birmingham in an April 1989 article on a locality-disproving experiment. “The principle of locality is so fundamental to some,” Rae wrote, “that I expect they will look on this as only a temporary set back and start anew on a search for a theory that preserves this concept and agrees with the results of all experiments performed so far.”
The critical point
Looking back at Jahn 30 years on, history has proved not to be on his side. The consensus against scientific research into psychic matters grew. His name did not appear any further in the pages of Physics World, apart from a book review critical of psychic research a few years later.
But the issue of how to distinguish genuine research from bogus or imperfect science is still with us, though in different forms. I don’t mean the difference between genuine discoveries and those that are later rescinded, such as the detection of the Higgs boson (2012) and of gravitational waves (2016) on the one hand, and of faster-than-light neutrinos (2011) and of gravitational waves from the early universe (2014) on the other.
Discover why the philosophy of physics is vital
Today’s version of the demarcation problem has more to do with legitimizing the authority of science – the status of evidence for things like the existence of global warming, alleged dangers of genetically modified foods or the cancerous potential of mobile phones. Jahn, who died in November 2017, was right about one thing though. Understanding demarcation is essential to science, scientific method, and humanity’s understanding of itself and its relation to the cosmos.
