Dec 242015

From a certain point of view, this blog concerns one of the mundane areas of science and engineering, doing our routine work under the twin shadows of Cosmology and High Energy Physics, where scientists work to uncover the meaning of the universe – or, as Stephen Hawking humbly put it, read the mind of God.

Curmudgeons have taken a dimmer view, especially with physicists publishing books and narrating TV shows about strings, dark energy, multiverses, and other critters that look like escapees from Professor Snape’s lab. Such a jaundiced view of transcendental physics seems especially justified by comparing the cosmological effort to two decades of exoplanet search, the latter of which has produced a daunting list of real planets using good old-fashioned science. Meanwhile, cosmologists and high energy physicists are presenting us growing array of theories whose support occasionally seems to rest on esthetic arguments.

As Star War fans might put it, the Curmudgeons have struck back. Like the computer scientists and mathematicians (and even biologists!) before them, the physicists are consulting the philosophers. One year after George Ellis and Joe Silk wrote that “Physicists, philosophers and other scientists should hammer out a new narrative for the scientific method that can deal with the scope of modern physics,” a workshop on Testing and Trusting in Physics at Ludwig Maximilian University addressed the awkward question of whether what the participants were doing were, ahem, science.

The old view of science popularized by Karl Popper was that a theory was not “scientific” if it was not falsifiable: if there was no experiment or sequence of experiments which could impeach the theory, then it was not a “scientific” theory. This standard seemed useful against pseudoscience: astrology is readily falsified (although devotees cling to it anyway) while creationism (which is rather slippery about how to deal with evidence) cannot be falsified and is therefore not scientific.

Falsifiability seemed to be a good way to keep honest people honest, but there were problems. Curmudgeons may be delighted to see Freudianism and monetarism exploded as pseudoscience, but since no one seems to have the imagination to dream up anything that could falsify evolution or the theory that the Roman Empire once existed, philosophers started looking for alternatives. One is Bayesian epistemology, which simply asks: if you are going to claim that cosmological inflation actually occurred, how much are you willing to bet?

Quanta Magazine reported that the philosophers reassured the physicists that (other than a few incorrigible curmudgeons) we are all Bayesians now. And the Bayesian bet turns out to be: do we believe in cosmological inflation enough to pursue it further? The answer to that question is, of course, yes.

Chemists and materials scientists should not be overly smug about all this: as Quanta Magazine observed, no one has seen an atom – but we’ve taken “photographs” of them. And as physicists are prone to observe, chemists and materials scientists are prone to believe in convenient fictions like chemical bonds and molecules. Considering the dangerous territory nanoscience is taking us, we should not be surprised if some time soon chemists and materials scientists find themselves, hats in hand, at the door of the friendly neighborhood Philosophy department.

Meanwhile, the pseudo-science problem remains. For example, two decades ago, a poll of Americans concluded that more Americans believed that the U. S. government was concealing evidence of extraterrestrials than believed that there were extraterrestrials to conceal. (Poll results vary, but it appears that about a third of the public seem willing to tell pollsters that aliens are abducting people and conducting experiments on them.) How to deal with this sort of pseudoscience seems beyond the philosophers.