A bad attack of physics envy

Physics is the easiest and least important of the sciences, and a very bad model for studying anything else.

I know, as a psychology/sociology graduate with a bias towards history, I’m probably just jealous. But there is still a case to answer. In particular:

1. Physics is easy. We only constructed physical laws first because they were obvious by comparison with the far more difficult laws of biology and intelligence.
2. Physics is unimportant. It would make no difference at all to anything that matters to human beings if some of the most basic facts of the physical universe were quite different.
3. Physics is a lousy model for any other science, and we have wasted long enough on physics-worship.

1. Physics is easy

Proposition No.1 is simple and obvious. Is it at all likely that we would have solved the most profound and difficult of scientific problems first, leaving only relatively superficial and easy problems for later? No. Is the study of physical structures and processes especially challenging by comparison with their chemical, biological or intelligent counterparts? No. You can do it in a lab, under nicely controlled conditions, and (at least by comparison with, say, organic systems) its findings are pretty easy to replicate and falsify.

Of course, the results have a pleasing universality. Everything I know about protons or light appears to be true of protons and light everywhere, and it seems pretty easy to identify and demarcate protons and light themselves, which can scarcely be said of higher level structures such as species or even organisms. How much harder then is it to comprehend language or consciousness?

2. Physics is unimportant

Proposition No.2 – that it would make little difference to anything that mattered to human beings if many basic physical facts were different – is pretty straightforward too. What if some prestigious lab announced tomorrow that quarks really were (as our German cousins have so presciently intuited) made of yogurt, and vice versa? Assuming that they continued to provide the necessary infrastructure of chemical and biological processes, what difference would it make? To anyone but physicists, none at all. So why should we regard our knowledge of physics as especially important?

In his masterpiece, Solaris, the great Polish sci-fi writer Stanislaw Lem speculated that the apparently intelligent planetary ocean that covered his eponymous planet was able to construct increasingly substantial human beings out of neutrinos, which the ocean was able to mould into atoms that would then generate the familiar chemical, biological and psychological structures needed to produce the creatures through which it communicated with its human visitors. In other words, the physical building blocks were different, but the architecture remained exactly the same. In that situation, what difference would it make if Lem were actually right, not just in fiction but in fact? Beats me.

It is not even as if physicists have a compelling track record regarding non-physical problems. True, many of the suggestions physicists have made to their neighbours have been very penetrating (most famously, perhaps, Schrödinger’s What is Life?). But equally eminent physicists have got it completely wrong. For example, Lord Kelvin, author of the second law of thermodynamics and the absolute temperature scale later named after him, notoriously condemned evolution because the timescales it required exceeded anything that could be supported by known physical processes. The Sun simply could not stay warm enough long enough for life on Earth to have evolved to its present level. ('On the age of the sun’s heat', Macmillan's Magazine, vol. 5, March 5, 1862, pp. 288-293, part 1, reprinted here.)

For Kelvin, who believed that 'overpoweringly strong proofs of intelligent and benevolent design lie all round us', this may not have seemed a fundamental difficulty, but physics's superior status to biology meant that is intervention was disastrous. Even ‘Darwin was so shaken by the power of Kelvin's analysis and by the authority of his theoretical expertise that in the last editions of On The Origin of the Species he eliminated all mention of specific time scales’ [source]. So science was put back several decades by the presumption that if it was impossible for something to happen according to current physical knowledge, that should be good enough for everyone else. The utterly compelling logic of evolution, driven by the thorough observation of the simplest biological facts and the simplest deduction, were not enough: the authority of physics was sufficient to stymie one of the few contributions to science that exceeded Kelvin’s own.

In short, not only would it not matter much if physics were quite wrong about basic physical realities, but sometimes science as a whole would be a lot better off if it trusted a little less to the alleged pre-eminence of physics and a bit more to the evidence and logic of each individual discipline. The adoration of quantum mechanics' doctrine of uncertainty is constantly casting its baleful shadow far and wide – such a great excuse for sloppy thinking, such an irresistible enticement to intellectual self-censorship, and such a pall of comfortable pessimism. Regardless of whether this is a valid interpretation of quantum theory (and my personal impression is that it is not),the root cause often seems to be an unthinking acceptance of the authority of whatever physicists say. The recent dominance of evolutionary and genetic research is having a similarly destructive effect on our thinking about human beings, and for essentially the same reason - the predominance of authority over findings and argument.

3. Physics is a bad model for science

Finally, physics is a lousy model for other sciences. Its very simplicity makes it susceptible to all manner of techniques and empirical superficialities it would be quite absurd to demand of other sciences. How could one possibly conduct ethology or ethnology in the laboratory or by experimental methods or the logic of ceteris paribus? What has the great mass of psychological experimentation that has striven to mimic physics contributed to our understanding of human nature? As one must expect of methods that trivialise the subtleties of human experience and action, only trivia.

Of course, I simplify, perhaps even trivialise a little too. But then when was there a time when physics was not aggrandised? Ernest Rutherford (a wonderful experimentalist) was not alone in believing that ‘In science there is only physics; all the rest is stamp collecting’. But then he also followed in the Kelvin tradition of opinionated prognosis, saying ‘The energy produced by the atom is a very poor kind of thing. Anyone who expects a source of power from the transformation of these atoms is talking moonshine’. With that kind of track record in physics, what on earth would compel me to listen to his opinions on anything else?

What is wrong with physics, then? Well nothing really. As far as it goes. But it only goes to the limits of physical structures and processes, beyond which it has no more to say than sociology has to say about steroid chemistry. Apart from (perfectly valid) generalities of the kind offered by Schrödinger et al., physics makes no useful predictions about higher sciences. What is more, it lacks the ability to do so not because they are no better than stamp-collecting or because the structures and processes of life or intelligence are too complex to be manageable but because they are qualitatively different. A quite different logic is at work in tulips and sperm whales and human beings.

Not that supra-physical entities are not also physical; but physics-worship tends inevitably to the invariably false ‘nothing-but-ism’. A living thing can be broken into its physical constituents, but then it is both literally and metaphorically dead, and there is nothing at the physical level that explains just what it is that makes something alive. This is not a plea for mysticism: one can’t deduce architecture from the physics of bricks either.

A far more appropriate definition would be to say that any method is scientific that delivers knowledge that is adequate to its object. On that basis, the methods of science are defined more rationally, which is to say, by a careful consideration of the goals it seeks to achieve (i.e., objective knowledge of a specific domain of reality), and not a priori by what happens to have been a useful approach in some of the easier areas of reality. Grovelling before the altar of physics really is the worst kind of anti-scientific argument from authority.

So let’s hear it for the higher sciences: chemistry, biology and whatever we end up calling the science of intelligence.