Boltzmann's Revenge

 

I find myself musing abstractedly sometimes on things I don't understand very well, like quantum mechanics and gravity. Having been told at university that it's OK not to understand or make sense of quantum mechanics, just use it, sends one's mind into a worryingly non-linear spiral, if you'll forgive the tautology of anxiety. There are ideas in abundance. When asked at a conference – along with many other specious and intractable problems 'which model of quantum mechanics they preferred' there was, predictably, considerable disagreement.

The physicist David Deutsch’s 'The Beginning of Infinity' is – according to reviews - 'resolutely and inspiringly optimistic about the potential for growth in scientific knowledge and in consequence about people's capacity to transform themselves and their environment for the better.' He further argues that 'the potential for new knowledge is limitless' and therefore the protection and enabling of science and its institutions is the bedrock from which no problem can be regarded as insoluble. This disregards the 'parochial and outdated' notion that things have to make conceptual sense. Such optimism is undoubtedly popular, but I find myself - if not believing - then certainly supposing that there is an 'end to things' - both in terms of the 'things' themselves and also our ability to comprehend them. Intelligence, like ready cash, is a finite commodity.

Physics and philosophy are a reluctant bride and groom, uneasily sharing the same untidily made bed, each distrustful of the other. I would ask a more fundamental question – what is the aim of scientific information gathering? It cannot be certainty – would that it could -  but its purpose is to weight the evidence in favour of one theory over another, which is all we can legitimately ask of a data set, flawed as its gathering might be. Schoolchildren are taught Galilean empiricism which reinforces a worldview that all is available for discovery if only the right tools were available. Karl Popper, said to be the greatest philosopher since Bacon, suggested that science advances by deductive falsification by a process of conjecture and refutation. He believed that it is imagination and creativity, not pure inductive reasoning that generates 'real' scientific theories which is why Einstein was able to study the universe with no more apparatus than a piece of chalk. Experiments test theories - they can't produce them. I like this. God playing hide-and-seek with the very best and still coming out ahead.

From the impossibly small to improbably large - nearly all physicists agree that on relatively small scales the distribution of galaxies is fractal-like: hundreds of billions of stars group together to form galaxies, galaxies clump together to form clusters, and clusters amass into superclusters. The point of contention, however, is what happens at even larger scales. According to most physicists, this Russian doll-style clustering comes to an end and the universe, on large scales, becomes homogeneous. I wonder why? Is the data set reliable enough? Some argue that the data shows the opposite: the universe continues to look fractal as far out as our telescopes can see. I have a Newtonian view – stuff carries on doing what it's doing till something happens to change it. If the stuff behaves in a statistically predictable way, it'll continue to do so. Presumably. 
Thermodynamics is another statistical black art. The graphic is, as every physicist knows, from the gravestone of statistical thermodynamicist Ludwig Boltzmann, the only scientist to have an equation on his tomb. People still argue that entropy doesn't exist but given the degree of disorder in my house after not having maintained its tidiness for some time, I'm inclined to disagree. The arrow of time seems to unfailingly generate chaos but the effort required to maintain it is more costly than leaving it alone. Much like the Universe, perhaps. God understands stochastic processes. Those with OCD tendencies can find comfort here - do look, it's probably more interesting than what's gone before. Random behaviour is no laughing matter as Ludwig so amply demonstrates.