Our brains may never be well-enough equipped to understand the universe and we are fooling ourselves if we think they will.
Why should we expect to be able eventually to understand how the universe originated, evolved, and operates? While human brains are complex and capable of many amazing things, there is not necessarily any match between the complexity of the universe and the complexity of our brains, any more than a dog's brain is capable of understanding every detail of the world of cats and bones, or the dynamics of stick trajectories when thrown. Dogs get by and so do we, but do we have a right to expect that the harder we puzzle over these things the nearer we will get to the truth? Recently I stood in front of a three metre high model of the Ptolemaic universe in the Museum of the History of Science in Florence and I remembered how well that worked as a representation of the motions of the planets until Copernicus and Kepler came along.
Nowadays, no element of the theory of giant interlocking cogwheels at work is of any use in understanding the motions of the stars and planets (and indeed Ptolemy himself did not argue that the universe really was run by giant cogwheels). Occam's Razor is used to compare two theories and allow us to choose which is more likely to be 'true' but hasn't it become a comfort blanket whenever we are faced with aspects of the universe that seem unutterably complex — string theory for example. But is string theory just the Ptolemaic clockwork de nos jours? Can it be succeeded by some simplification or might the truth be even more complex and far beyond the neural networks of our brain to understand?
The history of science is littered with examples of two types of knowledge advancement. There is imperfect understanding that 'sort of']' works, and is then modified and replaced by something that works better, without destroying the validity of the earlier theory. Newton's theory of gravitation replaced by Einstein. Then there is imperfect understanding that is replaced by some new idea which owes nothing to older ones. Phlogiston theory, the ether, and so on are replaced by ideas which save the phenomena, lead to predictions, and convince us that they are nearer the truth. Which of these categories really covers today's science? Could we be fooling ourselves by playing around with modern phlogiston?
And even if we are on the right lines in some areas, how much of what there is to be understood in the universe do we really understand? Fifty percent? Five percent? The dangerous idea is that perhaps we understand half a percent and all the brain and computer power we can muster may take us up to one or two percent in the lifetime of the human race.
Paradoxically, we may find that the only justification for pursuing scientific knowledge is for the practical applications it leads to — a view that runs contrary to the traditional support of knowledge for knowledge's sake. And why is this paradoxical? Because the most important advances in technology have come out of research that was not seeking to develop those advances but to understand the universe.
So if my dangerous idea is right — that the human brain and its products are actually incapable of understanding the truths about the universe — it will not — and should not — lead to any diminution at all in our attempts to do so. Which means, I suppose, that it's not really dangerous at all.