November 14th, 2008

Just one of Summum’s seven aphorisms states something definite:

Every cause has its effect; every effect has its cause; everything happens according to Law; Chance is just a name for Law not recognized; there are many fields of causation, but nothing escapes the Law of Destiny.

or as Einstein put it, “God does not play dice with the universe”.

This quintessentially Greek argument still divides science. The classical view of Aristotle/Newton/Laplace/Kant/Einstein is roughly that causation is universal; if we knew the initial conditions and laws of nature to sufficient precision, we would see the fundamental particles that make up the universe evolve in a quite predictable way, carrying with them the stars, dinosaurs, bloggers and blog readers they make up. There is the minor difficulty that none of the conditions actually holds: we don’t know the initial conditions, nor the list of particles, and no imaginable computer could calculate the trajectories of all of them, but let that pass. The universe – hell, multiverse – is its own computer, like Newton’s God.

On this view, the universe is a giant tram, and consciousness merely the view out of the back window. Sit back and enjoy. On one extreme interpretation, time itself is an illusion. Causation has no inherent time direction; the laws work just as well both ways. So you can see the universe as a timeless Jello block of determined relationships, like a video hologram that we just happen to play forward. Parmenides would love it.

But most physicists now think that the longstanding philosophy of science channelled by Summum is wrong. At the most fundamental level, chance rules. There are, they say, no hidden variables to restore determinacy at the quantum level. There really is no way even in principle to predict say when a given atom of U-235 will decay. Most of the time this makes no difference. The fundamental laws are statistical: so the partially lawless behaviour of individual particles aggregates into the precise patterns of classical physics, to a large number of decimal places. Unfortunately for our intuition and for Einstein, quantum mechanics works perfectly.

But the smoothness only holds most of the time. There are pathways that can magnify quantum variations into macroscopic effects. We can ignore the boundaries of black holes, but not the radioactive decay that causes many mutations in DNA and opens up the variation in phenotypes on which natural selection operates. If we could wind the tape of life back 3 billion years and run it again, we have no reason to think it would turn out identically the second time round, or even vaguely similar. This is uncomfortable for the Peoples of the Book: the workaround of an unknowable trickster God who rigs radioactive decay to achieve the desired result only makes matters worse. But we can console ourselves that real indeterminacy rescues the arrow of time of Genesis; there is no timeless Jello block.

The traditional reason for worrying about universal causation has been free will. Surely consciousness and the choices it enables make a difference to what happens to beings like ourselves? Darwinism reinforces this point. Our brains are large and energy-hungry, and produce consciousness. Such metabolically expensive features cry out for an adaptive explanation. So either consciousness makes a difference to behaviour, or it’s spam accidentally thrown off by a sufficiently complex neural computer, an exception to ordinary biological rules. The latter view has found support in Benjamin Libet’s finding that in some cases we become aware of motor instructions to our limbs after they have been sent. But in general, the spam theory runs counter to our deep-seated belief that things have reasons.

A more recent, and, related problem is that information seems in a lot of contexts to make a difference to events. We see the oncoming truck, the lion smells the zebra: what happens next seems to depend on the information, not just photons and pheromones. Dump consciousness and the problem does not go away. A computer, whether made of electronic circuits, billiard balls, Bagehot’s cams or trained flatworms, is built as a deterministic, Laplacean device. Look closely, and you can see the billiard balls or whatever bouncing off each other in a most satisfactory and orderly way. But set the computer to run a complex algorithm. Whether it stops depends entirely on the mathematics of the algorithm, and cannot be predicted by any amount of inspection of the machines’ entrails. In some cases it cannot, as Alan Turing showed, be predicted at all. So it looks as if information is in a way a domain of causation.

Summum is right to hedge it bets and allow the possibility of several such domains. But though conscious choice and information seem to cause things in a quite strong way, it’s silly to write these into a Law of Destiny we can never know. Gentle reader: if you think you have a mind of your own, for instance on the question whether to consign yours truly to the long list of bloggers unworthy of your valuable time, just make it up.

Share this post:
  • Twitter
  • StumbleUpon
  • Digg
  • Reddit
  • Facebook

Comments are closed.