Friday, July 31, 2009

Gravity and Sorcery

For all that science is, it still has problems dealing with reality. As a teacher of science and of the epistemology that comes with it, I've found that teaching people the difference between reality and representations of reality is very tough.

Take for example the idea of an atom. With things like X-ray crystallography and electron microscopy we can vicariously perceive things that purport to be atoms, or at least, the positions, the wraiths, the ghosts of atoms. Limited by time and space, we still cannot know atoms except at one remove, or more. But the evidence is clear that something is there, and we know its properties well.

The same thing occurs with gravity. We know how it seems to work; we are pretty good at estimating its effects and predicting its behaviour. But how does it work the way it works? Here is where we slip into hand-waving and analogies. Gravitons? Just a name for the supernatural entities that we hang our dreams of gravity on.

The list goes on. Dark matter, dark energy, string theory... our knowledge of the universe has become increasingly tenuous. By what criteria do we call it knowledge now? By the fact that we have found a connect-the-dots theory to account for everything we think we see? By the fact that we can use the theory to predict other things? But how does it work?

That's where we enter the realm of the sorcerer's construct. A sorcerer who knows nothing of science, given a modern gadget (say, a laptop computer with a solar-cell recharger), will eventually come up with an hypothesis of its workings that will account for its behaviour and, because the machine's logic is internally consistent, also account for future behaviours. But does he know how it works?

Think about it. He learns to launch a word-processor by clicking on its icon. He learns that when he presses the 'A' key, an 'A' appears on the screen. This behaviour is reliable, and it will hold true for all the keys — whatever is on the key is what appears on the screen. The simplest hypothesis is that there is a sympathetic link between the symbol on the key and the graphic on the screen. The nature of that link is so complicated that if this were a scientific experiment, scientists would throw out the real explanation by using Occam's razor. It would be far simpler to hypothesize that it works like a typewriter: mechanical action on keyboard impresses the screen with images.

We're in that position. We attempt to name ourselves the lords of creation, writing out our account of how the universe works. But we'll never get into the workings. Even with our analogies, our metaphors, our formulae, the universe is still a black box. We put stuff in, we see stuff, we figure out what stuff produces what stuff. But why does it produce stuff? All we have is the idea that the universe is consistent. And worse, we assume the simplest explanation is probably true.

And now, not even that. The more we know, the more we begin to suspect that the consistencies we find in the laws of physics are merely a local aberration. It's like when you first see a colour change during a titration, before you swirl the mixture. The local concentration has spiked, and the indicator has changed colour, but that situation is not true for the rest of the solution.

We're all sorcerers, just as Isaac Newton was proud to be. We have no idea of what is real, we advance no hypothesis that is worthy of the name; we only report what we see, predict what we think we will see, and are happy if it turns out right. That is what science is about; it is the predictable toy in the bag of jokes.

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