Sunday, September 20, 2009

Science is not about belief

Quantum mechanics is a triumph of the scientific method over common sense. It's weird. Mathematically weird, and it makes deeply strange predictions. Albert Einstein found it difficult to accept ("[God] does not play dice"), and spent many of his later years trying to disprove the theory. Richard Feynman remarked, "I think I can safely say that nobody understands quantum mechanics."

And yet it has the irritating habit of being right all the time. And when I said right, I mean it makes predictions that are accurate to upward of 20 decimal places. That's predictive power.

The moral of the story is that you don't have to believe science to accept that it is correct. Science can, and does, do violence to our common sense, our preconceptions, and our intuitions about the way the world works. Yet it is always correct (within certain parameters); otherwise it wouldn't be science.

Many people think that science "constantly changes its mind", and that that somehow makes it less worthy of acceptance than, say, religious dogma (which never changes). In fact the opposite is true. Every time a scientific theory is discarded, it's because a better one has come along which explains the evidence more accurately, or over a wider range of phenomena. That's exactly what happened to Newtonian gravity. It wasn't that Newton was wrong; rather Einstein was more right. Science is constantly improving, and that's precisely why it is so effective as a naturalistic philosophy.

And then there are those poor souls who claim things like "evolution is a matter of faith, just as much as creation is!" Rubbish. Hogswallop. I can't think of a word strong enough to describe just how wrong this statement is. It's an evil perversion of the truth: science is the opposite of faith.

Scientists don't throw the die and pray for a six. They throw the die over and over, measure the outcomes, and conclude that each number is just as likely to occur as the others. Or if the die is weighted, they will discover this fact. Then they think of a hypothesis to explain the phenomenon: "since each surface of the die has an equal area, and since the density is constant, the shape guarantees equal probability of outcomes." Once thought of, the hypothesis must be tested. What happens if we reduce the area of one side of the die? What if we add more sides, but ensure that they have equal area?

I have no idea if the above hypothesis is correct. Probably it isn't. But it illustrates the way scientists proceed. The results of their experiments are often surprising. Sometimes years of accumulated common sense have to be thrown away in a heartbeat. It can be emotionally wrenching, especially if you have a particular attachment to an idea that now turns out to be wrong.

This is the ruthless honesty of scientists: they never deny reality, no matter how hard it is to accept.


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