For centuries scientists believed that the universe was a vast machine - with enough detail, you could predict exactly what would happen. Then the cracks began to appear. It proved impossible to predict exactly how three planets orbiting each other would move.
Meteorologists discovered that the weather was truly chaotic - so dependent on small variations that it could never be predicted for more than a few days out. And the final nail in the coffin was quantum theory, showing that everything in the universe has probability at its heart. That gives human beings a problem. We understand the world through patterns. Randomness and probability will always be alien to us. But it's time to plunge into this fascinating, shadowy world, because randomness crops up everywhere.
