> If the complexity grew linearly with the number of particles being simulated, then doubling the number of partices would mean doubling the computing power req

> If the complexity grew linearly with the number of particles being simulated, then doubling the number of partices would mean doubling the computing power required. If, however, the complexity grows on an exponential scale – where the amount of computing power has to double every time a single particle is added – then the task quickly becomes impossible. But you only need to _actually_ simulate the universe on very few occasions (a few times every few billion years) on a very small scale. Otherwise, you only need to approximate...