That might seem like a hard limit, but processing power still doubles every twelve to eighteen months, and doubling is more extraordinary than people understand. There’s a story that the Emperor of China once lost his throne gambling with a peasant, because he agreed if he lost to pay a single grain of rice on the first square of a chess board and double the amount on each square on the next until he had covered the board. His debt for the final square was eighteen and a half million trillion grains. It is almost impossible to imagine the capabilities of a machine that much more powerful than the ones we have today, but I think we can accept it could hold quite a lot of simulations of our world.