Our Mathematical Universe: My Quest for the Ultimate Nature of Reality

by Max Tegmark

The rate of time flow perceived by an observer in the simulated universe is completely independent of the rate at which a computer runs the simulation, a point emphasized in Greg Egan’s science-fiction novel Permutation City.

Parallel universes are not a theory—they’re predictions of certain theories.

It’s proven remarkably hard to write down a theory that produces exactly the universe we see and nothing more.

job as scientists is to try to figure out how the world works, not to tell it how to work based on our philosophical preconceptions.