Math is everywhere: medicine, sports, banking, gambling, National Security Agency espionage.
And then there’s science, which has adopted math as the preferred method of description for life, nonlife and the entire physical universe. Math does a decent enough job at this to inspire wonder among physicists about why it works so well. The answer isn’t obvious, but Tegmark thinks he knows: It’s because reality is math. In fact, he contends, all mathematical structures are real. The internal reality of human perceptions is merely a pale approximation of the true external reality embodied in one of those mathematical structures.