Our Mathematical Universe by Max Tegmark

On microscopic scales, particles schizophrenically appear in two places at once, leading to the quantum conundrums mentioned above. At high temperatures, colliding particles change identity to me, an electron colliding with a positron and turning into a Z-boson feels about as intuitive as two colliding cars turning into a cruise ship. At low temperatures, liquid helium can flow upward. At high speeds, Einstein realized that time slows down, and curmudgeons on the Swedish Nobel committee found this so weird that they refused to give him the Nobel Prize for his relativity theory. We’ve repeatedly tested this prediction, and the results overwhelmingly support Darwin.

Darwin’s theory thus makes the testable prediction that whenever we use technology to glimpse reality beyond the human scale, our evolved intuition should break down. A cavewoman thinking too hard about what matter is ultimately made of might fail to notice the tiger sneaking up behind and get cleaned right out of the gene pool. Or three or four.“Evolution endowed us with intuition only for those aspects of physics that had survival value for our distant ancestors, such as the parabolic orbits of flying rocks (explaining our penchant for baseball). But if so, he’s a century ahead of his time. So perhaps it will turn out that there’s a sense in which Tegmark is right about all this.

Of course, the math now in use hasn’t succeeded in answering all of science’s big questions either. So in some way the “real” underlying mathematical reality must somehow be simpler than most of the math that scientists actually use. He further requires doing away with infinity, as math with infinities is subject to the Gödel undecidability theorem, which demonstrates that mathematical systems of sufficient complexity cannot be completely consistent. To believe, you need to accept the “block universe” view of spacetime, in which time and change are illusions because all spacetime already exists, just sitting there.

Tegmark’s case is not entirely convincing. And the last chapter veers into a rant about ways human civilization could self-destruct, having virtually nothing to do with the rest of the book at all.

The first half of the book is a semiautobiographical crash course in modern cosmology, of which Tegmark is a prominent practitioner. But it’s unfortunately more than 200 pages into the book before he actually begins to discuss his point. It’s fascinating speculation, presented engagingly.

Our Mathematical Universe by Max Tegmark