My God, It’s Full of Clones: Living in a Mathematical Universe

Abstract

Imagine there’s only math—physics is nothing more than mathematics, we are self-aware mathematical substructures, and our physical universe is nothing more than a mathematical structure “seen from the inside”: that’s what Max Tegmark’s Mathematical Universe Hypothesis (MUH) proposes. In this paper, I will discuss some consequences of the MUH. While Tegmark claims that the MUH implies the existence of an enormous but finite multiverse (to avoid the measure problem that occurs when you try to calculate probabilities within an infinite ensemble), I will argue that it implies the existence of the largest imaginable multiverse, the Maxiverse, where every imaginable conscious observation is guaranteed to happen. I will attempt to explain why, of all the worlds in the Maxiverse, we happen to live in one that can be understood by physical laws simple enough to be discovered (or, at least, approximated well enough for predictive and technological purposes). I will explore the issue of personal identity in the context of a Maxiverse that contains an infinite number of exact clones of myself, and discuss the Maxiverse Immortality Argument, the idea that I should expect my future subjective experience to be unbounded. Finally, I will consider the question of whether or not the Maxiverse hypothesis can make predictions that can be put to the test.