The concept of computation doesn’t in any way presuppose the existence of mind… and it’s an incorrect summarization of my work to say that I suggest “the universe is a computer”.

Computation is just about following definite rules. The concept of computation doesn’t presuppose a “substrate”, any more than talking about mathematical laws for nature presupposes a substrate. When we say that the orbit of the Earth is determined by a differential equation, we’re just saying that the equation describes what the Earth does; we’re not suggesting that there are little machines inside the Earth solving the equation.

About the universe: yes, I have been investigating the hypothesis that the universe follows simple rules that can be described by a program. But this is just intended to be a description of what the universe does; there’s no “mechanism” involved. Of course, we don’t know if this is a correct description of the universe. But I consider it the simplest hypothesis, and I hope to either confirm or exclude it one day.