There are a few problems with this claim, as well as the general idea that the universe is a computer. tl;dr: the claim doesn't even make sense, except perhaps

There are a few problems with this claim, as well as the general idea that the universe is a computer. tl;dr: the claim doesn't even make sense, except perhaps in some figurative sense. First, what a computer is cannot be identified with any physical system, because computation is observer-relative. There is no fact of the matter that some physical system is performing computations. Computation is not a natural kind. We can harness physical phenomena "computer-wise", that is, use physical phenomena to simulate computation, but it makes no sense to identify computation with physical phenomena as such. That physical phenomena involve quantities that can be computed does not mean the phenomena are performing computations as such. A simpler example of something analogous is a book. The print in a book, physically, is just a series of pigmented spots on sheets of something made of plant fiber. Physically, it isn't even "writing" per se, as writing is not a natural kind, but what we call the result of the act of writing. The pigmented spots on plant fiber are the only content, physically, of what is in a book. The content we think of when we speak of books is brought to the book by the reader who interprets the marks on the pages according to what he already has in his head. This is what reading is: interpretation, assigning meaning. The same is true of computers. Physically, no computation is occurring. Second, computation is about something. When a physicist or engineer computes the current in a circuit, he isn't manifesting the circuit. He is computing something about the circuit. Computation is an abstract activity of the mind. (We can use this in an argument against materialism.) Third, part of the reason why this identification of computation with physics is likely occurring is because the methodology or methodologies of physics necessarily strip reality of much of its substance and leave us with a mathematical, formal model expressed in computational terms. Guess what else is a formal model that involves computation? This allows us to talk about the formal equivalence or subsumption or whatever of physical models and computational models. That such a relationship exists isn't that surprising in retrospect.