Seth Lloyd, a professor of mechanical engineering and physics at MIT, published a paper and a book in which he shows that the universe can be regarded as a giant quantum computer. According to him, all observed phenomena are consistent with the model in which the universe is indistinguishable from a quantum computer, e.g., a quantum cellular automaton.
He considers the following two statements to be true:
- The universe allows quantum computation.
- A quantum computer efficiently simulates the dynamics of the universe.
To conclude with:
Finally, we can quantize question three: (Q3) ‘Is the universe a quantum cellular automaton?’ While we cannot unequivocally answer this question in the affirmative, we note that the proofs that show that a quantum computer can simulate any local quantum system efficiently immediately imply that any homogeneous, local quantum dynamics, such as that given by the standard model and (presumably) by quantum gravity, can be directly reproduced by a quantum cellular automaton. Indeed, lattice gauge theories, in Hamiltonian form, map directly onto quantum cellular automata. Accordingly, all current physical observations are consistent with the theory that the universe is indeed a quantum cellular automaton.
Does this theory hold up?