Penrose argues that human consciousness is non-algorithmic, and thus is not capable of being modeled by a conventional Turing machine, which includes a digital computer.

Penrose hypothesizes that quantum mechanics plays an essential role in the understanding of human consciousness.

Penrose states that his ideas on the nature of consciousness are speculative, and his thesis is considered erroneous by some experts in the fields of philosophy, computer science, and robotics.

[1][2][3] The Emperor's New Mind attacks the claims of artificial intelligence using the physics of computing: Penrose notes that the present home of computing lies more in the tangible world of classical mechanics than in the imponderable realm of quantum mechanics.

The billiard-ball computer was first designed some years ago by Edward Fredkin and Tommaso Toffoli of the Massachusetts Institute of Technology.