 Inspired by Ed Fredkin’s ideas on reversible computation (see Hagar 2016), Feynman was among the first to attempt to provide an answer to this question by producing an abstract model in 1982 that showed how a quantum system could be used to do computations. He also explained how such a machine would be able to act as a simulator for quantum physics, conjecturing that any classical computer could do the same task only inefficiently. In 1985 David Deutsch proposed the first universal quantum Turing machine and paved the way to the quantum circuit model (Deutsch 1989). The young and thriving domain also attracted philosophers’ attention. In 1983 David Albert showed how a quantum mechanical automaton behaves remarkably differently from a classical automaton, and in 1990 Itamar Pitowsky raised the question of whether the superposition principle may allow quantum computers to efficiently solve NP-complete problems. He also stressed that although one could in principle ‘squeeze’ information of exponential complexity into polynomially many quantum states, the real problem lay in the efficient retrieval of this information.