Scott Aaronson

Title: Could a Quantum Computer Have Subjective Experience?

Abstract: Following Deutsch and others in the 1980s, I'll argue that we can throw many debates about the

quantum/classical boundary into much sharper relief by examining the possibility of conscious quantum

computers: entities designed to violate the heuristic that "anything too much like ourselves" can be well approximated using classical probability theory. After explaining some of the paradoxes to which conscious

quantum computers give rise, I'll then discuss a speculative viewpoint that regards irreversible decoherence as a fundamental aspect of subjective experience: a viewpoint that (among other things) would rule out conscious quantum computers. I'll then explore the implications of that viewpoint for some other issues in science and philosophy, including Boltzmann brains, Newcomb's problem, and free will.

[Video (YouTube)]


S.A., The Ghost in the Quantum Turing Machine ( ).

Not without entanglement signal nonlocality violating linear unitary S-Matrix axioms.


Subquantum Information and Computation

It is argued that immense physical resources - for nonlocal communication, espionage, and exponentially-fast computation - are hidden from us by quantum noise, and that this noise is not fundamental but merely a property of an equilibrium state in which the universe happens to be at the present time. It is suggested that 'non-quantum' or nonequilibrium matter might exist today in the form of relic particles from the early universe. We describe how such matter could be detected and put to practical use. Nonequilibrium matter could be used to send instantaneous signals, to violate the uncertainty principle, to distinguish non-orthogonal quantum states without disturbing them, to eavesdrop on quantum key distribution, and to outpace quantum computation (solving NP-complete problems in polynomial time).
Comments: 10 pages, Latex, no figures. To appear in 'Proceedings of the Second Winter Institute on Foundations of Quantum Theory and Quantum Optics: Quantum Information Processing', ed. R. Ghosh (Indian Academy of Science, Bangalore, 2002). Second version: shortened at editor's request; extra material on outpacing quantum computation (solving NP-complete problems in polynomial time)
Subjects: Quantum Physics (quant-ph)
Journal reference: Pramana - J. Phys. 59 (2002) 269-277
DOI: 10.1007/s12043-002-0117-1
Report number: Imperial/TP/1-02/15
Cite as: arXiv:quant-ph/0203049