On quantum computing gaining mind share with the Dwave announcement.
He replied: the field [quantum computing] doesn't need acceptability. The idea will either be valid, or not. The claim [Dwave's] will either be true, or not.
On the most important uses of quantum computers:
The most important application of quantum computing in the future is likely to be a computer simulation of quantum systems, because that's an application where we know for sure that quantum systems in general cannot be efficiently simulated on a classical computer. This is an application where the quantum computer is ideally suited.
Perhaps in the long run, as nanotechnology becomes quantum technology, that will be a very important generic application.
It also thinks that fully operational universal quantum computers will force the acceptance of the many universes theory.
Deutsch: I think the watershed moment with quantum computer technology will be when a quantum computer -- a universal quantum computer -- exceeds about 100 to 200 qubits... What I mean here is a qubit which is capable of being in any quantum state, and is capable of undergoing any kind of entanglement with another qubit of the same technology, and all those conditions are actually necessary to make a fully fledged quantum computer... When I said you need 100 to 200, that probably means several hundred, or perhaps 1,000 or more, physical qubits.
He said more about nanotechnology only having psychological barriers to a lot more progress. We could and should be doing a lot more to make molecular nanotechnology happen except for psychological barriers.
Deutsch: Nanotechnology has the potential of making a huge change. But the only involvement of quantum computers is that it will make it easier to design nanotechnological devices. Apart from that I don't think it's a big technological revolution.
What it is though, philosophically, is taking a quantum world view. That is rather a revolution, but that could happen today and the only reason it has been sluggish in happening is psychological, and maybe quantum computers will help with this psychological process. That's a very indirect phenomenon