After reflecting more upon this conversation, I now think that the _physics_ community should press forward with quantum factoring experiments as a very high priority -- perhaps higher priority than the LHC. Quantum factoring may very well be the _first_ place to demonstrate discreteness in quantum _phase angle_. Quantum factoring is a win-win experiment: either way, you get a Nobel prize. If quantum factoring succeeds, you get a Nobel prize for proving the existence of a new & useful type of computational principle. If quantum factoring fails due to showing imperfections in our understanding of basic quantum theory, then you get a Nobel prize for that. At 08:23 PM 2/9/2013, Rowan Hamilton wrote:

Last time I checked the most accurate physical theory in human history was Quantum Electro-Dynamics. The value of the anomalous magnetic moment of the electron has been measured and compared to the QED theory to one part in 10^12.