[throw149102]

From my understanding, the quantum threshold theorem states that if you have a low base error rate (1-3%) you can apply multiple levels of a single quantum error correcting code to get arbitrarily low levels of errors on a logical qubit ("remove errors faster than you introduce them"). Right now that means that you need approximately 1000x physical qubits for 1 logical qubit, but to me that's a solid mathematical/theoretical demonstration that you can scale QC.

[grungegun]

You're right. I've looked at quantum codes before, but apparently my understanding was lacking - thanks for the info.