 The speculative idea is the following. As it turns out, collapse theories—one form of alternatives to quantum theory which aim to solve the measurement problem—modify Schrödinger’s equation and give different predictions from quantum theory in certain specific circumstances. These circumstances can be realised, moreover, if decoherence effects can be suppressed (Bassi, Adler, &amp; Ippoliti 2004). Now one of the most difficult obstacles that await the construction of a large scale quantum computer is its robustness against decoherence effects (Unruh 1995). It thus appears that the technological capabilities required for the realisation of a large scale quantum computer are potentially related to those upon which the distinction between “true” and “false” collapse (Pearle 1997), i.e., between collapse theories and environmentally induced decoherence, is contingent. Consequently the physical realisation of a large-scale quantum computer, if it were of the right architecture, could potentially shed light on one of the long standing conceptual problems in the foundations of the theory, and if so this would serve as yet another example of experimental metaphysics (the term was coined by Abner Shimony to designate the chain of events that led from the EPR argument via Bell’s theorem to Aspect’s experiments). Note, however, that as just mentioned, one would need to consider the computer’s architecture before making any metaphysical conclusions. The computer architecture is important because while dynamical collapse theories tend to collapse superpositions involving the positions of macroscopic quantities of mass, they tend not to collapse large complicated superpositions of photon polarisation or spin.