Solving the Measurement Problem? Complementarity and dynamical collapse theories

This lecture covers two approaches to the measurement problem. Recall that in Bell’s taxonomy of ‘six possible worlds of quantum mechanics’, there were three pairs of views: each with a romantic element, and an unromantic element. Our first approach is the romantic element in the pair one might call Endorsing the orthodox formalism. The corresponding unromantic view is instrumentalism: what Bell (2004: 188) calls ‘the purely pragmatic view’: associated with the one-liner ‘shut up and calculate’. The much-used phrase ‘Copenhagen interpretation’: (i) is ambiguous between these; and (ii) was invented by Heisenberg (cf. Howard (2004) for the history). Our second approach is the unromantic element in the pair one might call Changing the formalism. This pair says that: despite the orthodox formalism’s (especially the Schrödinger equation’s unitary evolution’s) supreme empirical success, it fails. The ‘collapse of the wavepacket’ is real: either (unromantically, i.e. our case) in inanimate nature, in a way that is tuned to recover the empirical success of the orthodox formalism; or (romantically, i.e. not our case), in the mind of the observer. (The subsequent lectures will take up both elements of Bell’s third pair: the pilot-wave, and the Everettian (aka: many worlds), interpretations.)