What is the Copenhagen interpretation?
An unobserved system, according to the Copenhagen interpretation of quantum theory, evolves in a deterministic way determined by a wave equation. An observed system changes in a random fashion, at the moment of observation, instantaneously, with the probability of any particular outcome given by the Born formula. This is known as the “collapse” or “reduction” of the wavefunction. The problems with this approach are: (1) The collapse is an instantaneous process across an extended region (“non-local”) which is non-relativistic. (2) The idea of an observer having an effect on microphysics is repugnant to reductionism and smacks of a return to pre-scientific notions of vitalism. Copenhagenism is a return to the old vitalist notions that life is somehow different from other matter, operating by different laws from inanimate matter. The collapse is triggered by an observer, yet no definition of what an “observer” is available, in terms of an atomic scale description, even in principle. For t
