  Is there a single linearly evolving Wave Function of the Universe that is
able to lead to all the nonlinearities we see around us? This proposal seems a
priori highly implausible. I claim that instead, in the real Universe,
generically only local wave functions exist. Non-local wave functions occur for
carefully engineered contexts such as Bell experiments, but there is no single
wave function for a cat or similar macroscopic objects such as a brain.
Contextual wave function collapse leads to a defensible version of the
Copenhagen interpretation, where classical macro levels provide the context for
quantum events and biological emergence. Complexity arises via adaptive
multiscale modular hierarchical structures that enable logical branching to
emerge from the underlying linear physics. Each emergent level is causally
effective because of the confluence of upwards and downwards causation that
takes place consistently with the underlying physics. Quantum chemistry
approaches in biological contexts fit this local wavefunction picture.
