For some sixty years it has appeared to many physicists that probability plays a fundamentally
different role in quantum theory than it does in statistical mechanics and analysis of measurement errors. It
is a commonly heard statement that probabilities calculated within a pure state have a different character
than the probabilities with which different pure states appear in a mixture, or density matrix. As Pauli put
it, the former represents “Eine prinzipielle Unbestimmtheit, nicht nur Unbekanntheit”. But this viewpoint
leads to so many paradoxes and mysteries that we explore the consequences of the unified view, that all
probability signifies only incomplete human information.
Interesting that Jaynes took that position! It seems to mesh with the MWI position on these things, that all quantum uncertainty about the future is really a kind of anticipated indexical uncertainty.
One thing it apparently taught Jaynes:
Interesting that Jaynes took that position! It seems to mesh with the MWI position on these things, that all quantum uncertainty about the future is really a kind of anticipated indexical uncertainty.
What were all the physicists smoking? .
There’s consistency there, but since when did consistency imply correspondence with reality?