Quantum state may be a real thing
Physicists summon up their courage and go after the nature of reality.
At the very heart of quantum mechanics lies a monster waiting to consume unwary minds. This monster goes by the name The Nature of Reality™. The greatest of physicists have taken one look into its mouth, saw the size of its teeth, and were consumed. Niels Bohr denied the existence of the monster after he nonchalantly (and very quietly) exited the monster’s lair muttering “shut up and calculate.” Einstein caught a glimpse of the teeth and fainted. He was reportedly rescued by Erwin Schrödinger at great personal risk, but neither really recovered from their encounter with the beast. The upshot is that we had a group of physicists and philosophers who didn’t believe that quantum mechanics represents reality but that it was all we could see of some deeper, more fundamental theory. A subclass of these scientists believed that the randomness of quantum mechanics would eventually be explained by some non-random, deterministic property that we simply couldn’t directly observe (otherwise known as a hidden variable). Another group ended up believing that quantum mechanics did represent reality, and that, yes, reality was non-local, and possibly not very real either. To one extent or another, these two groups are still around and still generate a fair amount of heat when they are in proximity to each other. Over the years, you would have to say that the scales have been slowly tipping in favor of the latter group. Experiments and theory have largely eliminated hidden variables. Bohm’s pilot wave, a type of hidden variable, has to be pretty extraordinary to be real.
This has left us with more refined arguments to settle. One of these is about whether the wave function represents reality or just an observer’s view of reality. (via Quantum state may be a real thing | Ars Technica)