Study Says Quantum Wavefunction Is a Real Physical Object

cekerr writes with this excerpt from an article in Nature "The wavefunction is a real physical object after all, say researchers. ... the new paper, by a trio of physicists led by Matthew Pusey at Imperial College London, presents a theorem showing that if a quantum wavefunction were purely a statistical tool, then even quantum states that are unconnected across space and time would be able to communicate with each other. As that seems very unlikely to be true, the researchers conclude that the wavefunction must be physically real after all. David Wallace, a philosopher of physics at the University of Oxford, UK, says that the theorem is the most important result in the foundations of quantum mechanics that he has seen in his 15-year professional career. 'This strips away obscurity and shows you can't have an interpretation of a quantum state as probabilistic,' he says."

Comments

Sensible

[exa]

"Abstract objects" or "mathematical objects" don't exist in general, so this suggestion is rather plausible. Of course, the reality of the wave function had been proposed before, but new arguments are sorely needed in philosophy of quantum mechanics.

Re:Sensible

[exa]

There have been several scientifically plausible interpretations. One thinks of MWI for instance.

It's just that some rather big names have unwittingly advocated superstitious, and completely nonsensical interpretations, the most famous of which are Copenhagen interpretation, Von Neumann Interpretation, and Penrose's assorted BS.

Re:Alternative...

[sexconker]

Because if the "wave function" is a real object, then there is no probabilistic nature to quantum shit - it just means we are currently unable to directly measure the "wave function" without "collapsing" it. If it's not probabilistic, all the fuzziness of quantum physics goes away. Schrodinger's cat is dead, Einstein was right when he said God doesn't play dice, entanglement is horse shit, everyone who works with string theory is a moron, etc.

Data vs Logic

[VernonNemitz]

The funniest thing is that this paper is coming out in the midst of the discussion of faster-than-light neutrinos. According to the interpretation presented in the article blurb at top, FTL neutrinos should be forbidden. If they actually exist, however, then that means that the quantum wave function really is a stastical thing and not a physical thing.

Re:Data vs Logic

[jd]

The latest experiments match the original observations. In the past day or so, they tweaked a number of parameters - such as the length of pulse - to see if more precise timing and more precise correlation would have any impact. The numbers didn't change. So, Scotty was wrong - we CAN break the laws of physics! (But the fine is 2795 Ningis if we're caught.)

the new debate

[Goldsmith]

In the Nature blurb, there's a bit of discussion at the end that quantum states might all be linked, entangled or not.

In most physics classes, you learn quantum mechanics by calculating the interactions between isolated states. This thought process is natural and useful for certain areas of physics, but you end up worrying about hidden variables and how particles which are essentially in different universes can possibly communicate. This view does not need the wave function to be real, it can just be a statistical tool.

An alternative way of thinking about things is the idea that there are no isolated states (and no measurement apparatus which can exist outside the quantum system). From that point of view, one wave function is sufficient to describe the entire universe, traced back to the big bang. You don't need to worry about spooky action, everything obeys causality just fine assuming the wave function is real. There are some cosmological issues still, and it's not clear such a unified state is possible in an infinite universe.

At least we're starting to all agree wave functions are real and not just a statistical tool.