"Then, in 2011 Pusey, Barrett, and Rudolph obtained the momentous result that, under a certain separability assumption, distinct pure quantum states have non-overlapping probability distributions this providing the first proof that the quantum state is a real thing in the terms outlined above. The separability assumption employed by PBR is that independently prepared pure quantum states correspond to a product of probability distributions over ontic states..."
PBR figures in this paper. It's a good read.
I understand "state of knowledge", maybe even yours, I hope. Remember (the very early) Russell here:
"My God in boots, the ontological argument is sound!" Or not.
BTW, RILLY liked your posts on Helium. Lots of thought there.
Before it's all over, I believe it will be shown that Galactic Jets from rapidly spinning Black Holes are also manifestations of quantum effects visible in the "Classical" Universe. Stay Tuned.
Thanx bhobba,
CW