[altrego99]

Yep this is hidden value theorem.

I think either the author messed up the concept badly, or what is more likely, the proponent of this 'QBism' doesn't get it.

He appears to think spooky action is just lack of information - something like "if I open the box and see white marble, you must have the black one". Possibly haven't read or doesn't understand EPR thought experiment (which shows how by choosing to make a certain kind of observation, what he and thus the other guy sees).

Looks like pseudoscience to me.

[gsteinb88]

Yeah, no, Chris Fuchs is definitely not doing pseudoscience. Please don't make judgements like that based on popular science writeups (though, this is actually one of the better ones I've seen on interpretations of QM, even if the figure is horribly misleading/wrong).

More generally, QBism is not a hidden variable theorem in any sense. What the article glosses over is that QBism does still require a modification to standard probabilities that (when combined with Baysian/information theoretic reasoning) gives you the measurement probabilities you actually see in the lab.

Chris Fuchs' writeups are pretty fantastic: http://perimeterinstitute.ca/personal/cfuchs/

Specifically, "Quantum Mechanics as Quantum Information, Mostly" is a short and fun introduction (okay, 32 pages, but pretty easy reading).

[gus_massa]

It's very difficult to read "Quantum Mechanics as Quantum Information, Mostly", in particular because it mixes the equations with unrelated comments like:

> A grain of sand falls into the shell of an oyster and the result is a pearl. The oyster's sensitivity to the touch is the source of a beautiful gem.

> Last year, I watched my two-year old learn things at a fantastic rate, and though there were untold lessons for her, there were a sprinkling for me too.

A better reading material is the solution of a simple exercise, that explains the difference between the usual approach and the QB approach. (Is there any differences in the results?)

Someone has suggested the double slit experiment, because it's nice and easy to explain with words, but the continuous distribution makes the calculations difficult. I prefer the three Stern-Gerlach experiments because it's discrete and the math is easier. I think I read that experiment in a Feynman book, but I don't remember the exact citation. (The SG in the middle is the equivalent to the double slit.)

I just found this PDF that explain clearly the situation: http://docslide.us/documents/spin-and-quantum-measurement-da... . It's the "Experiment 4" (subsection 1.2.4, page 10). Can you explain the differences between the usual and the QB approach in this experiment?