bhobba said:
QM is not 'voodoo' - it explains in a logical way its deductions. Some people just don't like what it says. That's fine - but don't try and make out there is some essential problem with QM like 'voodoo' - there isnt.
My chocie of the word "voodoo" was off the cuff, but not entirely unserious.
I don't dispute that the predictions of QM are arrived by by a logical, computable process. However what I would emphasise is that the physical events themselves(detector blips), on which the correlations are based, do not arise from a physical or logical process. If non-localism is forbidden, as SR would suggest, then no process involving elements of physical reality, or any simulation of such a process, can account for why the detectors individually beep or not. QM only accounts for the correllations of the beeps after the fact.
I feel obliged to elaborate on the "voodoo" remark, so I'll put forward the following deliberately unphysical thought experiment.
Two Voodoo Kings (L and R) meet at dawn, each bringing with them a pot containing an equal number of black and white beads. They perform some ritual or incantation on the pots, then leave, returning to their respective clinics having sworn an oath -- or hexed themselves-- not to communicate with each other in any way.
During the day, until dusk, an experimenter or experimenters can visit each king(L or R), as many times as they like, and ask for a bead drawing ritual to be performed. In the ritual, the voodoo king's cane is placed on the ground/table near the pot, and the tip moved so that it makes a certain angle between the pot and the cane. The king (L or R) then draws a bead from the pot. The color c_i of the bead B/W is recorded, along with the angle \alpha_i of the cane, and the current number i of rituals this king has performed on that day. The king then replaces the bead in the pot.
The experimenters requests generate an ordered set of drawing data from each king. i \quad c_{Li} \quad \alpha_{Li} and i \quad c_{Ri} \quad \alpha_{Ri} When draws with the same count number i are compared, it is found(*) that the drawn beads have the same color with probability \cos(\alpha_{Li} -\alpha_{Ri})^2. Nevertheless individually each King is found to have an equal chance in any given ritual of drawing a black or white bead.
It is clear that the above thought experiment corresponds
exactly to an EPRB experiment with photons. We can alter the settings by having the experimenter choose the cane angles, randomly or from a fixed set. We can have one experimenter, or two, or multiples. We can have the experimenter obtain draws in any order, or even all from one king and then the other. We can have the kings moved to opposite ends of the earth, or universe, or any other typical settings applied in thought or actual EPRB experiments.
And, in particular, we can assert that the data which results from these Voodoo rituals
cannot be explained by any local hidden variable model. And if we add special relativity -- to my understanding at least -- we can assert that no element of physical reality, or physical process, can be invoked to explain why a bead is drawn as either black or white. The advantage of this Voodoo king thought experiment is that we have done away with detectors, photons and experimental setups, and here it is to some way of thinking "intuitively clear" that there is no underlying physical explanation for why each bead is drawn black or white. The Kings will claim that it is "magic", "voodoo", "ghosts", etc, and in particular beyond the scientific/mathematical/intellectual/rational ability of human beings to explain, and in physics we have a term for this thesis and it is called "Bell's Theorem".
Of course if you allow non-locality these difficulties disappear immediately. It's just that relativity seems to be getting in the way of anyone doing that.
bhobba said:
My old statistical modelling professor would occasionally touch on such things - his eyes would roll back - he would say - its like studying Niechie - pointless really. Guess what - he was right.
I'd caution your old professor to be a little more careful in what he considers it pointless to discuss. Because under certain interpretations of EPRB experiments, philosophical mumbo jumbo is a very real element of our universe.
(*) I am probably not being entirely statistically precise here, but I will say that the data on agreement / disagreement of the beads is consistent with a dice with probabilities cos(a-b)^2 / sin(a-b)^2 being rolled for each paired draw. The setup could be modified so that the experimenter goes to each king with a fixed angle or set of angles, but I've kept things deliberately general here.
