Recent content by gill1109

I would call that *a* complete sample space. Complete in the sense that it is rich enough to be able to talk about all the probabilities of all events described in the original problem. It is also minimal, in the sense that it has the smallest possible number of elementary outcomes. But it is...

The sample space could be taken to be the set of pairs (drawer chosen, colour of sock chosen). It can be taken to have 3 x 2 = 6 elements, though one of them has probability zero, so could simply be erased. After that, give these 6 points probabilities as done above. Notice that the event...

Whether or not there are open questions, is clearly an open question.

I miss qBism as one of the interpretations. It is certainly is presently quite popular. It is a bit more than "shut up and calculate" because it is the claim that this is all that physics ought to do, namely tell an agent what they ought to believe given what they presently know. I also read in...

Bell likes to make jokes. He is very serious about the analogy between socks and particles, but his whole point is that according to quantum mechanical predictions, socks aren't like "quantum particles" at all.

I disagree. Unless we disagree about what is "real". If the wave function is real and there is no collapse of the wave function then nothing is real at all. There is just the wave-function of the universe, evolving deterministically. That's my personal opinion. I'm a mathematician, not a...

l1, l2, l3 and l4 are dummy variables. You certainly may give them all the same name "ell" if you like. These are integrals over "ell" lying in some space, of some function of "ell", with respect to "ell". The integral operation is additive. As long as you are integrating over the same space...

Actually, the two pictures in the original post are really the same. Different scientists simplified something pretty complicated in a different way. The Wikipedia drawing has merged the waveplates and the polarizing beam splitter. The idea is that by rotating the plate you rotate the...

There is not one kind of experiment. In 2015 there were four "loophole-free experiments". Two of them had photons speeding from a central location to distant measurement locations. One of them had electron spins associated with a defect in a diamond, at two distant locations. Both spins were...

Obviously, we never can be certain. But we could take it as some kind of working assumption. In fact, we could even say that our experience leads us to imagine it as very likely. After all, we can quite successfully predict what experiences we will get in the future, by "pretending" that there...

Quantum mechanics itself does not predict "action at a distance". On the contrary, it predicts that there is *no* action at a distance. I am talking about action at a distance with respect to things in the manifest, external world. Things most people would certainly admit to being "real". The...

Do you really mean "no way to accept it"? Don't you mean " no way to reject it"? (*I* think that probability is not due to incomplete knowledge but is an inherent ground-level feature of nature.)

Suppose we have N Stern-Gerlach devices. Measure N spins each initially in an equal weight superposition of up and down. We now have 2^N worlds all with equal weights. Now let N tend to infinity and you will find that in almost all of those worlds, very close to half of the spins came up "up"...

In a good experiment, Alice and Bob choose their measurement angles freely. Moreover, the time elapsed between choice of angle and registration of measurement outcome (on each side of the experiment) is so short (relative to the distance between the two measurement locations), that there is no...

Looking for local hidden variables is not, IMHO, an attempt to define pure chance. It's an attempt to avoid deciding whether or not "pure chance" is a fundamental physical feature of the universe. In other words, if we could "explain" quantum mechanics through (preferably local) hidden...