While you're up, get me a brain pill?

Should your brain hurt first thing in the morning?  Of course!  Here's why:(Background:  Bell's Theorem, or Bell's Inequality, goes " No physical theory of local hidden variables can reproduce all of the predictions of quantum mechanics.")Terry Rudolph, . . . a physicist at Imperial College London. . . .  gives the example of a die that can be prepared to give either even numbers, with a 1/3 probability of getting 2, 4 or 6; or prime numbers, with a 1/3 probability of getting 2, 3 or 5. The real state 2 can be produced by either preparation method, so the same reality underlies two different probabilistic models. The authors show, however, that the same reality cannot underpin different quantum states.  Their theorem does, however, depend on a controversial assumption: that quantum systems have an objective underlying physical state. Christopher Fuchs, a physicist at the Perimeter Institute in Waterloo, Canada, who has been working to develop an epistemic interpretation of quantum mechanics, says that he has avoided the interpretations that the authors exclude. The wavefunction may represent the experimenter’s ignorance about measurement outcomes, rather than the underlying physical reality, he says. The new theorem doesn’t rule that out.  Still, Matt Leifer, a physicist at University College London who works on quantum information, says that the theorem tackles a big question in a simple and clean way. He also says that it could end up being as useful as Bell’s theorem, which turned out to have applications in quantum information theory and cryptography. “Nobody has thought if it has a practical use, but I wouldn’t be surprised if it did,” he says.  Because it is incompatible with quantum mechanics, the theorem also raises a deeper question: could quantum mechanics be wrong? Everyone assumes that it reigns supreme, but there is always a possibility that it could be overturned. So Barrett is now working with experimentalists to check predictions that differ between the theory and the epistemic accounts it conflicts with. “We don’t expect quantum mechanics would fail this test, but we should still do it,” he says.Hurt yet?  This gives me a once-familiar feeling, which I first got back in 1966-67, taking courses in general relativity and quantum theory.  I think you can sum it up as "If this is so easy to say, why is it so hard to understand?"Joe