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Apr
17
awarded  Popular Question
Feb
21
awarded  Nice Question
Jan
9
awarded  Yearling
Dec
20
asked Lepton Universality and Pauli Exclusion
Nov
13
awarded  Popular Question
Nov
6
awarded  Notable Question
Oct
29
awarded  Revival
Oct
23
comment Can someone clarify whether the recent experiment closing all remaining loopholes to Bell's Theorem really shut the door on local realism for good?
arxiv.org/abs/1510.06712 tonight this preprint by Price and Wharton appeared on the Arxiv, discussing this issue and emphasizing Retrocausality as well as Superdeterminism as two remaining loopholes. They regard retrocausality as a form of local realism.
Oct
11
comment Smallest possible spinning clock?
@dmckee sorry I messed up the notifications above. Can you confirm that an electron does not work? How about a hydrogen atom? A hydrogen molecule? I think a small molecule like H2 or H2O might work in principle, if not in practice.
Oct
11
comment Smallest possible spinning clock?
Back to something like my original question: For fixed angular momentum (ie h-bar), the angular velocity is inversely proportional to the moment of inertia, of course. Therefore, you would want the spinning object's moment of inertia to be small enough that the rotation would be reasonably noticeable, but large enough that the object still behaves in a nearly classical manner. How big is that? AZgain, my guess is bigger than an electron, but smaller than a small molecule. Or is that too optimistic?
Oct
11
comment Smallest possible spinning clock?
@McKee and@ brucesmitherson Ah yes that is a good point. Suppose I now say I want a spinning clock with angular momenhtum exactly h-bar. At least in principle it could be an object as large as the earth, just spinning very slowly. This system would surely act quasi-classically and would work as a clock except for the fact that it would rotate so slowly it would be hard to detect the motion.
Oct
10
asked Smallest possible spinning clock?
Sep
4
comment Does a Buckyball spin like an electron or like a baseball?
Yes, one way to answer the question is to say that only point particles spin like an electron. So quarks, yes, but protons and neutrons, no. Then you have the photon. It has intrinsic spin, I think, but I hesitate to call it a point particle. Also, there is the little matter of spin one versus spin one-half.
Sep
1
asked What all has intrinsic spin?
Aug
28
answered Which photons pass through a circular annulus?
Aug
28
comment Which photons pass through a circular annulus?
Points for considering orbital angular momentum
Aug
28
comment Does a Buckyball spin like an electron or like a baseball?
I have accepted this answer, but I am still thinking about the boundary. A proton and a neutron are not point particles, so I would say they also spin like baseballs. Besides the electron, the photon which is not a point particle, but is a zero (rest) mass “particle” would not spin like a baseball. Similarly the gluon, the quark and the graviton would be non-baseball spinners. This leaves the neutrino, sdomewhat more uncertain, but still probably on the not baseball-like side. But everything else would fall on the spins like a baseball side.
Aug
28
accepted Does a Buckyball spin like an electron or like a baseball?
Aug
27
asked Does a Buckyball spin like an electron or like a baseball?
Aug
21
asked Which photons pass through a circular annulus?