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bio website motls.blogspot.com
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Hi, I am a string theorist and a publicist.


Mar
16
answered CP Violation of the CKM Matrix
Mar
16
revised What experiment would disprove string theory?
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Mar
15
comment Energy Measurements in a Two Fermion Double Well System
Dear Marty, the OP's question makes it absolutely clear that twistor59 is asking about the textbook example of spinless electrons so your discussion of the spins has nothing to do with the original question. In the real world, this "spinless electron" system is embedded in such a way that all the electrons we consider must be e.g. spin-up. In your spin-ful language, one only picks the two-electron states with $s_z=+1$ which really means the unique state from the triplet. Allowing different spins creates more states, and therefore the Pauli's principle becomes even less constraining.
Mar
13
comment Does the Pauli exclusion principle instantaneously affect distant electrons?
I think that Jim Parsons would still win in this respect, Phil. He has more physically accurate writers of the script, too.
Mar
13
revised Energy Measurements in a Two Fermion Double Well System
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13
revised Energy Measurements in a Two Fermion Double Well System
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Mar
13
comment Energy Measurements in a Two Fermion Double Well System
BTW I hope that what I wrote above seems consistent to what you've heard from Moshe Rozali - and, hopefully, an extension in some respects. That's because I believe that we have to offer the same treatment of things like two electrons in two wells. ;-) If you see some discrepancy between the two of us, I would like to see it. Thanks, twistor.
Mar
13
comment Energy Measurements in a Two Fermion Double Well System
The locality in QFT is totally exact, so you won't have even an infinitesimal probability to transfer a "little bit of information" along spacelike intervals of spacetime. Any apparent result that this is possible either pretends that some measurement may be done more accurately than it can, or it pretends that global measurements may be done locally, or does other mistakes. BTW in EPR-entangled pairs, one also transfers exactly 0 information because we can't "order" even our particle how it should be measured. But this double-well case isn't even entangled in any useful sense. It's not EPR.
Mar
13
comment Energy Measurements in a Two Fermion Double Well System
Thanks for your interest, twistor. You're exactly right. The inaccuracy of the total energy may be seen in "subtly different" ways, depending on the procedure. An apparatus that doesn't see the other well has to "cut" its vicinity in some way, and this creates an uncertainty. Alternatively, we may detect the electron in the first well and then measure the energy exactly, taking both wells into account. Then we will find out that the odds are exactly 50% and 50% for $E_1,E_2$ but we need to make a global measurement.
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Mar
13
answered Energy Measurements in a Two Fermion Double Well System
Mar
4
awarded  Nice Answer
Feb
22
awarded  Enlightened