About 9:45 pm now [13 Jan 2013]. Wigner, whom I once heard give a talk at UALR (1981, with P. J. Cheek), makes a point of charge conservation being different somehow in its derivation than the other conservation laws--momentum, energy, angular momentum, for instance. That was his point of view in 1949--I don't know how it changed later. But, his discussion starting on p. 10 of "S & R" was very abstract anyway. So I'm just noting it here, and also noting that he mentions . . .
charge quantization!
as something not explained by theory. (Oh yeh, if only we had Dirac magnetic monopoles, but that seems forgettable now).
So, with this pain in my right side bugging me tonight as I sit in bed writing this, I will turn to Crease & Mann's page 92 discussion of, if not quantization or conservation exactly, at least the reason for the electron's charge to be a physical constant:
"As Fritz London showed, the reason the phase can shift and not affect the charge is because of the gauge symmetry, which compensates for such changes by creating virtual photons--and hence an electromagnetic field--whose actions ensure the conservation of electric charge."
Okay, so it is about the idea of charge conservation. I'm looking for a similar statement in 't Hooft's 1980 Sci Am article but can't find it at the moment. But here's something else from the great Gerard, p. 8, 3rd column: "It is the symmetries of this kind, where the phase of a quantum field can be adjusted at will, that are called gauge symmetries."
10:20, time to quit. Actually, at the top of the last page [blogwise, at the bottom of my June 20th post] I quoted the sentences that follow the one of 't Hooft's I just quoted. So I've come full circle somewhat since this morning just before noon, or just after.
charge quantization!
as something not explained by theory. (Oh yeh, if only we had Dirac magnetic monopoles, but that seems forgettable now).
So, with this pain in my right side bugging me tonight as I sit in bed writing this, I will turn to Crease & Mann's page 92 discussion of, if not quantization or conservation exactly, at least the reason for the electron's charge to be a physical constant:
"As Fritz London showed, the reason the phase can shift and not affect the charge is because of the gauge symmetry, which compensates for such changes by creating virtual photons--and hence an electromagnetic field--whose actions ensure the conservation of electric charge."
Okay, so it is about the idea of charge conservation. I'm looking for a similar statement in 't Hooft's 1980 Sci Am article but can't find it at the moment. But here's something else from the great Gerard, p. 8, 3rd column: "It is the symmetries of this kind, where the phase of a quantum field can be adjusted at will, that are called gauge symmetries."
10:20, time to quit. Actually, at the top of the last page [blogwise, at the bottom of my June 20th post] I quoted the sentences that follow the one of 't Hooft's I just quoted. So I've come full circle somewhat since this morning just before noon, or just after.
