Thanks. It’s decent, actually, but there’s still some barrier. Increasing that barrier is changes to physics notation since then (no vectors!).
Fortunately my university library appears to have a copy of an older edition of Rohrlich’s Classical Charged Particles, which may help piece things together.
Feynman [wrote], ”It is therefore impossible to get all the mass to be electromagnetic in the way we hoped. It is not a legal theory if we have nothing but electrodynamics” [13, p. 28-4]; but he was unaware that the factor of 4⁄3 had already been accounted for [10]).
It’s worth noting that Feynman’s statements are actually correct. According to Wikipedia, the problem is solved by postulating a non-electromagnetic attractive force holding the charged particle together, which subtracts 1⁄3 of the 4⁄3 factor, leaving unity. Petkov doesn’t explicitly say that Feynman is wrong, but his phrasing might leave that impression.
Wikipedia points to the original text of a 1905 article by Poincaré. How’s your French?
Thanks. It’s decent, actually, but there’s still some barrier. Increasing that barrier is changes to physics notation since then (no vectors!).
Fortunately my university library appears to have a copy of an older edition of Rohrlich’s Classical Charged Particles, which may help piece things together.
Petkov wrote:
It’s worth noting that Feynman’s statements are actually correct. According to Wikipedia, the problem is solved by postulating a non-electromagnetic attractive force holding the charged particle together, which subtracts 1⁄3 of the 4⁄3 factor, leaving unity. Petkov doesn’t explicitly say that Feynman is wrong, but his phrasing might leave that impression.