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A comment on Why Feynman Diagrams Are So Important. Parent comment

Re:Why Feynman Diagrams Are So Important by ssivark on Thursday July 07, 2016 @11:42AM (#12050011)
It sounds murky because we were being silly the first time around. The physically relavant quantity was always the sum of all those contributions and we decided to (arbitrarily, in the grand scheme of physics) split things up under some scheme. So, in hindsight, the positive and negative infinities were artificially manufactured by our segregation scheme... there's not much to be bothered about in that regard.

That might still mean that there's more to be understood regarding notions of infinity or the convergence of amplitudes in quantum field theory.

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Re:Why Feynman Diagrams Are So Important by darkmighty on Thursday July 07, 2016 @01:42PM (#12050902)
As an example (not sure if applicable), you could do some calculation and get an alternating series as the result:

R = 1 - 1/2 + 1/3 - 1/4 ...

If you "explain" the positive part as being contribution from field A, and the negative part as a contribution from field B, both would be infinite, but the reality might be that splitting them is nonsensical.

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