As I understand it (e.g. from discussions around the Fermi field theory of the nuclear force), a spin 1/2 particle can emit a spin-1 particle and simultaneously flip its spin (say, spin +1/2 -> photon +1 & spin -1/2); but how does this work with spin-2 particles? Does it need to emit pairs in...
As I understand it, the fundamental unit of interaction in QED is a term with a pair of (spinor) electron factors and a (vector) photon factor, represented in a Feynman diagram as two (anti-)electron lines and one photon line meeting at a vertex.
I get the case where the photon and electron...
Late last year, I started a thread (https://www.physicsforums.com/threads/historical-paper-dump-sites.780669/#post-4907513) to solicit/compile a list of URLs with open access to historical papers; shortly after, I discovered that several of them weren't as open as they had been...This morning, I...
Planck's only lists ten papers; Boltzmann's had none -- though, the link to his article on plato.stanford *does* have a nice-sized "primary sources" section; it doesn't look comprehensive, but it's a good start; maybe I'll plug a few more names into Plato and see if the pattern continues.
The...
Does anyone have any suggestions for finding lists of all papers published by individual physicists?
Usually the Google machine turns up hits pretty quickly, but I've hit a brick wall looking for lists for Max Planck and Ludwig Boltzmann.
netlib.org/bibnet/ is amazing, but it's pretty narrow.
In most introductory QFT treatments, it's stated early on (and without proof) that particles with even integral spin are always attractive, while those with odd integral spin can be repulsive; sometimes this is even cited as evidence that the graviton must be spin 2 (I think Feynman's...
Thanks for the encouragement; I think the problem stems from my incomplete understanding of spin, particularly with regards to multiple particles. I've since found a few references where they show that the two-particle spin operators are I⊗σ and σ⊗I, as opposed to the naive versions I tried...
I suppose that's a last-ditch, break-glass-in-case-of-emergency-type option. But the internet's hours are more convenient.
However, the public libraries I've seen (note: small sample) don't have academic journals. I do remember my old college library had a pretty nice selection of printed...
So...apparently I spoke too soon about how generous Oxford and RSPA were; today, most of the articles I grabbed last week (10/31 and prior) are now pay-walled again. I remembered this happening before, and it looks like all of the articles I have (younger than 70 years at least) from RSPA are...
I'm looking for sites with historical journal articles -- ideally in English, but if there's none available, I can settle for the original. Specifically, I'm looking for stuff by (in no particular order, and certainly not exclusively) e.g. Heisenberg, Pauli, Dirac, Schrodinger, Feynman...
If I'm not mistaken (and I could very well be, as I'm a dilettante dabbler), the corresponding 1st-order diagram would be an incoming electron with momentum p, and an outgoing electron with a momentum (p-k) and photon with momentum k, so the perturbation expansion term would have a destruction...
I'm having some trouble grasping the meaning of the exchange term in the Hamiltonian Heisenberg gives in his classic 1932 paper (the one typically given as the first to describe nucleons via a spin-like degree of freedom; NOTE: I realize this isn't the same as what is today called isospin, but...
The prize goes to dextercioby! I'd downloaded that Darwin paper just this week (If all journals were as open as the Royal Society, the world would be a more wonderful place), but hadn't gotten to it yet (since it was one of a few hundred), but that's definitely a derivation...but, there's a...
@dlgoff, I watched the first half hour of so; I'd forgotten how much of a badass Feynman was...but I didn't catch the part in question.
@vanhees71, I know that was just intended to correvt the record, but it does nicely highlight some of the difficulties that early theorists would have had to...
Hey samalkhaiat,
That's probably the most concise derivation I've seen (and definitely undergrad level, which is also a big plus), so thanks for that...but, I'm actually looking for the historical record -- how it was originally derived without the benefit of a century of quantum mechanics...