Why against Stern-Gerlach experiment photons are said to be spin 1?
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From: Y.Porat on 12 Dec 2009 02:00 On Dec 12, 6:48 am, Tom Roberts <tjroberts...(a)sbcglobal.net> wrote: > Jarek Duda wrote: > > On 10 Gru, 21:04, Tom Roberts <tjrob...(a)sbcglobal.net> wrote: > >> Hmmm. I described this in terms of non-rel QM, and mentioned how it extends to > >> QFT. Your concept of there being "wave" and "corpuscular" descriptions is not > >> contained in either of them. You need to get a real QM/QED textbook, not a comic > >> book. > > > So in Your picture for example while electron-position creation, there > > appears (come from where? another dimension or something?) two points > > of infinite energy density ... with some magical labels containing > > their commutation relations ? > > Whatever makes you say that? > > The electron-positron pair is created, from the energy in the photon. They are > "brand new", and "came" from nowhere -- they were CREATED, which is why they > come in pairs with all their additive quantum numbers having exactly opposite > values. And "energy density" is not infinite -- these are QUANTUM OBJECTS (they > don't have sharp positions). The intrinsic properties of the e+ and e- are part > and parcel of them, including properties modeled by commutation relations.. > > > I agree that one of us should return to reality ... > > No hope -- neither you nor I know what "reality" is, so a "return" is not > possible. All we have are MODELS. And yes, those models are not complete. > > > These theories are not physics, but some APPROXIMATIONS - mathematical > > models which allow us to calculate some properties, estimate some > > probabilities ... > > Your first statement is wrong, as physics _IS_ constructing models of the world, > which necessarily involve approximations. > > > [...] > > > I agree that photons (don't have to, but) can carry angular momentum. > > Photons with definite momentum have non-zero angular momentum in any basis and > relative to any origin. They are QUANTUM OBJECTS, not pointlike classical > particles as you seem to think. They don't have sharp locations, which is why > the projection of their wavefunction onto angular momentum eigenfunctions has > nonzero amplitude for every one (when they have a definite momentum, as was the > case being discussed). > > > Please explain how these experiments shows that they also need to > > carry spin? > > The angular dependence of photon interactions directly implies they are spin 1. > > I repeat: you need to STUDY QM and QFT before you have any hope of understanding > spin. Or why the wavefunction for quantum objects with definite momentum has > nonzero amplitude for all possible angular momenta. > > This is getting overly repetitive. Don't expect me to respond > unless you actually LEARN something about the subject. > > Tom Roberts -------------- youtalked a lot sansaid nothing!! tghe only reasonable things you said are the words od doubt!! good for you after decades of pompous self confdece some cracks of doubt came even to a pompous crook that speaks his magic (empthy )words lke quantum and farthing 'quantum numbers ' anyway that is good toimpress your innocent students **it is **not** good enough to impress people who know some more physics *you cant cheat every one forever **!! Y.Porat --------------------- |