Why against Stern-Gerlach experiment photons are said to be spin 1?
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From: Y.Porat on 6 Dec 2009 12:57 On Dec 6, 6:59 pm, Tom Roberts <tjroberts...(a)sbcglobal.net> wrote: > Jarek Duda wrote: > > On 27 Lis, 17:31, Tom Roberts <tjroberts...(a)sbcglobal.net> wrote: > >> Translating what I said into the terms you used here: Since spin is > >> modeled DIFFERENTLY from angular momentum in QFT, they are different > >> aspects of a system. As I have said several times, spin is INTRINSIC to > >> a particle, but angular momentum is not -- that's QUITE DIFFERENT, in > >> both classical and quantum theories. In QFT, spin is modeled with a > >> definite-spin representation of the Lorentz group, but angular momentum > >> is modeled with eigenfunctions of the angular momentum operator -- > >> that's QUITE DIFFERENT. > > > Yes - that's quite different. > > Does free (not moving) electron have angular momentum? I don't think > > so ... > > Of course it does. The value of angular momentum depends on the point > around which you calculate it; classically any moving object has nonzero > angular momentum around any point not directly in line with its > velocity. Quantum mechanically, a free electron is modeled as a plane > wave, which when expanded in terms of angular momentum eigenfunctions > has a nonzero amplitude for every term in the infinite series (this is > true for any point used as the origin, and for any value of momentum, > including zero). > > > Returning to the field of nonzero vectors, only looking at spin/charge > > conservation, that to destroy one it has to meet with opposite one, > > that they appears in integer multiplicities ... strongly suggests that > > they have topological nature ... > > Whether or not elementary particles are related to topological defects > is an open question that is directly related to modern attempts to > formulate a theory of quantum gravity. No success so far. But the > "topological defect" due to spin would be a line, not a point, and is > not observed for particles. There is more going on than just spin.... > > Tom Roberts -------------------- the electron is not a point and not a line! you have to do one step forwards: it is planar !!! Y.Porat --------------------------------
From: cjcountess on 6 Dec 2009 14:08 Igor Just look at the evidence it speaks for itself. c in liniear direction x c in 90 degree angular direction creates a 90 degree arc which if constant creates energy in circular rotation and a balence of centripital and centrifugal forces. All discoveries do not follow mathematical logic as is already established. Somethings follow a certain incite, which can only be understood geometrically. Square root -1 is an example of this, not only my discovery of c as the natural unit square root of the natural unit -1, but also the one I referenced: An Imaginary Tale: The Story of the Square Root of -1 by Paul J. Nahin page 53 paragraph 2: âsquare root of -1 is directed line segment of length 1 pointing straight up along the vertical axis or at long last, [i = = 1 â 90 degree angle] This is so important a statement that it is the only mathematical expression in the entire book that I have enclosedâ page 54 paragraph 2: âmultiplying be square root of -1 is geometrically, simply a rotation by 90 degrees in the counterclockwise sense Because of this property square root of -1 is often said to be rotator operator, in addition to being an imaginary number.â page 104 paragraph 2: âIn a revealing article criticizing Einstein's and Minkowski's c , a national bureau of Standards physicist admitted that Square root of -1 has a legitimate application in pure mathematic, where it forms a part of various ingenious devices for handling otherwise intractable situationsâ Still, I thought I pointed out how (E=mc^2) = (E=mc^circled) and (c=i) very well, and if you cannot see it, maybe you lack a certain vision. No need to get upset and call names, it will not do you any good or support your argument. As for your statement "And the rest of is even more bizarre. Learn some actual physics. I told you to study conservation laws. Apparently, you didn't learn anything and so you're cursed to repeat your same ridiculous mistakes." If the laws of conservation as they now are written, is not in agreement with this, than perhaps they need to be reexamined. Conrad J Countess
From: Jarek Duda on 7 Dec 2009 03:08 On 6 Gru, 17:59, Tom Roberts <tjroberts...(a)sbcglobal.net> wrote: > > Yes - that's quite different. > > Does free (not moving) electron have angular momentum? I don't think > > so ... > > Of course it does. The value of angular momentum depends on the point > around which you calculate it; classically any moving object has nonzero > angular momentum around any point not directly in line with its > velocity. Quantum mechanically, a free electron is modeled as a plane > wave, which when expanded in terms of angular momentum eigenfunctions > has a nonzero amplitude for every term in the infinite series (this is > true for any point used as the origin, and for any value of momentum, > including zero). I've written - not moving. Electrons are mass particles - has velocities smaller than c - we can choose coordinates in which its not moving, just saying in one point. Does such electron (in its ground state) has angular momentum? > Whether or not elementary particles are related to topological defects > is an open question that is directly related to modern attempts to > formulate a theory of quantum gravity. No success so far. But the > "topological defect" due to spin would be a line, not a point, and is > not observed for particles. There is more going on than just spin.... Why do You think we don't observe them? For me they can give simple explanation of fermion coupling (like Cooper pairs, electrons in orbitals) or atomic selection rules (7th fig. in http://arxiv.org/abs/0910.2724 ) Threating them seriously could be also a reason that we don't fully understand magnetic reconnections "This process is not well understood: once started, it proceeds many orders of magnitude faster than predicted by standard models." http://en.wikipedia.org/wiki/Magnetic_reconnection
From: Y.Porat on 7 Dec 2009 04:15 On Dec 7, 10:08 am, Jarek Duda <duda...(a)gmail.com> wrote: > On 6 Gru, 17:59, Tom Roberts <tjroberts...(a)sbcglobal.net> wrote:> > Yes - that's quite different. > > > Does free (not moving) electron have angular momentum? I don't think > > > so ... > > > Of course it does. The value of angular momentum depends on the point > > around which you calculate it; classically any moving object has nonzero > > angular momentum around any point not directly in line with its > > velocity. Quantum mechanically, a free electron is modeled as a plane > > wave, which when expanded in terms of angular momentum eigenfunctions > > has a nonzero amplitude for every term in the infinite series (this is > > true for any point used as the origin, and for any value of momentum, > > including zero). > > I've written - not moving. > Electrons are mass particles - has velocities smaller than c - we can > choose coordinates in which its not moving, just saying in one point. > Does such electron (in its ground state) has angular momentum? > > > Whether or not elementary particles are related to topological defects > > is an open question that is directly related to modern attempts to > > formulate a theory of quantum gravity. No success so far. But the > > "topological defect" due to spin would be a line, not a point, and is > > not observed for particles. There is more going on than just spin.... > > Why do You think we don't observe them? > For me they can give simple explanation of fermion coupling (like > Cooper pairs, electrons in orbitals) or atomic selection rules (7th > fig. inhttp://arxiv.org/abs/0910.2724) > Threating them seriously could be also a reason that we don't fully > understand magnetic reconnections > "This process is not well understood: once started, it proceeds many > orders of magnitude faster than predicted by standard models."http://en.wikipedia.org/wiki/Magnetic_reconnection ----------------- you can know if some mass has angular momentum only through movement because that is the only way to test it !!! Y.Porat --------------------------
From: Jarek Duda on 7 Dec 2009 08:56
On 7 Gru, 10:15, "Y.Porat" <y.y.po...(a)gmail.com> wrote: > you can know if some mass has angular momentum > only through movement > because that is the only way to test it !!! I agree - saying that pure electron has angular momentum doesn't have too much sense... What it has is spin ... and so it's not made by rotating charge (neutrino...) - spin is something simpler and so more fundamental than charge! And what photon can have is just angular momentum - traveling twist- like excitation of the field - and there is no spin or charge needed for that. Photons are basic, nontopological excitations of all field theories ... their eventual angular momentum is continuous parameter, while spin is discrete one. |