Posted: Sep 15, 2011 6:59 am
zaybu wrote:I don't see the problem of "localizability". I have no idea from what this comes. It certainly not a topic in QFT. I have nine textbooks on my desk, and none even mention that concept.
Again I'm not claiming anything fundamentally controversial or new here, simply that I, personally, think that "field quanta" is better suited to photons than "particle", since particle implies a certain localizability.
The localizability issue not discussed in most textbooks on QFT, which are simply trying to give particle physicists the tools for calculating scattering amplitudes, no that's true. However, it is discussed in the research literature:
http://www.cft.edu.pl/~birula/publ/CQO7.pdf
http://prl.aps.org/abstract/PRL/v100/i18/e183603
http://www.lois-space.net/Workshops/Vaxjo080616-18/Presentations/tamburini.pdf
http://fau.academia.edu/MEHogan/Papers/280637/Gauge-Invariant_Photon_Wave_Function_and_Diffraction
http://arxiv.org/abs/quant-ph/0604169
http://www.nist.gov/pml/div684/fcdc/upload/preprint.pdf
zaybu wrote:All particles are subject to the Heisenberg Uncertainty Principle. It's just that fermions obey different statistics than bosons. The only time you will need to consider waves is when you are dealing with a large number of photons. In that case, the wave picture gives you adequate results. But when you deal with one on one: one photon with one electron, or two electrons exchanging a photon, then the particle picture is the only one that makes sense. Either that or you might as well throw Feynman's diagrams under the bus.
Imagine I have an ideal experimental setup - an optical cavity, and I put a single quantum of monochromatic light in there. Would you really want to call that a "particle" ?
Incidentally, do you think that two electrons really exchange photons when paticipating in the electromagnetic interaction ?