Posted: Sep 15, 2011 1:41 am
by eric8476
twistor59 wrote:Continued off topic discussion from this thread.

The topic in question revolves around whether it is appropriate that we should say that light is composed of particles. My position is this:

1 I fully accept that modern quantum field theory provides the best means for modelling interactions involving the electromagnetic field at a fundamental level.

2 Mode excitations can be induced in the electromagnetic field and these are discrete and countable, and referred to as "photons".

3 Photons do not have the same localizability properties as, say, electrons, and for this reason, I hesitate to call them particles, but prefer the term "field quanta".

Incidentally, it is not correct to say that the two slit experiment such as illustrated in the youtube video proves the particulate nature of light. Exactly the same "discrete flash" behaviour is obtained by treating the incident wave as a classical field, but the valence electrons in the detector according to quantum rules. (Note this does not mean that I don't think light is a quantum field, I most certainly do !). So Einstein was right, but for the wrong reason.

Real evidence for the discrete behaviour in light comes from photon antibunching experiments and scattering processes such as the Compton effect.

I believe Einstein thought that light was composed of "light atoms" which had point sources a bit like the Coulomb field, but summed up to produce the classical wave. That picture certainly wasn't right.

i wonder about a photon being matter or energy also. they show up on the double slit experiment detector indicating a structured form leaving a signature. is it that our measurements are not capable of determining the mass amount of photons, possible.

i noticed something, see the you tube video of the experiment posted by twistor59 in the first post on this thread. at about 40 seconds into the video the detector screen looks close to empty, after 40 seconds the detector screen fills up fast. is this some form of the compton effect? is there something to the behavior of the photons in quantity? to those reading this, add my name to the list of credits after receiving your nobel prize for answers to this ("corny" is my middle name, hehehe).

p.s. - did the issue of viewing electrons and photons in the double slit experiment get solved?

p.p.s. - @zaybu or others, when beaming a ray of light in the double slit experiment, do the detectors pick up the particles? and if not does that indicate that forces are not particles or does it indicate that detectors are not capable of picking up the particles? if the detectors do not pick up the particles, then that goes to particles permiating through the solid detectors and that could explain quantum tunneling better, correct?