How do Photons Reach the Speed of Light?

[turin]

If you think of one dimension of space as horizontal,x, and time as vertical, in the y direction, then massless photons move horizontally, ...

This is only correct from an interpretive QFT standpoint, but not if you consider photons as classical particles that follow a single, definite trajectory. I have personally done experiments that demonstrate a nonzero time of flight for light. Also, the design of the particle detectors used in the LHC (e.g. CMS) would not work (i.e. would not give meaningful results) if photons (and any other ultrarelativistic particles) had zero time of flight, because the readout of the detector excitationis based on a very accurate timing between the proton bunch collision and the different radii of the detector materials.

To put it in your terms, photons move diagonally with a slope of dy/dx=1/c; dy/dx=0 has been ruled out by countless experiments.

 

[heldervelez]

I read Post 24, and it offers no explanation, no cause. It only offers a math relation.
One can find at page 1506 de l' ACADEMIE DES SCIENCES (5 JUIN 1905) le doc. from M. H. Poincaré : ELECTRICITÉ . - Sur la dynamic de l'electron:
(en francais)
"en supposant que l'electron, déformable et compressible, est soumis à une sorte de pression constante extérieure don't le travail est proportionnel aux variation du volume"
in eng.:
"assuming that the electron, deformable and compressible, is subjected to a kind of constant external pressure whose work is proportional to the volume change"

It seems a 'cause', and one explanation is better than none.

 

[Matterwave]

I thought that usually the light cone is defined by the 45 degree line...(setting appropriate units where c=1). Space like separation is to the left and right of this cone, and time-like separation is top and bottom. In this way, events with space-like separations could not affect each other. I never read that the light cone is defined by the horizontal line...? Wouldn't that imply light moving at infinite speed?

Reference:
http://en.wikipedia.org/wiki/Light_cone

 

[jtbell]

Momentum can be zero even with v not zero.

Example?

 

[lightarrow]

Example?

mass = 0 (we were discussing hypotetical massless particles traveling at speeds less than c).