[Profpat]

Hi Dipayankar;

I found this regarding light but nothing yet on it being a dimensionless point particle. In fact if it were, it wouldn't really be anything, similar to the electrons being viewed as VIRTUAL point particles, or the " big bang " coming out of a dimensionless point particle. ( Nothing ).

Actually, photons are not particles in the physical sense that we normally associate with that word. Rather, they consist of discrete bundles of energy which are fixed in magnitude. As a result, each photon takes on some of the characteristics of a physical particle.
Viewed in this context, light still does not change its basic behavior. These apparent particles are electrically neutral, so they tend to travel in straight lines, without being affected by either magnetic fields or electrical fields.
If photons were actual physical particles, we would have trouble using them to explain some of the observed behaviors of light. For example, when light passes from a vacuum to a denser medium, such as Earth's atmosphere, it slows down in accordance with the density of the medium. This much, at least, makes intuitive sense. However, light then maintains a constant speed through the new medium — it does not continue to slow down as it continues to move. This does not seem to make much sense for physical particles, which should be subject to friction effects in a non-vacuum. Furthermore, when the light leaves the denser medium for a less dense one, it speeds up again. Definitely not the behavior one would expect from any kind of particle.

If you find something refering to light being a dimensionless point particle please let me know.

Best to you,

Pat