xxein: This is closely associated to Olber's paradox. Although
various explanations of it differ a lot.
The bottom line is that we can see distant stars. How did that light
get here? This prompts ballistic theories of light. But I cannot go
there. Light is an energy. (Did you ever get a sunburn or
melanoma?) Light follows through energy. That's why it can be
gravitationally bent by energy. We already know that gravity follows
an inverse square law and that it is a mass function rather than a
temperature function. It weakens with distance but never depletes
entirely. So it appears to be an all invasive energy.
Even icy dead comets are subject to this energy (and they have their
own gravity also). So it would be unreasonable to think that light
requires a mass/particle media when it has an energy media.
If I remember this right, Chris Hillman was the one who (back in the
sort of old days) made the early stages of this discussion group into
the present format of 'write or word'. Anyone who remembers something
like that, please reply.