Without having a deep physics explanation, I would like to share this thought:
What if the light carrying medium flows in to mass?
Imagine the medium is "pulverized" inside particles with mass, then catapulted outwards, only to recondense into medium again after some time.
I first had this idea when considering the two kinds of time dilation:
1) Time dilation because of relative speed.
2) Time dilation because of gravity.
Speed has [m/s] as unit, and gravity is an acceleration, with [m/s^2] as unit.
Could the second form of dilation just be the same as the first? Well maybe, if the medium gains speed towards the mass.
One can further imagine:
-Light as a wave would be curved by massive objects.
-The speed of light would always be observed the same at arrival, because the rate at which the medium is "consumed" is a property of mass itself.
-Redshift (big bang's expansion) could be explained by the constant recreation of medium in space.
As you can see, it's hardly a theory of everything, but it's certainly an interesting thought.