> Once you know speed of light is the maximum possible speed But he didn't postulate this at all. He simply postulated (as per Newton) that light is made of pa

> Once you know speed of light is the maximum possible speed But he didn't postulate this at all. He simply postulated (as per Newton) that light is made of particles with mass, which could thus be affected by gravity. Since they are moving at a finite speed, the light particles would be slowed down by gravity, and eventually completely stopped. He further proposed, based on this model, that the mass of an object could potentially be determined by determining how much slower the particles were moving. This doesn't work. Light doesn't really get slowed down by gravity, and you definitely don't have any slow light that was created from stars trillions of miles away. It's a cool idea, but doesn't work with how light actually propagates.