It’s been a long time since I’ve first questioned Einstein’s Special Theory of Relativity and his fixing of the speed of light (in vacuo) as a constant. For years, the idea somehow did not sit well with me. After all isn’t any velocity determined by a ratio of distance and time such as in the simple relationship d = rt? Why then should the computed speed of light be any different? Fixing c as a constant in the equation c = d/t, requires that to remain consistent, when d changes, t must also change at the same rate. And this is what Einstein proposed,
I’d like to show that it’s not necessary to fix the speed of light to explain certain observations without resorting to the rigmarole of Special Relativity and the contradictory conclusions forced by it. I will demonstrate this by imagining a simplified version of the Michelson Morley experiment, and why they could not detect the “ether.”
We start with these assumptions:
- The speed of light is not fixed.
- The addition of velocities applies to the speed of light.
- When light is reflected, it is actually re-propagated by the receiving atoms of the reflecting surface.
- The speed of light is constant relative to its source, not the observer.
Imagine a light source directed at a mirror at a fixed distance (d) from the source and that the system of source and mirror are moving through space at a velocity of v in a straight line from source to mirror, while the speed of light in a non-moving system is propagated through space at a velocity of c. Doing a few simple calculations, keeping our assumptions in mind, we come to conclusion that the M&M experiment must fail to detect linear motion through space.
First, we calculate the time (t1) it takes the light beam to reach the mirror: t1 = (d + vt1) / (c + v). We add vt1 to d since the total distance travelled through space is increased by the movement of the entire system. And the total velocity (c + v) follows assumption 2 above. This calculation reduces to t1 = d / c, as we might expect in a non-moving system.
Next, calculate the time (t2) it takes for the light beam reflected off the mirror to reach the original source: t2 = (d – vt2) / (c – v). The return distance is reduced by vt2 because of the motion, but the return rate is given by (c – v); remember assumption 4, and according to assumption 3 the light is re-propagated and the mirror is now the light source. Since the original source is approaching the mirror (the light source), the total velocity is given as (c – v)! This calculation also reduces to t2 = d / c, and the total time (t1 + t2) it takes for the entire trip is 2d / c, again, the same as in a non-moving system.
Therefore, it seems that the assumption that the speed of light in vacuo is a constant is not merely unnecessary, it is simply not correct.