I’ve asked several times on this blog why light has a speed. Here’s one example.
I’ve also wondered if the speed of light might have changed over time.
This science article discusses two studies that say maybe to the second question. One of those studies appears to have a similar view as mine as to why there is a speed of light. I found this interesting:
The second paper proposes a different mechanism but comes to the same conclusion that light speed changes. In that case, Gerd Leuchs and Luis Sánchez-Soto, from the Max Planck Institute for the Physics of Light in Erlangen, Germany, say that the number of species of elementary particle that exist in the universe may be what makes the speed of light what it is.
Leuchs and Sanchez-Soto say that there should be, by their calculations, on the order of 100 “species” of particle that have charges. The current law governing particle physics, the Standard Model, identifies nine: the electron, muon, tauon, the six kinds of quark, photons and the W-boson.
We know that the speed of light changes in different mediums. For example, it slows down when it travels through water or air vs. a vacuum, which is what gives us refraction. I’m not sure we know why this happens either.
I’m not sure I’ve mentioned it before, but I think the speed of light could be the fastest rate at which the fabric of this reality* can change states. In a vacuum, that’s pretty fast. When matter is around, that’s slower.
Matter and a vacuum is made of the same stuff, just in different states. When that stuff is in the state that produces matter (which I think may just be several pieces of the fabric interacting, which also affects other pieces of it –warping space-time — producing gravity), the rate at which the fabric can change states slows down. That may also be why matter can’t travel at the speed of light. Since the fabric has a slower change rate with matter than with no matter, there’s no way that the matter itself could go at the fastest rate of change of no matter.
I think it’s possible that light isn’t traveling at all. Rather, it’s just an energy state that is propagated through the fabric. Think of the energy waves that propagate out in the water from a rock being tossed in a pond. The water doesn’t flow away from the rock. The water is just the fabric that propagates the energy. The water in one spot of the pond is the same water as it was before and after the wave comes through, it just changed states for moment.
I know…sounds crazy. Notice, I use ‘could’ or ‘maybe’ a lot. But, given that nobody else has explained why light has a speed, I thought I’d give it a shot.
I know this will sound crazier, but this rate of change of the fabric reality is time. Without there being some impedance to that rate of change, there would be no time.
*I don’t know what the fabric of this reality is. Einstein called it space-time. I tend to think of it like string theorists — little bands of energy (or particles) that interact with one another and can change states. It seems they could be interacting with one another in the dimensions we can perceive and in dimensions that we cannot.
Think of an image on the TV (which, btw, the pixels in the TV have a max refresh rate that could be similar to the max state change rate). If the objects on the TV were self-aware, they may be able to sense their own 2D fabric, but not the third dimension from which the signal travels that tells each piece of the 2D fabric which state to be.