> Is there proof that something couldn't go faster than light No, and of course not. Any proof depends on having a mathematical model of how the universe work

> Is there proof that something couldn't go faster than light No, and of course not. Any proof depends on having a mathematical model of how the universe works, and while what you describe would certainly violate our current model, that doesn't mean our model is correct. We can say that we haven't seen anything like that, and that such an thing doesn't seem to be necessary for our current model, so the first stumbling block is - why should anyone spend time trying to flesh out this alternative model? We can also pose questions like, how does it get from above to below the speed of light? Is there ever a time when it's faster than 99.99999999999999999998% of the speed of light, and why don't we see them if they are so common that they can be used to explain quantum effects? What is the mechanism by which they lose momentum? Where does the energy go? How does it get coupled to quantum effects, including superfluid helium? Why don't we see anything like Cherenkov radiation, which occurs when a charged particle is going through a media (like water) where the local speed of light is slower than that of particle?