> Lastly, we don't really have a good physical understanding of matter at near C speed limits. With mass increasing as we approach C, I don't know we can assume the same physical properties of any material in classical models.
Yes, we do, and yes, we can. Matter travelling at near c relative to us behaves exactly the same as any other matter. That's what frame invariance means. From our perspective, yes, the ship would seem to have more mass, which is a direct result of the equivalence of mass and energy and the fact that it has a crap-tonne of kinetic energy. But from the ship's own perspective, its mass does not change at all- rather, the entire surrounding universe seems to become more massive.
Yes, we do, and yes, we can. Matter travelling at near c relative to us behaves exactly the same as any other matter. That's what frame invariance means. From our perspective, yes, the ship would seem to have more mass, which is a direct result of the equivalence of mass and energy and the fact that it has a crap-tonne of kinetic energy. But from the ship's own perspective, its mass does not change at all- rather, the entire surrounding universe seems to become more massive.