MOBE2001 writes: The bad news is that time does not change. Spatial velocity is given as dx/dt. Velocity in time(dt/dt) is nonsensical. As simple as that. In other words, no time travel to the past or the future, no motion in space-time, no wormholes and no hanky-panky with your great, great, great grandmother. There is only the changing present, aka the NOW. This is the reason that Sir Karl Popper called spacetime, "Einstein's block universe in which nothing ever happens" (Conjectures and Refutations). The good news is that distance is an illusion and we'll be able to travel instantly from anywhere to anywhere.