> That question, "Can you find out? Hell no," is relativity in a nutshell. If you really grasp what that means, the whole deal from simultaneity to time dilatio

> That question, "Can you find out? Hell no," is relativity in a nutshell. If you really grasp what that means, the whole deal from simultaneity to time dilation to curved spacetime all falls out more or less intuitively. (Of course it was harder to work out the first time :P) You cannot deduce relativity from the knowledge that you can't find out whether you're moving. In Newtonian physics you can't find out whether you're moving either. The essential ingredient is that the speed of light is the same in all reference frames. Furthermore curved spacetime is by no means trivial; that's general relativity. It took Einstein himself 10 additional years before he got from special to general relativity, and more still to really develop it.