> And you don't have to leave your frame of reference to see a difference between acceleration and gravity, they are distinguishable in any frame of reference.
One of Einstein's great contributions is the knowledge that this isn't actually true. If you're in a box with no windows it's literally impossible to tell if you're on the ground in a planet's gravity or if you're being accelerated in empty space.
One of Einstein's great contributions is the knowledge that this isn't actually true. If you're in a box with no windows it's literally impossible to tell if you're on the ground in a planet's gravity or if you're being accelerated in empty space.
http://en.wikipedia.org/wiki/Equivalence_principle