On Thu, Feb 13, 2014 at 8:39 PM, Edgar L. Owen <edgaro...@att.net> wrote:
> The accelerating elevator is in deep space. There are no tidal forces. > You can tell if spacetime is curved or not by observing if light moves in a straight line or not. If you were in deep space and the elevator was accelerating at 1g due to a attached rocket and you turned on a laser pointer that was aimed parallel to the floor you would notice that the light would not hit the spot directly across because by the time it took the light beam to cross the elevator the elevator would be moving faster upward than when the light beam started it's journey due to the acceleration. Thus you would observe the light beam hit a spot slightly below where it would have hit if the light moved in a straight line, so you would conclude that spacetime inside the elevator was curved. If the elevator was not in deep space but was just sitting on the surface of the Earth you would make the exact same observation and make the same conclusion about the curvature of spacetime. So you'd know spacetime was curved but unless the elevator had a window you wouldn't know if it was because it was in deep space being accelerated by a rocket at 1g or because it was sitting still on the surface of the Earth in the planet's 1g gravity field. John K Clark -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
