What you say is true, but Einstein did say that as craft approaches the speed of light, its rate of time flow decreases. But yes, the craft could never reach the speed of light because its mass would approach infinity.
Quoting Bill Hooper <[EMAIL PROTECTED]>: > Gavin wrote: > > Einstein ... also says that time on a craft moving at the speed of > > light (if > > such a thing were possible) would also cease. > > No, Einstein said the craft can't move at the speed of light (period). > He did not say anything about what would happen if a craft did move at > the speed of light. Such claims were invented by others who followed > after Einstein, most notably the producers of Star Trek, etc. > > You are correct in noting that time is affected by gravity and speed. > As with all other definitions in SI, the definition of the second > assumes that the measurements will be made with the caesium atom at > rest with respect to the observer. > > As far as I know, the relativistic effect of gravity on time (and other > measurements) is smaller than can be detected in the experiments that > define the units. When measurement precision reaches the state where it > is significant, the definitions will undoubtably (sp*) be amended to > include a statement such as "when measured in a zero gravitational > field". Does anyone know if this has been formally addressed yet? > > > Regards, > Bill Hooper > Fernandina Beach, Florida, USA > > *PS My spell checker does not like my word "undoubtably" and insists I > should be using "indubitably" (or "undoubtedly"). Do any of our grammar > experts have any advice on this? > >
