On Jul 3, 1:02 pm, stevendaryl3...@yahoo.com (Daryl McCullough) wrote: > harald says... > > >If you google search, you will find me explaining that Einstein > >claimed to have solved GRT's clock paradox. ;-) > > The use of GR to explain the results of the twin paradox is a little perverse,
Sorry but no, you missed the point (how is that possible after all these years?). The original clock or twin paradox is NOT the SRT exercise of textbooks at all, despite the fact that most confused commentators parrot that error. Instead, it is a challenge to GRT's postulate that an accelerated reference system may be considered to be "in rest". SRT does NOT pretend such a thing. On that point I therefore fully agree with Einstein.
> because GR is a generalization of SR. In the case of empty space far from any > large gravitating bodies, GR reduces to SR, so any GR solution to the twin paradox would have to have already been a solution in SR.
> Which is exactly the > case: GR solves the twin paradox in the exact way that SR does.
Impossible: according to Einstein and myself, there *was* no "twin paradox" in SRT.
> The equivalence principle allows us to *approximately* solve problems involving > gravity by using SR. That's what it's useful for. The other way around, using GR > to solve problems that involve acceleration in flat spacetime, makes little > sense, because you don't need GR. You just need SR + calculus.
Sure. That never was an issue, except (again) for later confused commentators.