On Jul 5, 3:00 am, stevendaryl3...@yahoo.com (Daryl McCullough) wrote: > harald says... > > >On Jul 4, 2:02=A0pm, stevendaryl3...@yahoo.com (Daryl McCullough) wrote: > >> It's hard for me to see how the "twin paradox" is a paradox in any > >> sense other than being a surprising result. > > >Just study Einstein's solution and see if you agree - or if you smell > >a dead cat. ;-) > > I'm not sure what "Einstein's solution" is, but for any problem > involving traveling clocks, the prediction of GR or SR is this: > > elapsed time on clock = Integral along the path > of square-root(|g_uv dx^u dx^v|) > > In SR, we can always choose coordinates so that g_uv is constant > and diagonal, with g_00 = 1, g_11 = g_22 = g_33 = -1. Then the > above expression reduces to: > > Integral along the path of square-root(1 - v^2/c^2) dt > > In General Relativity, or in SR with noninertial coordinates, > g_uv may in general vary from point to point, so there is an > apparent position-dependence to the rates of clocks. > > I really don't understand how the twin paradox is a consistency > challenge for GR. The fact that Einstein himself may have worried > about it doesn't mean anything to me. We're not dealing with holy > scripture, and Einstein is not a prophet. GR is a theory that stands > or falls independently of its creator. Einstein is not the last word on GR. > > What do you consider to be the *real* twin paradox? > > -- > Daryl McCullough > Ithaca, NY
The one that Einstein was confronted with - the first "twin" or "clock" paradox that we know of.
