> There is not a clean division between physicists & others on
>this. John Polkinghorne agrees with the argument you give here - but
>he's a particle physicist, not a general relativist.
> _One_ problem with your argument is that it would seem to
>require some preferred reference frame: "Now" is relative. Suppose
>events at times later than t = 0 in my rest frame don't really exist.
>For another observer who happens to be right next to me at my t = 0 but
>who is moving, some of those events should be in his/her present.
> Does God have a preferred space-time coordinate system? Taking
>the Incarnation seriously might make us want to say so, but we need to
>work out the implications of such an idea.
> George Murphy
You are right about the need for a simultaneity plane which defines "now"
absolutely. That doesn't exist in Einstein's preferred formulation of STR.
But it did exist in his first formulation where time was a parameter and
not a coordinate (dimension), and it does exist (at least the possibility
is there) in Lorentz's empirically equivalent formulation of STR. The
reason it disappears for Einstein is his positivism which led him to a
wholly operationalist definition of time and simultaneity.
Under some models of GTR, including the class of "physically realistic"
solutions, a privileged reference frame is possible.
I think we absolutely must distinguish between metaphysical time (God's
time) and the measured time of the physical universe. Even if we cannot do
better than an operationalist notion of physical time, we still are not
forced to give up the idea of absolute simultaneity.