Bill S. In your write up about Bob and Alice in the last paragraph
you say "there is no way we can know with certainty that it is
not actually possible to move relative to spacetime". I have
a problem with that because we are a part of spacetime. We can
move relative to another part of spacetime, but obviously we
cannot move relative to what we are a part of. You are correct
when you say that if only Alice and Bob exist in spacetime,
which may or may not be infinite, they can move only with
respect to each other. As I see it it they are infinitely far
apart then they essentially do not exist to each other. There
is no way for them to interact. Beyond that I don't see that
there is much that is very realistic about the situation in
any case. Thinking about it it seems that we may be in a
situation similar to the irresistible force and the immovable
object. A situation which can not in fact exist.
Bill Gill
