From what I have read spacetime curvature is equal to the mass/energy density plus 3 times the pressure. Now if you and I are the exact same location in spacetime but moving at different velocities we will measure different mass densities and pressures. Does this mean that gravity/curvature is velocity dependant and relative?
Every measurement is relative. Since there are only three basic units of measure; mass, time, and linear dimension; and all of these are affected by relativistic effects, we cannot say any measurement is absolute, including the curvature of spacetime.
That’s not quite true, Q.E.D. While the distance (delta-d) and the time (delta-t) between two events are relative, delta-d[sup]2[/sup] - (c*delta-t)[sup]2[/sup] is invariant. Also rest mass is sometime called invariant mass, because it does not depend upon the observer.
Quite so, DrMatrix. I was focusing on the OPs question and forgot to include that bit of information. Though, I believe my answer to the original question was still correct, unless I’m overlooking something fundamental again.