Four-dimensional Reality and Determinism; an Answer to Stein

1. We argue that the constancy of c implies a realistic now at a distance in all inertial systems, which in turn leads to determinism.

2. We elaborate that denying this violates physical consistency, that requires the concept “velocity”.

3. Physics implies models making the world observationally and logically coherent, also as to the experiences of different observers. Velocity and now at a distance are cases in point.

4. Retroaction – which implies a realistic future – can be demonstrated to appear in some experiments.

5. We give a demonstration of determinism via reality at a distance that has an effect here and now too.

6. If the phenomenon of Einstein, Podolsky and Rosen (EPR) does not imply retroaction, it makes necessary nonlocal signals. This is highly relevant to reality and “now” at a distance.

7. The clock paradox shows concrete visible consequences of “merely metrical” relativistic coordination and time flow at a distance.

Keywords: determinism, special relativity, indeterminism, clock paradox, block universe