C. W. Rietdijk
In 1966, C. W. Rietdijk published "A Rigorous Proof of Determinism Derived from the Special Theory of Relativity." It purports to prove that the world is pre-determined because of an argument from special relativity called the "relativity of simultaneity." J. J. C. Smart, a strong determinist, whose 1961 Mind article is one of the canonical sources for the standard argument against free will, had discussed in 1964 Hermann Minkowski's argument for a special-relativistic block universe. Smart was circumspect as to whether a "tenseless" view of time means that "the future is already somehow 'laid up' there." He does not yet claim, as does Rietdijk, that everything that is going to happen has already happened, an idea called actualism. Rietdijk's argument depends on paradoxes (the most famous being the twin paradox) that result from moving observers having different ideas about what events in their view correspond to "now." They have different "planes of simultaneity." "Now" means they have synchronized their clocks according to Einstein's famous procedure. A moving observer B thinks some event in his plane of simultaneous events is in B's future. At the same (cosmic time) moment A thinks that B is in his (A's) plane of simultaneity. But this is not a transitive relation. Just because A sees B as his "now" and B sees an event in A's future as B's "now" does not make the event in A's future "now" for A. In his 1989 book The Emperor's New Mind, Roger Penrose developed this idea as what he called the "Andromeda Paradox."