This least-known type of determinism has received amazingly little attention
so little, in fact, that it apparently has never been named. Because it is derived from
the special theory of relativity, I will call it "relativistic determinism".
According to relativity, simultaneity is relative. Absolute simultaneity would mean that there is a universal "now" or present, which applies to everything and everyone in existence. If there is no such universal present, however, then what one observer considers to be simultaneous with event E, another observer one who is moving relative to the first will consider to take place before or after E (observers who are in motion relative to one another are said to be in different "frames of reference"). This relativity of simultaneity is not a result of differences of measurement, such as those due to the unequal distance each observer has from the events in question. It is something that remains after allowances have been made for such differences.
The relativity of simultaneity implies that the future is determined (in a non-causal
sense) in the following way. Let us say that you at this moment are event A. That is, your
present self what you are doing, thinking, observing, and so on, at this moment
is A. Let's also say that there is an observer traveling in a very fast spaceship, who at this
very moment (from your frame of reference) is event B. Now for B, that is, for the spaceship
traveler at this moment, there is an event C which, from B's perspective, lies in the past. The interesting thing is that it is possible for C to be an event which, from A's perspective, is still in the future. That is, C hasn't happened yet as far as you're concerned. Nonetheless, there is someone right now (again, from your perspective) who regards C as having already occurred. And if that is the case, then how can C be avoidable?
If an event which is in your future is in someone else's past, and that someone else is in your present (or even in your past!), then it is inevitable that the event will take place. Event C must come about, no matter what. And this scenario can in principle apply to any future event. Thus, all future events are determined.
The above argument seems to me unquestionably valid. The only way an indeterminist can reject it, I believe, is by rejecting the relativity of simultaneity. Since special relativity has been experimentally confirmed many times, rejecting it may seem all but impossible. But it is not. One must make a distinction between a theory's experimental results and its correct interpretation. It is possible that the observable confirmations of relativity are compatible with a different theory that reintroduces absolute simultaneity. In fact, the basic equations of special relativity were first arrived at while assuming absolute space and time (and thus absolute simultaneity). Given our present knowledge, however, I believe it is more reasonable to accept relativistic determinism than it is to reject it.
©1996, 2000 Franz Kiekeben