Time Travel and Free Will

The concept of time travel has tantalized mankind for as long as there has been literature, and has become especially prominent in recent decades with the rise of Science Fiction as a genre. How can a past still vivid in memory or an inevitable future be completely inaccessible to us except for the instant in which it passes, and what would happen if it was not? Various branches of physics have been trying to answer this since Einstein postulated that one could slow the passage of time by accelerating one’s self. Yet like so many other esoteric branches of science, ignoring the technicalities of achieving time travel in the first place (widely regarded to be impossible anyways), the topic lies firmly in the realm of philosophy and religion to qualify any theories.

The feasibility and nature of time travel lie in three questions:

• Is there free will (in the sense of metaphysical autonomy)?
• What does this imply about the nature of the universe?
• If that nature does not preclude time travel, what are the consequences of it?

The fundamental question to all of this is the first, for in it is vested a greater question: is there a soul – a supernatural? From a pure materialist standpoint, free will cannot exist, for a human being is no more than the complex interaction of his molecules, ultimately completely predictable could we account for all the molecular motion in his body. Though the brain is so complex as to give the illusion of self-awareness and choice, it is still just an illusion and we are no more than the sum of our parts.

If, however, free will does exist, then it would imply that we are greater than the sum of our parts, self-awareness being the hallmark of having risen above being a bundle of molecules interacting in complex fashion – having a soul, so to speak, something that is separate from yet manifest in the matter comprising the body.

So what does this mean for time travel? The first case – one of pure determinism – means that any human endeavor, no matter how complex or grandiose, is nothing more than the inevitable emergence of high-level order from the force with which the universe began long ago. Time travel then would then not be something creatable by mankind, for we cannot affect the universe in any proactive way. If this is the case, then any paradox caused by time travel chanced upon by wormhole or other natural methods would necessarily be inconsequential, meaning that one cannot change the past because will have already been changed (except for Denzel Washington, whose salary has sufficient mass to distort space-time to his bidding). And in the case that time travel is the intersection of parallel universes at different points, then any change in the past will not affect the future in which one travelled there, your presence in the other inevitable anyway. Changes made in a deterministic universe cannot be recursive.

If however, we do have free will and our will is formed outside the physical realm, then we do have the capability of affecting the universe in a substantiative way. Assuming time travel is physically possible, the very act of building a successful time machine demonstrates the existence of metaphysical free will by causing the universe to unfold in ways it otherwise would not. It is only in this case that a recursive paradox could exist: Since alternate universes are inherently deterministic being probabilistic, their presence precludes the existence of the supernatural, at least dwelling in us, so our universe is all we have to deal with. Time travel of any sort then, assuming the existence of the soul, is necessarily impossible, if we are to assume cause-and-effect are inherent to the nature of time-space (rather than artificially introduced by a deity, as one would draw a flip book – in which case we are still determined beings, only by a different determinant).

One’s views on time travel and physics are then dependent on one’s fundamental philosophic and religious assumptions. As in universal origins, the question for each of us is which set of assumptions we will start from: Will our views on the nature of the universe affect our belief or lack thereof in the soul, or will we draw our views on the nature of the universe from our belief in the soul?

-Inspired by a late night conversation with the ineffable devil’s advocate Joseph Sileo.