What is Time?

Time seems to be one of those things like “likelihood” which can’t be defined in terms of other things; only via circular definitions. But there are some things that we can say about it.

Recently I was trying to figure out what the distinguishing characteristics of time are, other than the fact that we feel it passing. I came up with three things that go some way to defining time:

  • Things that are “in the future” cannot be predicted with certainty
  • Disorder increases as time passes
  • We feel that we are “freely” making decisions that affect the future

All of these three things seem like they might be related. Let’s take the whole issue of free will. There are many who say, for reasons I can’t quite fathom, that free will is an illusion. I take that back on second thoughts; the reason so many people think this, is that they believe, wrongly, that the future is predictable and determined by the present state of our universe and the laws of physics.

This is not in fact true. Newtonian physics seems to define a predictable universe, but Newtonian physics does not govern the behaviour of objects at the subatomic scale, or even the atomic scale. For subatomic particles, you need quantum mechanics. Many people think that quantum mechanics says that the behaviour of subatomic particles is “random”; but this isn’t the real kicker of quantum mechanics. The real kicker is that the observed state of a subatomic particle depends on the experiment you do to observe it. Since all our experimental apparatus are made up of vast collections of subatomic particles — at least from a certain points of view — the apparatus themselves should not have a state until they are observed. But to us, they certainly appear to have a state, independent of our observation.

This brings up the “problem of measurement” in quantum mechanics. At what level does an “observation” occur? At what level does quantum mechanics strangely cease to apply, if it does at all? If you’ve listened to my podcast, you’ll see that I like to play around with the idea that perhaps quantum mechanics does apply at all levels. The mathematical and philosophical difficulties of quantum mechanics aren’t solved simply by this assumption, but it’s an interesting approach to play with.

At any rate, the idea that the universe has a state, which leads to its future state, appears to be quite wrong, based on all available evidence. There really is no contradiction between physics and our intuitive experience of free will. Many people want free will to be an illusion, because it seems “unscientific”. I don’t think it is unscientific at all; we just need to allow science to change and progress, in the same way that “fields” were once considered unscientific but are now fully accepted by scientists.

Many, shall we say, mystical types, believe this opens the door to everything from God to telepathy. Again, this point is arguable, but I personally see no evidence for God or telepathy or any other religious or psychic phenomenon. There’s nothing there to explain.

Now, suppose we had a universe in which the future could be known, in principle, and could be predicted from the universe’s current state. There would be no possibility of free will being anything other than a a weird illusion; our emotions certainly could not be regarded as separate entities to our brains in any way at all, and could have no efficacy. There wouldn’t be any need for time either; Einstein/Minkowki’s four-dimensional spacetime would be more than the convenient abstraction, applying only to specific predictable situations, that it actually is; it would be a true representation of reality. Scientifically, however, we simply don’t live in that kind of a universe.

We’ve tied together the unknown nature of the future together with free will. But what about entropy, the tendency of things to become more disordered? Could we have an unknown future and genuine free will without entropy? I’m not sure about this, but I think, probably, no. Entropy works in a deterministic universe — for example, the particles in a gas would still be subject to entropy, even if they all behaved in a perfectly Newtonian way. But such a gas would behave in a way that was, in principle, totally predictable. Clearly, we can’t have free will and a genuinely unknowable future in a Newtonian universe. But what if we had the universe that we currently have, and yet we didn’t have entropy? What if things had no tendency to become more disordered?

It seems to me (and I admit to not having fully thought this through in detail) that we probably couldn’t have free will either. Any decision we made could only affect the subatomic level, where quantum physics clearly operates. Subatomic effects could not “follow through” to create macroscopic effects. We really would be the sum of our parts, and nothing more. Or am I wrong about this?

This is a very answerable question as far as I can see; just one that requires more thought than I have currently put into it …

Finally, if I’m right about all this, it cannot be coincidence that we have here two phenomena that allow us to have free will. Neither do I believe the universe was arranged by an intelligent being, unless that intelligent being is actually us. It seems to me that there must be a close relationship between these three things, so that one is just a manifestation of the other.

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