Today’s topic of free will was chosen by Virginia W at Westwood High School. But was the topic freely chosen or was it already determined?
The answer has to do with the way our universe works. According to modern scientific theory, the universe can be broken down into a number of rules which govern how things interact. These rules are often presented to us as a series of confounding mathematical equations.
That, for example, is a formula of general relativity. Which would explain things including black holes:
[Both images courtesy of Wikipedia. For the rest of the images in this searches, thank Google search.]
Now, if you would agree at least that the movement of galaxies and stars are determined by rules, the laws of physics, the question is how far down does this go? Rather, a more interesting way is to look the opposite way, starting from the tiniest things we know: subatomic particles:
We can’t actually see them. But we know they are there. And we know about their properties through the laws of physics nonetheless.
How far up does this go? Combine subatomic particles together in certain ways and you get atoms. Put atoms together and you’ve got molecules, but wait, aren’t we now in the realm of chemistry?
These things are governed by formulas nonetheless. And when we put a bunch of these molecules together, we get a cell. Have the right kind of cell, and it’s a neuron. Your brain is a vast collection of interacting neurons:
Wouldn’t it follow that these also obey some rules? Even though we haven’t found these rules yet, all the neuron’s building blocks follow physical laws that are never violated. I remember Stumbling Upon this picture a couple of years ago, and it is still shocking. It shows the uncanny similarity between the structure of neuron clusters and the structure of galaxy clusters:
Point is, everything, including your brain, is governed by a set of rules. (You might hear in the news every so often that some law is broken, but that is only because the theory about the rule was incorrect, not the rule itself.)
Here is the tricky part. Suppose we knew all the rules, knew what the universe started from, and had a sufficiently powerful enough computer to run our universe as a simulation. (All 3 of these are far beyond are reach at the moment, especially the third, which is impossible, but is here for sake of thought experiment.) Because of the rules, the simulation would start running and emulating our universe exactly.
Sometime in the simulation a star would form, and there would be eight planets around it. On the third closest one, life forms would appear, eventually ones intelligent enough to question their own existence. They would ask, “Do we have free will?” And I’ll say, “No, but…”
The answer is no, because if everything is governed by rules, then there is not any “intelligence” inside the simulation that is not part of something programmed into the simulation beforehand. What happens in the simulation only depends on what rules we decided upon and in what condition we started it, both choices having been made before the simulation ever began. There is no actual “free will” inside the simulation.
But there is always a “but.” Even supposing we figured out all the laws of our universe and its initial state, it would be physically impossible to create a simulation that could run our universe in at least real time.
Suppose in some simulation you have some number of particles. Further supposing that your computer has perfect, 100% efficiency, in that one particle in the computer could match one particle in the simulation, you would not be able to ever run the simulation, because you need as many particles in your computer as your entire universe contains! So you could run a partial simulation or a less detailed one, but this wouldn’t match your universe. Or you could slow it down, so you simulate only a fraction of the universe at a time (but still you would need storage).
The point here is, we physically cannot simulate our universe. We would need more particles than our universe contains. Even if we could tap into the resources of another universe, we would run into the problem that eventually in the simulation, the resources of another simulated universe would be tapped, thus requiring even more resources in the original universe. And so on.
So even though the universe might be determined, we can treat life as if we have free will anyways because we can never know what will come next. For all practical purposes, we do indeed possess free will. But theoretically, we don’t.
Edit: Here is a post I wrote later on an intriguing simulation aspect of determinism.