Do humans truly have free will?
For example if fate is real, and everything is bound to a set timeline, is free will as we perceive it real? Or is it just a false perception to us?
While there is an argument for this around the concept of fate, it's also a serious question for AI research as well. The science and mathematics behind this question is not that complicated, but it does tend to fly in the face of our own empirical observations and the experience we have of being human. Let's start with the science.
Since Einstein, our concept of the universe revolves around a 4 dimensional space-time, in which time is merely another dimension of our universe. This becomes important because when discussing symmetry (a very important concept in physics which shows that we can predict what will happen in one place, orientation or time based on observations of the same phenomena in a different place, orientation or time) we see that time is as much bound to the laws of physics as any other direction.
With the single exception of the second law of thermodynamics (entropy, we'll get to that) all the laws of motion we understand work in both directions of time. If all these laws work in both directions, then it becomes clear that it's possible to predict the future by observing the past and extrapolating. If these laws hold perfectly in both directions of time and we are bound by them also, then the universe is algorithmic in nature, and that means 3 things;
1) We are algorithmic in nature also
2) It's possible for a computer to be aware because it's algorithmic
3) Free will (by definition) has to be an illusion because an algorithmic universe means that the future can be accurately predicted with enough information and (by extension) no choice we can make is able to change that future.
So, how does entropy apply? Well, entropy has been described in many different ways but the important point to note is that in a closed system (the universe), order degrades over time. For our purposes, this explains why we can only remember in one direction of time; the brain lays down memories (increased local order) through the release of heat (decreased global order) in the temporal direction set by entropy. That means that even if space-time is a static object, we appear to remember it through a lineal sequence because of the ways our memories are set down.
Lots of implications here, but let's get to the meat of it for the purposes of this question; if space time is deterministic (algorithmic) in nature, free will must be an illusion. If space time is non-algorithmic in nature, then algorithmic behaviour can still exist (it's a subset of non-algorithmic possibilities) but it's now possible that the human mind is non-algorithmic in nature meaning that it's possible that free will exists for us.
Even if that's the case, it means that computers cannot ever achieve human awareness because they are algorithmic in nature, and therefore at best could only simulate a subset of the functions of the brain and therefore could not achieve free will.
There's another scary thought here. The vast majority of science (physics in particular) is based on the idea that the universe is deterministic in nature, or that in other words we know how the universe works because we've seen how it works in the past. In order for us to have free will, it would mean that the universe can't be fully deterministic. Sure, the vast majority of it could still function according to algorithmic principles, but our own free will implies that at least part of the rest of the universe may not.
If that is the case, then all that we know about the universe must in some way be called into question. We cannot be certain of the past, or the future. In fairness, no scientist would ever say they were certain about concepts like the Big Bang, relativity, quantum mechanics, etc. But, if we could ever prove that free will did actually exist, we would have to be less sure of these things than we are today.
Is it possible that the organic brain is the only aspect of the universe that operates outside deterministic principles? Sure, it's possible. But, it's not very likely. So, that leaves us with one provable theory and two possibilities;
1) Computers can never have free will as they operate on deterministic principles.
a) If humans also operate on deterministic principles, our free will is a lie
b) If not, then free will may not be a lie, but proving that would force a re-think of all modern scientific principles to date.
Either way it would be both a thrilling and terrifying discovery.