There are two questions that science has not yet been–and may not ever be–able to answer.
Question 1: Where did everything come from?
Physics tells us that you can’t get something from nothing. And yet, the universe is filled with a ton of stuff. Where did it all come from? Either it was created (which violates physics as we know it), or it has just somehow … always been.
Question 2: Do we have free will?
Whether we humans have an exact or precise understanding of the rules (we don’t), nature follows rules. We could call them laws. And as far as we can tell, those rules are consistent across the observable universe.
These rules govern everything from the interactions of subatomic particles to the formation of galaxies. Particle A with its velocity, energy, etc. interacts with particle B with its velocity, energy, etc., and this is what happens.
The closer our understanding of the rules matches nature’s reality, the better our models are at predicting outcomes. If we had an absolutely precise model of nature, the outcome of any event could be predicted.
We do not know the precise rules, but nature “knows.” So one way to look at things is that nature is applying its rules to the totality in each moment in order to determine the outcome, which is the next moment.
I’ll say the rules are consistent if they always result in the same outcome given an identical situation. For example, if 1 + 1 is 2 today, tomorrow, and every time we sum 1 and 1, then that is consistent. And if the rules of nature are consistent, then the universe is deterministic.
This would mean that state of each moment is determined by the initial state of the universe and subsequent methodical application of the rules. All of the particles, atoms and molecules that make up the universe–including those that are your brain–are simply having their fates unfold mechanically, along a path that was effectively preordained at the origin of the universe.
Therefore, either the rules are inconsistent (and physics will hit a limit where events are determined by chance and cannot be predicted), or we do not have free will.