[Rant] Determinism, Free-will and Quantum

Purely rant

Does a particle in a chamber of a fluid make the same path again and again, if the physical factors such as temperature, pressure, viscosity and all other atmospheric variables are constant all the attempt? In other words, Is the movement of a particle reproducible? I know there are thousands of variables which is almost impossible to create again, but I am asking from a theoretical perspective. During one of my relatives’s funerals, people talked about a lot of scenarios of what might have happened, if things had happened differently. At this very moment, a question raised in my mind was, Are all these things determined, because the previous position of the particle leads to the current position of particles, which depends on the initial state of particles and other external factors? I will try to elaborate above question further. But before that, I want to confront the readers that I am not a proper quantum scientist, to argue things academically, these are just a bunch of my thoughts.

I assume that you know, here particle means, literally everything in a universe. We are all made up of particles (atoms, molecules), which are moving in some path, and the question is whether the movement is determined and completely influenced by the previous position and initial state of things. When we see things from classical physics, this seems to be more straightforward, and it says “Yes” to the above theory, which is the movement of every particle is deterministic. Here is where Quantum Physics, came into play, I guess. I never studied Quantum physics in my school, and I am not sure whether I forgot completely about those chapters. So for this curious question, I started studying these topics a little bit. When I started, the idea was more aligned towards the theory of Laplace’s demon.

Laplace’s demon presents the same concept that, if someone knows the precise location and momentum of every atom in the universe at a given time, then it can be calculated and the future state of those particles can be predicted. Of course, the number of particles and calculations require supercomputers, but as mentioned we are talking in theoretical terms, which provides the mindset to us, that everything happening in the universe is determined at least from the laws of classical physics. This concept is further explored in many movies like Arrival, where the past influences the future or both past and future are always bound, and things can not be changed.

Alternatively let us reduce the system size to a human body. Each of our decisions in a situation is influenced by many factors, but the most important one is the chemical reaction inside the brain, which creates certain emotions to make the decisions. Evolutionary biologists claim that this is determined when the human was born since those chemical reactions are heavily influenced by genetics. This means how we are going to react and make decisions are already encoded in our genes, we can’t do anything about it.

Anyway, are these even theoretically true? , the answer is strong No, it seems.

Heisenberg’s uncertainty principle states that both the position and momentum of a particle at a given time, can not be calculated accurately. This is a major conflict with our above theory, that states can not be constructed by previous states even if we know their position. [You can go read the proof of the uncertainty theory and why it is accepted in a scientific community]. That’s all, there is randomness, and there is free will, at least at the scale of the universe. So you can still regret your mistakes and choices, is that so?

However, the past can not be changed, which means the time is linear and the particle’s position and momentum are bounded. So at least on the practical scheme of things, things are determined.