Is it theoretically possible to "predict the future?"?

In order for this to be possible one would require an absolute understanding of sub atomic physics. Essentially one would have to know a few things that we essentially know nothing about currently. One, how and why sub atomic particles behave the way they do (which, currently, seems very chaotic, mind you)

However, if these certain events are not actually chaotic, but occur under specific conditions for specific purposes, that means one could accurately predict the probability of each event. (much like predicting that two hydrogen atoms combined with an oxygen atom will most likely produce water)

Two, if we gain a specific understanding of sub atomic interactions, would we then be able to understand how our brains work on it’s smallest level? I’ll use a very basic and dumbed down example. What if we discovered that when a certain group of Photons react a certain way in our brains, we picture the image of our pet dog, sparky?

Would it then be possible, if paired with the possibility of reaching the “Computing Singularity”, would we be able to predict the actions and reactions of a group of people?

I’m not sure how much sense this actually makes, but bear with me.

If one can map out every single particle in person X’s body, and understand the probablity of all possible events that can occur in that person’s body, could you accurately predict that person’s behaviour?