Well... Its not so much.. Well.. Some people think that if we know the position and velocity of every single atom in a single point in time, we could calculate the whole timeline of the future. While it would be impossible to know if this is true, even if it was and theerotically we calculated the future, it would account for the decision of every person, because decisions do make a difference, even if we could alredy know what that difference will be.

But this isnt widely accepted, and is just a theory, and there is no way to validify it