Not sure if this is the correct forum to post this thread, but here we go. I'm a layman in physics and mathematics, and recently, I was reading about the Laplace's Demon and how, according to classical mechanics, the future could be entirely determined if some entity (the Demon) could have complete knowledge about the position and velocity of every particle in the universe. That caught my interest. Today, we know that Laplace's Demons isn't true because of the second law of thermodynamics and quantum mechanics (Heisenberg Uncertainty Principle). But I think that the concept of Laplace's Demon (that every single event in the future is exactly determined by just positions and velocities of particles) is very interesting, indeed. So, even if we can show that Laplace's Demon isn't possible for a bunch of reasons, I wonder if there's some similar theoretical construct which follows the same principles (but takes thermodynamics and quantum mechanics into account). So I think my question is: could the universe be deterministic, even with entropy and Heisenberg Uncertainty, and what information should the Demon know so as to be aware of all the past and future events (wave functions? I don't know)?