Say it is possible to calculate future of a sufficiently complex physical system like a person on a Turing machine by knowing the current state of the system.

Say it is possible to calculate future of a sufficiently complex physical system like a person on a Turing machine by knowing the current state of the system. Then, according to this idea, the calculation can not be simplified by using some kind of formula that predicts the final state, and one needs to fully compute all the intermediate states, which means your computation is fully equivalent to that person living for the time for which you want to calculate the final state. So time here is the internal time for the system of your calculation, and not related to the time you take to calculate. This internal time is nothing more than a counter you use, and You can actually stop your calculation, change something in the initial state and calculate again. I find this fascinating because it kind of explains the universe being predictable, and people having free will: everything is predefined, but only way to know what the choice of complex system will be is letting that system to make the choice! If the view that consciousness can be explained without requiring quantum physics is correct, then this is true independently of specifics of simulated/real universe, and is just the way information/computation works. But then maybe Penrose is right, and consciousness can't be calculated on a Turing machine, and we still have lots of interesting science to discover.