You’re like everyone down here. You understand a hundredth of the truth and think you’ve got it licked.
This switches back and forth between a story about a researcher who disappeared while searching for the fundamental nature of reality, and a story of posthumans living in a strange simulated reality. I enjoyed it a lot, though it’s definitely just “part 1” and we’ll have to see whether the next parts can bring everything together well.
A fun idea mentioned in passing: for beings living in a simulation, time travel could be possible (if the simulator facilitates it), since they’re in “a closed system” and the simulator “itself knows what the denizens are going to do”. Although I would point out that in general, the only way for the simulator to know what happens at some future time is to actually run the simulation up to that time. So if you’re in a simulated universe and you see a vision of the future, it’s more like you’re seeing a vision of what has happened in another copy of your universe. And (assuming it’s a vision of events you have influence over, as opposed to, say, warning you that the simulated sun is going to have a solar flare next week) your own future will be different, since the future history that you saw came from a simulation that did not include you having the vision. Unless the simulator has gone to the trouble of constructing a paradox such that the vision it shows you causes you to behave in a way that makes the vision come true. Presumably only a very tiny fraction of all possible visions would have that self-fulfilling property and finding them would be extremely computationally challenging…