Well, we are a part of a physical system whose laws correspond to mathematical formulas, but aren't formulas, they're existing physical, energetic relationships

Well, we are a part of a physical system whose laws correspond to mathematical formulas, but aren't formulas, they're existing physical, energetic relationships maintained magically in realtime. And, yeah, it's magic, this universe we live in, my friend. So, while the math is reversable, time is a one-way street by virtue of the construction of the physical universe, which is not reversable. And it's that way because that's how this magnificent universe was instantiated. It may sound trite, but sometimes Occam is bang-on. As well, there are endless unknowns, but there are also unknowables. All matter is >99% empty, not counting field interactions. I don't know how much of it can be understood, but some of it is likely to be unknowable.