I just read the Wikipedia article on Rule 110 and there was a short remark that the simplicity of that rule might imply that it can exist in physical systems in nature. "Physical systems may also be capable of universality— meaning that many of their properties will be undecidable, and not amenable to closed-form mathematical solutions." I have two questions:
- On which scales could such a system occur? Could parts of our brains be turing complete? Could movements of stars and galaxies follow simple rules like that?
- What kind of properties wouldn’t we be able to decide and what would be the implications of it?