I have recently been reading and watching Chiara's take on universal constructor theory. I knew about VonNeumann probes, as for instance described in Asimov's 2001 sequence. I hadn't taken in his constructor theory in a cellular automaton environment, as proposing something computationally discontinuous to a Turing machine.. if it is.

My intuition, is that there is a difference in the topological transformations VonNeumann and Turing machines are capable of, that can be related to number theory. The practical mechanism of the Turing machine tape has always as I understand it in philosophy, not been understood as limiting the capacity to simulate all other machines and environments, including other machines. So if there is a limit here on the power of Turing machines, what is it? And why isn't it better known?

Chiara is suggesting universal constructors may solve quantum gravity issues, and concerns around minds, meaning and Searle's Chinese room critique of computation as consciousness. It certainly sounds promising.

Can anyone help me understand exactly what the differences are between VonNeumann & Turing machines? Are they fundamentally -ontologically- different, or can the former be simulated by the latter? What are the relevant papers or other texts by VonNeumann? What else should I be reading or watching to understand this area?