Is there a better introduction to these ideas than Wikipedia? It makes intuitive sense, but I'd like to see the proof of this statement. Wikipedia mentions a "good regulator theorem", but the citation is pretty bad: "Conant 1970".
But I'm still interested if there's a better introduction.
Edit #2: Looks like Ashby's 1956 book around page 207 has an argument based on information entropy. I haven't read it, just skimmed it. I'll look more closely later. You can download the book here: http://pespmc1.vub.ac.be/ASHBBOOK.html
The whole "cybernetics" field is pretty weird to me, I think the notation and lingo have sort of moved on (I could easily be wrong and biased without realizing).
However the theorems you are talking about have useful, well studied analogs in the field of control theory.
Edit: The paper must be this: https://www.tandfonline.com/doi/abs/10.1080/0020772700892022...
But I'm still interested if there's a better introduction.
Edit #2: Looks like Ashby's 1956 book around page 207 has an argument based on information entropy. I haven't read it, just skimmed it. I'll look more closely later. You can download the book here: http://pespmc1.vub.ac.be/ASHBBOOK.html