Certainly Wolfram didn't invent the notion of a universal system, nor claim to, nor was that intended to be implied above, as bad as my writing might be. Indeed, on page 1125 of NKS he discusses Church's and Turing's contributions.
What Wolfram repeatedly points out throughout his book is that the threshold for such universality is much lower than one might suspect given the complications involved in, say, a Turing machine. And because that threshold is so low, there exists the possibility that much of the natural world that is not obviously simple is exhibiting universal computation.
What Wolfram repeatedly points out throughout his book is that the threshold for such universality is much lower than one might suspect given the complications involved in, say, a Turing machine. And because that threshold is so low, there exists the possibility that much of the natural world that is not obviously simple is exhibiting universal computation.