A visit from Bob Rosebrugh

Nicoletta and I have Bob Rosebrugh visiting for two weeks. We are getting some nice work done (I will report later) in which the Yang-Baxter equations play a part.

We went on Tuesday to a physics lecture by Professor David Sherrington (Oxford, Center for Non-Linear Studies LANL, Santa Fe Institute) on the theme of complexity in physics which seemed to be a review of rather old material with a relation to the original work of Baxter. The slogan of the work is that "complexity is not complication". By complexity, which they think of a good thing, the subject in which they make progress, the physicists in this field mean the types of complicated behaviours which may arise from a regular net of very simple components. A complicated (uninteresting) system instead is a complicated net of  (possibly) complicated components. It is the same kind of view held by another type of physicist regarding cellular automata.
OK. Complex systems in this sense are worth studying, but to pretend as they do that this explains economic systems, the brain etc seems to me to totally ignore the ideas of organization, structure, hierarchy etc. Computers, for example, are not designed as cellular automata.
It seems to me that the slogan is designed to promote physics as central, a suspicion that was confirmed a little by the speaker who said that "people think that physicists are arrogant" and who presented a slide with a star-shaped diagram (or should I say a pre-Copernican diagram) with physics at the centre and connections between the centre and many other subjects (economics, biology, mathematics, informatics,...) but no connections between these other subjects.