[xaa]

Well, "physics" really encompasses just about everything, including biology, so I am implicitly limiting it to things which would not fall into another, more specific field, such as engineering or meteorology. Right, word choice.

Using any definition for "physics" close to this, while the percentage of biological questions that involve complex systems is close to 100%, it is much lower in physics. The subsets of physics problems that do involve complex systems will suffer the same predictive problems.

In fact, this conversation has got me wondering whether "complex system" really means anything more than "a system whose behavior is hard to predict". I know that complex systems have other common attributes, but really the unpredictability seems to be the defining feature.

This is a long way of saying "I agree that we don't really disagree" :)