I am a dynamicist with a focus on the nature of sustainable human-environment systems. My research career spans some 45 years, and includes experience in astronomy and astrophysics, management, operations research, mathematics education, and system dynamics. I have held research and teaching positions at Yale University, Kitt Peak National Observatory (Arizona), and the Australian National University. For the last 20 years I have worked on the development of practical approaches to integrative research and adaptation in complex situations. This work, which revolves around a blend of concepts from system dynamics and cognitive science, has been carried out in collaboration with community, student, academic, industrial and professional groups.