Pumping and Jumping: Toward Simple Rules for Creatures Great and Small

Date(s) - 10/14/2014
4:05 pm

Dr. Stephen Vogel, James B. Duke Professor Emeritus, Department of Biology, Duke University

The parts of organisms that pump liquids or throw projectiles (including themselves) vary at least 100,000-fold in length and these outputs serve diverse tasks. Two devices help us discern order amid this complexity. We can seek matches between predicted and empirical scaling exponents – an approach familiar to biologists. Or, we can contrive dimensionless indices, of especial value because they have no residual length dimensions. We use those latter (but not necessarily the usual indices) too rarely, given their proven utility in the hands of engineers. Both do proper scientific service as predictive generalizations.

Dr. Steven Vogel joined the Duke Faculty in 1966 and retired forty years later; most of his effort is now extramural. His work has explored the ways in which animals and plants deal with the immediate physical world in which all of us live, in particular with its mechanical aspects. He has worked on systems that include flight in insects, self-ventilating burrows and sponges, the thermal behavior of leaves in nearly still air, the mechanical behavior of plants in potentially destructive winds and the ballistics of very small biological projectiles. In recent decades, his main output has been books that explore the interface between biology and mechanical engineering, as well as textbooks for biological fluid mechanics and comparative biomechanics.