Roughly half our work is related to understanding the interaction of life and the environment, while the other half is purely physical, with an emphasis on fluid mechanics.  In all cases we focus on dynamics and seek the reconciliation of mathematical and physical theory with observations.  The following brief list describes some areas of sustained interest over the last several years.  To learn more about current interests, check our most recent publications or contact us for more information.

Earth's carbon cycle

Earth's carbon cycles through the atmosphere, oceans, living organisms, and rocks.  How does the carbon cycle work?  The problem ostensibly falls at the intersection of earth science, biology, and chemistry.  However, observations spanning a wide range of environments and biogeochemical transformations exhibit common features suggesting that simple physical mechanisms exert significant control.  We seek a fundamental understanding of these physical processes and explore their relevance to present and past environmental change. 

Co-evolution of life and the environment

The geologic record suggests that major events in the history life nearly always occur concurrently with environmental change.  To understand how and why these changes occur, we study the geochemical, fossil, and molecular records and relate them to environmental dynamics.  We are especially interested in the early oxygenation of the environment, the evolution of multicellular life, and mass extinctions. 

Geometry of natural forms

The natural world contains abundant examples of geometric organization.  We seek the mathematical expression of such forms and shapes and relate them to the physical mechanisms responsible for their formation.  A particularly rich set of problems occurs in the growth of valley and river networks, for which the physics of flow and diffusion yield precise, verifiable predictions.  We are particularly interested in developing a comprehensive understanding of the ramification of stream networks.  Some of our recent work has also focused on mechanisms of biofilm growth and their relation to the geometry of Earth's earliest fossils and the environmental conditions responsible for their formation.