Making a Splash; Breaking a Neck: The Development of Complexity in

Physical Systems

Presented by

Leo Kadanoff

Work done by

Michael Brenner, Peter Constantin, Todd Dupont, Leo Kadanoff, Albert

Libchaber, Sidney Nagel, Robert Rosner, and many others


We study the motion of fluids, with the aim of developing a

fundamental understanding of fluid flow. Our program is characterized

by close cooperation among experimenters, theoreticians, and

simulators. The world about us exhibits many beautiful and important

fluid flows. Consider clouds and waves, storms, and earthquakes,

sunspots and mountain-building. What can we learn from all this


Mostly our work involves solving particular problems, e.g. 'how does

heat flow in a pot of water heated over a flame'. But, in following

these problems we soon get to broader issues: predictability and

chaos, the likelihood of very extreme outcomes, and the natural

formation of complex 'machines'.

In the end, we try to ask if there is a 'science of complexity' and

are there natural 'laws' of complex things. My answer is 'no', but I

do see important lessons to be learned from studying such systems.