Water is perhaps the most ubiquitous, and the most essential, of any molecule on earth. Despite 300 years of research, however, the 63 anomalies that distinguish water from other liquids lack a coherent explanation. This talk will introduce some of these 63 unsolved mysteries, and will demonstrate some recent progress in solving them using concepts borrowed from various disciplines including chemistry and physics. In particular, we will present evidence from experiments designed to test the hypothesis that water displays a special liquid-liquid critical point C'. Above C', water is a single liquid phase, punctuated by a locus of maximum correlation length called the Widom line. Below C', water can separate into two distinct liquid phases distinguished by their density. This new concept of a critical point is also proving useful in understanding some of the anomalies of other liquids, such as silicon, silica, and carbon. The talk will discuss the possibility that phenomena that occur on crossing the Widom line are related to the changes in local structure that occur when the system changes from the ``HDL-like'' side to the ``LDL-like'' side. We will review evidence for changes in dynamic transport properties, such as diffusion constant and relaxation time. We plan to further test the effect of the Widom line on simple model systems that display a liquid-liquid critical point, such as two-scale symmetric potentials, and to further explore the hypothesis that the observed glass transition in biomolecules is related to the liquid-liquid phase transition.

Prof. Gene Stanley received a B.A. from Wesleyan University and a Ph.D. from Harvard University. He has published over 800 papers, has written or edited 15 books and recently received the Highly-Cited Award from Science Citation Index (5,898 citations). He received the 2001 National Science Foundation Distinguished Teaching Scholar Director's Award for integrating forefront research with undergraduate teaching in an effort towards empowering majors and non-majors to learn fundamental concepts through interactive visualization experiences. Stanley is also keenly interested in reforming scientific instruction at the secondary level, hoping to transform instruction so that students can use the computer as a personalized tool of enquiry. He has received four honorary doctorates, a Guggenheim Fellowship, the American Physical Society's Centennial, Richtmyer, Turnbull, Saha and Bose lectureship prizes, and the Massachusetts Professor of the Year award of the Council for Advancement and Support of Education.

The meeting will be held at the Lincoln Lab Auditorium at 4:00 PM. Refreshments will be served at 3:30 PM.  Registration is in the main lobby.  Foreign national visitors to Lincoln Lab require visit requests.  Please pre-register by e-mail to reception@ll.mit.edu and indicate your citizenship. You will not receive a confirmation of your pre-registration, however, your badge will be ready for you when you register.  Please use the Wood Street Gate.  For directions go to http://www.ll.mit.edu/.  For other information, contact Ed Altshuler, Chairman, at  (781) 377-4662, or edward.altshuler@hanscom.af.mil