The Society for Industrial and Applied Mathematics (SIAM) awarded the 2012 John von Neumann Lecture to Sir John Ball of the University of Oxford in recognition of his deep contributions to our understanding of the mechanics of materials via the calculus of variations and other branches of mathematical analysis.

The citation especially notes his pioneering work on existence theorems and constitutive models for nonlinear elasticity, cavitation in solids, irregular minimizers and material microstructure, and, more recently, defects in liquid crystals.

The John von Neumann Lecture is awarded each year by SIAM to a mathematician or scientist for outstanding contributions to the field of applied mathematical sciences and their effective communication to the community. Established in 1959, SIAM's flagship lecture is given in honor of the Hungarian-American mathematician after whom it is named, and whose pioneering research encompassed the fields of mathematics, physics, economics, computer science, and statistics.

Professor Ball accepted the prestigious award from SIAM President Nick Trefethen at the Prizes and Awards Luncheon, following which, he delivered The John von Neumann Lecture, Liquid Crystals for Mathematicians, on Tuesday, July 10, at the SIAM Annual Meeting in Minneapolis, Minnesota.

An important and versatile interface for electronic visual displays in a wide range of equipment from calculators to television screens, liquid crystals are the working substance behind a multi-billion dollar industry. Representing a class of soft matter systems that exhibit properties intermediate to solid crystals and isotropic fluids, they present an intriguing subject for mathematical analysis. In a very engaging lecture, Dr. Ball described various branches of mathematics, including partial differential equations, the calculus of variations, multiscale analysis, scientific computation, dynamical systems, algebra and topology, that can explain the math behind liquid crystals. Watch a brief video recapping his prize lecture: http://youtu.

Sir John Ball is Sedleian Professor of Natural Philosophy at the Mathematical Institute of the University of Oxford; Director of the Oxford Centre for Nonlinear PDE; and Fellow of The Queen's College. His main areas of research include the calculus of variations, nonlinear partial differential equations, infinite-dimensional dynamical systems and their applications to nonlinear mechanics. Dr. Ball earned his undergraduate degree in mathematics at the University of Cambridge and a D. Phil at the University of Sussex.

Among the many prizes he has received is the 1999 SIAM Theodore von Kármán Prize. He has served as a Council Member of the Engineering and Physical Sciences Research Council (1994-1999), and as President of the Edinburgh Mathematical Society (1989-90) and the London Mathematical Society (1996-1998). He started a 3-year term as a Member of the Executive Board of International Council for Science (ICSU) in 2012 and is currently President of the International Mathematical Union.

The John von Neumann Lecturer receives an honorarium of $5,000 and a framed, hand-calligraphed certificate.

**About SIAM**

The Society for Industrial and Applied Mathematics (SIAM), headquartered in Philadelphia, Pennsylvania, is an international society of over 14,000 individual members, including applied and computational mathematicians and computer scientists, as well as other scientists and engineers. Members from 85 countries are researchers, educators, students, and practitioners in industry, government, laboratories, and academia. The Society, which also includes nearly 500 academic and corporate institutional members, serves and advances the disciplines of applied mathematics and computational science by publishing a variety of books and prestigious peer-reviewed research journals, by conducting conferences, and by hosting activity groups in various areas of mathematics. SIAM provides many opportunities for students including regional sections and student chapters. Further information is available at www.siam.org. [Reporters are free to use this text as long as they acknowledge SIAM]