Abstract

Sir John Ball is a distinguished mathematician and the Sedleian Professor of Natural Philosophy at the University of Oxford. He is renowned for his work on elasticity theory and the mathematics of microstructure arising from phase transformations in solids, relating to calculus of variations, nonlinear partial differential equations and infinite-dimensional dynamical systems. Beyond his research, Sir John is a champion of international cooperation and the advancement of science and mathematics in developing countries, as a member of the Executive Board of the International Council for Science and the President of the International Mathematical Union from 2003-2006.

Vortices, cracks, cavities, dislocations, phase boundaries and disclinations are all examples of material defects. In some mathematical models they may be described by singularities in solutions, whereas in others they may be represented differently. The lecture will describe how the understanding of such defects raises interesting mathematical, scientific and philosophical issues, and can lead to the discovery of new materials and phenomena.

Everyone is welcome. Free for members, £2 on the door for non-members. Followed by refreshments (that means smoothies, cheese and grapes!).