Liquid crystals are materials whose properties are intermediate between normal fluids and solid crystals and have widespread use as the working substance for computers, TV, and watch displays. The lecture will introduce these materials and what mathematics can say about them, and in particular, discuss how different theories of liquid crystals describe orientational defects in different ways.
John Ball is a Professor of Mathematics at Heriot-Watt University, Edinburgh, and formerly a Sedleian Professor of Natural Philosophy at Oxford. He is the current President of the Royal Society of Edinburgh and a former President of the International Mathematical Union. He specializes in the applications of nonlinear analysis to problems of materials science, liquid crystals, and computer vision. Among various awards, he received the 2018 King Faisal Prize for Science, the 2018 Leonardo da Vinci Award from the European Academy of Sciences, and the 2022 De Morgan Medal of the London Mathematical Society.