Tom McLeish was a theoretical physicist whose work is renowned for increasing our understanding of the properties of soft matter. This is matter that can be easily changed by stress — including liquids, foams and biological materials.

Although Tom's work was mostly theoretical, he also worked closely with those performing experiments and in industry. He made significant advances in modelling the structure and properties of complex entangled molecules, blends of substances that don't usually mix (like oil and water), and modelling micro-structures under flow. This allows us to more easily predict complex fluid behaviour and processing in an industrial setting.

He was the Director of the UK Physics of Life Network, a research-council funded collaboration of physical and life scientists building research across disciplinary divisions. Tom's other interests as Professor of Natural Philosophy in York University's Physics department included the philosophy and theology of science as well as historical studies of medieval science. He was a member of York's Centre for Medieval Studies and the author of Faith and Wisdom in Science (OUP 2014) and The Poetry and Music of Science (OUP 2019).

Professor Tom McLeish FRS died on 27 February 2023.