Keith Ball is a pure mathematician who specialises in the fields of functional analysis and information theory. In collaboration, he solved a longstanding question in information theory concerning whether the central limit theorem of probability is driven by an analogue of the second law of thermodynamics. Keith’s solution made use of a new formula for information.
Among Keith’s proofs in functional analysis is one relating to Tarski’s ‘plank’ problem in many dimensions. The plank problem derives its name from a question concerning the minimum number of planks required to cover a convex tabletop.