Leigh Trapnell professor of quantum physics, University of Cambridge
In my field (quantum computing and cryptography) the great innovations are yet to come (but I am happy with my discovery of quantum cryptography). Otherwise, I find my perception of the greatest invention very much dependent on my location and occupation - when I work in Singapore (one of my favourite places on the planet) I can only agree (at least on this point) with Lee Kuan Yew - it is aircon! When in Cambridge I firmly believe it is a bicycle and when 30 metres under water I am sure it is the open circuit two-stage diving regulator.
Artur Ekert is Leigh Trapnell professor of quantum physics, Department of Applied Mathematics and Theoretical Physics, University of Cambridge and professorial fellow of King’s College.