Robert Silbey 1940-2011.

The Royal Society Theo Murphy International Scientific Meeting Quantumcoherent energy transfer: implications for biology and new energy technologies was one of the last scientific meetings attended by Bob Silbey, who died on 27 October 2011. As always, he brought his combination of erudition, clear thinking, wit and general good humour to Chicheley Hall. Here, a mixed group of experimentalists and theoreticians had come together to talk about how quantum effects may underlie natural photosynthetic light harvesting and the implications of the ubiquity of such effects in natural systems for non-biological solar energy to fuel conversion. Bob’s special skill of moving easily between the two worlds of theory and experiment was a key ingredient in the success of the meeting. Indeed, conferences were always livelier and more enjoyable when Silbey was present. The deep resonant voice commanded the room, steered the discussion and produced many of the most memorable moments and comments. Bob had an extraordinary range as a theorist who was particularly adept at describing complex phenomena. He was a wizard of the many uses of unitary transformations which reduced a complex problem to one of simplicity and transparency. He moved with ease from excitons to conducting polymers to tunnelling in condensed media, where he showed that renormalized tunnelling could slow down enormously the irreversible tunnelling from one well to another.