LORD PORTER OF LUDDENHAM, 1920­2002

Abstract

GEORGE PORTER, who died on 31 August 2002, not only was a Nobel Prize winning scientist, but had also earned international respect as a statesman, as a hugely engaging populariser of science, as a spokesman for science in the developing world, and as one who made great efforts to bridge the perceived gap between the two cultures of Arts and Science. George Porter was brought up in Yorkshire, whose inhabitants are caricatured as being down-to-earth, gritty, determined, and perhaps less humourful than those from other parts of the United Kingdom. That he was dedicated to his science, and to his fellow-men, is not in doubt, and he was always incisive and not afraid to speak his mind, so he had some traits typical of his origins. However, in the second half of his life, when I knew him, he was a polished, witty, urbane individual equally at home in academe, in the corridors of power, or in the Institution that he loved, and that was his home for twenty years, the Royal Institution of Great Britain, in Mayfair, London. He could not thus be said to be a true Yorkshireman in every sense. George Porter developed an early passion for science while at school in Thorne, Yorkshire, so much so that his artisan father bought for him an old bus in which the young George could carry out experiments, thus preserving the family home from chemical disaster. He studied for his first, B.Sc., degree in chemistry at the University of Leeds, where he was Ackroyd Scholar. From 1941 to 1945 he served in the Royal Navy, largely on antisubmarine duty in the Western Approaches, an experience that was to stand him in great stead when he turned to research after the Second World War. That was carried out at Cambridge, under the supervision of R.G.W. Norrish, with whom George shared, with Manfred Eigen of Germany, the 1967 Nobel Prize for the study of reactions. The scientific problem at the time is simply stated. Many chemical reactions take place on a time-scale so that following their course in real time was precluded by the slow response of available detectors, yet these reactions were those of very significant interest to the community. One approach to their study was to slow down the reaction rate by drastically cooling the chemical mixture, which George did succeed in doing, thus laying the foundations of what was to become the so-called matrix isolation technique. However, it is clearly desirable to study chemistry under ambient conditions; to achieve this goal, Porter and Norrish's approach was to use a short pulse of light to initiate some chemistry, and then to study the chemical species produced, confined at this stage of progress to those lasting about a millisecond, on the basis of absorption of light by a continuous monitoring beam. This worked well, but the huge leap forward, which led to the award of the Nobel, was to use for the monitoring process a second pulse of intense light, delayed with respect to the first, so that by carrying out repeated experiments with the interrogatory pulse at successive delay times, a complete picture of the evolution of the chemistry in real time could be constructed. This technique, inspired by Porter's naval experience with signaling lamps, is now universally applied to photochemical reactions, and termed Flash Photolysis. The technique moved during George Porter's lifetime and under his leadership from the millisecond range in 1949, through microseconds in the 1950s, to nanoseconds in the 1960s after the invention of the laser in 1960 by Theodore Maiman, through picoseconds in the 1970s and 1980s, and to femtoseconds in the nineties, at Imperial College, where Porter moved in 1987. Now attoseconds are in prospect. George used to like to ruminate that in his lifetime, the time period that defined fast had been reduced by as many orders of magnitude as the time from the beginning of the universe to the present (not quite true, but only by a factor of ten or so! …