One of the most innovative scientists of the 20th century, Lord Porter of Luddenham, who has died aged 81, shared the 1967 Nobel Chemistry Prize for his pioneering work with Prof Ronald Norrish at Cambridge on high-speed, light-driven chemical reactions.
It might seem that chemical reactions taking a few millionths of a second or even less are remote from everyday affairs: they are not.
Underpinning George Porter's science was a bedrock of everyday reality, a profound concern for the future of humankind and for the interlinked biological and physical systems of the planet. He knew - and said as often as possible - that the sun and the chemistry of life on earth are inseparable, and that humankind must learn to make creative use of sunlight or perish.
Occasionally he went further, condemning research imbalance and, in this context, pointing out that if sunbeams could be used as weapons, then, long ago, governments would have poured money into light-driven physics and chemistry.
Sunbeams cannot and governments did not. Yet with a career based on the triggering and interpretation of high-speed chemical reactions by means of very short pulses of light (flash photolysis), it was inevitable that Porter would, in the end, bring his knowledge and skills to bear on the photo-chemist's holy grail, an understanding of the mechanisms by which carbohydrates are synthesised from carbon dioxide and water in the green leaves of plants.
In many ways this is the ultimate high-speed, light-driven chemical reaction, remarkable in that wherever it occurs in nature, the desired forward reaction (synthesis) is not accompanied by the theoretically expected back reaction. Coupled with enzyme (catalyst) efficiency about a thousand times that of the best industrial processes, photosynthesis is distinguished as an extraordinary phenomenon deserving of special study, quite apart from it being by far the most important chemical reaction on earth. It has turned out, repeatedly, to be one of the most difficult to unravel.
It was therefore not surprising that Sir George (he was knighted in 1972), who sought challenge and whose research team concentrated on important light-driven chemical reactions during his 20 years as director and resident professor of the Royal Institution of Great Britain (1966-85), accepted the chairmanship of a new centre for photochemistry and photosynthesis at Imperial College, London, in 1987.
From the 1960s, Porter had argued that if research were to unravel and harness photosynthesis and thus resolve the looming energy problems of the planet, then, provided that population could be stabilised, mankind might at last look forward to a truly sustainable future. He was being practical in the proper technical sense, although he recognised that his optimism embodied elusive ideals that, however well research went, might easily become tarnished before the transitions he sought could be realised.
When his directorship of the Royal Institution came to an end, he became president of the Royal Society (1985-90). He thus gained a powerful platform from which to express his views on research and, initially, to condemn the downward spiral of support for fundamental studies typical of successive Thatcher administrations. Porter's views on science were crystal clear: its ultimate purpose was to understand ourselves and our place in the universe. Far from being remote from everyday life, this purpose was primitive; every child asks questions of the kind that scientists ask, he said.
It followed that he had a great interest in young people and the way they might be encouraged toward an understanding of science; in the special educational provisions required by gifted children; and in the need to improve the level of scientific understanding of the general public.
In the Royal Society under Porter, they went hand in hand with critical studies of national science policy. As an important voice in a growing uproar, Porter condemned the British government for developing a policy under which the pursuit of knowledge was diminishing, not by oversight or as an essential measure of economy, but in deference to the pursuit of affluence.
Individual, innovative science essential to the long-term future was being neglected as a result of a massive government-driven distortion of basic support towards short-term industrially "relevant" research.
Porter was emphatic and courageously outspoken: industry should do its own research and a lot more of it. The pursuit of knowledge in universities should not be allowed to suffer simply to make good industrial shortcomings. The government must realise that abrupt changes of policy and imposed reorganisations are far more damaging than useful.
In the 1970s, the traditional weight within government of Royal Society views was said to have diminished, yet, within a year of his appointment, British science policy changed. Core sciences and the pursuit of knowledge were given new support alongside a declaration that public funds were to be redeployed toward strategic research and that industry should support its own market research.
At this time, however, new problems arose. Normal public apathy towards science became antipathy. Scientists were blamed for global pollution, accused of playing God by manipulating genes, and of breaching moral codes by interfering with human embryos.
These difficult issues were all faced squarely and clearly by Porter, who sympathised with and even encouraged public concern. Science must keep its house in order.
Porter was born in Stainforth, North Yorkshire. He went to Leeds University as an Ackroyd scholar in 1938. The war intervened, and, during his final year, although he was already showing a great gift for the study of chemical kinetics, he took a special course in radio physics which enabled him to go into marine radar.
His involvement with physics and with short-wave propagation and reflection were to prove crucial to the later development of his career.
In 1945, he went to Cambridge University as a postgraduate research student with Prof Ronald Norrish, and began studies of the very elusive short-lived intermediaries (free radicals) in photochemical reactions. These disappear, as it were, almost as they are born, yet if they could be visualised step by step, they would reveal the route by which the reaction took place.
Porter came up with the idea of using pulses of light whose duration was shorter than the lifetime of the free radicals. Would chemical systems "pinged", and their spectra resolved on an equally short time-base, reveal transient and hitherto invisible participants in their reactions? They did: flash photolysis was rewarded by a Nobel Prize. It has revealed, with successively shorter light pulses, chemical transients that are crucial to reactions but whose life-span is only a fraction of a billionth of a second. This is the timescale of living biochemistry. Porter opened a window on to a hitherto quite impenetrable world. He was created a life peer in 1990.He is survived by his wife, Stella Brooke, whom he married in 1949, and two sons, John and Andrew.
George Porter, Lord Porter of Luddenham, born December 6th, 1920; died August 31st, 2002