George Porter (1920–2002): The Architect of the Microsecond
George Porter, Baron Porter of Luddenham, was a titan of 20th-century physical chemistry. He is best remembered for developing "flash photolysis," a revolutionary technique that allowed scientists to observe chemical reactions occurring in the blink of an eye—or, more accurately, in a millionth of a blink. His work transformed chemistry from a study of "before and after" into a real-time observation of the molecular "during."
1. Biography: From Radar to the Royal Society
George Porter was born on December 6, 1920, in Stainforth, Yorkshire. The son of a local council clerk, Porter’s interest in chemistry was sparked by a chemistry set and nurtured at Thorne Grammar School. He earned a scholarship to the University of Leeds, graduating with a degree in Chemistry in 1941.
His career was immediately interrupted by World War II. Porter served as a Radar Officer in the Royal Navy, an experience that proved serendipitous. The technical mastery of electronics and pulse technology he gained while working on naval radar would later become the hardware foundation for his Nobel-winning research.
Following the war, Porter moved to Emmanuel College, Cambridge, to conduct postgraduate research under Ronald Norrish. After a brief period as a professor at the University of Sheffield (1955–1966), where he built a world-class department, he became the Director of the Royal Institution in 1966. He concluded his career as a professor at Imperial College London and served as President of the Royal Society from 1985 to 1990. Porter passed away on August 31, 2002, in Canterbury.
2. Major Contributions: Capturing the Fleeting
Before Porter, the intermediate stages of chemical reactions were theoretical constructs. Scientists knew that molecules changed, but the "transition states"—the short-lived, highly reactive species like free radicals—vanished too quickly to be measured.
Flash Photolysis
In 1949, Porter and Ronald Norrish developed flash photolysis. The technique used a powerful burst of light (the "flash") to disrupt stable molecules and create reactive intermediates. A second, weaker flash followed at a precise microsecond interval to record the absorption spectrum of these fleeting substances.
Advancing the Time Scale
While his early work focused on the microsecond (10-6 seconds) scale, Porter was never satisfied. As laser technology emerged in the 1960s, he pushed the boundaries into the nanosecond (10-9) and eventually the picosecond (10-12) realms. This allowed him to study the primary processes of photosynthesis, specifically how plants harvest light energy with near-perfect efficiency.
3. Notable Publications
- Chemical Reactions Produced by Very High Intensity Light Flashes (1949, Nature): The seminal paper, co-authored with Norrish, that introduced flash photolysis.
- The Kinetics of Elementary Gas Reactions (1950): A foundational study on the behavior of free radicals.
- Chemistry for the Modern World (1962): An accessible book demonstrating his commitment to science education.
- Primary Processes in Photosynthesis (Various papers, 1970s–80s): A series of influential works exploring electron transfer in biological systems.
4. Awards and Recognition
- Nobel Prize in Chemistry (1967): Awarded jointly with Ronald Norrish and Manfred Eigen "for their studies of extremely fast chemical reactions."
- Knighthood (1970): For services to science.
- The Order of Merit (1989): A personal gift from the Queen, limited to 24 living members.
- President of the Royal Society (1985–1990): The highest administrative honor in British science.
- Peerage (1990): Created Baron Porter of Luddenham.
5. Impact and Legacy
Porter’s legacy is twofold: scientific and social.
Scientific Impact:
By proving that "unstable" intermediates could be observed, he birthed the field of femtochemistry (later perfected by Ahmed Zewail). Every modern study of reaction kinetics, atmospheric chemistry (such as the breakdown of the ozone layer), and photobiology owes its methodology to Porter’s flash photolysis.
Social Impact:
Porter was a passionate advocate for the "Public Understanding of Science." He revived the Royal Institution’s reputation as a center for public engagement, famously delivering the BBC Christmas Lectures in 1969 ("The Natural History of a Sunbeam"). He co-founded COPUS (Committee on the Public Understanding of Science) in 1985, arguing that a democracy cannot function if its citizens are scientifically illiterate.
6. Collaborations
- Ronald G.W. Norrish: His PhD supervisor and Nobel co-recipient. Their relationship was famously "prickly"—Norrish was an old-school academic, while Porter was a visionary experimentalist. Despite their personal differences, their intellectual synergy changed chemistry.
- The Royal Institution: Porter worked in the tradition of Michael Faraday, viewing the RI not just as a lab, but as a stage for science.
- Manfred Eigen: Though they worked independently, their combined efforts in the 1950s and 60s provided the full toolkit for studying fast reactions in both gases (Porter) and liquids (Eigen).
7. Lesser-Known Facts
- The Glassblower: In the early days of flash photolysis, Porter was known for his exceptional skill in glassblowing. He personally constructed the complex vacuum lines and reaction vessels needed for his experiments.
- Naval Influence: He often remarked that his time in the Royal Navy was his "true" education in experimental physics. The massive capacitors used in early flash photolysis were often repurposed surplus equipment from wartime radar installations.
- The "Porter" Unit: While not an official SI unit, colleagues often joked about the "Porter," a measure of how quickly a scientist could explain a complex concept to a layperson.
- Sailing: A lifelong sailor, he found a parallel between the precision required to navigate a boat and the precision required to timing a laser pulse.