Professor Sir Peter Hirsch FRS (1925-2025): a scientific giant

Sir Peter Hirsch, affectionally known as ‘PBH’ to his many friends, pioneered the use of transmission electron microscopy to study defects in crystals, particularly dislocations, and modelled the mechanical properties of a wide range of materials in terms of their defect structures. With his research student, Mike Whelan, he used electron microscopy to provide the first direct evidence of dislocations in crystals, a controversial hypothesis at the time. His research ranged from basic to applied and was underpinned by a deep understanding of crystallography. He had a huge influence on the field of materials science, both in the UK and internationally, and many people have commented to me that if there were a Nobel Prize in Materials Science, he would have won it. He was modest, kind, generous, laughed a lot and there was a twinkle in his eye.

Sir Peter’s life story is astonishing. He was born in 1925 in Berlin to Jewish parents. When he was nine, his parents divorced. His father died two years later, in 1936. On the night of 9 November 1938, Peter, aged 13, directly witnessed the events of Kristallnacht (the Night of Broken Glass), when German youths smashed windows and invaded the homes of Jewish families. Peter’s older brother, Hans, was already in the UK. His mother, who had remarried, devised a cunning plan to get herself and Peter out of Germany. She asked an English friend to send her a telegram demanding that she attend her son, Hans, in London with the fake news that he was seriously ill. So she travelled to London, leaving Peter behind in Berlin. Once in London, she arranged for Peter to be placed on a Kindertransport train, which arrived on 1 January 1939.

Peter went to Sloane Grammar School in Chelsea, knowing no English. However, he learned rapidly, excelled at science, and in 1943 he was offered a place at St Catharine’s College, Cambridge, where he studied Natural Sciences, specialising in Physics. He graduated with first-class honours in 1946 and joined the crystallography group of the Cavendish Laboratory, where, under W. H. (Will) Taylor, he obtained a PhD in 1951 on X-ray diffraction of work-hardened metals. His first postdoctoral position, funded by the National Coal Board, was on the crystallography of coal, research that is still cited today. He was appointed Assistant Director of Research in Physics in 1957, University Lecturer in 1958, and Reader in Physics in 1964. In 1965, with Howie, Whelan, Pashley, and Nicholson, he published Electron Microscopy of Thin Crystals, which remained the standard text on the subject for many years. The book had a yellow cover and was known as the ‘yellow bible’.

Peter was not only a great scientist but also a brilliant manager and organiser of his Metal Physics group in the Cavendish Laboratory. He was elected a Fellow of the Royal Society in 1963. In 1966, he was offered the post of Professor of Metallurgy and Head of Department of Metallurgy at both Cambridge and Oxford Universities. Cambridge had a large Metallurgy Department, the best in the UK, whereas the Oxford Department was very small. Peter told me that he chose Oxford because he relished the challenge of building it up. Peter moved to Oxford in 1966, becoming the Isaac Wolfson Professor of Metallurgy, Head of the Metallurgy Department, and a Fellow of St Edmund Hall. I was one of twelve people Peter took to Oxford from his Metal Physics group in Cambridge (I went as a postdoc). He was the Head of Department of Metallurgy (then Materials) at Oxford for 26 years, until his retirement in 1992, during which time he built up the department into the leading Metallurgy and Materials Department in the UK, and arguably the best in the world. Peter also developed strong links with leaders across many industries, and he was the Founding Chairman of Isis Innovation (now Oxford University Innovation), set up to exploit the University of Oxford's research. Peter was knighted in 1972 for “Services to Industry”.

Between 1982 and 1984, Sir Peter was the Chairman of the UK Atomic Energy Authority (UKAEA). This was a huge job at this critical time for the development of nuclear power in the UK, requiring substantial contact with government ministers and others. Peter loved science and his Department so much that he said he would only accept the job if it were part-time, so he could continue as Head of the Oxford Department. He also asked for a car and driver to take him from the Department to the UKAEA and to meetings elsewhere. Peter’s reputation was so high that his conditions were accepted. His chauffeur and car were often seen outside the Department waiting for him to finish a meeting. I was once in Peter’s office discussing a scientific problem when his secretary knocked on his door, entered and said that a government minister was on the phone to speak to him. Peter said “Tell him that I will call him back”.

Peter’s love of science was demonstrated in many other ways. For example, when he was away on holiday, he would ring members of his Department from a telephone box in the street to say “I’m ringing from a call box so my wife won’t find out. How is your experiment going?”

After his retirement, Sir Peter devotedly looked after his ill wife, who was in a wheelchair, for many years. However, to keep interacting scientifically with his colleagues, he arranged for a carer to look after her every Friday so that he could come into the Materials Department and discuss research, particularly with Professor Peter (Pete) Nellist. Pete recalls that, on Saturday mornings, Sir Peter would frequently phone him at home to suggest a solution to a problem they had been discussing the previous day.

Peter published his last first-author paper in 2013, when he was 88 (Hirsch et al., 2013). I was privileged to be an author, as was Pete Nellist. It describes a particularly complicated dissociation of a dislocation in GaN, imaged using high-resolution electron microscopy. All the authors struggled to understand the atomic structure of this dissociated dislocation. Sir Peter beat us all in solving this problem! He produced a 3D atomic model of the dissociated dislocation he had made at home using balls of plasticine for atoms! Remarkable!

Sir Peter celebrated his 100th birthday in 2025, with 100 guests, at a lunch at his Oxford college, St Edmunds Hall, which he gave for his friends. Although he used a walker, his mind was still very active, and he gave a brilliant speech!

Sir Peter was a scientific and engineering colossus. A truly great man. But he was also extremely modest, kind and generous. He helped so many people, particularly with his time. He loved to laugh and to greet people with a smile. His passing is the end of an era. 

References

Hirsch, P. B., Lozano, J. G., Rhode, S., Horton, M. K., Moram, M. A., Zhang, S., Kappers, M. J., Humphreys, C. J., Yasuhara, A., Okunishi, E. & Nellist, P. D. (2013). Philos. Mag. 93, 3925–3938.