Peter Hirsch (1925-) materials scientist, studied at Cambridge University, where he also spent the first part of his career. Here he used micro-beam X-ray diffraction to study cold-worked metals and later researched the structure of coal. In 1956, Mike Whelan, one of his research students, used an electron microscope to make the first direct observations of moving dislocations in thecrystal structure of materials, which play an important part in controlling their properties. Hirsch subsequently built on this research to establish a group to develop techniques for studying the underlying physics of metals. In 1966 he moved to Oxford as head of the Department of Metallurgy, a role he held until retirement in 1992. He was chairman of the UK Atomic Energy Authority, part time, between 1982 and 1984, and also played a key role in establishing the technology transfer company Isis Innovations.