Sir John Edwin Enderby

Doctor of Science

18 July 2006 - Orator: Professor Sir Michael Berry

Mr Vice-Chancellor:John Enderby

John Edwin Enderby was born in Lincolnshire, on the 16th of January 1931, which makes him 75 years young. He went to school in Chester, and then obtained a Teacher’s Certificate with Distinction at Westminster College London, whose Wright Prize he won in 1953. University life began at Birkbeck College, where he earned a first class honours degree in physics in 1957. He stayed at Birkbeck for his PhD, supervised by Norman Cusack; his thesis, completed in 1962, concerned properties and problems of liquid metals.

A formative experience had been his national service in the Middle East, from 1949 to 1951. Working in the communications branch “convinced me of the importance of physics and mathematics”, he says.

His career as a professional academic began in Huddersfield, where he lectured from 1957-1960. He moved first to Sheffield, where he was a lecturer and reader during the 1960s, and then to Leicester, where he was appointed as professor and became Head of Department. In 1976, he moved to a chair here in Bristol. He was Head of Department here from 1981 until 1994. Thirteen years seems a very long time, but his headship was interrupted from 1985-1988 when he took leave to be Directeur-Adjoint of the Institut Laue-Langevin in Grenoble – the premier neutron beam facility.

At the heart of his research career, resulting in nearly 200 scientific papers, are neutrons. He realised early on that these tiny particles, when generated in beams from nuclear reactors, can be used as a clean probe to explore the structure of matter in its various condensed states. The cleanness comes from the fact that that the electrons surrounding the atomic nuclei are transparent to the neutrons, which therefore get scattered directly from the nuclei themselves. Neutrons are quantum particles, so they travel as waves and scatter coherently. When they leave the sample, they display interference patterns which, when decoded, give precise information about the relative positions of the nuclei. The technique of neutron diffraction is complementary to the more familiar X-ray and electron diffraction techniques.

John Enderby’s particular contributions involved multicomponent liquids: alloys, liquid semiconductors and ionic liquids. The problem, as he put it, was that “The structural properties of liquids that contain more than one atomic species are difficult to unravel”. In other words, it is hard to disentangle the arrangements of atoms in the different components. To do this, he exploited the fact that different isotopes of the component nuclei – that is, nuclei with different numbers of neutrons bound in them – are arrayed in the material in the same way but scatter neutrons differently. By using samples with different degrees of isotopic enrichment, and measuring the differences in the way neutrons were scattered – that is, the intensities of neutrons emerging in different directions – he succeeded in determining the detailed microscopic structure of a variety of materials.

One outcome was a fuller understanding of the relationship between local chemical bonding and macroscopic electrical properties. This is because in a metal it is not only the neutrons in beams sent into the sample that scatter from the atomic nuclei: the electrons that are there already scatter too, in ways that determine the electrical conductivity. Some of this early work laid the foundation for John Enderby’s later connection with our University, because it gave detailed support to theories of liquid metals that had just been developed in Cambridge by John Ziman, who came to Bristol in 1964.

In the 1970s, he began to study the structure of ionic liquids, that is the correlations between the positions of the different types of ions. In particular, in aqueous solutions, so important in biology, he discovered surprising quasi-lattice structures. I quote: “a true change in the structure of water occurs as salt is added”. We are speaking here of genuine structure associated with real atoms in the liquid – this isn’t homoeopathy.

Another of John Enderby’s achievements exploited the fact that nuclei emerge not only in different directions, giving information about the positions of the atoms, but also with different energies. Measuring these energies is the basis of an important variant of the neutron diffraction technique, because it gives information about the microscopic motions of the nuclei, on scales of nanoseconds.

His productive research continues, much of it in collaboration with his Bristol colleagues. In recent years, he has discovered a new class of liquid semiconductors, developed non-invasive probes of conductivity and dielectric response without contacts, and applied these in medical research, for example to glucose structure and levels in humans.

John Enderby has received a glittering series of honours. In 1985 he was elected a Fellow of the Royal Society. His citation included the following: “Enderby applies imaginatively conceived and rigorously executed experimental methods to critical theoretical problems, thus establishing firm foundations for our knowledge of the liquid state.” In 1997 he was awarded a CBE, and in 2004 came a knighthood.

The scientific enterprise relies not only on first-rate researchers but also on people willing to shoulder administrative responsibilities. As just indicated, John Enderby’s research has been of the highest international standard. But he has also been a good citizen of the academic community, far beyond the call of duty. If I were to list all the administrative responsibilities he has undertaken, we would be here all afternoon. So here are just a few – and I will not even mention the numerous consultancies in which he has applied his expertise to help British industry:

• Governor of Leicester Polytechnic;

• Member (also Chairman) of Physics and Neutron beam Committees of the Science and Engineering Research Council;

• Sectional Committee of the Royal Society;

• Council, Institute of Physics;

• Chair of Physics Panel for the Research Assessment Exercise in 2000-2001 – a position of great power and influence, where it would be very easy to lose one’s friends. He didn’t, which is a testament to the scrupulous fairness, actual and perceived, with which he discharged this responsibility;

• Editor of Proceedings of the Royal Society. I have that job now, and particularly appreciate the work he put into it: transforming that prestigious ancient publication into a modern journal, and sweeping away old practices (for example, the need to communicate papers through Fellows of the Society);

• Vice-President and Physical Secretary of the Royal Society;

• And, last but certainly not least, since 2004 he has been President of the Institute of Physics.

John Enderby is a family man, supported by his wife Susan and taking delight in his four children. It might seem that he has no time to relax, but when he does he enjoys (and I quote from Who’s Who) gardening, woodwork, and watching Association football, to which I add – because I’ve seen him – walking his dog.

Mr Vice-Chancellor, I present to you Sir John Enderby as eminently worthy of the degree of Doctor of Science, honoris causa.