Professor David Tabor

Cambridge physicist and a founding father of 'tribology' - the study of friction between surfaces

Friction, the resistance to sliding motion between two solid surfaces, is a fact of common experience. We could not walk or propel a car without it, yet it is a source of wasted energy and leads to wear which limits the life of most mechanical artefacts. Not surprisingly, its origin has attracted enquiring minds from Leonardo da Vinci onwards. But a proper scientific study of the subject, later to be named "tribology" dates from the foundation of a research group in Cambridge in 1946 by Philip Bowden and David Tabor.

David Tabor's father, surprisingly for a Jew, was an NCO in the Russian Imperial Army. However, the official anti-Semitism of the time cost him his job and led to the family's leaving Russia and eventually settling in London, where David was born in 1913. He was apparently brilliant at school, which led to his studying science at Regent Street Polytechnic and Imperial College, London. He then became a Research Student at Cambridge under the supervision of Philip Bowden, thus starting a most successful collaboration which lasted the rest of Bowden's life.

David Tabor was rooted in a traditional, humane form of Judaism. It was central to his being, and the way he related to others. For almost seven decades, he was one of the pillars of the Cambridge Jewish community. He had a deep love of the biblical and rabbinical texts, and a profound knowledge of Hebrew. He had a lifelong commitment to the State of Israel and the search for a just peace with the Palestinians. Judaism was David Tabor's home - but it never became a straitjacket.

By chance, Bowden was in his native Australia in 1939 and was persuaded by the Australian government to set up a laboratory in Melbourne University to study friction and lubrication in bearings. He invited Tabor to join him. The laboratory was transferred to CSIRO Melbourne and acquired the name "Tribophysic" (from the Greek tribos, rubbing). It was in Melbourne that David Tabor met and married Hanna, his wife for 62 years.

In 1946 Bowden and Tabor returned to Cambridge to set up a research laboratory, first in the Department of Physical Chemistry and later in the Cavendish Laboratory (Department of Physics), which was to play such a crucial role in the growing subject of tribology. The laboratory had various names, but eventually settled for Physics and Chemistry of Solids. For those fortunate to have worked there it was as always "PCS" and David Tabor was "DT". The laboratory was a carefully managed, almost self-contained research institute with a remarkable reputation, complemented by a unique "family atmosphere".

Tabor was elected a Fellow of Gonville and Caius College in 1957 and appointed Professor of Physics in 1974. In 1968 Bowden died of lung cancer, aged 65, and Tabor became head of the group until his retirement in 1981. Their collaboration resulted in the seminal Friction and Lubrication of Solids (Part I published in 1950 and Part II in 1964).

It was recognised at the outset that real surfaces in contact would only touch at the small areas at the peaks of their inevitable surface roughness, where the pressure would be high and where friction would be generated. This led to a study of indentation hardness and Tabor's excellent little book Hardness of Metals (1951), recently reprinted. It was also maintained that at these intimate contact areas the surfaces would adhere through the action of molecular forces.

Tabor's preoccupation with adhesion gave rise to his best scientific work. Two gifted research students, to whom he gave generous credit, built an apparatus which was able to measure the variation of Van de Waals force with separation of two surfaces at separations of less than 50 nanometres. A modern version of this apparatus ("The Surface Force Apparatus") is one of the major tools of 21st-century tribology. Work on the friction of rubber on glass gave rise to a simple theory of adhesion which has become an indispensable tool of nanometre science. The work of the group included impact, thin lubricant films, friction of polymers, diamond and ice.

The tradition of the laboratory was for elegant experiments, direct observation and simple physical reasoning rather than elaborate mathematical analysis. Tabor's physical intuition was legendary. Most of his simple explanations of experimental observations were confirmed by subsequent detailed analysis. No expense was spared with high-quality measuring equipment, much constructed in the laboratory. A good example was the development in the laboratory of high-speed cameras to study the detailed processes in liquid and solid impact.

Tabor recognised that the work of the group was interdisciplinary, involving inputs from physics, chemistry, materials, mathematics and engineering. He suggested the name "tribology" to embrace the whole field, which has been adopted worldwide. In his modest and unassuming way, Tabor played a leading role among the UK scientific community in promoting tribology. He was instrumental in forming the Tribology Group of the Institute of Physics and served as its first chairman. His scientific achievements were recognised by his election to fellowship of the Royal Society in 1963 and he was the recipient of the first Gold Medal awarded by the Tribology Trust (1972), the Guthrie Medal of the Institute of Physics (1975) and the Royal Medal of the Royal Society (1992). In 1995 he became a Foreign Associate of the US National Academy of Engineering.

Former members of and visitors to PCS are to be found all over the world. They all speak of the kindness and inspiration they received from David Tabor. My first meeting with him characterises the man. In 1953 I was a Research Student in Manchester working on a friction problem. Tabor travelled up from Cambridge to give an evening lecture to an audience of industrial engineers, who gave him a rather rough time in search of quick fixes to their problems. After the lecture, I introduced myself. Although his bed must have called, he insisted on going down to a basement laboratory to find out just what I was doing and invited me to visit him in Cambridge.

Kenneth Johnson