Graham Farmelo ponders Malcolm Longair's study of the Cavendish, a physics laboratory with few rivals.
Maxwell's Enduring Legacy: A Scientific History of the Cavendish Laboratory
By Malcolm Longair
Physics laboratories are a relatively recent innovation. They started to spring up 150 years ago, centuries after investigators began trying to understand the inanimate world using observation and rational thought. Chemists were ahead of the game — their first laboratories appeared a quarter of a millennium earlier (D. Lowe Nature 521, 422; 2015).
In 1927, Ernest Rutherford spoke at the opening of the H. H. Wills Physics Laboratory at the University of Bristol, UK. He said: “Our pure science laboratories should in the main be set aside for fundamental research.” Those that did research relating to industry should be funded by the government or manufacturers, in places “where the research workers can come into close contact with manufacturing conditions”. Rutherford was at the time director of the Cavendish Laboratory at the University of Cambridge, UK — a world-leading institution for experimental physics. Today, his purism looks almost quaint, with most academic physics laboratories relying heavily on support from industry and other sources.
In what is patently a labour of love, the astronomer Malcolm Longair now gives us a comprehensive scientific history of the Cavendish in Maxwell's Enduring Legacy. Longair, who was the lab's head from 1997 to 2005, describes its inception well. Its early development in the 1870s, on a small site near the centre of town, was bankrolled by the university's chancellor, William Cavendish. He was among those who wanted to ensure that Cambridge could continue to supply top-notch graduates to help to administer the increasingly technological British Empire. Several sceptics, particularly among the champions of the prestigious natural-sciences course, the Tripos, argued that experimental training was unnecessary. The mathematician Isaac Todhunter wrote: “Experimentation is unnecessary for the student.” He believed that “the student should be prepared to accept whatever the master told him”.
The venture made an excellent start, Longair shows, when James Clerk Maxwell was appointed its first director. A strong mathematician with almost superhuman physical intuition, he was determined to nurture experimentation, and had extraordinarily wide interests. He was as eager to explore the new technology of wireless telegraphy as he was to master modern topological mathematics. After his death in 1879 at just 48, the university appointed as his successor John William Strutt, Lord Rayleigh, a versatile physicist who went on to discover argon and win a Nobel prize. Strutt's five years in the post consolidated the reputation of the lab. He was succeeded by theorist J. J. Thomson, who, although not a dexterous experimenter, discovered the electron at his bench there in 1897. With Thomson at the helm, the Cavendish rivalled the mighty Imperial Physical Technical Institute in Berlin as the world's pre-eminent centre for experimental physics.
The next director, Rutherford, died unexpectedly in 1937 after a botched operation. In the quest to find his successor, Longair says, the crystallographer Lawrence Bragg was the “obvious choice”. This surprised me. In 1992, theoretical physicist Rudolf Peierls, who knew the lab well, told me that Rutherford's deputy James Chadwick (discoverer of the neutron) was the widely tipped successor, and that the failure to appoint him led to “a minor scandal”. Either way, Bragg proved a far-sighted leader, and his promotion of crystallography yielded impressive results. Notably, Francis Crick and James Watson gave the Cavendish one of its greatest triumphs by identifying the structure of DNA in 1953.
The quantum theorist Nevill Mott, appointed director in 1954, continued the policy of diversification and expansion. Teaching and research activity doubled, and the lab's Radio Astronomy Group, led by Martin Ryle, had a series of successes, most famously the discovery of pulsars by Jocelyn Bell Burnell in 1967, working with her supervisor Antony Hewish (A. Hewish et al. Nature 217, 709–713; 1968). By this time, the Cavendish was so large that its director was not so much a powerful commander-in-chief as chair of a company, as Longair aptly describes it.
The lab's research had outgrown its space: the number working there had risen from around a dozen in the 1870s to some 40 times that number. In 1973, the next director, Brian Pippard, moved the Cavendish to much larger premises in West Cambridge, the workplace of about 1,000 people. Longair chronicles this move and presents the achievements of Pippard and his successors as Cavendish Professor of Physics, Sam Edwards and Richard Friend, with detail that will satisfy the most assiduous reader of annual reports. The breadth and depth of the areas of physics now being explored by the laboratory are remarkable: all its previous specialities, as well as everything from optoelectronics to medical physics, thin-film magnetism and the physics that underlies studies of the sustainability of the global economy.
Longair's history is in the form of a well-organized modern physics book, most of its 22 sections replete with charts, tables and lucid technical explanations presented neatly in boxes. Abundant diagrams, photographs, line drawings, floor-plans and facsimiles of historical documents give fascinating insights into the lab's development. Very much the account of an insider, the book would have benefited from a wider international perspective.
It would also have been interesting to hear more about the challenges that the lab faces to preserve its eminence. Rutherford kept an eye on almost every research project — no longer feasible for even the most energetic director — and took personal responsibility for keeping his fiefdom fleet of foot so that it could respond quickly to developments. The main challenge of directing the laboratory today, I imagine, is to ensure that the elephant can keep dancing.