Blackett: Physics, War, and Politics in the Twentieth Century

  • Mary Jo Nye
Harvard University Press: 2004. 272 pp. $39.95, £25.95, €36.90 0674015487 | ISBN: 0-674-01548-7
Speaking out: Patrick Blackett was labelled a traitor for arguing against UK work on an atomic bomb. Credit: HULTON-DEUTSCH/CORBIS

A prominent scientist visits the United States at election time and records a “conservative turn in American politics and an eagerness to talk about preventive war”. Rather than trim his sails to meet the prevailing wind, he redoubles his determination to speak the truth about weapons of mass destruction. He subsequently writes a book that is criticized from all sides, and is labelled a defeatist, even a traitor of sorts. It will take many years for the historical consensus to catch up.

The scientist was Patrick Blackett, and the book was his 1948 work The Military and Political Consequences of Atomic Energy. “The experiences of Blackett in his public campaign against nuclear weapons,” writes his biographer Mary Jo Nye, “illustrate the risks to a physicist of writing about a subject other than physics, as well as the circumstances that might compel one to do so.”

The traditional function of a biography was to provide lessons, drawn from a past life, by which contemporary readers should aspire to live their lives. The emphasis was on character. Nye's biography of Blackett, although modern in its approach to the history of science, is nevertheless oddly traditional. In seeking to provide an account of how the physicist could navigate so successfully between theory and experimental craft, and between the laboratory and the corridors of power, she focuses on his virtuous characteristics, including “versatility of imagination”, “tough skepticism” and being “fiercely independent”.

The children of a century ago were blessed: the most radical technologies of their day could be taken apart, built, rebuilt and understood with their own hands. “I spent every hour out of school making wireless sets and model aeroplanes,” Blackett recalled. The knowledge gained from this tinkering got him into the Royal Naval College at Osborne House on the Isle of Wight: the admissions board judged him the “right sort of boy”. The young naval cadet built his own cameras. On active duty he witnessed the Battle of the Falklands in 1914. In quieter moments he continued with photography.

Blackett's manipulative skill flourished when, after demobilization, he joined Ernest Rutherford's Cavendish Laboratory at the University of Cambridge, where the most remarkable series of discoveries in twentieth-century physics were crafted.

Blackett constructed automatic cloud chambers in which the passage of a particle triggered a photograph of the event. Working with Giuseppe Occhialini, he turned the device towards the mysterious cosmic rays. “What not everyone had the chance to see,” Occhialini later noted, “was the passionate intensity with which he worked. I can still see him, that Saturday morning when we first ran the chamber, bursting out of the darkroom with four dripping photographic plates held high, and shouting for all the Cavendish to hear, ‘One on each Beppe, one on each!’.”

But, as Nye writes, intensity was balanced by tough skepticism. In 1932, faced with a small number of extraordinary tracks, Blackett identified them with one of his colleague Paul Dirac's most exotic predictions, positively charged electrons. Yet he refused to rush into print — one reason why the 1936 Nobel prize went to his rival at the California Institute of Technology, Carl Anderson.

Francis Everitt, one of Blackett's students, claimed that two remarks encapsulated Blackett's outlook: “Make sure you gather plenty of data,” and “Treat your research like a military campaign.” Others, too, clearly learned the lesson. When Blackett restarted his cosmic-ray programme at Manchester University after the Second World War, George Rochester and Clifford Butler soon announced their discovery of kaons, or K-mesons, in Nature: “There are two photographs containing forked tracks of a very striking character. These photographs have been selected from five thousand photographs taken in an effective operation time of 1,500 hours”. Plenty of data there.

Nor is it surprising that the ex-naval cadet treated research like a military campaign. However, during the war Blackett achieved something with far greater ramifications: he treated military campaigns as research, inventing a new science, operational research, as a result. In 1933, Blackett had moved to Birkbeck College, London. The problems he faced of limited financial support for his impoverished physics laboratory were easily outweighed by the advantages of his “fierce independence”, free from Rutherford and free to choose his own research direction.

London also meant induction into the political establishment. The socialist Blackett was recruited by Henry Tizard to advise on air defence, in particular the development of radar. After war broke out, he assembled interdisciplinary teams of scientists to work closely with military personnel. The stuff of the operations rooms — flight books, radio-location data and ship positions — became the data of operational research. This was a new science, not because its approach was new, but because it marked a close and supplementary relationship between scientific expertise and military power.

When Blackett wrote in November 1941 to his friend Michael Polanyi, an émigré chemist of opposing political views, Blackett asked: “You speak as if it is always a duty to publish the ‘truth’. If I had published the truth of what I have known of parts of our war effort, I would certainly be locked up. Should I have done so?”. What was the truth in question? Blackett had sided with Tizard in opposing Frederick Lindemann's advocacy of bombing civilian populations, and he had done so on the basis of operational research. By then, other means of mass destruction were being debated.

From 1940, Blackett sat on the MAUD Committee, assessing the likelihood that research on nuclear chain reactions would lead to a practical atomic weapon within the timespan of the war. At first he was the lone British voice calling for the weapon to be developed only by the United States. After the war, and particularly after the 1946 McMahon Act broke with any pretence of joint UK–US responsibility for the bomb, Blackett argued vehemently against a British bomb project. He tried private routes of influence, but was rebuffed by the prime minister, Clement Attlee. So he went public, writing The Military and Political Consequences of Atomic Energy.

“Neither communist nor pacifist, Blackett had no argument with war,” writes Nye, so why did Blackett take such “an outspoken and unpopular political position on matters of nuclear policy immediately following the Second World War?” Because his naval and operational-research experience taught him that policy decisions driven by inadequate knowledge were likely to be wrong. And because he was appalled by war-games theorizing, which he viewed as inhuman.