Shortly after Hiroshima a contributor to the New Statesman, recalling that Lucretius, an early atomist, had taken to philosophy to escape the corruption and decadence of his time, wrote:
Roman Lucretius, filled with deep disgust
At superstition, politics and lust,
Found atoms helpful.
We, in our position, try lust, and politics and superstition.
This note describes a similar transmogrification.
Early in 1939 the atomically informed world became aware, from an experiment by Otto Hahn in Germany and subsequent analysis, that an atom bomb had moved from science fiction to being a technical possibility. It was clear that if the proportion of the rare isotope in uranium could be increased sufficiently (“enhancement”) a chain reaction involving neutrons and the release of a lot of energy, that is, a bomb, might be achieved.
In theory this enhancement might be produced by a well‑known electromagnetic method. This approach was later developed at the University of California in Berkeley and production carried out in a massive plant at Oakridge, Tennessee. But that plant, together with an alternative diffusion plant, had produced by July 1945 only enough enhanced uranium for the one untested bomb dropped at Hiroshima. It was to this electromagnetic process that 1 and another New Zealand scientist were sent in July 1944.
The world was in no state to cope with the implications of this new weapon. Hitler had taken over Austria early in 1938; in August he had taken part of Czechoslovakia, declaring at Munich that it was his last demand, early in 1939 he took the rest. Czechoslovakia happened to have the only known uranium deposits in Europe.
Inevitably governments accepted the real possibility of Germany producing a bomb and some explored the possibility of making one themselves. Any doubts about Germany’s interest were later dispelled by its seizure of the output of the Norwegian heavy water plant, the only conceivable use for which was in a reactor. This was a device which had emerged soon after Hahn’s experiment. In addition to forming the heart of nuclear power stations, it produces plutonium, an artificial element from which an alternative bomb could be made. The British and the Norwegian underground mounted several costly operations, the last in 1944, to cut off this supply.
Seven countries explored the question. Britain started early and its significant advances stimulated American interest. The two merged in 1943. Canada and France joined in and some French scientists went to Canada when France fell. The Canadian project received a major boost from the British when they found that the Americans, happy to have their assistance in producing enhanced uranium and in the development of the actual bomb at Los Alamos, were less enthusiastic about sharing the more important reactor technology. In order not to be left behind in the postwar world, Britain helped the Canadians develop a reactor at Chalk River. Six New Zealanders joined them in 1944 and made a significant contribution.
Germany made a substantial effort in the early part of the war, though it achieved less than expected – some excellent physicists had fled the country. The Russian programme was interrupted by the German invasion, but restarted. The Japanese started in 1940 and although their navy lost interest in 1941 their army supported a not very effective effort until their laboratory in Tokyo was destroyed by American bombing in April 1945.
In normal times scientists dislike secrecy. It conflicts with the publication and criticism which is central to research and to the standing of the scientist. Few are attracted to military applications. But from 19 39 times were not normal and the real apprehension about Germany’s potential progress made it possible to enlist an amazing range of talent which bridged the gap between basic research and a very sophisticated application in six years.
The threat of war had not only made the attempt to develop a bomb inevitable. it had also been the instrument that made success attainable. The value of that success was more debatable.
Just how debatable became very clear when the production of the first bombs in July 1945 forced the filial decision of how, if at all, the bomb would be used.
In the absence of a bomb or unconditional surrender, the Americans planned to invade Japan in November, anticipating heavy casualties (possibly half a million), the Russians having agreed secretly, in return for concessions, to help by invading Manchuria in August. Bombing of Japanese cities had caused very heavy casualties – 84,000 were killed in Tokyo in one night. The capture of the Japanese island of Okinawa, fanatically defended, had cost 12,000 American and over 100,000 Japanese lives. Fighting throughout south‑east Asia, the Pacific and China, and the death of allied prisoners in camps was taking a continuing toll.
There was no doubt that the use of the bomb, even on a concentrated target such as Hiroshima, would cost fewer lives, Japanese and American, than the planned invasion.
The alternative to the use of the bomb was a rapidly negotiated peace. Speed was necessary to limit the deaths, allied and Japanese (and after August, Russian), which would occur even without an actual landing. But the possibility of ending the war without Russian involvement and so limiting their postwar influence in the area gave the Americans further reason for speed.
It was known that Japan was making peace approaches through Russia, with which it had a neutrality pact. The Japanese Prime Minister favoured a negotiated peace but the war faction in the cabinet and the army believed they could repulse the first American invasion and then negotiate better terms.
Several groups of American scientists had argued that the bomb should be demonstrated ill a non‑lethal way on a barren island to United Nations observers or dropped in Tokyo Bay. But no one could think of a way that it could be made so convincing that it would end the war. Even after both bombs were dropped the military faction in the Japanese cabinet wanted to hold out for conditions aimed at preserving the honour and standing of the army and certain to be unattainable, so this view was probably correct.
One group of scientists proposed that the Japanese be offered peaceful development in the homeland if they surrendered, with the threat of the new weapon if they refused. A similar carrot and stick approach was considered at political levels but for no clear reason dropped.
The failure to try this simple option or some variant of it was a serious one which weakened the case for the bomb’s use, even if the chances of success were not high. Those chances would have increased if, in spite of the real difficulties, the reality of the threat could have been reinforced by a non‑lethal demonstration.
When the second bomb was dropped three days after Hiroshima, leaving the Japanese no time to react, many of us were shocked and puzzled. When it later became clear that the primary reason for haste was to finish the war before Russia’s intervention on August 15, the decision became understandable, but not more defensible. The Americans could have adopted the carrot and stick approach and if it failed could have deferred a decision until after the Russian intervention. If that intervention had failed to prompt a surrender, the subsequent use of the bomb would have been more defensible.
No country could ask its forces to continue the fighting in the Pacific, South‑cast Asia, China and Manchuria when it had the means to end it. Japan would have had casualties in these areas as well as from the conventional bombing the Americans would have had to maintain to avoid or simplify an invasion. Experience showed these casualties would have been heavy, even before an actual invasion, very probably exceeding those likely from an atomic bomb. The use of a single bomb, following a final warning, shortly after the Russian intervention would have been a far smaller moral burden, albeit at some immediate political cost.
Finally, after both bombs were dropped the emperor supported the civilian faction against the military in the cabinet ill seeking only the retention of the imperial institution as a condition of surrender.
With the dropping of the bomb one important task of the scientific community was to promote public debate on how the world could cope with a country being able to inflict unprecedented damage with virtually no warning.
One of the first to enter the debate was Sir James Chadwick, the head of the British mission to the United States. A Nobel Prize winner and discoverer of the neutron, he used his position to deflate the American euphoria about the bomb. President Truman, apparently relying on the estimate of General Groves, head of the Manhattan project, that it would take Russia 20 years to make a bomb, rather than his scientific advisers who said three to six years (it took four), had encouraged the belief, taken up by the press, that America’s atomic supremacy would last many years.
Chadwick, better placed than any American official to contradict publicly the President and his senior military adviser, called a press conference immediately after Nagasaki to say that any sophisticated industrial power with access to uranium, including Russia, Germany or Japan, could have one within five years. In a less public way members of the British group (including its New Zealand members) as they dispersed from Berkeley wrote to the British Prime Minister, Clement Attlee, stressing that there were no fundamental secrets about the bomb and urging the exchange of information as a step towards global control. Since then many scientists, notably the American-based Federation of Atomic Scientists, have effectively promoted information and debate on the issues.
Robert Oppenheimer left the project in October 1945, but chaired the principal advisory committee on nuclear policy. In that role he opposed the development of the hydrogen bomb, hoping that this would elicit a positive Russian response and slow, perhaps reverse, the nuclear race. For this and for past irrelevant security considerations his clearance was withdrawn and America lost a courageous, brilliant and principled man from its corridors of power. Over the years many others of ability and principle have been discarded or walked away. The effect on the quality of decisions has been all too obvious.
Like many on the Manhattan project, I had no background in atomic physics, but took whatever skills I had and adapted to the demands of the job. I left atomic physics permanently the day I left Berkeley.
The British group, which was impressive, comprising a wealth of current and future FRSs and a future Nobel Prize whiner, made a major contribution to upgrading the performance of the electromagnetic process – but I wonder whether such a wealth of talent was sensibly concentrated on what was the least satisfactory method of producing a charge. George Page and I joined it quite late and I wonder even more about the significance of our more modest efforts.
So what was the point of our involvement? I am sure that the six who went in 1944 to Chalk River made a valuable contribution to that reactor which had very little to do with winning World War II but a lot to do with helping the British and Canadian nuclear programmes.
Of the eight who went in 1944 and a ninth later, two never returned to work in New Zealand, and four returned to work in different fields. All three who stayed in atomic work and returned to New Zealand left again.
It might have made sense if we had embarked on a substantial nuclear programme immediately after the war – but that was never remotely realistic. For reasons which I think are sound, we have never acquired even a research reactor. The Institute of Nuclear Sciences which has done excellent work, notably in carbon dating, was relatively slow to develop.
It was an enterprising but poorly conceived effort to give New Zealand a head start in the nuclear age. It failed.
Robin Williams, now retired, was head of the Applied Mathematics Laboratory of the DSIR before becoming Vice‑chancellor at Otago University and at the Australian National University and then chairman of the State Services Commission.