Thursday, August 06, 2009

Hiroshima in the making

On the 6th August 1945 at 0816 local time an atom bomb was dropped over the city of Hiroshima. The 40th anniversary of this event was marked by the following essay in our journal.

The idea that the material world is composed of enormous numbers of exceedingly small entities called atoms was first propounded about 450 BC by the Greek philosopher Leucippus and his pupil Democritus. It was not until 1911, however, when Ernest (later Lord) Rutherford published a paper putting forward the nuclear model of the atom, that the proposition gained general acceptance. It may seem hard today to realise that the paper caused no commotion in the world of physics - Rutherford himself does not appear to have considered this discovery as the epoch-making event it tumed out to be. In fact, this is not surprislng since no commercial application could be envisaged for the work, unlike x-rays and radium which had obvious medical uses and were soon seen as potential sources of profit.

Where no such profitable application appeared the research was funded largely out of universities' private resources and co-ordination between researchers .depended largely on their own individual efforts. This situation was not to change until the stage had been reached when it began to look as though this decomposition of matter, occurring naturalIy in the radioactive materials, could be achieved artificially in a controlled manner to the extent required for a large explosion. The relevant work between the two world wars led to the discovery of the fission process and the possibility of a chain reaction.

It would be too long a story to detail the steps by which these discoveries were made, but it is worth noting that the whole process, even jf unco-ordinated, involved a large number of scientists of many nationalities. En route the dream of the old alchemists, of transmuting one element into another, was realised although the end product was not as they had envisaged, By 1939 it had been shown that nuclear combustion, releasing a million times the energv of chemical combustion, was indeed possible.

When war broke out the scientists involved expressed considerable scepticism about whether an atomic bomb was feasibie. The politicians were even more doubtful. - Margaret Gowring recalls that Churchill at this time was more concerned that the so-called "fifih column" might exploit fears about "a terrible new uranium explosive" to force Britain to accept a surrender! (Britain and Atomic Energy, 1939-45, Macmillan, 1964.) Many scientists were directed to other vital war work at places such as the Royal Aircraft Establishment, although some uranium research continued at a very slow pace. A change in attitude was brought about as much by the fear that Germany might get a head start as any more rational consideration. A number of scientists who had fIed from Nazi persecution gave assistance to the Allied powers and the teams competing in this grim race were truIy international both in the sense of their composition and in the debt they owed to past knowledge.

Eventually, in early 1940, the British government set up a small sub-comrnittee under the Committee for the Scientific Survey of Air Warfare - which was to be known by its code name of the Maud Committee - to examine the available evidence and report back to the government on the chances of success. Their report, issued in July 1941, gave a positive answer and was remarkable in its prescience. Only in two respects was it deficient: it was two years early in its foreeast of when a bomb would be ready and it erred in its assessment of the prospects of plutonium as a fuel (the Nagasaki bomb used this method).

The stage had now been reached when uranium research was no longer the exclusive concern of a few individuaIs in universities. The horrors of atomic warfare could be envisaged fairly clearly, even though practical demonstration was still some way off. The Maud Committee were able accurately to compare the devastation expected from an A-bomb with known effects of TNT and they also had a reasonable understanding of the effects of radiation. They commented: .

"It is very difficult to estimate the extent of their [fission products] effect especially as the most important substances would be those of long life, which are the hardest to study under laboratory conditions. It does however seem certain that the area devastated by the explosion would be dangerous to life for a considerable time."

The conclusions of the Maud Committee and similar work in America led to a decision to manufacture. After Pearl Harbour, America went onto a full war footing, and they no longer saw any need to share their secrets with the British. Already they were looking ahead to the post-war world and resurned industrial competition - an attitude which led to considerable friction within the Alliance. The American capitalists saw the chance to supplant British interests in the latter's erstwhile colonies and Roosevelt appeared to side with Stalin against Churchill at some of the wartirne conferences. The British reluctantly had to accept a very junior role in the A-bomb project, and virtually none in the dedsions about dropping one in anger.

Before any bombs were ready, however, Germany and Italy had surrendered and so the question was whether the weapon should be used against Japan. The politicians and militarists were still riddled with sceptidsm and it did not therefore figure prorninently in their strategy. At first the British and Americans wanted Russia to enter the war with Japan. There were obvious problems about Russian entry, as clearly Stalin wanted to strengthen Soviet influence in Manchuria and in the territories lost to Japan in the 1904-05 wars. The Chinese government of Chiang Kai-Shek was party to negotiations over these issues and any agreements reached at the Yalta conference were cLearly of an unstable nature.

The first successful test on 16 july 1945 caused a change in the attitude to Russia, as the possibilitv of forcing Japan to surrender without help now loomed. Considerable disagreements surfaced over how Japanese resistance could best be ended. As early as September 1944, Roosevelt and Churchill agreed that "when a bomb is finalIy available it might perhaps, after mature consideration, be used against the Japanese who should be warned that this bombardrnent will be repeated unill they surrender ." (Gowring, M., op. cit., p.370). In May 1945 a brief but heated debate began in America, involving scientists as well as politicians and the arrned forces, The case for warning Japan was argued in front of President Truman himself, A "harrnless" demonstration of the bomb's power, perhaps with Japanese observers present, was proposed but the idea foundered on two main counts: there was still no certainty that the bomb would work, or that if it did it would induce surrender.

Deep divisions still existed after the successful test and it was impossible to get a consensus view in the necessary time. This may have been the reason why Trurnan later came to exaggerate and indeed to glory in the personal part he played. When Robert Oppenheirner regretted his part in the project, saying that he felt he had "blood on his hands", Truman told Dean Acheson. "Don't you bring that fellow around here again. After all, all he did was to make the bomb. I'm the guy who fired it off' (Pringle, P. & J. Spiegelman. The Nuclear Barons, Sphere 1985, p.95).

One factor that is often understandably underplayed by official accounts was the strength of the "Peace Party" in Japan. It is quite incorrect to think of the country as completely dorninated by a military caste headed by an autocratic Emperor. Gowring reports:

"The Peace Party had ernerged within the Japanese Cabinet as early as April 1945, but it had to move with extreme circumspection in the face of fierce opposition from the military. However in ]uly, whlle the Allied leaders were assembling at Potsdam, the Japanese Emperor himself authorised peace feelers through Russia. Japan, it was ernphasised, would never accept unconditional surrender but was anxious for discussions about a negotiated peace. Stalin gave Mr Churchill an accurate account of these approaches ... "

Deterrnined efforts to encourage the Peace Party were hindered by disunity in the Allied camp, and the Potsdam Proclamation to Japan, following the conference of that name, was a solernn warning of the destruction to comeijf they did not surrender forthwith. However it did not describe the new weapon and when Trurnan, after yet more intemal debate, informed Stalin he merely said that America now had "a weapon of unusually destructive force". The Russians and Japanese, through their intelligence networks, probably had a good idea what was meant, but they could not say so openly. The Russians had in fact already started work on their own atom bomb.

Three days after the Potsdam Proclamation, on 29 July, the Japanese Prime Minister announced that his government would ignore it, but four days later further peace feelers were sent through Moscow with "qualilled adrnission of the Potsdam Proclamation as a basis of discussion". This however brought no response before the Hiroshima bomb was dropped on the now infamous 6 August a further appeal for surrender followed, failing which more bombs would be dropped

The Japanese militarists had in the past been accustomed to dictate terms to the Emperor; now however Hirohito sided with the Peace Party against the influence of the arrned forces. The Japanese cabinet was hopelessly split, and even Hiroshima did not break the deadlock. Communications had been cut and the hawks refused to believe what they had been told and had to visit the area themselves to be convinced. No agreed statement could be made. The Allies responded by advandng the date for the bombing of Nagasaki, which coincided with the entry of Russia into the war. The last stand of the armed forces was at an end. The atornic bomb which fell on Hiroshima killed 64,000 people within four months and the bomb on Nagaski 39,OOO people.In addition, 72,000 people were injuted in Hiroshima and 25,000 in Nagasaki. At Hiroshima four square miles were totally devastated and nine square miles were very badly damaged.

It is futile to speculate on how the destruction compares with what might have occurred had non-nuclear options been adopted - all the altematives were terrible in terms of the killing and mairning of workers on both sides. Such conjecture would merely encourage the notion that saving lives was a major consideration.


Further reading:

Hiroshima and after!

Why they dropped the bombs

No comments: