- Young Einstein
- First World War
- League of Nations
- war resistance
- against Nazism
- atomic bomb
"Because of the danger that Hitler might be the first to have the bomb, I signed a letter to the President which had been drafted by Szilard. Had I known that the fear was not justified, I would not have participated in opening this Pandora's box, nor would Szilard. For my distrust of governments was not limited to Germany."
The photograph shows a postwar reconstruction of the signing.
Einstein and the atomic bomb
'Politics is for the moment. An equation is for eternity.' In 1905 Einstein had published his revolutionary equation showing that matter and energy were equivalent and interconvertible. There was much speculation by scientists on how that atomic power might be released, and, once released, sustained (by what is called a 'chain reaction', on which ordinary fuels and explosives rely). During the 1920s and 1930s many physicists struggled with the problem. Einstein was right: science was international. American, Australian, British, Danish, Dutch, French, German, Hungarian, Italian, New Zealand, Russian, Swiss and Yugoslav scientists between them made the various research breakthroughs needed to show that an atom of uranium could be split by a neutron beam and would readily produce a chain reaction - thus releasing enormous amounts of energy. It only remained to put it to the test.
The Hungarian physicist Leo Szilard tried hard to stop publication of the news (which broke in January 1939) that atomic fission was possible: he was afraid that Germany might try to make an atomic bomb if it knew. But the principle that scientific information should be shared was a matter of pride; it was released.
Then news came that Germany had forbidden exports of uranium ore from Czechoslovakia (which it had recently invaded). Szilard panicked: Germany must be making a bomb already. The only other stocks of good uranium were in Belgium - they had to be protected, thought Szilard, from falling into German hands. He went to America to get help from Einstein: Einstein was someone people would listen to. Szilard remembered that visit well: 'The possibility of a chain reaction in uranium hadn't occurred to him, but as soon as I began to tell him about it he saw what the consequences might be.' A letter, signed by Einstein, was sent to the American president, Franklin Roosevelt.
It began: 'Some recent work leads me to expect that the element uranium may be turned into a new and important source of energy in the immediate future. Certain aspects of the situation seem to call for watchfulness and, if necessary quick action....This new phenomenon would also lead to the production of bombs, and it is conceivable that extremely powerful bombs of a new type may be constructed....Some of the American work on uranium is now being repeated in the Kaiser Wilhelm Institut in Berlin.' Roosevelt replied: 'I found this data of such import that I have convened a board to investigate.'
Apart from a second letter written when the advisory board seemed to be dragging their feet, Einstein took no other part in the UK/US study of uranium fission or in the USA's Manhattan Project which created the first atomic bombs. In fact, before Szilard's visit Einstein had not been convinced that nuclear fission was likely, at least in his lifetime; he was reported to have likened it to 'shooting birds in the dark in a country where there are few birds'. His response to Szilard's news was prompted by different belief: that if 'the enemies of mankind' were developing an atomic bomb, the only deterrent was for America to make one first. 'If I had known that the Germans would not succeed in constructing the bomb, I would never have lifted a finger.'
Einstein also believed that the USA would treat the discovery with respect and would resist actually using the bomb. He was not the sort of cynical realist who would foresee that America's atomic research would now be managed by the military. (When it was found that Germany had no bomb, someone said, 'That's wonderful; we won't have to use ours'. A US army officer retorted, 'Of course you understand that if we have such a weapon we are going to use it'.)
In April 1945 Leo Szilard came to Einstein again, this time to share his deep fear that the USA would start an atomic arms race. Once again Einstein wrote to the President, enclosing a strong warning (written by Szilard) against using the atomic bomb. But the letter was still unopened on Roosevelt's desk when he died. The new president, Harry Truman, was too busy taking office to be accessible, though the scientists tried hard to get through.
In a letter to the New York Times in 1945, Einstein quoted recent words of Franklin Roosevelt: 'We are faced with the pre-eminent fact that if civilisation is to survive we must cultivate the science of human relationship - the ability of peoples of all kinds to live together and work together in the same world, at peace.' Well, Einstein continued, 'we have learned, and paid an awful price to learn, that living and working together can be done in one way only - under law. Unless it prevails, and unless by common struggle we are capable of new ways of thinking, mankind is doomed.'
The first atomic bomb was dropped on Hiroshima (not on its military installations but on the civilian centre of the city) on August 6 1945. Up to 140,000 people were killed. Thousands were to die much later, of radiation-related diseases: the death toll had reached 192,000 in 1995. When Einstein heard the news, he uttered a cry of anguish. On August 9 a second bomb was dropped on Nagasaki. It killed 73,884 people outright, and injured 76,769 more; these figures do not include those who died later from radiation.