Quantum and Nuclear

Szilard’s eureka moment

Stories from Physics for 11-14 14-16 16-19 IOP RESOURCES

Leo Szilard, a Hungarian physicist, worked in Berlin during the 1920s. Because he was a Jew, Hitler’s rise to power led him to flee to London. On the 13 September 1933, Szilard was walking on Southampton Row in Bloomsbury having just read Ernest Rutherford’s pronouncement in The Times the day before that: “Anyone who looked for a source of power in the transformation of the atoms was talking moonshine.” Szilard recalled that:

…as I was waiting for the light to change and as the light changed to green and I crossed the street, it suddenly occurred to me that if we could find an element which is split by neutrons and which would emit two neutrons when it absorbed one neutron, such an element, if assembled in sufficiently large mass, could sustain a nuclear chain reaction.

During his time in London, Szilard rented a small room at the Strand Palace Hotel which used to be a maid’s cupboard. The room gave access to a communal bathroom and Szilard used his bath time to daydream about nuclear fission. He usually went to bathe at 9am but one day, a concerned maid knocked on the door at noon to ask: “Are you alright, sir?” The abstracted physicist had been in the bath for three hours, thinking about beryllium’s role in fission.


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