Just how many Allied lives these weapons saved is open to debate and the mathematics of deaths-for-lives is, anyway, a distasteful equation. It will never be known exactly how many people were killed immediately, and in the following months, by the atomic bombs: there may have been as many as 140,000 in Hiroshima and 70,000 in Nagasaki it's estimated another 72,000 were injured at Hiroshima and 25,000 at Nagasaki.īoth Hiroshima and Nagasaki were industrial cities contributing to the Japanese war effort. The immense pressure caused by the explosion drove forward a furious gale as the mushroom cloud boiled upwards the pressure lessened and the wind swept back towards ground zero. When the atomic bomb detonated over Hiroshima the temperature at its heart reached one million degrees Centigrade thermal energy hurtled across the ground and radiation released by the explosion flashed outwards. Another bomb was dropped on Nagasaki on August 9th. Only three weeks after the Trinity test, on Monday August 6th, a B-29 bomber nicknamed "Enola Gay" dropped the first atomic weapon on Hiroshima. However once the military was involved Aeby said "there wasn't much room for argument." Robert Oppenheimer, who oversaw the research, certainly knew about it. There had been a serious proposal along those lines designed to show the Japanese just what they might expect if the war was to continue. I was all in favour of some kind of demonstration, as were any number of people, that didn't involve destroying a city." "I was sad that they felt they needed to do that. How did Aeby feel when the bomb was dropped on Hiroshima? "After a few loud hurrahs it got pretty quiet and people began to think a little bit about the meaning of all this." He went back to Los Alamos that afternoon and developed the pictures, all of which were reasonable exposures one of them became famous as the colour image of the arrival of the atomic age. He felt a great sense of accomplishment at the end of 3 years work. What was his reaction to this momentous event? At the actual detonation he said his first reaction was "Did I get the picture?". It was obvious the light was too bright so I shut the lens and dropped down the diaphragm and fired three more times in rapid succession," said Aeby. The explosion "Jarred the earth and knocked us back a bit from the shock wave. He had the shutter of his camera open there had been speculation that the bomb might fizzle and he wanted to have a picture if that happened. Aeby was about 9 kilometres from ground zero. In the instant before the balloons and their detectors were destroyed they flashed their data back to recording instruments. Additional gamma ray detectors were buried at some distance, their sensitive probes sticking out of the sand.Īt 5.29am the bomb was detonated. The balloons were about 20 metres away from ground zero. To obtain measurements of the yield of the first atomic bomb, gamma detectors were flown from barrage balloons at heights of 150-300 metres. On Monday 16th July, 1945, Aeby was given permission to take a camera out into the New Mexico desert where the new weapon was to be detonated the test was code-named Trinity. They, and other groups, were working in secret to develop an awesome weapon, dreadful enough, it was reasoned, to bring the war with Japan to an end. In the early 1940s Jack Aeby was a technician working with Emilio Segrè's research group at Los Alamos, USA. (Click here for an overview of this article)