3 ms·

Interestingly the blue flash was caused by electrons, which had been excited by the radiation, transitioning back to a lower energy state and giving off photons

Interestingly the blue flash was caused by electrons, which had been excited by the radiation, transitioning back to a lower energy state and giving off photons! The reason people survived is because radiation from a source falls off by the inverse square law, so as long as you have a small source and a short burst of radiation, distance is great. It's more surprising to me that they didn't use more remote devices for these kinds of experiments.

YeGoblynQueenne 10y ago
>> It's more surprising to me that they didn't use more remote devices for these kinds of experiments. They did, but these also caused accidents. See the Lady Godiva device: https://en.wikipedia.org/wiki/Godiva_device https://en.wikipedia.org/wiki/Godiva_device Otto Frisch received a larger than intended dose of radiation when leaning over the original Lady Godiva device for a couple of seconds. He noticed that the red lamps (that normally would flicker intermittently when neutrons were being emitted) were 'glowing continuously'. Frisch's body had reflected some neutrons back to the device, causing it to go critical, and it was only by quickly leaning back and away from the device and removing a couple of the uranium blocks that Frisch escaped harm but, he said, "if I had hesitated for another two seconds before removing the material ... the dose would have been fatal". On 3 February 1954 and 12 February 1957, accidental criticality excursions occurred causing damage to the device, but fortunately only insignificant exposures to personnel. This original Godiva device was irreparable after the second accident and was replaced by the Godiva II. If I understand this correctly (the closest I got to being a nuclear phycisist is having met an astrophycisist once) this happened during the setup of an experiment. I think normally the experiments with this device were sort of automated (they dropped a rod between two masses, so gravity killed the reaction quickly). [https://en.wikipedia.org/wiki/Criticality_accident#Recorded_incidents https://en.wikipedia.org/wiki/Criticality_accident#Recorded_...]

YeGoblynQueenne 10y ago

>> It's more surprising to me that they didn't use more remote devices for these kinds of experiments. They did, but these also caused accidents. See the Lady Godiva device: https://en.wikipedia.org/wiki/Godiva_device https://en.wikipedia.org/wiki/Godiva_device Otto Frisch received a larger than intended dose of radiation when leaning over the original Lady Godiva device for a couple of seconds. He noticed that the red lamps (that normally would flicker intermittently when neutrons were being emitted) were 'glowing continuously'. Frisch's body had reflected some neutrons back to the device, causing it to go critical, and it was only by quickly leaning back and away from the device and removing a couple of the uranium blocks that Frisch escaped harm but, he said, "if I had hesitated for another two seconds before removing the material ... the dose would have been fatal". On 3 February 1954 and 12 February 1957, accidental criticality excursions occurred causing damage to the device, but fortunately only insignificant exposures to personnel. This original Godiva device was irreparable after the second accident and was replaced by the Godiva II. If I understand this correctly (the closest I got to being a nuclear phycisist is having met an astrophycisist once) this happened during the setup of an experiment. I think normally the experiments with this device were sort of automated (they dropped a rod between two masses, so gravity killed the reaction quickly). [https://en.wikipedia.org/wiki/Criticality_accident#Recorded_incidents https://en.wikipedia.org/wiki/Criticality_accident#Recorded_...]