History
The first nuclear fission process discovered was the fission induced by neutrons. Because cosmic rays produce some neutrons, it was difficult to distinguish between induced and spontaneous fission events. Cosmic rays can be reliably shielded by a thick layer of rock or water. The spontaneous fission was identified in 1940 by Soviet physicists Georgy Flyorov and Konstantin Petrzhak by their observations of uranium in the Moscow Metro Dinamo station, 60 metres (200 ft) deep underground.
Cluster decay was shown to be a superasymmetric spontaneous fission process.
Read more about this topic: Spontaneous Fission
Famous quotes containing the word history:
“We have need of history in its entirety, not to fall back into it, but to see if we can escape from it.”
—José Ortega Y Gasset (1883–1955)
“When the history of guilt is written, parents who refuse their children money will be right up there in the Top Ten.”
—Erma Brombeck (20th century)
“The history of persecution is a history of endeavors to cheat nature, to make water run up hill, to twist a rope of sand.”
—Ralph Waldo Emerson (1803–1882)