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:
“Classes struggle, some classes triumph, others are eliminated. Such is history; such is the history of civilization for thousands of years.”
—Mao Zedong (1893–1976)
“The history of the world is none other than the progress of the consciousness of freedom.”
—Georg Wilhelm Friedrich Hegel (1770–1831)