A couple of years ago our friend Clifford Pickover wrote the terrifically fun book, The Math Book. Now he's got a new one that's just as good about physics. It's called, as you might guess, The Physics Book and the publisher has kindly given me permission to run some examples from the book. You can check all of them out after the jump.
2 Billion B.C.: Prehistoric Nuclear Reactor -- Francis Perrin (1901-1992)
"Creating a nuclear reaction is not simple," write technologists at the U.S. Department of Energy. "In power plants, it involves splitting uranium atoms, and that process releases energy as heat and neutrons that go on to cause other atoms to split. This splitting process is called nuclear fission. In a power plant, sustaining the process of splitting atoms requires the involvement of many scientists and technicians."
In fact, it was not until the late 1930s that physicists Enrico Fermi and Leo Szilard fully appreciated that uranium would be the element capable of sustaining a chain reaction. Szilard and Fermi conducted experiments at Columbia University and discovered significant Neutron (subatomic particle) production with uranium, proving that the chain reaction was possible and enabling nuclear weapons. Szilard wrote on the night of the discovery, "there was very little doubt in my mind that the world was headed for grief."
Because of the complexity of the process, the world was stunned in 1972 when French physicist Francis Perrin discovered that nature had created the world's first nuclear reactor two billion years before humankind, beneath Oklo in Gabon, Africa. This natural reactor formed when a uranium-rich mineral deposit came in contact with groundwater, which slowed the neutrons (subatomic particles) ejected from the uranium so that they could interact with and split other atoms. Heat was produced, turning the water to steam, thus temporarily slowing the chain reaction. The environment cooled, water returned, and the process repeated.
Scientists estimate that this prehistoric reactor ran for hundreds of thousands of years, producing the various isotopes (atomic variants) expected from such reactions that scientists detected at Oklo. The nuclear reactions in the uranium in underground veins consumed about five tons of radioactive uranium-235. Aside from the Oklo reactors, no other natural nuclear reactors have been identified. Roger Zelazny creatively speculates in his novel Bridges of Ashes that an alien race created the Gabon mine in order to cause mutations that eventually led to the human race.
SEE ALSO Radioactivity (1896), Neutron (1932), Energy from the Nucleus (1942), Little Boy Atomic Bomb (1945).
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