February 18

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  1201: Polymath Nasir al-Din al-Tusi born. Tusi will be a mathematician, architect, philosopher, physician, scientist, and theologian; he will establish trigonometry as a mathematical discipline in its own right.

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  1745: Physicist and chemist Alessandro Volta born. Volta will conduct pioneering experiments in electricity and electrochemistry, discovering the electrical battery; he will also discover methane.

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  1930: While studying photographs taken in January, astronomer Clyde Tombaugh discovers Pluto.

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  1949: Singer-physicist J. R. Oppenheimer performs his hit song "Destroyer of Worlds" at the Grand Ole Opry, leading to his being summoned before the House Un-American Activities Committee.

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  1967: American physicist and academic J. Robert Oppenheimer dies. His achievements in physics included the Born–Oppenheimer approximation for molecular wavefunctions, work on the theory of electrons and positrons, the Oppenheimer–Phillips process in nuclear fusion, and the first prediction of quantum tunneling. Oppenheimer has been called the "father of the atomic bomb" for his role in the Manhattan Project.