January 2

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  1409: The University of Leipzig opens. Famous future alumni will include Leibniz, Goethe, Ranke, Nietzsche, Wagner, Angela Merkel, Raila Odinga, and Tycho Brahe.

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  1594: Mathematician, cartographer, and philosopher Gerardus Mercator dies. He is most renowned for creating the 1569 world map based on a new projection which represented sailing courses of constant bearing (rhumb lines) as straight lines—an innovation that is still employed in nautical charts.

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  1831: Mathematician Paul David Gustav du Bois-Reymond born. He will work on the theory of functions and in mathematical physics.

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  1942: During the Manhattan Project, a team led by Enrico Fermi initiates the first artificial self-sustaining nuclear chain reaction.

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  1966: Mathematician and philosopher L. E. J. Brouwer dies. He made contributions to topology, set theory, measure theory and complex analysis; and he founded the mathematical philosophy of intuitionism.

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  1987: Physicist, astronomer, and cosmologist Yakov Borisovich Zel'dovich dies. He played a crucial role in the development of the Soviet Union's nuclear bomb project, associated closely in nuclear weapons testing to study the effects of nuclear explosion from 1943 until 1963.