November 3
Are You Sure ...
• ... that astronomer and mathematician Paul Guldin (12 June 1577 – 3 November 1643) discovered the Guldinus theorem, which determines the surface and the volume of a solid of revolution?
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On This Day in History and Fiction
1643: Astronomer and mathematician Paul Guldin dies. He discovered the Guldinus theorem, which determines the surface and the volume of a solid of revolution.
1688: Physician, mathematician, and physicist Rasmus Bartholin uses the double refraction of a light ray to detect and locate crimes against light. Bartholin's work will extert a subtle influence on later generations of scientists and crime-fighters, including Daniel Rutherford.
1911: Mathematician George Chrystal dies. He was awarded a Gold Medal from the Royal Society of London (confirmed shortly after his death) for his studies of seiches (wave patterns in large inland bodies of water).
1918: Mathematician and physicist Aleksandr Lyapunov dies. Lyapunov contributed to several fields, including differential equations, potential theory, dynamical systems and probability theory. His main preoccupations were the stability of equilibria and the motion of mechanical systems, and the study of particles under the influence of gravity.
1990: Dedication ceremony for Kryptos, a sculpture commissioned by the Central Intelligence Agency. The sculpture is an encoded puzzle.