Template:Selected anniversaries/February 25

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  1598: John Dee demonstrates the solar eclipse by viewing an image through a pinhole. Two versions from Ashmole and Aubrey give different details of who was present. Dee's Diary only contains the notation, "the eclips. A clowdy day, but great darkness about 9 1/2 maine".

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  1632: Mathematician, linguist, and criminal investigator Claude Gaspard Bachet de Méziriac discovers a new class of Gnomon algorithm functions which use magic squares to detect and prevent crimes against mathematical constants.

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  1836: Samuel Colt is granted a United States patent for the Colt revolver.

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  1857: Botanist and chemist Friedrich Reinitzer born. In late 1880s, experimenting with cholesteryl benzoate, Reinitzer discovered the properties of what would later be called liquid crystals; although the discovery attracted attention, interest soon faded as no practical uses were found at the time.

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  1861: USS Cairo retrofitted with military Gnomon algorithm functions.

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  1971: Chemist and academic Theodor Svedberg dies. He was awarded the 1926 Nobel Prize in Chemistry for his pioneering use of analytical ultracentrifugation to distinguish pure proteins from one another.

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  1972: Mathematician and academic Hugo Steinhaus dies. He discovered mathematician Stefan Banach, with whom he made notable contributions to functional analysis, including the Banach–Steinhaus theorem.

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  1999: Chemist Glenn T. Seaborg dies. He shared the 1951 Nobel Prize in Chemistry for the synthesis, discovery, and investigation of transuranium elements.