Template:Selected anniversaries/February 14

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  1404: Polymath Leon Battista Alberti born. Alberti epitomized the Renaissance man: humanist author, artist, architect, poet, priest, linguist, philosopher, cryptographer.

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  1744: Mathematician John Hadley dies. Hadley laid claim to the invention of the octant, two years after Thomas Godfrey claimed the same. Hadley also developed ways to make precision aspheric and parabolic objective mirrors for reflecting telescopes.

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  1855: Texas is linked by telegraph to the rest of the United States, with the completion of a connection between New Orleans and Marshall, Texas.

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  1876: Alexander Graham Bell applies for a patent for the telephone, as does Elisha Gray.

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  1904: Engineer and inventor Charles William Oatley born. He will develop of one of the first commercial scanning electron microscopes.

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  1943: Mathematician David Hilbert dies. He discovered and developed a broad range of fundamental ideas in many areas, including invariant theory and the axiomatization of geometry.

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  1944: Physicist and academic Owen Willans Richardson uses thermionic theory to compute optimal Valentine's Day card.

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  1950: Physicist and engineer Karl Guthe Jansky dies. He was one of the founding figures of radio astronomy.

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  1951: Theoretical physicist and crime-fighter Richard Feynman uses principles of quantum electrodynamics to compose state-of-the-art Valentine's Day cards.

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  1990: The Voyager 1 spacecraft takes the photograph of planet Earth later become famous as Pale Blue Dot.

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  2017: Steganographic analysis of famed illustration Alice and Niles Dancing reveals three terabytes of love letters between mathematicians Alice Beta and Niles Cartouchian.