Template:Selected anniversaries/January 23
1656: Blaise Pascal publishes the first of his Lettres provinciales.
1805: Inventor Claude Chappe dies. He invented and developed a practical semaphore system that eventually spanned all of France -- the first practical telecommunications system of the industrial age.
1854: Mathematician Leopold Kronecker discovers new family of Gnomon algorithm functions.
1862: Mathematician David Hilbert born. he will discover and develop a broad range of fundamental ideas in many areas, including invariant theory and the axiomatization of geometry.
1898: Electrical engineer and inventor Oliver Blackburn Shallenberger dies. He invented the first successful alternating current electrical meter, which was critical to the general acceptance of AC power.
1941: Charles Lindbergh testifies before the U.S. Congress and recommends that the United States negotiate a neutrality pact with Adolf Hitler.
1967: John Brunner uses scrying engine to detect and expose crimes against mathematical constants.
1968: Mathematician, academic, and crime-fighter Werner Fenchel publishes new class of Gnomon algorithm functions which pioneer the use of nonlinear programming to detect and prevent crimes against mathematical constants.
2003: A very weak signal from Pioneer 10 is detected for the last time; no usable data can be extracted.
2007: CIA officer and author E. Howard Hunt dies. Along with G. Gordon Liddy, Hunt plotted the Watergate burglaries and other undercover operations for the Nixon administration.