December 21, 2018




Jan Łukasiewicz (dob) was regarded as one of the most important historians of logic.  He was born in Lemberg, a city in the Galician kingdom of Austria-Hungary (now Lviv, Ukraine). Lukasiewicz' work focused on philosophical logic, mathematical logic, and history of logic. He worked on the concepts of traditional propositional logic, the principle of non-contradiction and the law of excluded middle. Modern work on Aristotle's logic builds on the tradition started in 1951 with the establishment by Łukasiewicz of a revolutionary paradigm. The Łukasiewicz approach was reinvigorated in the early 1970s in a series of papers by John Corcoran and Timothy Smiley, which inform modern translations of Prior Analytics by Robin Smith in 1989 and Gisela Striker in 2009.  In 2008 the Polish Information Processing Society established the Jan Łukasiewicz Award, to be presented to the most innovative Polish IT companies.


First Flight of Schnellbomber:   On December 21, 1936, the German Luftwaffe ran a first flight of the infamous Junkers Ju 88. They referred to it as a Schnellbomber (translation: Fast Bomber) and was too fast for even fighters of the era to intercept.  When it was first flown, the Junkers managed to reach speeds of about 580 km/h (360 mph). The streamlined fuselage was modeled after the Dornier Do 17, but carried fewer defensive guns, but by the fifth prototype, it set a closed-circut record in March 1939, of 1,000 km (620 mi) carrying a 2,000 kg (4,410 lb) payload at a speed of 517 km/h (320 mph).


German submarine was sunk.  On December 21, 1941 the HMS Deptford and Samphire launched depth charges on U-457 sinking her at coordinates 44°02′N 20°10′W . U-457 had been part of the infamous Nazi Wolf Pack and had attacked allied convoy HG 76 in the North Atlantic, north-east of the Azores and sank the Annavore, a 3,324 ton Norwegian merchant ship. (The convoy consisted of 32 cargo ships and was escorted by five destroyers, seven corvettes and one aircraft carrier.)

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