|
1921 In Science
The year 1921 in science and technology involved some significant events, listed below. Astronomy and space science * Commencement of Gas Dynamics Laboratory the first Soviet research and development laboratory to focus on rocket technology. Cartography * Winkel tripel projection proposed. Chemistry * Étienne Biéler and James Chadwick publish a key paper on the strong interaction. * December 9 – Thomas Midgley discovers the effective anti-knocking properties of tetraethyllead, which is used in "leaded" gasoline (petrol). Exploration * Danish explorer Lauge Koch first sets foot on and names Kaffeklubben Island, the northernmost point of land on Earth. Mathematics * John Maynard Keynes publishes '' A Treatise on Probability''. * Marston Morse applies the Thue–Morse sequence to differential geometry. * Emmy Noether publishes ''Idealtheorie in Ringbereichen'', developing ideal ring theory, an important text in the field of abstract algebra. * First publication of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extreme Points Of Earth
This article lists extreme locations on Earth that hold geographical records or are otherwise known for their geophysical or meteorological superlatives. All of these locations are Earth-wide extremes; extremes of individual continents or countries are not listed. Latitude and longitude Northernmost * The northernmost point of land is the northern tip of Kaffeklubben Island, north of Greenland (), which lies slightly north of Cape Morris Jesup, Greenland (). Various shifting gravel bars lie farther north, the most famous being Oodaaq. There have been other islands more northern such as 83-42 and ATOW1996 but they have not been confirmed as permanent. Southernmost * The southernmost continental point of land outside Antarctica is in South America at Cape Froward, Magallanes Region, Chile (). * The southernmost point of (liquid) water is a bay on the Filchner–Ronne Ice Shelf along the coast of Antarctica (), about south of Berkner Island. ** The southernmost point ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nicolae Paulescu
Nicolae Constantin Paulescu (; 30 October 1869 (O.S.) – 17 July 1931) was a Romanians, Romanian physiologist, professor of medicine, and politician, most famous for his work on diabetes, including patenting ''pancreine'' (a pancreatic extract containing insulin). The "pancreine" was an extract of bovine pancreas in salted water, after which some impurites were removed with hydrochloric acid and sodium hydroxide. Paulescu was also, with A. C. Cuza, co-founder of the National Christian Union and later, of the National-Christian Defense League, an early ultranationalist and anti-Semitic Romanian party. He was also a leading member of the militant religious fascist Iron Guard. Early life and education Born in Bucharest, he was the first of four children of Costache and Maria Paulescu. He displayed remarkable abilities as early as his first school years. He learned French language, French, Latin and Ancient Greek at an early age, so that a few years later he became fluent in all the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cairo Pentagonal Tiling
In geometry, a Cairo pentagonal tiling is a tessellation of the Euclidean plane by congruent convex pentagons, formed by overlaying two tessellations of the plane by hexagons and named for its use as a paving design in Cairo. It is also called MacMahon's net after Percy Alexander MacMahon, who depicted it in his 1921 publication ''New Mathematical Pastimes''. John Horton Conway called it a 4-fold pentille. Infinitely many different pentagons can form this pattern, belonging to two of the 15 families of pentagon tiling, convex pentagons that can tile the plane. Their tilings have varying symmetries; all are face-symmetric. One particular form of the tiling, dual to the snub square tiling, has tiles with the minimum possible perimeter among all pentagonal tilings. Another, overlaying two flattened tilings by regular hexagons, is the form used in Cairo and has the property that every edge is collinear with infinitely many other edges. In architecture, beyond Cairo, the Cairo tiling ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
