Terpenes are produced by plants and their building block are units of isoprene.
In 1911 Haworth took an appointment as a demonstrator at the Imperial College of Science and Technology in London and in 1912 he was appointed a lecturer at the University of St. Andrews in Scotland. At St. Andrews he became interested in the chemistry of carbohydrates while working with Thomas Purdie and James Irvine. Haworth organized the laboratories at St. Andrews for the production of chemicals and drugs during the First World War. In 1920 he was called to take the chair of chemistry at the University of Durham. The following year he succeeded Philips Bedson as director. In 1925 Haworth was appointed professor and director of chemistry at the University of Birmingham where he remained until 1948. Then he became the dean of science and he served as an acting vice-principal from 1947 to 1948.
Haworth's research centered around carbohydrates and he determined the structures of many, including maltose, cellobiose, lactose, gentiobiose, melibiose, gentianose, and raffinose. He was also responsible for discovering the glucoside ring structure of normal sugars. Normal sugars that are five or six carbons long form a ring structure where the terminal hydroxyl nucleophillically attacks the aldehyde carbon forming an glycosidic bond. He developed Haworth projections which are two dimensional representations of three dimensional sugar structures. Haworth was also the first person to chemically synthesize vitamin C, the first vitamin artificially synthesized.
For his work understanding the structures of carbohydrates and the synthesis of vitamin C Haworth shared the 1935 Nobel Prize in Chemistry with Paul Karrer. In 1947 Haworth was knighted. In 1977 the Royal Mail issued a postage stamp honoring Haworth for his Nobel Prize and the synthesis of Vitamin C.
He died suddenly on his 67th birthday, March 19, 1950.
Anon, "Walter Norman Haworth: 1883-1950" in Advances in Carbohydrates(1951)6:1
Norman Haworth Nobel Biography
Norman Haworth Wikipedia Entry
Sunday, March 18, 2012
Sunday, March 11, 2012
In 1837 he returned to the Ecole Polytechnique as an astronomy assistant. His first major piece of work was looking in to the stability of the solar system. In 1840 Dominique Arago, the director of the Paris Observatory, suggested he look into the motion of Mercury, which he did. LeVerrier predicted the start of the transit of Mercury of May 1845 to within 16 seconds. Next Arago had LeVerrier look in to the motion of Uranus, which was not moving as predicted. LeVerrier calculated that the perturbations of Uranus' orbit were due to the presence of another planet, further from the sun than Uranus. Unknown to Arago and LeVerrier, in England, John Crouch Adams had previously reached the same conclusion. Adams had sent his work to George Airy, the royal astronomer and James Challis, the director of the Cambridge Observatory. Neither man acted on Adams' findings until after LeVerrier had published his work in June of 1846. After LeVerrier published, Airy attempted to observe the planet, but it was not seen until September of 1846 when what would be named Neptune was observed by Johan Galle and Heinrich d'Arrest in Berlin.
In 1849 he was elected to the French Legislative Assembly. In 1852 he was appointed a senator and member of the Superior Council of Public Instruction on which he served until 1870. When Arago died in 1854, LeVerrier became director of the Paris Observatory. He was removed as director in 1870 but was reinstated in 1873. He was awarded a gold medal by the Royal Society of London in 1868 and 1876. He has craters named after him on the Moon and on Mars and he is one of the 72 names inscribed on the Eiffel Tower.
He died in Paris on September 23, 1877.
Anon.;"Urbain-Jean-Joseph LeVerrier" in Proceedings of the American Academy of Arts and Sciences(1978)13:454-455
Dunkin, E. "M LeVerrier" in The Observatory (1877)1:199-206
Leverington, David; Babylon to Voyager: A history of Planetary Astronomy; Cambridge University Press; 2003
Urbain LeVerrier Wikipedia Entry
Sunday, March 4, 2012
While studying conventional physics at the university Gamow met with other students to read the papers coming from western Europe that were defining the new science of quantum mechanics. Gamow was interested in the new theories and sometimes neglected his studies in classical physics. In 1928, after being admonished for unsatisfactory academic progress, he was given a fellowship which allowed him to go to Germany. Gamow traveled to Gottingen, where he studied under Max Born at the Institute for Theoretical Physics. While there he authored a paper explaining why radioactive nuclei emit low energy alpha particles, but when bombarded by alpha particles of higher energy they are not incorporated by the nuclei. Alpha particles are a product of radioactive decay composed of two protons and two neutrons, a helium nuclei. After four months in Gottingen Gamow's money ran out and he headed home. On the way back to Russia he stopped in Copenhagen, Denmark where he ended up staying for eight months. While there he had the chance to present a paper to the Royal Society of London, quite an honor for a 25 year old scientist.
After Gamow returned to the Soviet Union he decided to leave due to the increased political repression. In 1932, after three aborted attempts to defect, which were not noticed by the authorities, he was granted passports so that he and his wife, Rho, could go to a conference in Brussels. After the conference Gamow tried to find work in Europe. He did get a few temporary positions but it was not until 1934 that he could find a permanent position at George Washington University in Washington D.C. In 1940 Gamow was naturalized as a U.S. Citizen. He remained at George Washington University until 1956. Despite his knowledge of atomic physics during the Second World War he did not work on the Manhattan Project, but stayed at Washington University and did some consulting for the United States Navy. In 1954 he became a visiting professor at the University of California at Berkeley and in 1956 he took a position at the University of Colorado at Boulder, where he remained for the rest of his career.
Gamow studied beta emission, the emission of an electron by a radionuclei and nucleosynthesis, the creation nuclei larger than a single proton (hydrogen) inside stars. Stars are powered by atomic reactions such as hydrogen forming helium and releasing energy. Helium, with its two protons and two neutrons, then is used to form even numbered atomic elements (beryllium, carbon, and oxygen). Gamow worked to popularize the big bang theory, the theory that the universe and all the matter in it was created in a big bang. Gamow's most important work in astrophysics was on understanding the generation of red giants, stars that have exhausted the supply of hydrogen at their core. When the reaction producing helium stops the core collapses due to gravity. The conversion of hydrogen into helium continues in the region surrounding the stellar core, which expands creating a red giant star. After the 1953 discovery of the structure of DNA Gamow attempted, unsuccessfully, to solve the problem of how the genetic code translates into proteins. Gamow was also an award winning writer of both scientific and popular books. The physics tower at the University of Colorado, in Boulder is named after him.
Gamow died on August 19, 1968.
Interview with George Gamow by Charles Weiner on April 25, 1968. Neils Bohr Library and Archives, American Institute of Physics; online at aip.org
Hufbauer, Karl; "George Gamow: 1904-1968" in Biographical Memoirs; National Academy Press; 2009
George Gamow Wikipedia Entry