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[1198] COCKCROFT, Sir John Douglas English physicist Born: Todmorden, Yorkshire, May 27, 1897 Died: Cambridge, September 18, 1967
Cockcroft, the son of a textile manu facturer, was educated at Manchester College of Technology, taking his degree in electrical engineering. He served as an 755 [1198] COCKCROFT HINSHELWOOD
artilleryman in World War I, and man aged to survive the Battle of the Somme. After the war he entered Cambridge University, where in 1928 he received his Ph.D. He studied under Ernest Rutherford [996] and for a time worked with Ka- pitza [1173] on magnetic fields at liquid helium temperatures. His interest turned to nuclear physics and his training in electrical engineering stood him in good stead, for he occupied himself with the problem of accelerating particles in an electric field. During the 1920s the only particles that could be used for bombarding and breaking down the atomic nucleus (a process popularly termed “atom- smashing”) were alpha particles emitted by naturally radioactive elements. Ruth erford had done wonders with them and had exploited them to the limit, but it was now necessary to go beyond that and find particles of still higher energies. Cockcroft, with the assistance of Wal ton [1269], devised an instrument in 1929 that could build up voltages (a voltage multiplier) and, in so doing, ac celerate protons (which are easy to ob tain by ionizing hydrogen atoms) to en ergies higher than those of natural alpha particles. His inspiration, here, lay in Gamow’s [1278] theoretical work on par ticle bombardment. In April 1932 Cockcroft and Walton bombarded lithium with such protons and produced alpha particles. It was clear that what they had done was to combine lithium and hydrogen to form helium. This was the first nuclear reac tion brought about through artificially accelerated particles and without the aid of any form of natural radioactivity. The voltage multiplier was quickly outmoded by the cyclotron invented by Lawrence [1241], but the principle had been es tablished and Cockcroft and Walton were awarded the 1951 Nobel Prize in physics as a result. Both during and after World War II, Cockcroft was engaged in work having to do with the development first of radar, then of the atomic bomb. He su pervised the construction of nuclear re actors in Canada, for instance. And, as it happened, his very first artificially in duced nuclear reaction, that of lithium with hydrogen, proved to be of great im portance in the development of the hy drogen bomb. In 1939 Cockcroft took up a profes sorial post at Cambridge and in 1946 he was head of the Atomic Energy Re search Establishment at Harwell. In 1960 he became master of the newly founded Churchill College at Cambridge. He was knighted in 1948 and in 1961 received the Atoms for Peace award. [1199] WITOG, Georg Friedrich Karl German chemist
Wittig studied at the University of Tübingen, but this was interrupted by military service during World War I. After the war he graduated from the University of Marburg in 1923 and re ceived his Ph.D. there in 1926. As a teacher he moved up the ranks of uni versities till he attained a professorship at Heidelberg in 1956. He worked chiefly with phosphorus- containing organic compounds, studying those that contained a negative charge on one or another of the carbon atoms, a “carbanion.” This balanced the work of H. C. Brown [1373] on boron-containing organic compounds, and those that con tained a positive charge (“carbonium atoms”). As a result, Wittig and Brown shared the 1979 Nobel Prize for chemis try. [1200] HINSHELWOOD, Sir Cyril Nor man English physical chemist Born: London, June 19, 1897 Died: London, October 9, 1967 Hinshelwood was the son of an ac countant. His professional life was spent at Oxford, both as student (winning a scholarship in 1919 and obtaining his doctorate there in 1924) and as member of the faculty. He became professor of chemistry there in 1937, succeeding Soddy [1052].
[1201] REICHSTEIN WYCKOFF
His interest was primarily in kinetics, the study of the rate at which chemical reactions proceed. In analyzing this rate, one could deduce the mechanisms by which the reactions took place. Even in so seemingly simple a reaction as that of hydrogen and oxygen to form water, a complex chain of events had to take place, in which the hydrogen molecules (made up of a pair of atoms) had to split apart into “atomic hydrogen.” A hydrogen atom could then combine with an oxygen molecule, liberating a free ox ygen atom, which could combine with a hydrogen molecule, liberating a free hy drogen atom, and so on. Such “chain reactions” could be used to explain the formation of large- polymer molecules and many other chemical events. It could also by used to explain the fact that at a certain temper ature, a mixture of hydrogen and oxygen would explode. Nemst [936] had made use of such mechanisms in connection with the light-catalyzed reaction of hy drogen and chlorine. In 1928 Hinshelwood showed that below this temperature the chain reac tion was stopped at the walls of the ves sel before it had a chance to reach explosive rates, and above the tempera ture it was not. Semenov [1189] had come to a similar conclusion the year be fore. Hinshelwood and Semenov, for their work on reaction mechanisms, shared the 1956 Nobel Prize in chemis try.
Hinshelwood was knighted in 1948 and served as president of the Royal So ciety from 1955 to 1960. He retired in 1965.
[1201] REICHSTEIN, Tadeusz (rikhe'- shtine)
Polish-Swiss chemist Bom: Wloclawek, Poland, July 20, 1897 Reichstein’s father was an engineer who, during Reichstein’s childhood, worked in Kiev in the Ukraine. In 1905 the family left Russia (which had just lost a war and was suffering the up heavals of an abortive revolution), mov ing first to Berlin and then to Zürich, Switzerland. In 1914 they became Swiss citizens. Reichstein received his doctorate in 1922 under Staudinger [1074] in the State Technical College at Ziirich. In 1931 he was appointed assistant to Ru- iiöka [1119], a fellow naturalized Swiss citizen, and a fellow student under Stau dinger.
Reichstein was one of those who in 1933 succeeded in synthesizing ascorbic acid (vitamin C) shortly after that vita min’s identification by King [1193], Ha worth [1087] having also succeeded inde pendently that same year. His chief la bors, however, were during the 1930s, when he and his colleagues isolated the various corticoids just as Kendall [1105] was doing in the United States. For this he shared the 1950 Nobel Prize in medi cine and physiology with Kendall and Hench [1188], [1202] WYCKOFF, Ralph Walter Gray- stone American crystallographer Born: Geneva, New York, Au gust 9, 1897 Wyckoff graduated from Hobart Col lege in his hometown in 1916 and went on to gain his Ph.D. at Cornell Univer sity in 1919. He became early interested in the use of X rays in determining crystal struc ture after the fashion of the Braggs [922, 1141]. He went on to other methods of dealing with submicroscopic structures, working with ultracentrifuges and elec tron microscopes. Following an idea of R. C. Williams [1339], he developed the technique of spraying a thin film of metal obliquely over objects in an electron microscope field. A metal-free area would form in the shaded region behind each object, and this area would, by its shape and size, tell something about the height and shape of the particle. Electron micros copy thus became three-dimensional, so to speak. He carried through the laboratory
[1203] STRUVE
JOLIOT-CURIE [1204] preparation of a vaccine against a virus disease (equine encephalitis). In 1959 he accepted a post as profes sor of physics at the University of Ari zona.
[1203] STRUVE, Otto (stroov) Russian-American astronomer Born: Kharkov, Russia, August 12, 1897 Died: Berkeley, California, April 6, 1963
Struve was the fourth in a dynasty of noted astronomers. His great-grandfather was F.G.W. von Struve [483], who had been one of the first to measure the parallax of a star. Struve’s university ed ucation was interrupted by World War I. He served in the field artillery with the Russian army on the Turkish front dur ing World War I, then went on to gradu ate with honors from Kharkov Univer sity in 1919. The post-Revolutionary disorders in what had now become the USSR drove Struve (who fought with the counter revolutionary “Whites”) first to Turkey in 1920, then to the United States in 1921. He obtained his Ph.D. at the Uni versity of Chicago in 1923 and became an American citizen in 1927. He taught at the University of Chicago, remaining there till 1947. Struve dealt with every phase of stellar astronomy, working out contemporary notions of the evolutionary processes within stars. He discovered interstellar matter, the thin gas that spreads between the stars. First he noted calcium, which had prominent spectral lines, then the much more important hydrogen, which was soon to be so significant in the work of radio astronomers such as Oort [1229],
Struve was one of those who turned from the view of men like Jeans [1053] that planetary systems were excessively rare. He devised mechanisms, instead, whereby such systems were normal de velopments in stellar evolution. Thus, he noted that some stars rotated rapidly; others, like our own sun, quite slowly. The slow stars, he felt, were slow be cause they had lost angular momentum to planets and were therefore centers of stellar systems. Combined with the geochemical work of men such as Urey [1164], it began to seem more and more likely that life itself (even intelligent life, perhaps) was com mon in the universe. • In 1950 he accepted a professorship at the University of California and in 1959 became director of the National Radio Astronomy Observatory at Green Bank, West Virginia. Struve was childless, and with his death the Struve astronomical dynasty came to an end. [1204] JOLIOT-CURIE, Irène French physicist Born: Paris, September 12, 1897 Died: Paris, March 17, 1956 Irène was the elder daughter of Pierre and Marie Curie [897, 965] and was educated privately for years, though she finally attended the Sorbonne. She was brought up without religion. During World War I she served as an army nurse.
While working as her mother’s assis tant, she met Frédéric Joliot [1227], another assistant, who was also an athe ist. Finding their views thoroughly com fortable and compatible, they were mar ried in 1926 and had a happy life to gether. When ill health forced her mother to retire, Irène succeeded to her post. In their work, she and her husband were a unit, sharing the triumph of the 1935 Nobel Prize in chemistry, just too late for her famous mother to witness it, for Marie Curie had died the year before. Irène also shared in her husband’s perils during the period of the German occu pation of France. It was not till 1944 that she and her children were smuggled into Switzerland. In 1936 Irène had served a short pe riod in the cabinet of Léon Blum and after World War II was active in move ments considered Communist-influenced. In 1954 her application for membership in the American Chemical Society was rejected because of the society’s disap 758 [1205] BJERKNES
NORRISH [1206] proval of her politics. She died, like her mother, of leukemia, brought on un doubtedly by her years of work with hard radiation. [1205] BJERKNES, Jacob Aall Bonnevie (byerk'nes) Norwegian-American meteo rologist
Norwegian parents), November 2, 1897
July 7, 1975 Bjerknes’s father, Vilhelm Bjerknes (himself the son of a professor of math ematics), was a Norwegian physicist who taught at the University of Stockholm from 1895 to 1907. During the nine teenth century, Norway was under the Swedish crown, but in 1905 it gained its independence. Two years later, the elder Bjerknes transferred to the University of Oslo in Norway’s capital. It had been his own alma mater and the younger Bjerknes was educated there too, gaining his doctorate in 1924. The two men, father and son, orga nized a network of weather-observing stations all over Norway during World War I. From the reports received, they worked out the theory of polar fronts, which serves as the basis of modern weather forecasting. They showed by 1920 that the atmo sphere is made up of air masses that are more or less sharply differentiated in temperature between warm tropical air masses and cold polar air masses. The sharp boundaries between them they called “fronts” from an analogy with the battle lines that had so impressed themselves on the minds of men during the war just ended. During the 1920s and 1930s the manner in which the masses fought it out were analyzed. In 1939 the younger Bjerknes came to the United States and the next year (un able to return to a Norway that had been occupied by the Nazis) obtained a professorial position at the University of California. He was naturalized as an American citizen in 1946. Meanwhile, World War II occasioned a new meteorological discovery. Ameri can bombers, flying high across the Pacific on their way toward Japan, some times found themselves virtually motion less. They had entered a stream of rap idly moving air, blowing from west to east. This was the jet stream. There are two of these, one in the northern hemisphere and one in the southern, at a height of from six to nine miles. The usual velocity of the wind is from 100 to 200 miles per hour, though speeds of 350 miles and more have been recorded. They make winding girdles about the earth, following the paths be tween the polar and tropical air masses and therefore usually marking the re gions of greatest storminess. The changing course of the jet streams from day to day is now also taken into account in plotting the movements of the air masses and in attempting to predict future events in the changing weather pattern.
In 1952 Bjerknes made use of pictures of cloud covers taken by rockets as a new aid to weather analysis. Thus, mete orology entered the space age. [1206] NORRISH, Ronald George Wreyford English chemist
1897
Died: Cambridge, June 7, 1978 Norrish’s education at Cambridge (via a scholarship) was interrupted by World War I, during which he served as a lieu tenant in the artillery. He returned to Cambridge after the war, graduating in 1921 and receiving a Ph.D. in 1924. He remained on the faculty of Cambridge, reaching professorial status in 1937 and retiring in 1965. Between 1949 and 1955 he and his co worker Porter [1443] began to investi gate very fast chemical reactions. Work ing with a gaseous system at equilibrium, they illuminated it with ultra-short flashes of light. This introduced a mo mentary disequilibrium and the time taken to reestablish equilibrium was then 759 [1207] BLACKETT
BLACKETT [1207] measured. In this way, chemical changes taking place in but a billionth of a sec ond could be studied. As a result, Norrish and Porter shared half the 1967 Nobel Prize in chemistry, the other half going to Eigen [1477] for his independent but similar work. [1207] BLACKETT, Patrick Maynard Stuart Blackett, Baron English physicist
Blackett entered a naval school in 1910, at thirteen, to train as a naval officer. The outbreak of World War 1 came just in time to make use of him and he was at sea throughout the war, taking part in the Battle of Jutland. With the war over, however, he re signed from the navy and went to Cam bridge, where he studied under Ernest Rutherford [996] and obtained his master’s degree in 1923. In 1933 he be came professor of physics at the Univer sity of London, moving on to Man chester in 1937. It was Blackett who first turned to the wholesale use of the Wilson [979] cloud chamber. Rutherford had observed scin tillation effects on a screen of zinc sulfide and had interpreted those as indicating that he had succeeded in converting ni trogen to oxygen through the bombard ment of the former with alpha particles. Blackett felt the need for more direct ev idence of this. In the early 1920s, therefore, he went to work with the cloud chamber. He bombarded nitrogen within the cloud chamber with alpha particles and ex panded the chamber periodically in order to catch any tracks that might be formed. He took over 20,000 photo graphs, catching a total of more than 400,000 alpha particle tracks. Of these tracks, just eight involved a collision of an alpha particle and a nitrogen mole cule. From the forked tracks that re sulted, it was possible to show that Ruth erford’s contention that elements had been transmuted was correct. These first photographs of a nuclear reaction in progress, taken in 1925, were immensely impressive, and if anything was needed to dramatize the Wilson cloud chamber this was it. Blackett turned the cloud chamber to other uses as the 1930s approached. He almost discovered the positron but An derson [1292] was a few months ahead of him there. He also studied cosmic rays, and here an idea struck him. There was no way of knowing when an interesting event was taking place in the cloud chamber, so that the chamber had to be expanded at random and as often as possible in the hope of catching something. In 1932, therefore, Blackett placed a Wilson cloud chamber between two Geiger [1082] counters. Any cosmic ray particle passing through both Geiger counters had to pass through the cloud chamber. Blackett arranged the circuits so that the surge of current set up in the two counters operated the cloud cham ber. In this case, the chance of a significant photograph in these “coinci dence counters” was enormously in creased.
In 1935 Blackett showed that gamma rays, on passing through lead, sometimes disappear, giving rise to a positron and an electron. This was the first clear-cut case of the conversion of energy into matter. This confirmed the famous E—mc2 equation of Einstein [1064] as precisely as did the more numerous examples, earlier observed, of the con version of matter to energy (and even more dramatically). During World War II, Blackett worked on the development of radar and the atomic bomb. His strong backing of Watson-Watt [1155] was one of the cru cial factors in the decision to back radar development and that proved the salva tion of Britain. Blackett worked under George Thomson [1156] in the atomic bomb project and urged that such re search be centered in the United States for efficiency and security. After the war, however, he was one of those most vociferously concerned with the dangers of nuclear warfare. In 1948 he was awarded the Nobel Prize in phys ics for his work with and upon the Wil son cloud chamber. 7 6 0
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