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706 [1110] FRISCH
SIEGBAHN [ H U ]
their sizes. The more distant the cluster, the more marked this departure from the expected brightness. What’s more, the more distant the cluster, the redder it seemed. The easiest way of explaining this was to suppose that incredibly thin wisps of dust filled interstellar space and that over vast distances there was enough dust to dim and redden the light of the farther clusters. By taking this dimming effect into account, the size of the galaxy was shown to be smaller than expected, since the dimness of the distant clusters was not due to distance alone. Where Shap- ley [1102] had thought the galactic cen ter to be 50,000 light-years away, a 30,000-light-year figure seemed now more accurate. [1110] FRISCH, Karl von Austrian-German zoologist
20, 1886 Von Frisch obtained his Ph.D. from the University of Munich in 1910. He served at the Zoological Institutions of Rostock, then Breslau, and finally Mu nich in 1925. The destruction of the Munich Institu tion during the bombings of World War II led him to shift to the University of Graz in Austria for a while, but again he returned to Munich in 1950. He is best known for his research on bees. Making use of Pavlov’s [802] con ditioned reflexes he forced bees to “tell” him of such highly personal matters as the colors they saw. (He had already as certained in this manner in 1910 that fish could distinguish differences in color and intensity of light and that they had an acute sense of hearing.) Beginning in 1911, he conditioned bees to go to certain locations for their food and then would alter the color of those locations to see if the conditioning to one color would stop them from flying to another. Conditioned to black, they would fly to red with equal readiness, but not to a place radiating ultraviolet which still looked black to human eyes. They could see ultraviolet, but they could not see red. Von Frisch also interpreted the man ner in which the bee communicated its findings to its colleagues of the hive. Having obtained honey from a new source, the returning bee would “dance,” moving round and round, or side to side. The number of the evolutions and their speed gave the necessary information as to the location of the new source. Von Frisch also showed that, in flight, bees could orient themselves by the direction of light polarization in the sky. In 1973 he was awarded a share of the Nobel Prize for physiology and medicine for his work, receiving it at the age of eighty-seven and thus tying the mark of Rous [1067] in this respect.
(seeg'bahn) Swedish physicist
1978
Beginning in 1914, Siegbahn, who ob tained his Ph.D. at the University of Lund in 1911, turned his attention to X rays. Barkla [1049] and Moseley [1121] had been forced to work comparatively crudely with the X rays produced by different elements. Siegbahn developed improved techniques whereby the wave lengths of the X rays produced could be determined accurately. In this way he discovered groups of X rays less penetrating and longer in wave lengths than the characteristic X rays studied by Moseley. In short, he pro duced veritable X-ray spectra for each element. From these different groups of X rays, it was possible to support strongly the view of Bohr [1101] and others that the electrons in the various atoms were arranged in “shells.” The different bands of X rays were labeled K, L, M, N, O, P, and Q in order of in creasing wavelengths and the electron shells were similarly lettered in order of increasing distance from the atomic nu cleus.
In 1924 Siegbahn, shortly after having joined the faculty of the University of Uppsala, even managed to refract X rays 7 0 7
[1112] KÖHLER
KEILIN [1113] by means of a prism, showing another similarity of this form of radiation to light. In that same year, he was awarded the Nobel Prize in physics for his devel opment of X-ray spectroscopy. Siegbahn was director of the Institute of Experi mental Physics of the Swedish Royal Academy of Sciences in Stockholm from 1937 until his retirement in 1964. [1112] KÖHLER, Wolfgang (koiler) Russo-German-American psychologist
Estonia, January 21, 1887 Died: Enfield, New Hampshire, June 11, 1967 Kohler’s birthplace was then (as now, since the Soviet takeover of Estonia) part of Russia. He was educated, how ever, in Germany, obtaining his doctor ate at Friedrich-Wilhelm University, Ber lin, in 1909. He became a lecturer at the University of Frankfurt in 1911. During World War I he found himself in the Canary Islands controlled by neu tral Spain and was unable to return home over an ocean controlled by Ger many’s enemies. He amused himself in his involuntary exile by studying the be havior of hens and chimpanzees. He found striking examples of the ability of the chimpanzees to make use of what, in human beings, would be called reason. In one case, a chimpanzee, after trying in vain to reach bananas with a stick that was too short, suddenly picked up another that had deliberately been left nearby, joined them, and so brought the fruit within reach. In an other, a chimpanzee piled one box on another to reach bananas. In neither case was training, experience, or imitation in volved; there seemed, rather, the flash of insight—something that was shown to be, for the first time, not limited to Genus Homo. To Köhler it seemed that learning in volved the entire pattern of a process, made plain by such sudden insights, rather than a plodding progression from portion to portion of the process. He was one of the founders of the Gestalt school of psychology; “Gestalt” being the Ger man word for “pattern.” In 1921 Köhler obtained a professorial position at the University of Berlin. When Hitler came to power in Ger many, Köhler fearlessly expressed his anti-Nazi views and by 1935 it was clear that if he stayed longer it would only be to enter a concentration camp. He left for the United States and took a post at Swarthmore College. He became an American citizen in 1946. In 1956 he moved on to Princeton and in 1958 to Dartmouth. [1113] KEILIN, David (ky'lin) Russian-British biochemist Born: Moscow, March 21, 1887 Died: Cambridge, England, Feb ruary 27, 1963 Keilin was bom of Polish parents, temporarily residing in Moscow. His col lege education was conducted in the West, at Liège, Belgium, and in Paris, where he earned his Ph.D. at the Sor bonne in 1917. By then he had been in vited to Cambridge, where he remained for the rest of his life. He began his career as an en tomologist, working on the life cycles of flies. In 1924, however, he was studying the absorption spectrum of the muscles of the horse botfly and noticed four ab sorption bands that disappeared when the cell suspension was shaken in air but reappeared afterward. He concluded that there was a respira tory enzyme within cells that absorbed oxygen and, presumably, catalyzed its combination with other substances. He called it cytochrome. With further inves tigation he was able to show that cellular respiration involved a chain of enzymes that passed hydrogen atoms from one compound to another until, by way of cytochrome, those hydrogen atoms were combined with oxygen. This fit well with the work of Warburg [1089], Cytochrome turned out to be an iron- containing enzyme and Keilin went on to investigate other iron-containing enzymes such as catalase and peroxidase, which also were in one way or another involved with oxygen. 7 0 8
[1114] ROSE
HOUSSAY [1115] [1114] ROSE, William Cumming American biochemist
April 4, 1887 Rose obtained his Ph.D. at Yale in 1911 and took his postdoctoral work in Germany. His first professorial appoint ment was at the University of Texas in 1913. In 1922 he joined the staff of the University of Illinois, remaining there until his retirement in 1955. Rose’s special area of research in volved the role of the amino acids in nu trition. From about the turn of the cen tury it had been realized that some pro teins were more valuable nutritionally than others, thanks to the work of men like Hopkins [912]. Rats lost weight and eventually died, for instance, if their only source of proteins was the zein of com. They resumed growth and recov ered health, however, if a bit of casein, the protein of milk, was added to their diet before it was too late. It was suspected that the difference lay in the nature of the amino acid building blocks in the two proteins. Rose began experimenting, therefore, with diets in which there was no intact protein, only a mixture of free amino acids. He found that rats would thrive on casein that had been broken down to amino acids but lost weight if the various known amino acids were mixed in the proportions in which they were thought to be present in casein.
Either it was important for casein to remain intact (which seemed incredible, since it was broken down in the digestive process before absorption) or it con tained an unknown amino acid that was essential to nutrition. Rose accepted the latter explanation and buckled down to the search. He succeeded in 1935 in finding threonine, the last of the nutri tionally significant amino acids to be dis covered. Adding threonine to his artificial mix ture of amino acids gave Rose what he wanted—a diet on which rats could live. He then tried diets from which one amino acid or another was absent. Some times the subtraction of a particular amino acid made no difference; the ani mal could manufacture it out of the remaining amino acids in its diet. At other times, the subtraction of a particu lar amino acid resulted in loss of body nitrogen, tissue wastage, and other un pleasant symptoms. That amino acid could not be formed from the others by the animal and, in its absence, protein could not be synthesized. (For protein to be synthesized, all necessary amino acids must be present.) Amino acids which had to be present in the diet were called essential amino acids. By 1937 Rose had shown that of the twenty or so amino acids that were present in nearly every protein molecule, only ten were dietarily essential to the rat. Threonine was one. In the 1940s Rose advanced a notch in the animal kingdom and began similar nutritional experiments with graduate students, feeding them on carefully con trolled diets in which free amino acids were the only nitrogen source. Here only eight amino acids proved essential. The amino acids, arginine and histidine, es sential in the rat, were not essential in the adult human being. The case of his tidine was quite surprising since there had been reasons for assuming it would prove essential. Repeated experiments confirmed the finding and by the early 1950s it was accepted. Rose even calculated the minimum daily requirement for each of the essen tial amino acids. His work thus placed the problem of protein nutrition, which had occupied nutritionists since the time of Magendie [438] a century before, on a firm and rational basis at last. [1115] HOUSSAY, Bernardo Alberto Argentinian physiologist Born: Buenos Aires, April 10, 1887
Died: Buenos Aires, September 21, 1971 Houssay, the son of French immi grants to Argentina, was educated at the University of Buenos Aires, from which he received his medical degree in 1911 and where he had already achieved professorial status in 1910. 709 [1116] HERTZ
SCHRÖDINGER [1117]
As a medical student he grew inter ested in the pituitary gland, a small hor mone-producing structure suspended from the base of the brain. It was shown by him (independently of P. E. Smith [1090]) and, later, by Li [1382] to have numerous crucial functions in the body. In particular, Houssay showed that it affected the course of sugar metabolism. The anterior lobe of the pituitary seemed to produce at least one hormone that had an effect opposite to that of the in sulin first isolated by Banting [1152] and Best [1218]. Removal of the pituitary from a dia betic animal reduced the severity of the diabetes, since such insulin as is formed is not countered by the pituitary secre tion. On the other hand, injection of pi tuitary extracts increased the severity of diabetes, or produced a diabetic condi tion where one did not exist before. For his demonstration of the complex in terlocking of hormonal effects, Houssay shared the 1947 Nobel Prize in medicine and physiology with the Coris [1192, 1194]. Some years before, however, Houssay had fallen out with Juan Domingo Per6n, then dictator of Argentina. In 1943 he had been dismissed from his university post, along with 150 other ed ucators, for taking too firm a pro American stand at a time when Argen tina was flirting with the German Nazis. Now, on Houssay’s receiving the Nobel Prize, the controlled Argentinian press, rather than rejoicing at this first award of the science prize to a Latin-American, complained that the award was politi cally motivated as a blow to Peron. Houssay responded that one must not confuse little things (Peron) with big things (the Nobel Prize). He continued his research work on a private basis and in 1955, after Peron had been driven into exile, he was rein stated.
[1116] HERTZ, Gustav Ludwig German physicist Born: Hamburg, July 22, 1887 Died: Berlin, October 30, 1975 A nephew of Heinrich Hertz [873], Gustav Hertz obtained his doctorate at the University of Berlin. He fought on the German side in World War I and was severely wounded. He worked with Franck [1081] to es tablish the quantized nature of the atom’s internal structure and shared with him the 1925 Nobel Prize in physics. In 1928 he was appointed professor of physics at the Technical University, Ber lin-Charlottenburg. Since he was of Jewish descent, he was forced, after Hitler came to power, to re sign his post in 1934. Nevertheless, he remained in Germany through World War II, and even survived. He was taken by the advancing Soviet Army and from 1945 worked in the Soviet Union and in East Germany. In 1955 he was ap pointed professor of physics at the Uni versity of Leipzig in East Germany until his retirement in 1961. [1117] SCHRÖDINGER, Erwin (shroi'- ding-er)
Austrian physicist Born: Vienna, August 12, 1887 Died: Alpbach, January 4, 1961 Schrödinger, the only son of a pros perous factory owner, was taught at home as a youngster. He then attended the University of Vienna and obtained his Ph.D. in 1910. In World War I he served as an artillery officer on the southwest front. More fortunate than Moseley [1121], he survived unharmed. In 1918 he made up his mind to aban don physics for philosophy, but the city in which he had hoped to obtain a uni versity post was lost to Austria in the peace treaties. Schrödinger therefore re mained a physicist. After the war Schrödinger went to Germany and by 1921 had a professorial appointment at the University of Stutt gart. As soon as Schrödinger learned of the matter waves postulated by De Broglie [1157] (reading of it in a footnote in one of Einstein’s [1064] papers) and the concept of the electron as having wave properties, it occurred to him that the picture of the atom as built up by Bohr
[1117] SCHRÖDINGER PANETH
[1101] could be modified to take those waves into account. Once this was done, the Bohr atom might even be improved. In Schrödinger’s atom the electron can be in any orbit, around which its matter waves can extend in an exact number of wavelengths. This produced a standing wave and therefore did not represent an electric charge in acceleration, so that the electron, as long as it remained in its orbit, need not radiate light and did not violate the conditions of Maxwell’s [692] equations. Furthermore, any orbit between two permissible orbits where a fractional number of wavelengths would be re quired is impermissible. This accounts for the existence of discrete orbits, with nothing possible in between, as a neces sary consequence of the properties of the electron, and not as a mere arbitrary de duction from spectral lines. Schrödinger, along with others like Dirac [1256] and Bom [1084], worked out the mathematics involved in this concept. The relationships that were derived (sometimes referred to as wave mechanics and sometimes as quantum mechanics) placed Planck’s [887] quan tum theory on a firm mathematical basis a quarter century after it was first pro mulgated. The key relationship in the mathematical fabric is referred to as the Schrödinger wave equation. Schrödinger’s work on the subject was published in 1926 and it was later shown that the matrix mechanics of Heisenberg [1245], advanced in 1925, and Schrö dinger’s wave mechanics were equiv alent, in that everything explained by one was explained by the other. Psy chologically, wave mechanics was more attractive because it offered the mind a picture of the atom, however ungrasp- able that picture might be. In 1933 Schrödinger was awarded the Nobel Prize in physics for his work on wave mechanics, sharing it with Dirac. In 1928 Schrödinger had succeeded Max Planck as professor of theoretical physics at the University of Berlin, but in the same year that he earned the Nobel Prize, Hitler came to power. Schrödinger did not wish to remain, and left for his native Austria. Although not Jewish (and therefore not directly threatened) he made no secret of his de testation of the Nazis and their anti Semitic policy. He once interfered with storm troopers bent on a pogrom. He nearly got himself killed for his pains. When Austria was absorbed by Nazi Germany in 1938, he went to England and in 1940 became professor at the School for Advanced Studies in Dublin, Ireland. He was joined there by Dirac, his fellow adventurer in the realms of wave mechanics. In 1956 Schrodinger returned to Vienna and lived out the rest of his life there. [1118] PANETH, Friedrich Adolf (pan'et) German-British chemist Born: Vienna, Austria, August 31, 1887
Died: Mainz, Germany, Septem ber 17, 1958 Paneth, the son of an eminent physiol ogist, obtained his Ph.D. from the Uni versity of Vienna in 1910. He visited Great Britain, where he worked with Soddy [1052] and Ernest Rutherford [996], then taught at various universities in Germany. In 1933 the coming to power of Hitler made it advisable for him to leave Germany for Great Britain. He returned to Germany only in 1953. In 1913 he had worked with Hevesy [1100] in the use of radium D as a tracer in determining the solubility of lead salts. Paneth went on to use the technique for studying the unstable hy drides of lead and bismuth. The tech nique for studying compounds that existed only evanescently made it possi ble for him to demonstrate the existence of free radicals in the course of organic reactions. During the 1920s he worked out methods for determining trace amounts of helium in rocks. This made it possible to determine their age, since uranium in rocks very slowly liberated helium. In particular, Paneth used the technique for measuring the age of meteorites and this was an important step toward determin Download 17.33 Mb. Do'stlaringiz bilan baham: 
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