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[ 1121
]. During the 1920s two subatomic parti cles were known: the electron, discov ered by J. J. Thomson [869], and the proton, discovered by Rutherford. The protons were all located in the nucleus, but if the nucleus contained enough protons to make up its mass, it would have too large a positive charge. Thus, the helium nucleus has a mass equal to four protons, but a charge equal only to two protons. It was thought, therefore, that the nucleus must contain a few elec trons to neutralize some of the proton charge. The electrons would not affect the mass much since they were ex tremely light particles. It was even thought that the electrons would act as a “cement” to hold the protons together, for without the electrons the similarly charged protons would repel each other and fly apart. According to this view point, the helium nucleus would contain four protons and two electrons for a mass of 4 and a positive net charge of 2. There were theoretical reasons, how ever, for dissatisfaction with the theory of the proton-electron nucleus, and there were also theoretical reasons for suspect ing that an uncharged particle might exist. In the 1920s Rutherford and Chadwick made several attempts to lo cate such a particle but failed. The difficulty was that uncharged particles did not ionize molecules of air and it was through this ionization that sub atomic particles were most easily de tected.
Between 1930 and 1932, however, some physicists, including Bothe [1146] and the Joliot-Curies [1204, 1227], noted that when certain light elements such as beryllium were exposed to alpha parti cles, some kind of radiation was formed which showed its presence by ejecting protons from paraffin. The proper inter pretation was not made, unfortunately. It was Chadwick in 1932 who re peated these experiments and showed that the best way of explaining the effects was to suppose that the alpha par ticles were knocking neutral particles out of the nuclei of the beryllium atom and that these neutral particles (each about as massive as a proton) were in turn knocking protons out of paraffin. In this way, the neutral particle (a neutron) was discovered. The neutron proved to be by far the 729
[1150] CHADWICK
BANTING [1152]
most useful particle for initiating nuclear reactions and Chadwick received the 1935 Nobel Prize in physics. At that time it was yet to be discovered that among the reactions initiated by neu trons was uranium fission. This Hahn [1063] and Meitner [1060] were to show three years later. With the discovery of the neutron it was realized that the nuclei of atoms did not have to contain any electrons. In stead, as Heisenberg [1245] soon sug gested, the nucleus was made up of protons and neutrons. Thus, the helium nucleus contained two protons and two neutrons for a total mass of 4 and a total positive charge of 2. Different isotopes of a particular element all contained the same number of protons (and therefore the same number of electrons in the periphery—and it was on the electron number and arrangement that the chemi cal properties depended) but possessed different numbers of neutrons. Thus, of the two varieties of chlorine atoms, one contained 17 protons and 18 neutrons for a total mass of 35, while the other contained 17 protons and 20 neutrons for a total mass of 37. The two isotopes would be distinguished as chlorine-35 and chlorine-37. Thus, finally, the iso tope theory of Soddy [1052] and Aston [1051], advanced two decades before, was rationalized. The proton-neutron view of the nu cleus met all the theoretical requirements but one: What kept all the positive- charged protons crowded together into the tiny nucleus? For an explanation of this, it was necessary to wait just a few years for the calculations of Yukawa [1323].
In 1935 Chadwick became professor of physics at the University of Liverpool. He remained out of Germany in World War II, fortunately, and served instead as head of Great Britain’s phase of the atomic bomb project, spending some time in America. Indeed, he began work toward an atomic bomb shortly after Meitner announced the fact of fission and well before the United States was stirred to action. He was knighted in 1945. [1151] NICHOLSON, Seth Barnes American astronomer Bom: Springfield, Illinois, November 12, 1891 Died: Los Angeles, California, July 2, 1963 Nicholson, the son of a geologist, at tended Drake University in Des Moines, Iowa, then went on to take his Ph.D. in 1915 at the University of California. That year he joined the staff of Mount Wilson Observatory at Pasadena, re maining there until his retirement in 1957.
Nicholson carried out delicate mea surements of astronomical temperatures. In 1927, for instance, he discovered that the surface temperature of the moon dropped nearly 200 Centigrade degrees during its eclipse by the shadow of the earth. Such a precipitous drop indicates that stored heat from deeper layers reaches the surface only very slowly and has given rise to the belief that the moon is covered with a layer of loose dust, the vacuum between the dust particles being an excellent heat insulator. He also mea sured the surface temperature of Mer cury, finding a maximum of 410°C. Nicholson joined the select company of Galileo [166] and Barnard [883] as the discoverer of satellites of Jupiter. He discovered one in 1914, while still a graduate student, two in 1938, and a fourth in 1951. The four discovered by Nicholson are small objects (probably captured asteroids) very distant from Jupiter. So are additional satellites dis covered by others in the twentieth cen tury. These brought the total number of Jupiter’s moons to more than a dozen. [1152] BANTING, Sir Frederick Grant Canadian physiologist
November 14, 1891 Died: Near Musgrave Harbour, Newfoundland, February 21, 1941 At the University of Toronto, Banting, the son of a farmer, began studies for the ministry, then transferred to the 730
[1152] BANTING
BANTING [1152]
study of medicine. He obtained his medi cal degree in 1916 and served for the re mainder of World War I as a medical officer overseas. He was wounded at Cambrai and in 1918 was awarded the Military Cross for heroism under fire. After a short period of medical prac tice, Banting grew interested in diabetes mellitus, a disease in which the chief biochemical symptom was the presence of abnormally high glucose levels in the blood and the eventual appearance of glucose in the urine. At the time, this disease meant slow, but sure, death. A generation earlier, suspicion had arisen that the pancreas was somehow connected with it, for removal of the pancreas in experimental animals brought about a diabetes-like condition. Once the hormone concept had been propounded by Starling [954] and Bayliss [902], it seemed logical to suppose that the pancreas produced a hormone that controlled the manner in which the body metabolized its glucose molecules. An in sufficient supply of this hormone caused glucose to pile up and led to diabetes. Of course, the chief function of the pancreas was to produce a digestive juice. Nevertheless, there were numerous little patches of cells within the pancreas (called Islets of Langerhans after the man who had first described them a half century earlier) which differed from the rest of the gland. These might well be the source of the hormone. The hormone had even received a name, insulin, from the Latin word for “island.” There had already been successful iso lations of hormones—notably Kendall’s [1105] isolation of thyroxine, the thyroid hormone—so it occurred to a number of people to attempt to isolate insulin from the pancreas. If that could be done, the isolated hormone might be administered to human diabetics, who could then sur vive the disease indefinitely while medi cation continued. All attempts to isolate insulin failed, however, for the digestive enzymes in the pancreas broke up the in sulin molecule (a protein) as soon as the pancreas was mashed up. In 1920 Banting read an article de scribing how tying off the duct through which the pancreas delivered its digestive secretion into the intestines caused the pancreatic tissue to degenerate. This gave Banting the key idea. The Islets of Langerhans, not being involved in pro ducing the digestive secretions, should not degenerate. If the rest of the pan creas did, then there would be no diges tive enzymes left to break up the insulin, which would still be present in full. In 1921 he went to the University of Toronto with his idea, and, after some trouble, persuaded a professor of physi ology, John J. R. Macleod, to grant him some laboratory space and assign him a co-worker, who turned out to be Best [1218], After that, Macleod went off on a summer vacation. Together, Banting and Best tied off the pancreatic ducts in a number of dogs and waited seven weeks. The pancreases had by then become shriveled and use less to the dogs as digestive organs but the Islets of Langerhans were still in fine shape. From such pancreases, they ex tracted a solution that could then be sup plied to the dogs who had been made di abetic by the removal of the pancreas. The extract quickly stopped the symp toms of diabetes. Banting and Best called the hormone “isletin” but Macleod, who now decided to take an interest, insisted on the older “insulin.” The experiments were completed in 1922, and in 1923 Banting and Macleod were awarded the Nobel Prize in medi cine and physiology, the first Nobel Prize awarded to Canadians. Millions of dia betics have, since that time, been able to live reasonably normal lives. Among these were Eastman [852] and Minot [1103], as well as George V of England and the writer H. G. Wells. Banting was furious, however, that the prize had been shared with Macleod, who had merely given them laboratory space, and not with Best, who had borne his fair share of the labor. It was only with difficulty that Banting was per suaded to accept the prize and when he did so, he gave half his share of the money to Best. Banting was voted an annuity by the Canadian Parliament in 1923 and the Banting Research Foundation was es tablished for him. A Banting-Best profes 731
[1153] STURTEVANT WATSON-WATT [1155]
sorship was established at the University of Toronto and in 1934 Banting was knighted. With the coming of World War II, Banting was once again involved in med ical war work. He served as a major in the Canadian Army, but was less fortu nate this time. He died in a plane crash over Newfoundland. [1153] STURTEVANT, Alfred Henry (stur'tuh-vant) American geneticist Born: Jacksonville, Illinois, November 21, 1891 Died: Pasadena, California, April 5, 1970 Sturtevant was the son of a mathe matics teacher turned farmer. The fam ily moved to southern Alabama in 1899. In 1908 Sturtevant entered Columbia University, where it was possible for him to live with his older brother, who was teaching Latin and Greek at Barnard. Sturtevant’s brother encouraged the young man to study genetics, and this he did to such effect that in 1910 he was able to work in T. H. Morgan’s [957] laboratory. He obtained his Ph.D. in genetics under Morgan in 1914, and for some years worked with Muller [1145]. In 1928 he obtained a profes sorship in genetics at the California Insti tute of Technology, remaining there till his death. Sturtevant’s best-known advance was the principle of mapping the position of genes on a chromosome by the fre quency with which crossing over sepa rated them. The greater the frequency the farther apart the genes. He published details of the technique in 1913. The four chromosomes of the fruit fly were soon mapped in detail in this way. Stur tevant presented a map of the fourth and smallest of the chromosomes in 1951. [1154] MURPHY, William Parry American physician
February 6, 1892 Murphy studied at the University of Oregon, graduating in 1914. After a spell of teaching, he went on to medicine and obtained his medical degree from Harvard University in 1920. At Peter Bent Brigham Hospital he worked with Minot [1103] in developing the liver treatment for pernicious anemia and shared with him and Whipple [1059] the 1934 Nobel Prize in medicine and physiology. [1155] WATSON-WATT, Sir Robert Alexander Scottish physicist Born: Brechin, Angus, April 13, 1892
Died: Inverness, December 6, 1973
Watson-Watt was educated at the Uni versity of St. Andrews and taught there from 1912 to 1921. Even then he was interested in the reflection of radio waves. That they were reflected was known, for it was their reflection from ionized layers in the upper atmosphere that made long-distance broadcasting possi ble, as Kennelly [916] and Heaviside [806] had made clear. The reflection was sharper as wavelength decreased, and in 1919 Watson-Watt had already taken out a patent in connection with radiolocation by means of shortwave radio. Though the technology is rather com plicated, the principle is simple. Radio waves travel at an accurately known ve locity, the velocity of light. A pulse of very shortwave radio waves (now called microwaves) can be sent out and, upon striking an obstacle and being reflected, will return to the sender. The difference in time between emission and reception can then be converted into distance; and, of course, the direction from which the reflection is obtained is the direction of the obstacle. By 1935 Watson-Watt, as a result of continued experiments, had patented im provements that made it possible to fol low an airplane by the radio-wave reflec tions it sent back. The system was called 732
[1156] THOMSON
DE BROGLIE [1157]
“radio detection and ranging” (to “get a range” on an object is to determine its distance) and this was abbreviated to “ra. d. a. r.” or “radar.” Research was continued in secrecy and by the fall of 1938, the time of the Munich surrender to Hitler, radar sta tions were in operation. By the time of the Battle of Britain in 1940, radar made it possible for the British to detect on coming German planes as easily by night as by day, and in all weathers, including fog. The German planes found them selves consistently outguessed and, with all due respect to the valor of the British airmen, it was radar that won the Battle of Britain. The principles of radar had been worked out in Germany too, during the 1930s. However, it is reported that Hitler and Goering decided that it was fit only for defensive warfare and that since the German armed forces would never have to stand on the defensive, radar might be ignored. By the time they learned better, it was fortunately too late. American electrical engineers had been working on radar systems as early as 1931, but Watson-Watt’s labors and the wartime pressures had given Great Brit ain the lead. In 1941 Watson-Watt vis ited the United States and helped the Americans complete the job and set up radar systems of their own. In 1942 he was knighted. American radar at Pearl Harbor in 1941 detected the oncoming Japanese planes, but the warning was tragically ignored. Radar, of course, has developed myr iad peacetime uses since World War II (including even its use in the detection of storms and the mapping of the sur face of Venus). [1156] THOMSON, Sir George Paget English physicist Born: Cambridge, May 3, 1892 Died: Cambridge, September 10, 1975
Thomson, the only son of J. J. Thom son [869], was educated at Cambridge, graduating in 1913 and beginning re search under his father. World War I came, and after time spent in the army and in war work on aerodynamics, he re turned to physics, doing some work under Millikan [969] in the United States, and was appointed professor of natural philosophy at the University of Aberdeen in 1922. In 1927, very shortly after Davisson [1078] had published his work, Thomson published his own independent observa tion on electron diffraction. He achieved his results by passing fast electrons through metallic foil (using thin gold foil of a type developed by Frédéric Joliot-Curie [1227] in 1927), much as Laue [1068] had passed X rays through a crystal. Thomson obtained the same sort of diffraction pattern with electrons that Laue had obtained with X rays and that was strictly in accordance with De Broglie’s [1157] theory. Consequently he shared the 1937 Nobel Prize in physics with Davisson. In 1930, he accepted a post at the University of London. During World War II, Thomson was chairman of the British Commission on Atomic Energy. In 1943 he was knighted, and in 1952 he became master of Corpus Christi Col lege, Cambridge. [1157] DE BROGLIE, Louis Victor Pierre Raymond, Prince (broh'- gleeO French physicist Born: Dieppe, Seine-Mame, August 15, 1892 De Broglie was bom into a noble French family, his ancestors having served the French kings in war and di plomacy as far back as the time of Louis XIV. His great-great-grandfather died on the guillotine during the French Revolu tion. De Broglie was educated at the Sor bonne. It was only after obtaining his de gree in history that he entered the French army in World War I, became involved in radio communication there, and decided to turn to science. (During 733
[1157] DE BROGLIE APPLETON [1158]
the war, his role as a radio engineer had kept him stationed in the Eiffel Tower.) He went back to his education with the new aim in mind and in 1924 ob tained his doctorate with a thesis dealing with the quantum theory. It was in the year before that, however, that, inspired by the need for a symmetric inverse of the Compton [1159] effect—if waves were particles, why might not particles be waves?—he did his great work. By a rather simple combination of the formula of Einstein [1064], which re lated mass and energy, and that of Planck [887], which related frequency and energy, he showed in 1923 that with any particle there ought to be an as sociated wave. The wavelength of such waves (which are not electromagnetic in nature, and have since come to be called matter waves) is inversely related to the momentum of the particle, which in turn depends on its mass and velocity. The wavelength is so small for any siz able body such as a baseball, or even a proton, that it would seem hopeless to try to detect it. For a body as light as an electron, however, the wavelength ought to be as large in magnitude as some of the X-ray wavelengths and that should be detectable. As a matter of fact, Davis son [1078] and G. P. Thomson [1156] managed to detect it in 1927. This particle-wave dualism for the electron matched the wave-particle dualism for the photon as worked out by Compton. Einstein’s contention that mat ter was but a form of energy and that the two were interconvertible made more common sense when it could be seen that particles were always wavelike, and waves always particle-like. Mass and en ergy then came to seem much the same in structure after all and Einstein’s view was no longer astonishing. Schrödinger [1117] used the new wave concept of the electron to build a picture of atom structure in which the jumping electron particles of Bohr [1101] gave way to standing electron waves. Simi larly, the static electrons of Lewis [1037] gave way, in connection with chemical bond formation, to the reasonating elec tron waves of Pauling [1236]. De Broglie was consequently awarded the 1929 Nobel Prize in physics. In 1945 he became technical adviser to the French atomic energy commission. [1158] APPLETON, Sir Edward Victor English physicist Born: Bradford, Yorkshire, September 6, 1892 Died: Edinburgh, Scotland, April 21, 1965 Appleton, the son of a millworker, had an early ambition to become a profes sional cricket player but won a scholar ship which took him to Cambridge and to science. At Cambridge, Appleton studied under J. J. Thomson [869] and Ernest Rutherford [996], which in itself was a good start for a bright young man. Appleton served as a radio officer during World War I, which interrupted his stud ies but introduced him to the problem of the fading of radio signals. After the war he looked into the prob lem in earnest and was helped by the fact that by 1922 commercial broadcast ing had started in Great Britain, so there were plenty of powerful signals to play with. Appleton found that fading took place at night and he wondered if this might not be due to reflection from the upper atmosphere, a reflection that took place chiefly at night. If so, such reflec tion might set up interference since the same radio beam would reach a particu lar spot by two different routes: one. di rect, and two, by bouncing off the layers of charged particles postulated by Ken nelly [916] and Heaviside [806] twenty years earlier. If so, the two beams might arrive out of phase, with partial cancel lation of the wave. Appleton began to experiment by using a transmitter and receiver that were about seventy miles apart and by altering the wavelength of the signal and noting when it was in phase so that the signal was strengthened and when out of phase so that it was weakened. From this he could calculate the minimum height of reflection. In 1924 he found that the Kennelly-Heaviside layer was some sixty miles high. 7 3 4
[1159] COMPTON
COMPTON [1159]
At dawn the Kennelly-Heaviside layer broke up and the phenomenon of fading was no longer particularly noticeable. However, there was still reflection from charged layers higher up. By 1926 he had determined these to be about one hundred and fifty miles high and they are sometimes called the Appleton layers. Further experiments over the next few years detailed the manner in which these charged layers altered in behavior with the position of the sun and with the changes in the sunspot cycle. These stud ies initiated the modem investigation of the layer of air above Teisserenc de Bort’s [861] stratosphere. Because of the high content of ions, the air above the stratosphere is often called the iono sphere, a name first suggested by Wat- son-Watt [1155]. The ionosphere became a prime object of study when rocket re search became practical a generation after Appleton’s discovery. By 1924 Appleton had become a pro fessor of physics at the University of London, and in 1936 he was appointed professor of natural philosophy at Cam bridge, succeeding Wilson [979]. During World War II he was in charge of Brit ish atomic bomb research, and in 1941 he was knighted. In 1944 he became vice-chancellor of Edinburgh University, but the climax of his career came in 1947 when he was awarded the Nobel Prize in physics. [1159] COMPTON, Arthur Holly American physicist Born: Wooster, Ohio, September 10, 1892 Died: Berkeley, California, March 15, 1962 Compton, the son of a Presbyterian minister, graduated from Wooster Col lege (where his father was dean) in 1913 and obtained his Ph.D. at Prince ton University in 1916, taught physics at the University of Minnesota for a year, then served an additional two years as engineer for the Westinghouse Lamp Company in Pittsburgh. In 1919 he spent a year at Cambridge University, studying under Ernest Rutherford [996]. When he returned to the United States the next year, it was to become the head of the physics department at Washington Uni versity in St. Louis, Missouri. In 1923 he moved on to the University of Chicago. Compton carried further the re searches of Barkla [1049] involving the scattering of X rays by matter. Barkla had been able to ascertain the nature of the scattered X rays only by very rough measurements of absorbability. Comp ton, however, had the technique of the Braggs [922, 1141] at his disposal and was able to measure the wavelengths of the scattered X rays accurately. When he did this, he found in 1923 that some of the X rays had, in scatter ing, lengthened their wavelength. (This was named the Compton effect in his honor.) A few years later, Raman [1130] was to make a similar discovery in con nection with visible light. Compton was able to account for this by presuming that a photon of light struck an electron, which recoiled, sub tracting some energy from the photon and therefore increasing its wavelength. This made it seem that a photon acted as a particle and it was Compton who suggested the name “photon” for the light quantum in its particle aspect. Thus, after more than a century, the par ticulate nature of light, as evolved by Newton [231], was revived. However, the particulate nature was rendered much more sophisticated by the theories of Planck [887] and Einstein [1064] and it did not obliterate the wave phenomena established by such nineteenth-century physicists as Young [402], Fresnel [455], and Maxwell [692]. What it amounted to was that Comp ton brought to fulfillment the view that electromagnetic radiation had both a wave aspect and a particle aspect, and that the aspect that was most evident depended on how the radiation was tested. De Broglie [1157] was at the same time showing that this held true also for ordinary particles such as elec trons. This famous duality impresses some people as a “paradox” that implies 735
[1159] COMPTON
HALDANE [1160]
the universe is too mysterious to be pen etrated by reason. Actually, it is per fectly understandable, for instance, that a man should have, let us say, two different aspects, one as a husband and one as a father, and that each aspect be comes prominent according to circum stances. It is no more paradoxical or mysterious that photons or electrons should have more than one aspect. For his discovery of the Compton effect, Compton received the Nobel Prize in physics in 1927, sharing it with Wil son [979]. About 1930 Compton turned his atten tion to cosmic rays. Millikan [969], who was the outstanding man in the field at the time, believed that cosmic rays were electromagnetic in nature, like gamma rays but even more energetic. If this were so, then cosmic rays ought to re main unaffected by the earth’s magnetic field and ought to strike all portions of the earth’s surface about equally. If, on the other hand, cosmic rays consisted of charged particles as Bothe [1146] main tained, for instance, then they ought to curve in the earth’s magnetic field, and more ought to be detected in polar re gions as one approached the magnetic poles, and less in tropic regions. Compton became a world traveler for this research, conducting a series of painstaking measurements, which showed that a “latitude effect” did exist. Cosmic rays were indeed affected by the mag netic field so that they must consist, at least in part, of charged particles. De spite Millikan’s continued adherence to the electromagnetic view, further re search has consistently strengthened the particle view until now there is no rea sonable doubt of it. (Compton, so often linked with Millikan in any discussion of cosmic ray research, was like Millikan in being an outspokenly religious scientist.) During World War II, Compton was one of the top scientists in the Manhat tan Project that developed the atomic bomb, and he remained on the best terms with the military. He directed the research on methods of producing pluto nium and, ultimately, approved the use of the atomic bomb over Japan. After the war, he returned to Wash ington University as chancellor in 1945, serving till 1953. [1160] HALDANE, John Burdon Sanderson English-Indian geneticist Born: Oxford, England, Novem ber 5, 1892 Died: Bhubaneswar, India, December 1, 1964 Haldane, the son of a noted physiol ogist, entered science as an assistant to his father, at the tender age of eight. He studied the humanities at Oxford, but his heart remained in science. He served in World War I, the horrors of which disil lusioned him with conventional pieties and made of him an outspoken atheist. After the war, he worked as a bio chemist at Cambridge. He was particu larly interested in genetics and in 1932 was the first to estimate the rate of mu tation of a human gene. He became best known for his experi ments on himself designed (sometimes in horrendous fashion) to study the behav ior of the human body under stress. For instance in 1942 he and a companion spent forty-eight hours in a tiny subma rine to check whether a particular sys tem for purifying the air supply would work. He also subjected himself to ex tremes of temperature, carbon dioxide concentration, and so on. In the 1930s he became a Communist, was quite outspoken about it and even served as editor of the London Daily
writer of science popularization. He was active in aiding refugees from Nazi Germany and helped Chain [1306] get a position with Florey [1213]. He left the Communist Party (though remaining a Marxist) as a result of his disillu sionment with the Lysenko [1214] ascen dancy in the Soviet Union, something that was bound to disturb any reasonable geneticist. His dissatisfaction with British policy, however, remained strong enough to force him into self-exile to India in 1957. 7 3 6
[1161] LARSON
BAADE [1163]
As a further gesture of turning his back on his homeland, he accepted Indian citi zenship. [1161] LARSON, John Augustus Canadian-American psychiatrist
December 11, 1892 Larson graduated from Boston Univer sity in 1914 and obtained his Ph.D. at the University of California in 1920. His interest in criminology led him to study medicine and he obtained his M.D. from Rush Medical College in 1928. He served as psychiatrist at prisons, hospi tals, and health centers. It occurred to him that lying involves an effort that telling the truth does not, and that the fear of being caught lying ought to elicit an involuntary flow of adrenaline that could be detectable by the changes in body properties it brought about. He therefore devised a machine, the “polygraph,” which could simultaneously and continuously record the pulse rate, breathing rate, blood pressure, and per spiration secretion. Such changes would, or should, be greater when a lie was told than when the truth was told. The in strument was promptly named a “lie de tector.” It is not infallible, but it has proved useful. [1162] DART, Raymond Arthur Australian-South African anthropologist and surgeon Born: Brisbane, Australia, February 4, 1893 Dart was educated in Australia and got his medical degree in 1917. He went to South Africa in 1923 and remained there afterward. His professional life was largely that of surgeon and anatomist, but his fame arose from a nonmedical discovery. In 1924 a small skull that, except for its size, looked human, was discovered in a limestone quarry in South Africa. Dart was then working at the University of Witwatersrand in Johannesburg and the skull was taken to him. He recognized it as a primitive precursor of Homo sa piens and called it Australopithecus (“southern ape”). The discovery was a controversial one and Dart and others, such as Broom [959], were forced to start a systematic hunt for similar fossil relics. They found a number, enough to prove that the first skull was no mistake. The australopithe- cines are now a well-established part of the developing hominids, which include, as non-African specimens, the “Java Man” discovered by Dubois [884] and the “Peking Man” of East Asia. The findings of still earlier fossil relics of prehuman creatures in eastern Africa make it appear fairly certain that man’s ancestors developed from the primitive primate stock in that continent. [1163] BAADE, Walter (bah'duh) German-American astronomer Born: Schröttinghausen, Westphalia, March 24, 1893 Died: Gottingen, June 25, 1960 Baade, the son of a teacher, was in tended for the Protestant ministry, but in high school, he decided he wanted to be an astronomer. He obtained his Ph.D. at Göttingen in 1919, a hip ailment having exempted him from service in World War I. After eleven years on the staff at the University of Hamburg, Baade went to the United States in 1931. It was there at Mount Wilson and Palomar ob servatories that he made his great contri butions to astronomy. In 1920, to be sure, he had made the interesting discovery of the asteroid Hi dalgo, whose orbit carries it as far out as the orbit of Saturn. It was then, and is now, the farthest known asteroid. By an odd coincidence, Baade in 1948 discov ered the asteroid Icarus, the orbit of which carries it to within 18 million miles of the sun, closer than Mercury and therefore the innermost known as teroid. Obviously, as Kuiper [1297] and Nicholson [1151] were also to show, dis coveries remain to be made within the 737
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solar system, even though Baade referred to the asteroids, with a kind of good-na tured contempt, as “vermin in the sky.” Outside the solar system, Kuiper in 1941 found a patch of nebulosity in about the position of Kepler’s [169] nova. It was in 1942, however, that Baade made his most notable contribution. As an “enemy alien,” he could not engage in war work, so he was forced to con tinue in pure science. He took advantage of the wartime blackout of Los Angeles, which cleared the night sky at Mount Wilson, to make a detailed study of the Andromeda galaxy with the 100-inch telescope. He was able to resolve some of the stars in the inner regions of the galaxy for the first time. Before then, Hubble’s [1136] efforts at resolution had only obtained a view of the blue-white giants of the spiral arms. Baade noted that the brightest stars of the galactic interior were not blue-white, but reddish. To Baade it seemed that there were two sets of stars of different structure and history. He called the bluish stars of the galactic outskirts Population I and the reddish stars of the interior Popula tion II. Population I stars are relatively young and are built up out of the dusty surroundings of the spiral arms. Popula tion II stars are old and are built up in the dust-free regions of the nuclei. When the 200-inch telescope came into operation after World War II, Baade continued his investigations and located over three hundred Cepheids in the Andromeda galaxy. He found that Cepheid variable stars occurred both among the Population I and Population II stars, but that the period-luminosity curve worked out for them by Shapley [1102] and Leavitt [975] applied only to Population II. It was Population II that occurred in globular clusters and in the Magellanic clouds so that the distances worked out within our own galaxy, and as far as the Magellanic clouds outside the galaxy, were all right. However, the distances of the outer galaxies, as worked out by Hubble, were based on Population I Cepheids, and for these, Baade in 1952 worked out a new period-luminosity curve in which the stars for a given period proved much more luminous. This meant that the An dromeda galaxy must be far more distant than Hubble had thought if the blue- white Cepheids in its spiral arms were as dim as they seemed. The Andromeda galaxy was not 800,000 light-years dis tant, then, but over 2 million fight-years away. The entire universe increased its volume twentyfold. Now if time is imagined as running backward, it would take the galaxies (moving at their observed velocities) 5 or 6 billion years to come together into contact, rather than the 2 billion years that would have been required in Hub ble’s smaller universe. This gave the ge ologists, who knew the earth’s solid crust to be better than 3 billion years old, ample time for earth’s evolution. (Actu ally, the universe shows signs of being far older than 6 billion years, though our own solar system is almost certainly no older. The present figure most often ac cepted for the age of the universe is 15 billion years.) Baade’s discovery also meant that the Andromeda galaxy and the other galaxies, being so much farther than had been thought, must also be that much larger in order to appear as bright as they seem from the earth. Our own gal axy was no longer an outsize example, much larger than all others, but was of average size. It was smaller than the Andromeda galaxy, for instance. As Co pernicus [127] had dethroned the earth and Shapley the sun, so Baade dethroned our galaxy from its position of preemi nence. With the scale of the universe growing ever grander, attention began to switch from individual galaxies to groups and clusters of galaxies, a field of research in which Zwicky [1209] achieved promi nence. The construction of radio telescopes, following Jansky’s [1295] initial discov ery of radio radiation from outer space, offered a new tool for the investigation of great distances. One of the strongest radio sources in the sky, for instance, could be localized to no object within the range of the 200-inch telescope. In 1959 Baade found a distorted galaxy in the 738
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constellation Cygnus that proved to be the source. The radio waves emitted by the galaxy could be distinctly detected at a distance of 260 million light-years. It was seen that with radio telescopes of practical size, distances could be penetrated that could not be reached by any optical tele scope of practical size. The age of the radio exploration of the universe began in earnest. In 1958 Baade returned to Gottingen in Germany, and there the enlarger of the universe died. [1164] UREY, Harold Clayton American chemist Born: Walkerton, Indiana, April 29, 1893 Died: La Jolla, California, Janu ary 5, 1981 Urey was the son of a schoolteacher who was also a lay minister. His father died in 1899. His mother remarried and his stepfather was also a clergyman. He studied at Montana State Univer sity, majoring in zoology and graduating in 1917. Work during World War I turned his attention to high explosives and through that to chemistry generally. He obtained a scholarship and went on to a Ph.D. in 1923 at the University of California, where he worked with Lewis [1037]. In 1923 he traveled to Copenha gen and spent a year in Bohr’s [1101] laboratory. After joining the Johns Hop kins faculty in 1924, he went on to Co lumbia University in 1929. In 1931 Urey tackled the problem of heavy hydrogen. There had been sugges tions that there might be a form of hy drogen with atoms twice the mass of the ordinary hydrogen atom, almost from the moment that Soddy [1052] had ad vanced the isotope theory. Accurate measurements of the mass of the hydro gen atom, however, revealed that any heavy isotope, if present at all, could only be there in very small concen tration. It seemed to Urey that the vapor pres sure of ordinary hydrogen ought to be greater than heavy hydrogen’s. That meant that if a quantity of liquid hydro gen was vaporized, the ordinary hydro gen atoms would be more easily removed and the last bit of liquid would be richer in heavy hydrogen than the original had been. Atoms of heavy hydrogen, with a more massive atomic nucleus, would have lone electrons with energy levels slightly different from those in ordinary hydrogen atoms. This would mean that, if heated, their spectral lines would be at wavelengths slightly different from those of ordinary hydrogen. Perhaps through the evaporation of liquid hydrogen, the concentration of the heavy form might be increased to the point where it could be detected spectroscopically. Urey consequently evaporated four liters of liquid hydrogen by slow stages down to a single cubic centimeter and then investigated the spectrum of that final bit. Sure enough, the ordinary ab sorption lines of hydrogen were accom panied by faint lines that were in exactly the positions predicted for heavy hydro gen. The name deuterium was given to the heavy isotope. Once the existence of the isotope was proved, it did not take long for water containing high proportions of deuterium (so-called heavy water) to be prepared, notably through the work of Lewis. Bio chemically significant compounds could then be prepared with deuterium in place of hydrogen and, thanks to the pioneer work of Schoenheimer [1211], the use of isotopic tracers in working out the intri cate pattern of chemical reactions within living tissue was initiated. Urey was awarded the 1934 Nobel Prize in chemistry for his feat. Since he refused to travel to Sweden that year be cause his wife was pregnant, he delivered his Nobel lecture the next year. Urey began to investigate methods of separating isotopes of other elements and was the first to put to use the fact that heavier isotopes tended to react a bit more slowly than their lighter twins. By taking advantage of differences in such reactivity and by devising procedures whereby these differences could con stantly be built up, he was able in the late 1930s to prepare high concentrations of such isotopes as carbon-13 and ni 739
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trogen-15, which are found in natural carbon and nitrogen but ordinarily only in small concentration. Schoenheimer put these to profitable use in biochemical research also. Experience with isotope separation turned out to be useful indeed in the early 1940s when the United States’ de velopment of the atomic bomb required methods of separating the rare isotope uranium-235 (needed for the bomb) from the much more common uranium- 238. After World War II, hydrogen-2 (Urey’s own deuterium) turned out to be of key importance to the development of the even more horrible hydrogen bomb. In 1945 Urey joined the faculty of the University of Chicago and in 1952 that of the University of California. Urey was one of the scientists most concerned with the developing danger to mankind repre sented by the nuclear weapons that owe so much to his own isotopic research. In the postwar years he busied himself with geophysics, a study that, it would seem, could not be turned to destructive pur poses.
Here, too, his interest in isotopes proved useful. Isotopes of a given ele ment differ in speed of reactivity, the more massive being somewhat slower to react. This difference changes in extent, slightly, with change in temperature. Thus, the proportion of oxygen isotopes in a seashell depends on the temperature of the ocean at the time the shell was formed. By working with fossil shells, Urey and his co-workers were able to prepare a history of changing ocean tem peratures over long geologic periods. Urey also worked out detail theories of planetary formation based on situa tions such as those postulated by Weiz- sacker [1376], in which the planets are viewed as having been built up by accu mulating smaller fragments. Urey was one of those who maintained that the planets were formed by processes that retained comparatively low temperatures throughout and, like Otto Struve [1203], suspected life to be common in the uni verse. Urey also believed that the early atmo sphere of the earth was a reducing one, rich in hydogen, ammonia, and methane —something like the atmosphere of the giant outer planets today. It was in his laboratories in 1953 that Miller [1490] conducted his startling experiments relat ing to the possible origin of life under such conditions. Urey took firm stands on political and social issues. He was against war, against nuclear power, and denounced Senator Joseph McCarthy at a time when it was rather dangerous to do so. [1165] SIMON, Sir Franz Eugen Francis German-British physicist
1893
Died: Oxford, England, October 31, 1956 Simon was born into a well-to-do fam ily. He served in the German army for four years during World War I, reaching the rank of lieutenant in the field artil lery. He then studied at the University of Berlin and attained his Ph.D. in physics in 1921 under Nernst [936]. He earned a professorial appointment at Berlin in 1927 and went on to Breslau in 1931. He was lecturing at Berkeley as a visit ing professor when Hitler came to power. Simon knew better than to return to Germany under those conditions and went to Oxford instead, where he re mained until his death. Simon was interested in low-tempera ture physics. The method used to get liquid gases, right down to Kamerlingh Onnes’s [843] liquefaction of helium, was by the use of the Joule-Thomson effect, but that had reached as low a temperature as was practical. During his stay at Oxford, Simon worked out methods for withdrawing heat by lining up paramagnetic mole cules at very low temperatures and then allowing their orientation to randomize, abstracting further heat from their sur roundings and lowering the temperature still farther. He went on to do the same with nuclear spins, a harder task but one that reached still farther toward the un attainable absolute zero. Just before Si mon’s death, his group reached a low of 7 4 0
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20 millionths of a degree above absolute zero.
Simon used his low temperatures to demonstrate more firmly than ever be fore the validity of the third law of ther modynamics, which had been advanced by his old teacher, Nemst. Simon was knighted in 1955. [1166] NODDACK, Walter Karl Frie drich
German chemist Born: Berlin, August 17, 1893 Died: Bamberg, Bavaria, Decem ber 7, 1960 Noddack was educated at the Univer sity of Berlin, and he obtained his Ph.D. under Nemst [936] in 1920. In 1922 he began a long search for two elements (atomic numbers 43 and 75) that still remained undiscovered. As sociated with him in this endeavor were Ida Tacke [1187] and Otto Berg. Three years of careful fractionation of ores in which the missing elements might be found finally resulted in the detection of element 75 in May 1925. It was named rhenium after the Rhine River. It was the last stable element to be discov ered. All elements discovered since, in cluding element 43 (and, it is believed, all elements likely to be discovered in the future), are radioactive. Noddack, Tacke, and Berg also an nounced the discovery of element 43 and called it “masurium” after a region in East Prussia. This, however, turned out to be an error. In 1926 Noddack and Tacke married and together they continued research on rhenium.
[1167] SZENT-GYORGYI, Albert (shent-jee-awr'j ee) Hungarian-American biochemist
tember 16, 1893 Szent-Gyorgyi’s full name is Albert Szent-Gyorgyi von Nagyrapolt, and the odd Hungarian spelling of the middle portion should not be allowed to obscure the fact that in English it would be sim ply Saint George. He was bom into a family of noted scientists but was him self an indifferent student at first. He was receiving top honors by the time he finished high school, however. Szent-Gyorgyi spent the early years of World War I in the Austrian army, was decorated for bravery, but seeing no sense to the war, deliberately wounded himself and returned to his studies. He obtained his medical degree in 1917 at the University of Budapest. The Austrian defeat in 1918 impover ished the family and Szent-Gyorgyi fol lowed the call of further education abroad. During the 1920s he studied under Michaelis [1033] in Berlin and under Kendall [1105] at the Mayo Clinic in the United States. He obtained his Ph.D. at Cambridge University in 1927 and in 1932 he returned to Hungary as president of the University of Szeged. In 1928, while still at Cambridge and working in Hopkins’s [912] laboratory, Szent-Gyorgyi isolated a substance from adrenal glands (whose function he was investigating). TTiis substance easily lost and regained hydrogen atoms and was therefore a hydrogen carrier. Since its molecule seemed to possess six carbon atoms, Szent-Gyorgyi named it hex- uronic acid (“hex” is “six” in Greek). He also obtained it from cabbages and oranges, both rich in vitamin C. This caused him to suspect it might actually be the vitamin. In this, however, he was anticipated, for in 1932 King [1193] re ported the isolation of vitamin C and found it to be identical to hexuronic acid. He reported this only two weeks before Szent-Gyorgyi could make a simi lar announcement. The 1930s were the golden decade of vitamin research, with men like Williams [1104] performing prodigies, and Szent- Gyorgyi doing his bit too. He studied how ascorbic acid was used in the body and noted a rich source for it in Hun garian paprika (the town of Szeged, where he worked, was the center of the paprika-growing area). In 1936 he iso lated certain flavones, which had the property of altering the permeability of capillaries—the ease, that is, with which 741
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substances could pass through the capil lary walls. Whether these are actually vi tamins is doubtful but, for a time at least, they were referred to as vitamin P. Szent-Gyorgyi also studied the oxygen uptake of minced muscle tissue, using Warburg’s [1089] methods. If the system was untouched, the rate of oxygen up take would die down, as some substance within the tissue was used up. Szent- Gyorgyi tried adding substances that might conceivably be located on the pathway of the overall chemical change involved in oxygen uptake, the change from lactic acid to carbon dioxide. In 1935 he found that any of four closely related four-carbon compounds—malic acid, succinic acid, fumaric acid, and oxaloacetic acid—would serve to restore activity. Since each would do it alone, it followed that the body could intercon vert them and that perhaps all four were on the pathway. Krebs [1231] continued this line of research and used Szent- Gyorgyi’s discovery, plus his own added material, to work out the Krebs cycle. For all this work, particularly that on vitamin C, Szent-Gyorgyi was awarded the 1937 Nobel Prize in medicine and physiology. He kept on working thereafter. He began to study the chemical mechanisms of contracting muscle. He found the muscle protein to consist of two loosely bound portions, actin and myosin, and named the union “actomyosin.” He worked out mechanisms whereby adeno sine triphosphate (ATP), a compound possessing Lipmann’s [1221] high-energy phosphate bonds, initiated changes lead ing to muscle contraction. His views are not conclusive, however, and the subject is still wide open. During World War II, Szent-Gyorgyi was active in the anti-Nazi underground, and incurred considerable danger, from which he was saved only by Swedish (fortunately un-neutral) aid. After the war, however, Hungary was occupied by Soviet forces and Szent-Gyorgyi felt he had earned some repose. In 1947 he emigrated to the United States and be came an American citizen in 1955. In the United States he joined the staff of the Marine Biological Laboratories at Woods Hole, Massachusetts. In the 1960s his attention turned to the thymus gland, which in 1961 had been shown to be involved in the initial establishment of the body’s im munological capabilities. Szent-Gyorgyi isolated several substances from thymus that seem to have some controlling effect on growth. His old age has seen no les sening in his fiery concern for humanity as he spoke out loudly and forcefully against the madness of war. [1168] 5PIK, Ernst Julius Soviet astronomer
part of Russia, now part of the USSR), October 23, 1893 In 1916 Opik joined the staff of the Tashkent Observatory in Uzbekistan and in 1924 he moved to the Astronomical Observatory in Tartu Estonia. After World War II he worked in Germany, in Ireland, and at the University of Mary land in the United States. His work has been primarily with me teors and in the early 1920s he worked out the theory of their entry into the at mosphere and of the effect upon them of atmospheric resistance and atmospheric heating. It is an example of how difficult it is to keep ivory-tower theory from becoming of practical use, when we con sider that these considerations of “abla tion”—the effect of heating on a heat resisting substance and the manner in which it is peeled away as a result—has proved to be of great importance in con nection with the design of nose cones and heat shields for ballistic missiles and rocket ships. [1169] DOISY, Edward Adelbert American biochemist Born: Hume, Illinois, November 13, 1893 Doisy was educated at the University of Illinois, graduating in 1914. He ob tained his doctorate at Harvard Univer sity in 1920 after a two-year delay owing 742
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to service in World War I. He joined the faculty of the St. Louis University School of Medicine in 1923 and re mained there during his professional life. The university’s department of biochem istry was named in his honor in 1955. In 1929 he was the first to prepare es trone, a female sex hormone, in crys talline form. In 1939 the group he headed worked out the chemical consti tution of two varieties of vitamin K and for this he shared with Dam [1177] the 1943 Nobel Prize in medicine and physi ology.
[1170] BOSE, Satyendranath Indian physicist Born: Calcutta, January 1, 1894 Died: Calcutta, February 4, 1974 Bose, the son of an accountant, was educated at Presidency College in Cal cutta, where Jagadischandra Bose [893] (no relation) was among his teachers. He obtained his master’s degree in math ematics in 1915 at the top of his class. A paper of his in 1924 came to the at tention of Einstein [1064], who praised it enthusiastically for its handling of Planck’s [887] quantum theory. This gave Bose entry to western Europe and in France he worked with Langevin [ 1000 ], Einstein generalized Bose’s paper and worked out a type of quantum statistics useful in considering subatomic particles that is still called Bose-Einstein statistics. Another variety worked out two years later by Fermi [1243] based on Dirac’s [1256] exclusion principle was worked out in 1926. This is Fermi-Dirac statis tics.
Subatomic particles, depending on whether they follow one set of statistics or the other, are called “bosons” or “fer mions.” The photon and other exchange- particles, for instance, are bosons. [1171] OPARIN, Alexander Ivanovich Soviet biochemist
3, 1894
Oparin graduated from Moscow Uni versity in 1917, and was professor of plant biochemistry there after 1929. Oparin is best known for his book The Origin of Life on Earth, published in 1936. The question of the origin of life on the primordial earth through the blind and random processes of physics and chemistry had been speculated upon by scientists even as far back as Darwin [554] but few were willing to spend time on a subject concerning which so little could be known (it seemed) and over which so much controversy was sure to arise. Such theories, which treated the origin of life in mechanistic fashion, were bound to offend the religious, but Oparin lived in a nation that, after 1917, was officially atheistic. He had nothing to fear from governmental piety. Postulat ing the presence of a methane/ammonia atmosphere and a source of energy in the sun, Oparin reasoned out the steps by which life might gradually have come into being. He opened the door and biochemists of the West gratefully stepped through. The work of men such as Miller [1490] and Ponnamperuma [1457] was the re sult. The Soviet government established a biochemical institute in Oparin’s honor in Moscow in 1935. In 1946 Oparin be came its director. [1172] OBERTH, Hermann Julius Austro-German engineer
(then part of Hungary, now part of Romania), June 25, 1894 Oberth, the son of a physician, studied medicine but was interrupted by World War I, during which he served in the Austro-Hungarian army. He was wounded and during a period of en forced idleness he grew interested in the problem of astronautics, becoming one of the pioneers of the field along with Tsiolkovsky [880] and Goddard [1083]. His experiments were dismissed by the Austro-Hungarian war ministry as folly, 743
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and after the war, in 1922, when he tried to get a Ph.D. at Heidelberg with a dissertation on rocket design, it was re jected. Eventually, Oberth published that dissertation, partly at his own expense, as The Rocket Into Interplanetary Space in 1934. The book achieved considerable popularity. In 1938 Oberth joined the faculty of the Technical University of Vienna and he became a German citizen in 1940. During World War II he worked with von Braun [1370] at Peenemunde. After the war he worked in Italy and then in the United States. He retired in 1958 and returned to Germany. [1173] KAPITZA, Peter Leonidovich (ka'pih-tsuh) Soviet physicist
Kapitza, the son of a tsarist general, graduated in 1919 from the Petrograd Polytechnic Institute, then for his gradu ate work traveled to England in 1921 where, as it turned out, he was to spend fourteen years. During that interval he worked in Ernest Rutherford’s [996] lab oratory, pioneering in the production of large (though temporary) magnetic fields, and was elected a member of the Royal Society, the first foreigner to be so elected in two centuries. In 1934, after one of his annual visits to the Soviet Union to see his mother, he did not return. Rutherford suspected it was a forced detention, but Kapitza re mained in the Soviet Union thereafter, apparently voluntarily. His most renowned work was in con nection with the extremely low tempera tures of liquid helium, a field first opened up by Kamerlingh Onnes [843]. Kapitza was one of those who studied the unusual properties of helium II (that is, helium in the form that exists at tem peratures below 2.2 °K, that is, within 2.2° of absolute zero). He showed he lium II conducted heat so well (eight hundred times as rapidly as copper, the best conductor at ordinary temperatures) because it flowed with remarkable ease. Helium II flows even more easily than a gas, having a viscosity only one thou sandth that of hydrogen at normal tem perature and pressure (and hydrogen is the least viscous gas). Kapitza’s work on helium II was pub lished in Moscow in 1941. This work on extremely low temperatures was then carried onward by Landau [1333]. During World War II, Kapitza at tempted to rescue his old friend Bohr [1101] from Denmark but the British were there first. Kapitza quietly refused to work on Soviet nuclear weapon re search and was kept under virtual house arrest for seven years. After Stalin’s death, however, he became extremely ac tive in space research. In the 1950s Kapitza also turned his attention, in part, to ball lightning, a puzzling phenomenon in which plasma (high-energy gas, with its atoms and molecules broken up into electrically charged fragments) maintains itself for a much longer period than seems likely. Kapitza’s analysis involves standing waves; that is, trains of waves that rein force each other and remain in being over appreciable periods of time. He was allowed to visit England in 1966 and the United States in 1969 to receive awards. For his work on low- temperature physics, Kapitza shared in the 1978 Nobel Prize in physics. [1174] Download 17.33 Mb. Do'stlaringiz bilan baham: 
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