Biographical encyclopedia
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[1141] BRAGG
BRAGG [1141]
proach to within 16 million miles of the earth, two-thirds the distance of Venus at its closest and only half the distance of Mars.
A long, detailed program was set up. Fourteen observatories in nine countries took part. Seven months were spent on the project and nearly three thousand photographs were taken. The position of Eros was determined on each one of them. Ten years of calculations, under the leadership of Jones (who in 1933 had been appointed astronomer royal), followed. In 1942 Jones finally published the result as 93,005,000; and the dis tance of the sun had been established with greater accuracy than ever before, to one part in ten thousand, in fact. Jones was knighted in 1943 for this. His mark was not improved until the late 1950s when pulses of radar were sent out to strike Venus and bounce back. From the time lapse between pulse and echo, still more accurate figures for the scale of the solar system were obtained. Under Jones, the Greenwich Observa tory moved from the time-honored head quarters it had occupied since Flam steed’s [234] time two and a half cen turies earlier. The growth of London had engulfed Greenwich with smog and pol lution and made the site unfit for astro nomical work. After World War II, therefore, the observatory was moved to Sussex, and Jones moved with it, staying till his retirement in 1955. [1141] BRAGG, Sir William Lawrence Australian-English physicist Born: Adelaide, Australia, March 31, 1890 Died: Ipswich, England, July 1, 1971
William Lawrence Bragg was the son of William Henry Bragg [922] and was born while his father was teaching at Adelaide University. He was an infant prodigy and, like his father, he studied mathematics and physics, entering the University of Adelaide at the age of fifteen and getting an honors degree at eighteen. He then entered Trinity Col lege, Cambridge, where he studied under Wilson [979]. While still a student he was intrigued by the work of Laue [1068], who had diffracted X rays by passing them through a crystal. Although he was at Cambridge and his father at Leeds, they labored together on the problem (after discussing the subject during a summer vacation). They worked out the mathematical de tails involved in the diffraction, showed how to calculate wavelengths of the X rays, and deduced certain facts concern ing crystal structure from the manner of the X-ray diffraction. For instance, it was possible to show that crystals of sub stances such as sodium chloride con tained no actual molecules of sodium chloride but only sodium ions and chloride ions arranged with geometric regularity. In the case of sodium chloride, each sodium ion was equidis tant from six chloride ions while each chloride ion was equidistant from six sodium ions. There was no particular connection between one individual so dium ion and one individual chloride ion.
This had a profound effect on theoret ical chemistry and led, for instance, to Debye’s [1094] new treatment of ion dissociation. The results of the experiments were published in 1915 under the joint names of father and son, and they shared the Nobel Prize in physics for that year. The son achieved the unusual feat of becom ing a Nobel Prize winner at the age of twenty-five, the youngest ever to receive such an award. He lived to celebrate the fifty-fifth anniversary of the award, also a record. After the war, during which he served in the artillery, Bragg proposed the no tion of “ionic radii,” which was to prove quite fruitful in connection with Pau ling’s [1236] theory of resonance. In 1919 William Lawrence Bragg ac cepted a professorship of physics at Manchester University. In 1938 he be came professor of physics at Cambridge and director of the Cavendish Labora tory, succeeding Rutherford [996] in that post and remaining there till 1953. In 724
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later years he was particulary interested in lecturing on science to young people. He was knighted in 1941 and retired in 1965. [1142] FISHER, Sir Ronald Aylmer English biologist Born: London, February 17, 1890 Died: Adelaide, Australia, July 29, 1962 Fisher was the son of an auctioneer and the surviving member of a pair of twins. He graduated from Cambridge in 1912 and channeled his mathematical talents and interests into the field of statistics and, through that, genetics. He placed on a much firmer footing methods for sampling in order to achieve full randomization, and methods for varying different factors in an experi ment (“analysis of variance”). Fisher particularly considered the statistical na ture of inheritance according to Mendel's [638] laws and showed that it fit Dar win’s [554] doctrine of natural selection. He labored to make sense out of blood group inheritance and clarified the man ner of inheritance of the Rh blood-group series. He was knighted in 1952. In 1959, upon his retirement, he emigrated to Australia. [1143] ARMSTRONG, Edwin Howard American electrical engineer Born: New York, New York, December 18, 1890 Died: New York, February 1, 1954
In his teens, Armstrong read the story of Marconi [1025] and his experiments in popular books of science, and before he was twenty he was building his own radio transmitter and broadcasting sig nals with it. He went on to Columbia University and earned a degree in elec trical engineering in 1913, studying under Pupin [891]. In 1912, while still but in his third year at Columbia, he devised the “regenerative circuit,” which supplied radio with its first amplifying receiver and reliable transmitter. During World War I, Armstrong, then a Signal Corps officer, grew interested in methods of detecting airplanes. Existing systems, developed by Fessenden [958], detected them by the sound waves they emitted but Armstrong believed it might be more sensitive and efficient to detect the electromagnetic waves set up by their ignition systems. Those waves were too high in frequency to be received easily, so Armstrong devised a circuit that low ered the frequency, then amplified that. He named it a superheterodyne receiver. Actually, this was developed too late to play a role in the war (although it was used in radar equipment in World War H), but it could be used for recep tion of any radio waves, and with it radio sets became easy to use. It was no longer necessary to be an electrical engi neer to tune in radio signals. With super heterodyning added to the radio, it could be done by the twist of a dial. Radio sets became hugely popular. Armstrong returned to Columbia after the war and found himself a millionaire. However, there was long and messy liti gation with De Forest [1017] over who owned the patent for the regenerative circuit. Armstrong lost the case after fourteen years and two appeals to the Supreme Court, but the scientific com munity seemed to feel the judgment was in error. Armstrong’s greatest triumph was still ahead of him. In 1934 he became pro fessor of electrical engineering at Colum bia and in 1939, after six years of labor, he defeated the problem of static. In ordinary radio sets, signals are car ried by systematic alteration of the am plitude of the carrier signal, the alteration following the variation in amplitude of the sound waves being transmitted. This is amplitude modulation, or AM. Unfor tunately, thunderstorms and electrical appliances also modulate the amplitude of the carrier wave, doing it randomly. This random modulation is, of course, converted into random sound at the re ceiver; in other words, static. Armstrong devised a method of trans 725
[1144] HEYROVSKf MULLER [1145]
mitting a signal by systematic alteration of the frequency of the carrier signal. This is frequency modulation, or FM, and it virtually eliminated static. FM radio came into popularity after World War II, particularly for programs of seri ous music, and it is also used in the sound circuits of television sets. Unfortu nately FM will work only for carrier waves of high frequency and these can not be transmitted much beyond the ho rizon. The area of reception for a given FM transmitting station is therefore lim ited—and again there was patent litiga tion. Armstrong, a contentious man, made a great deal of money but lost it all in un fortunate business and legal mis adventures. He was increasingly certain there was a conspiracy against him and in 1954, in a fit of depression or despair, he jumped to his death from his apart ment window. [1144] HEYROVSKY, Jaroslav (hay- rof'skee) Czech physical chemist Born: Prague, Czechoslovakia (then part of Austria-Hungary), December 20, 1890
Heyrovsky, the son of a professor of law, studied at the University of Prague and then, between 1910 and 1913, in London. He was on holiday in Prague when World War I broke out, so he could not return to London. He served in the Austro-Hungarian army, but managed to obtain his Ph.D. in 1918. He did postdoctoral work in London, where he worked under Ram say [832] and in 1926 joined the staff of the University of Prague, reaching the rank of professor of physical chemistry in 1926. Beginning in 1918, and inspired by a question asked of him on his doctoral examination, Heyrovsky worked out a device whereby an electric potential could be put across mercury electrodes that were so arranged that a small drop of mercury was repeatedly falling through a solution to a mercury pool below. An electric current flowed through the solution and as the potential was heightened, the current reached a plateau that depended on the concen tration of certain ions in the solution. By measuring this plateau, one could deter mine the concentration of those ions in a solution of unknown composition. The theory had been worked out a generation earlier by Nernst [936], but now Heyrovsky had put it to work as “po- larography,” a word he coined in 1925. It proved a very delicate analytical tool. The Polarographic Institute was founded by Czechoslovakia in 1950 and Heyrovsky, who had managed to con tinue his work even during the German occupation (thanks to the protection of a courageous German co-worker), was made its director. The technique was not properly appreciated at first and it was not till 1959 that Heyrovsky was awarded the Nobel Prize in chemistry. [1145] MULLER, Hermann Joseph American biologist Born: New York, New York, December 21, 1890 Died: Indianapolis, Indiana, April 5, 1967 Muller founded what was probably the first high school science club at Morris High School in the Bronx, New York. He entered Columbia University on a scholarship in 1907 and carried on through to his doctorate in 1916. In 1911 he began work, under T. H. Morgan [957], on the genetics of the fruit fly and had ample opportunity to see how mutations appear. Muller, how ever, was impatient with waiting; he believed that geneticists did not neces sarily have to. When he began independent research he sought methods of hastening the rate of mutation. He found in 1919, for in stance, that raising the temperature in creased the number of mutations. Fur thermore, this was not the result of a general “stirring up” of the genes. It al ways turned out that one gene might be
[1145] MULLER
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affected while its duplicate on the other chromosome of the pair (chromosomes occur in pairs) was not. Muller decided, consequently, that changes on the molec ular or submolecular level were involved, changes that were hastened by heat. It occurred to him to try X rays. They were more energetic than gentle heat, and on striking a chromosome they would certainly have an effect on a point. By 1926 he could see that he had hit home. X rays greatly increased the mutation rate. This served several useful purposes. First, it increased the number of mutations that geneticists could study in a given time. Second, it showed that there was nothing mystical about a mutation; it was but the result of a chemical change that man could himself initiate. (In fact, Blakeslee [1029] was soon to show that ordinary chemicals, and not just radiation, could bring about mutations.) This pointed the way toward the work of molecular biologists like Crick [1406] a quarter century later. Eventually Muller received the honor due him: He was awarded the 1946 Nobel Prize in medicine and physiology. In the early 1930s Muller went to Germany but left with the rise of Hitler. (Muller was of part-Jewish descent.) He then went to the USSR at the invitation of Vavilov [1122] but left in 1937, after openly opposing Lysenko’s [1214] views on genetics. Muller’s studies of mutations had con vinced him that the vast majority were deleterious. To be sure, in the course of evolution the few useful ones survive and the deleterious ones tend to die out, but for this to continue, there must not be too many deleterious ones. If the mu tation rate is increased, the absolute numbers of imperfect individuals may become too great for species survival. Muller therefore began to work in two areas. First, he tirelessly warned against needless X-ray therapy and diagnosis in medicine. It was well known that expo sure to hard radiation could cause cancer —which, from his standpoint, was a mu tation in which a normal cell became cancerous. However, Muller was con cerned about ordinary mutations, too, and wanted to see that gonads were effectively shielded in all those exposed to X rays under either medical or indus trial circumstances. After World War II, Muller was particularly active in point ing up the danger of a rising mutation rate because of radioactive fallout from nuclear bomb tests and in 1955 joined seven other scientists including Einstein [1064] in a plea to outlaw nuclear bombs.
Second, Muller, like a latter-day Gal ton [636], but with far more genetic in formation at his disposal, pushed for some sort of eugenic measures to im prove the genetic health of the human species. One imaginative notion that he strongly supported was the establishment of sperm banks so that the genetic en dowment of gifted men could be widely spread through space and time. [1146] BOTHE, Walther Wilhelm Georg Franz (boh'tuh) German physicist
January 8, 1891 Died: Heidelberg, February 8, 1957
Bothe, the son of a merchant, obtained his education at the University of Berlin, studying under Planck [887] and obtain ing his doctorate in 1914. He taught at Berlin after graduation with some time off for service during World War I (most of which he spent as a prisoner of war in Russia), then went on to profes sorial positions at Giessen and at Heidel berg, where he worked with Geiger [1082]. In 1934 he became director of the Max Planck Institute for Medical Research. In 1929 he devised a method of study ing cosmic rays by placing two Geiger counters one above the other and setting up a circuit that would record an event only if both counters recorded virtually simultaneously. This would happen only if a cosmic ray particle, streaking down from above, shot vertically through both counters. Other particles would be com ing from some other direction and would 727
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pass through one counter and not the other, or, if coming from the right direc tion would be insufficiently energetic to go through both. Such “coincidence counting” turned out to be very useful in measuring short intervals of time. Such times, a billionth of a second and less, were still long enough to allow much to happen on a subatomic scale. He used this technique to demonstrate that the laws of conser vation of energy and of momentum were as valid for atoms as for billiard balls. For devising this method of coinci dence counting and for the research re sults obtained with it, Bothe received a share, along with Born [1084], of the 1954 Nobel Prize in physics. Even a successful scientist is not al ways successful. In 1930 Bothe had re ported that strange radiations were emerging from beryllium exposed to bombardment with alpha particles. He did not, however, interpret the meaning of his results properly. Neither did the Joliot-Curies [1204, 1227], who repeated the experiment, and it was left to Chad wick [1150] to discover the neutron. In 1944 Bothe constructed Germany’s first cyclotron, an instrument first de vised by Lawrence [1241] in the previous decade.
[1147] JEFFREYS, Sir Harold English astronomer Born: Fatfield, Durham, April 22, 1891
Jeffreys studied at St. John’s College at Cambridge and is best known for his col laboration with Jeans [1053] in working out the tidal hypothesis for the origin of the earth. Where men such as Helmholtz [631] and Kelvin [652] had spoken of the earth’s age in terms of tens of millions of years, Jeffreys was among the first to raise the ante to several billions. He also demonstrated that the giant outer planets, Jupiter, Saturn, Uranus, and Neptune, have frigid surface temper atures, and are not, as some thought, still warm from interior heat. He was knighted in 1953. [1148] NORTHROP, John Howard American biochemist Born: Yonkers, New York, July 5, 1891 Northrop was the son of a zoology in structor at Columbia University, one who was killed in a laboratory explosion. This did not prevent the son from fol lowing a scientific career. He obtained his Ph.D. in 1915 at Columbia and then joined the Rockefeller Institute for Med ical Research (now Rockefeller Univer sity) working under Loeb [896]. After Sumner’s [1120] discovery of crystalline urease, Northrop began the work that broke the back of the enzyme controversy. By 1930 he had crystallized pepsin, the protein-splitting digestive en zyme in gastric secretions. In 1932 he announced the crystallization of trypsin and in 1935 that of chymotrypsin, both protein-splitting digestive enzymes of the pancreatic secretions. He purified them and studied them carefully and since then dozens of enzymes have been crys tallized by a number of researchers and all have proved to be proteins. With the work of Sumner and Northrop, enzymes ceased altogether to be mysterious substances but came to possess a known chemical nature. Northrop shared with Sumner and with Stanley [1282] the 1946 Nobel Prize in chemistry. [1149] HUMASON, Milton La Salle American astronomer Born: Dodge Center, Minnesota, August 19, 1891 Died: Mendocino, California, June 18, 1972 Humason entered astronomy by the back door, beginning his career as a jani tor at the Mount Wilson Observatory. Working with Hubble [1136] who rec ognized his talent, and continuing in the investigation of distant galaxies, Huma son measured the speed of recession of about eight hundred galaxies, some as distant as 200 million light-years. In 1956 he and others, making use of new 7 2 8
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data, refined Hubble’s law (that the speed of recession of a galaxy is propor tional to distance) in order to allow a greater speed of recession in the far past. This would fit in with the “big bang” theory of Lemaitre [1174] and Gamow [1278] and not with the continuous cre ation theory of Thomas Gold [1437]. Early in his career, in 1919, he en gaged in a search for a planet beyond Neptune at the request of Pickering [885]. He failed through an odd and frustrating accident. It later turned out that the image of Pluto, the sought-for planet, had actually been obtained but had fallen on a small flaw in the photo graphic plate. The discovery had to wait eleven additional years for Tombaugh [1299]. [1150] CHADWICK, Sir James English physicist Born: Manchester, Lancashire, October 20, 1891 Died: Cambridge, July 24, 1974 Chadwick was educated at the Univer sity of Manchester and after graduating in 1911 worked under Ernest Rutherford [996], who was teaching there at the time. In 1913 he was awarded the same scholarship that had brought Rutherford from New Zealand to England eighteen years before. Chadwick allowed it to carry him to Germany, where he in tended to work with Geiger [1082], Un fortunately World War I broke out and he found himself an enemy alien in terned for the duration. In 1919 he was back in England, doing research at Cambridge. He worked with Rutherford again on the bombard ment of elements with alpha particles. In 1920 he used the data gained in these experiments to calculate the positive charge on the nuclei of some atoms and his results fitted nicely into the theory of atomic numbers worked out by Moseley
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