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[1392] VAN ALLEN VAN ALLEN [1392]
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[1392] VAN ALLEN VAN ALLEN
advances in weaponry had been made during the early 1940s. The rockets that had fascinated Goddard [1083] during the decades preceding World War II fas cinated others as well. The most success ful group of rocketeers were developed in Germany and of these an important member was Wernher von Braun [1370]. During the war, these men developed the V-2 rocket for Hitler’s armies. After the war the reserves of unused V-2s fell into American hands, and under Van Allen’s leadership these were turned to research use. Equipment de signed to test cosmic ray intensity was included in the payload and results were telemetered (that is, turned into appro priate coded changes in radio signals) back to earth from the hundred miles and more of height reached by the V-2s. Here, Van Allen’s experience in minia turization stood him in good stead, for it was necessary to cram as much equip ment as possible into the very limited area in the payload that the rocket could lift far into the outer regions of the at mosphere. The V-2s were an amazing production, but they were only the first of the mis siles, the model-T, as it were. The United States took to designing new and better missiles and these were pressed into the program of research of phenom ena in the upper atmosphere as well. In 1952 Van Allen began to make use of rockoons, combinations of balloons and rockets, the idea of which had occurred to him in 1949. A rocket would be lifted into the stratosphere by a balloon and from there would fire off, on signal from the ground. With most of the atmo sphere below it, air resistance was elimi nated and a small rocket could reach heights that only a large rocket, fired from the ground, could reach. Van Allen became professor of physics at the University of Iowa in 1954 and then he and his associates began to talk of something new. A payload sent out into space by rocket could be given a ve locity and direction of flight that would take it into an orbit about the earth where it would remain for extended pe riods. It would, in effect, be a man-made satellite. Slowly, government officials were won over to the scientific impor tance of such an enterprise. In 1955 President Dwight D. Eisenhower of ficially announced that within two years such an artificial satellite would be launched. This was to be in conjunction with the International Geophysical Year (usually abbreviated IGY), which was to run from July 1, 1957, to December 31, 1958, during one of those peaks of solar sunspot activity first brought to the at tention of scientists by Schwabe [466] a century before. This was to be a pro gram of research designed on a vast in ternational scale, a truly global effort, in which not only the globe itself (includ ing its glaciers, its polar regions, and its atmosphere) but even nearby space were to be explored. It all turned out to be an extremely successful affair, too successful in some respects for American peace of mind. The Soviet Union took a major part in the IGY and announced that it too would place satellites in orbit. The United States government, public, and even scientists paid little attention to this, however. Little was known about Soviet efforts in science and, specifically, in rocket research, and much was thought to be known concerning Soviet backwardness. It therefore came as a shock to all seg ments of American society when the So viet Union proved as good as its word and sent up the first artificial satellite (Sputnik I—“sputnik” being the Russian word for “satellite’’) on October 4, 1957. The Soviets had scheduled it for the cen tenary of the birth of Tsiolkovsky [880], and said as much in advance, and were only a month late. They sent up the sec ond artificial satellite (Sputnik II), car rying a dog, a month later. Although the United States went through an unedifying period of panic, the event proved salutary. It is doubtful if the public, or Congress, for that mat ter, would have been willing to endure the expense involved in space explora tion, did they not view it in the ignoble light of an item in the cold war with the Soviet Union. Van Allen was on a ship in the South 851
[1392] VAN ALLEN VAN ALLEN
Pacific, on his way toward Antarctica, when the news of the Soviet satellite came through. He hurried back to the United States to participate in American efforts to hasten its own satellites. The American Vanguard program, designed to send up the satellites announced by Eisenhower, proved an expensive fiasco for the most part (though it did score one important success). The army, how ever, using Von Braun (whom the United States inherited from the defunct Nazi war machine) finally sent up Ex plorer I, the first American satellite, on January 31, 1958. Its payload was much smaller than that of the Sputniks, but this was made up for by Van Allen’s miniaturization, which packed the smaller payload with a surprising quan tity of sophisticated instrumentation. The age of space, which opened with Sputnik I, was to bring the promise of technological advance of breathtaking magnitudes, as in the communications satellites pioneered by Pierce [1351]. It was also to bring new information about the earth itself, as O’Keefe [1412] was to show. It was to promise improved weather forecasting through observations of the cloud cover and atmospheric movements of the planet as a whole, as seen from space. It even brought back new information concerning other worlds, such as the map of the other side of the moon, first sent back in October 1959 by a Soviet “lunar probe,” and in formation concerning Venus sent back by an American “Venus probe” in De cember 1962. One piece of startling information in the early years of the space age came from the first Explorers of 1958 and the work of Van Allen. Van Allen’s interest in cosmic rays made it certain that Ex plorer I carried instruments designed to check the cosmic ray count (and that of other energetic particles) of nearby space. The counters reached a surpris ingly high level, then went dead. The same was true of a more rugged counter on Explorer III, which was launched in March 1958. Van Allen’s previous work led him to suspect that the counters had stopped working not because the particle count had fallen to zero, but because it had gone too high for the counter to handle. He designed a counter with a lead shield that would only accept a small fraction of the particles (like a man wearing tinted glasses to ward off light that is too bright). Such a counter went up with Explorer IV on July 26, 1958, and the results were conclusive. There was far more high-energy radiation in nearby space than anyone had dreamed. The regions of high-energy radiation encircle the earth in the neighborhood of the equator, curving in toward the polar regions, which are themselves relatively free. These belts of radiation are popu larly called the Van Allen radiation belts, though in the early 1960s the term magnetosphere was accepted as the for mal name. From the shape of the magnetosphere it seemed likely that the particles making it up were trapped in the earth’s mag netic field, spiraling about the magnetic lines of force from pole to pole (mag netic lines which Elsasser [1279] at tributed to events far in the earth’s inte rior). This was tested in August 1958 by exploding an atomic bomb several hun dred miles above the earth’s surface, in an experiment referred to as Project Argus. The distribution of the charged particles produced by the bomb showed conclusively that the magnetic field was the determining factor in the formation of the magnetosphere and that, indeed, gave the belts this name. Other such high-altitude tests, backed by Van Allen at first, succeeded in 1962 in producing changes in the magnetosphere, a result generally deplored by the scientific com munity.
The magnetosphere and, even more so, the sudden and unpredictable increases in radiation intensity produced by solar flares, seemed to pose a difficult problem as far as the manned exploration of space is concerned. The orbital flight of Gagarin [1502] and those who followed him showed that man is reasonably safe in the immediate neighborhood of the earth, and, twelve years later, Armstrong [1492] touched down on the moon. 8 5 2
[1393] SALK
HOFSTADTER [1395] [1393] SALK, Jonas Edward American microbiologist
tober 28, 1914 Salk, the son of a Polish-Jewish gar ment worker, graduated from the Col lege of the City of New York in 1934 and went on to obtain a medical degree in 1939 from New York University Col lege of Medicine. Through the 1940s he served on the faculty first of the Univer sity of Michigan School of Public Health, then of the University of Pitts burgh School of Medicine. After the Enders [1195] group had shown the way to culture polio virus and make quantities available for experi mentation, Salk began his attempts to kill the virus in such a way as to make it incapable of causing the disease but ca pable of producing antibodies that would then be active against living polio virus. By 1952 he had prepared a vaccine he dared try on children who had recovered from polio and who would therefore be resistant to infection. The vaccine in creased the antibody content of the chil dren’s blood and so seemed effective. He then tried it on children without a his tory of polio and was again successful. In 1954 the vaccine was prepared in quantity. By 1955 the news of the Salk vaccine broke and there was certainly the biggest medical brouhaha since Jenner [348] first discovered smallpox vaccination a cen tury and a half earlier. The newspaper headlines and the wild publicity resulted in the overhasty use of some vaccine samples that were prepared with insuffi ciently stringent precautions. Some two hundred cases of polio were caused by vaccine injections, with eleven deaths. The vast majority of inoculations did no harm, however, and greater care pre vented such sad events in succeeding years. With the Sabin [1311] vaccine as another weapon in the armory, poliomy elitis had, within a decade, ebbed to only a twentieth of its previous incidence. In 1963 Salk became director of the Salk Institute for Biological Studies at San Diego, California. [1394] SYNGE, Richard Laurence Mil lington (sing) English biochemist Born: Liverpool, October 28, 1914
Like Martin [1350], Synge, the son of a stockbroker, studied at Cambridge University, graduating in 1936 and ob taining his Ph.D. in 1941. He spent the years from 1936 to 1939 in Hopkins’s [912] laboratory. He is chiefly known for his collabo ration with Martin in the development of paper chromatography, work for which he shared with Martin the 1952 Nobel Prize in chemistry. Since 1948 he has been at the Rowett Research Institute in Scotland. He used paper chromatography to work out the exact structure of the very simple mole cule (for a protein) of Gramicidin S. This led directly to the work of Sanger [1426],
[1395] HOFSTADTER, Robert American physicist Born: New York, New York, February 5, 1915 Hofstadter was educated at the Col lege of the City of New York, from which he graduated magna cum laude in 1935. He did graduate work at Princeton University, receiving his Ph.D. in 1938. During World War II he worked on Van Allen’s [1392] proximity fuze for the National Bureau of Standards. After serving on the faculty of Princeton Uni versity, Hofstadter accepted a position as professor of physics at Stanford Univer sity in 1950, becoming head of the de partment in 1954. At Stanford he had an opportunity to make use of the university’s large “linear accelerator.” This accelerated particles by moving them, with successive pushes, in a straight line, rather than in a spiral as was the case with Lawrence’s [1241] cyclotron, or in a circle as with Kerst’s [1367] betatron. The relativistic mass in crease does not affect the situation in straight-line acceleration so that a linear
[1395] HOFST ADTER WELLER
accelerator can be used to produce very high-energy electrons in less complicated fashion than the betatron can. (On the other hand, linear accelerators have the disadvantage of taking up tremendous quantities of space; it can easily be two miles long, or more. For this reason, al though it is one of the earliest types of particle accelerator invented, the “linac” is built less frequently than the various members of the cyclotron family.) Hofstadter studied the scattering effects imposed on high-energy electrons by atomic nuclei and from those effects deduced information about the structure of the nucleus. The more energetic the electrons, the closer they approached the nucleus before bouncing or veering off, and the more sharply details could be deduced. By 1960 he was using electrons ener getic enough to enable him to “see” within individual protons and neutrons. In 1961 he announced that the protons and neutrons were made up of a central core of positively charged matter, about which were two shells of mesonic mate rial. In the proton, the meson shells were both positively charged. In the neutron, one of the shells was negatively charged in such a way that the overall charge was zero. From his observations Hofstadter fur ther deduced the possible existence of mesons more massive than those already known; these included what he called the rho-meson and the omega-meson. Both were shortly detected and were found to be very short-lived. The omega-meson lasts for only 0.0000000000000000000 0001 second before breaking down. In a way Hofstadter’s work represents another step in the steady progression to ward more and more fundamental knowledge. Chemistry attained a deeper and better understanding when Dalton [389] divined that matter consists of atoms and Mendeleev [705] discovered the order underlying the elements built up of those atoms. Better understanding, still, came when the structure of the atoms themselves was deduced and clarified by men like Ernest Rutherford [996]. With the mid-twentieth century, however, the list of known subatomic particles had grown lengthy and the rela tionships among them uncertain. It was time for a still more fundamental order to be uncovered and Hofstadter’s work was headed in this direction, as was Gell-Mann’s [1487]. For his work Hofstadter received the 1961 Nobel Prize in physics, sharing it with Mossbauer [1483]. [1396] MEDAWAR, Sir Peter Brian English biologist
British parents), February 28, 1915 Medawar studied at Oxford Univer sity, graduating in 1939 and obtaining his doctorate in 1948. By that time he was serving as a professor of zoology at the University of Birmingham. He trans ferred to the University of London in 1951. Acting on Burnet’s [1223] sugges tion, Medawar inoculated the embryos of mice with tissue cells from another strain, hoping that the embryos had not yet gained the ability to form antibodies against it. If so, then by the time the em bryo entered independent life and could form antibodies, the “foreign” proteins might no longer be treated as foreign. This turned out to be the case. Once the embryo mice entered independent life, they were able to accept skin grafts from those strains of mice with which they had been inoculated in embryo. For this discovery Medawar shared the 1960 Nobel Prize in medicine and physiology with Burnet. [1397] WELLER, Thomas Huckle American microbiologist Born: Ann Arbor, Michigan, June 15, 1915 Weller was the son of a professor of pathology at the University of Michigan, and there he received his college educa tion, graduating in 1936. He then en tered Harvard University Medical School and obtained his medical degree in 1940. 854 [1398] HOYLE
TOWNES [1400] During World War II he served as a medical officer in Puerto Rico, but with the end of the war he returned to Har vard and joined Enders’ [1195] group. He shared the 1954 Nobel Prize in medi cine and physiology with Enders and Robbins [1410], He was also the first to discover how to grow the German measles virus in the laboratory and how to isolate the chicken pox virus. [1398] HOYLE, Sir Fred English astronomer Born: Bingley, Yorkshire, June 24, 1915 Hoyle obtained his master’s degree from Cambridge University in 1939, and during World War II worked on radar development. He returned to Cambridge in 1945 and is a professor of astronomy there.
He has accepted Gold’s [1437] con tinuous creation theory and expounded it in several books for laymen. (In this re spect, he is a worthy successor to those other astronomer-writers, Jeans [1053] and Eddington [1085]. In fact, Hoyle has gone further and is perhaps the most eminent of those contemporary scientists who have written science fiction under their own names.) Hoyle has described a scheme of nu clear reactions within stellar interiors, which goes far past the hydrogen-to- helium mechanism elaborated by Bethe [1308], Hoyle suggests that the helium nucleus itself, once the temperature reaches a high-enough point, “burns” further to produce nuclei of carbon and oxygen. Still more “burning” produces magnesium, sulfur, and other elements up to iron. Iron is the limit, for in its atoms the energy content is at a mini mum and it cannot take part in energy- yielding nuclear reactions. A point is then reached, according to Hoyle, where gravitation is no longer countered by radiation pressure and the star collapses catastrophically, in a mat ter of minutes, to the white dwarf stage. Such lower elements as remain in the star’s outer layers “ignite” to form a supernova explosion (if the star is mas sive enough) and the energy released forms the heavy atoms beyond iron. Out of the thin gas strewn through space by supernovas, “second-generation stars” rich in the heavier atoms are formed. In 1946 Hoyle suggested that the sun was originally a double star and that the companion had blown itself up, leaving the planets behind, richer in the heavier elements than the remaining sun is. He also suggested, in the late 1970s, that interstellar dust clouds and comets might include actual life forms and that cometary pollution, so to speak, may be the cause of sudden pandemics on earth. This is not taken seriously by most scien tists. [1399] BARGHOORN, Elso Sterrenberg (barg-hawm) American paleontologist Born: New York, New York, June 30, 1915 Barghoorn obtained his Ph.D. from Harvard University in 1941 and, after his early teaching stints, joined the fac ulty of Harvard in 1946 and became a full professor of botany in 1955. He has been particularly interested in fossil plants, and the work for which he is best known is his analysis of tiny bits of carbonized material in ancient rocks, which seem to be the remains of ancient and primitive fossil cells. If Barghoorn’s notions of this “pre-Cambrian” life are correct, and many scientists think they are, then the record of life has been traced back for over 3 billion years, or to the point where the earth was not yet 1.5 billion years old. [1400] TOWNES, Charles Hard American physicist
July 28, 1915 Townes, the son of an attorney, at tended Furman University in his home town, graduating summa cum laude in
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