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526 [815] KAPTEYN
KAPTEYN [815] later, however, Mohoroviiic [871] was to obtain more constructive results. In addition to various British honors, Milne received the Order of the Rising Sun from the Japanese emperor. [815] KAPTEYN, Jacobus Cornelius (kahp-tine') Dutch astronomer
1851
Died: Amsterdam, June 18, 1922 In 1878 Kapteyn, the son of a school master, who had graduated from the University of Utrecht, was appointed professor of astronomy at the University of Groningen, and thereafter he spent a dozen years painstakingly measuring and recording the positions and brightnesses of the stars of the southern hemisphere. (These were always less well known than those of the northern hemisphere, which had been visible to the eyes of civilized man for six thousand years, and where 90 percent of the population, and virtually all of the observatories, were to be found.) Kapteyn used Gill’s [763] photographs and after ten years published a catalog of 454,000 stars within 19° of the South Celestial Pole. He used his mass studies of stars to elicit information concerning our galaxy. For instance, he decided to count stars as Herschel [321] had done a century earlier and to determine, from the num ber of stars to be found in varying direc tions, the shape of the galaxy. Telescopes were better than in Herschel’s day and the task might have been unbearably te dious had not Kapteyn decided in 1906 that random areas of the sky be selected and the stars within those areas only be counted. It would amount to a straw poll of the heavens and, indeed, Kapteyn may be considered the originator of sta tistical astronomy. Many observatories collaborated. In the last year of his life, Kapteyn was able to announce the shape of our galaxy as deduced from these counts. He con cluded, as Herschel had before him, that it was a lens-shaped object with our sun located near the center. His notion of the size of the galaxy, however, was nine times the size of Herschel’s estimate, for he believed it to be 55,000 light-years in diameter and 11,000 light-years thick. (A light-year is the distance traveled by light in one year, or 5,880,000,000,000 miles.)
This galactic model clashed, however, with another that was being proposed by Harlow Shapley [1102]. Kapteyn died too soon to see the disagreement re solved in favor of Shapley. Kapteyn’s interest in the stars on a mass basis led him also to study their proper motions. One star studied by Kapteyn, now called Kapteyn’s star, has the second most rapid proper motion known. Only Barnard’s [883] star moves more quickly. The motions of the stars had first been detected by Halley [238] and by studying the proper motions of various stars, Herschel had been able to show that the sun itself was moving through space. However, down to Kap teyn’s time the general feeling had been that the proper motions of the various stars were distributed randomly, that the stars resembled an aimlessly moving swarm of bees. Kapteyn, however, discovered that some of the stars of the Big Dipper, plus a number of other stars widely scattered over the skies, were all moving in the same direction at about the same veloc ity. By 1904, in fact, he had found that the stars could be divided into two streams, moving in opposite directions, three fifths of them in one direction, two fifths in the other, a notion later ex tended to fainter stars by Eddington [1085]. In this way, our galaxy was re duced to a kind of order. Kapteyn him self did not penetrate the meaning of his results; this was done a quarter century later by Oort [1229]. Through the mass study of proper mo tions Kapteyn was able to detect in any given group of stars the common motion imposed upon all of them by the motion of our own sun. This common motion (like the landscape seeming to move backward when viewed from the win dows of a moving train) was smaller the more distant the group of stars, and by
[816] CHAMBER!. AND BEIJERINCK
this means, Kapteyn was able to deter mine stellar distances beyond the previ ous limits possible. [816] CHAMBERLAND, Charles Édouard (shahn-ber-lahn') French bacteriologist
March 12, 1851 Died: Paris, May 2, 1908 Chamberland served as an associate of Pasteur [642] from 1875. He worked on the conditions required to kill bacterial spores in order to make certain of the sterility of solutions and equipment. He brought the autoclave into use. It is an airtight heating device which could be used for temperatures above the boiling point, and it quickly became an indis pensable item for use in bacteriology laboratories, hospitals, and so on. He also improved methods of filtering out bacterial cells from solutions, pro ducing filters of unglazed porcelain that were superior to anything then in use. These Chamberland filters made possible the discovery of viruses by Ivanovsky [939] and Beijerinck [817]. [817] BEIJERINCK, Martinus Willem (by'er-ink) Dutch botanist Born: Amsterdam, March 16, 1851
Died: Gorssel, January 1, 1931 Beijerinck was the son of a tobacco dealer, who had gone bankrupt when Martinus was two. Beijerinck’s earliest scientific interest was botany, but he ma jored in chemistry at the Delft Poly technic School, where he had the finan cial help of an uncle and where Van’t Hoff [829] was a close friend. After graduating from college, he taught bot any in order to support himself and con tinued working toward his Ph.D., which he finally obtained in 1877. As a botanist Beijerinck in the early 1880s became interested in the tobacco mosaic disease, which dwarfed the to bacco plants and mottled their leaves in a mosaic pattern. He searched for a causative bacterium and found none, but the search got him interested in bacteri ology. He took a position as bacteri ologist for an industrial concern and set about learning more on the subject, trav eling about Europe at the expense of the firm. He succeeded in one respect, for he discovered one of the types of bacteria that live in nodules on leguminous plants and that convert atmospheric nitrogen into useful and soil-fertilizing com pounds. In 1895 he returned to academic life, at the Delft Polytechnic School he had once attended. There he also returned to the tobacco mosaic disease. He pressed out the juice of infected leaves but could still locate no suspicious bacteria, nor could he grow anything in culture media. And yet the juice possessed the capacity of infecting a healthy plant. He passed it through a porcelain filter that could take out any known bacterium, even the smallest, and it was still infective. Nor was it a mere toxin, for he could infect a healthy plant and from that infect an other and from that infect another and so on, so that whatever the infective agent was, it grew and multiplied. Now, Pasteur [642] had found no caus ative agent for rabies and had specu lated on germs too small to see with the microscope, but he confined himself, in this case at least, to speculation. To be sure, Ivanovsky [939] a few years earlier had observed that tobacco mosaic dis ease could be transmitted by a filtered liquid; but he believed there was a flaw in his filter and that the disease was bac terial. It was Beijerinck who, in 1898, published his observations and boldly stated that tobacco mosaic disease was caused by an infective agent that was not bacterial. He believed the liquid itself was alive and he called the disease agent a “filterable virus”; virus is but Latin for “poison.” In this way he discovered the class of disease agents that cause not only ail ments of plants and animals, but also polio, mumps, chickenpox, influenza, the common cold, and a number of other diseases among man. It took another generation, however, with a line of re-
[818] MAUNDER
LODGE [820] search climaxing in that of Stanley [1282] a few years after Beijerinck’s death to show that the virus was not liquid but consisted of particles. [818] MAUNDER, Edward Walter English astronomer
Maunder was appointed as assistant in the Royal Observatory at Greenwich in 1873 after passing a civil service test in photography and spectroscopy. Until then, Greenwich had been concerned chiefly with positional astronomy; now it entered into the world of astrophysics. Maunder worked at the observatory for forty years, dealing largely with pho tographing the sun and studying sun spots. He interested himself in the his tory of astronomy, too, and there he came across something that proved more important than any of his current re search. He found that through the period from 1645 to 1715 there was a remark able lack of reports on sunspots, al though there were ample reports before 1645 and (of course) after 1715. He suggested that this was due not to faulty reporting but to an actual dearth of sunspots during that period. This was not taken seriously at the time the report was issued, but in re cent years additional researches have confirmed Maunder’s findings and now the existence of Maunder minima, pe riods of many decades in length during which the sun is relatively free of spots, is well accepted. [819] BERLINER, Emile (behr-lee'ner) German-American inventor
20, 1851 Died: Washington, D.C., August 3, 1929
Berliner was educated in Germany, where he worked as an apprentice printer, and in 1870 came to the United States. He worked as chief inspector for the Bell Telephone Company, which was then rapidly exploiting BeU’s [789] in vention. In 1877 Berliner patented a ver sion of the modem mouthpiece two weeks before Edison [788] patented what was virtually the same thing. Edison re tained patent rights but not until after fifteen years of litigation. In 1904 Berliner scored a more definite victory over Edison: He devised the flat phonograph record in which the needle vibrated from side to side. Its greater compactness allowed it to replace Edison’s cylinder (with a needle vibrat ing up and down) almost at once. And indeed the familiar “platters” of today are of Berliner’s design. In the early decades of the twentieth century, he was one of those who turned their attention to aeronautics, and he did useful work on airplane motors. He also carried on a vigorous campaign against the use of raw milk and in favor of com pulsory pasteurization, a campaign that was carried through to victory to the great benefit of the health of Americans. [820] LODGE, Sir Oliver Joseph English physicist Born: Penkhull, Staffordshire, June 12, 1851 Died: Lake, near Salisbury, Wilt shire, August 22, 1940 Lodge, the son of a merchant, origi nally aimed for a business career but, at tracted to science by the lectures of Tyndall [626], he entered the University of London. He obtained his doctorate in 1877 and, in 1881, was appointed pro fessor of physics at that institution. In the 1890s he grew interested in electromagnetic radiation and he con ducted experiments similar to those of Hertz [873] and Marconi [1025] but working with shorter radio waves. These made him one of the forerunners of radio communication. He was knighted in 1902 for his work in the field. He had a receptive mind and this, in the early 1900s, made him a champion of the new and radical theories of atomic structure advanced by young men like Ernest Rutherford [996] and Soddy [1052]. As early as 1894, he suggested that radio signals might be emitted from the 529 [821] FITZGERALD FITZGERALD
sun. He was correct, but it was not till half a century had passed that such sig nals were detected. After 1910, this same receptive mind involved him increasingly in an attempt to reconcile what seemed to him the di vergences between science and religion. This, in turn, led him into a fixed belief in the possibility of communicating with the dead, a belief inspired by the hope of somehow reaching his youngest son, killed during World War L He became a leader of psychical research, and is one of the prime examples of a serious scien tist entering a field that is usually the do main of quacks. [821] FITZGERALD, George Francis Irish physicist
1901
FitzGerald, a nephew of Stoney [664], received his early education from a sister of Boole [595]. In 1866, he entered Trinity College in Dublin, graduating in 1871, and in the final decades of his life served as professor of natural philosophy there. Through his efforts, he greatly ad vanced the development of technical ed ucation in Ireland. In his youth he made his mark as a scientific conservative, for he was un impressed by the theory of electromag netic radiation put forth by Maxwell [692] and even went so far as to publish a paper maintaining that it was impossi ble to produce lightlike waves by oscil lating electric forces. Not many years after this paper was published, Hertz [873] showed it could be done. Later, FitzGerald’s vision improved. When J. J. Thomson [869] demonstrated in the 1890s that the cathode rays consisted of particles far smaller than atoms, FitzGerald was one of the first to hop on the subatomic particle band wagon and to predict that vast new ad vances in knowledge of the atoms were about to be made. He was also the first to suggest that the comets were not con tinuous objects in the ordinary sense, but that even their nuclei were stony aggre gates.
He is best known, however, for his ex planation of the failure of the famous experiment performed in 1887 by Mi- chelson [835] and Morley [730]. Michel- son and Morley had failed to detect any difference in the velocity of two beams of light traveling in different directions even though, because of the earth’s sup posed motion through the ether, it was thought that such a difference in velocity ought to have existed. FitzGerald’s solution, advanced in 1895, was that the distance covered by the light beam altered with the velocity of motion of the light source in such a way as to allow the beam of light to seem to travel at the same velocity in all directions. Thus, when by ordinary New tonian mechanics one might expect that a beam of light would move more slowly over a certain distance because of the motion of the light source, the distance contracts just enough to cause the light beam to save the necessary time to make it appear to be moving at only its usual velocity. FitzGerald presented a simple formula to describe the amount of con traction of distance with velocity of mo tion that would just cancel out what would otherwise be differences in light’s velocity. All material objects would have to be contracted as well, but such con traction is only perceptible at vast speeds. Thus, a foot rule would contract to six inches, when velocity had reached the enormous value of 161,000 miles a second. At the speed of light, 186,282 miles a second, contraction would be complete and all objects would have zero length in the direction of motion. Since a negative length would seem to have no meaning, this FitzGerald contraction was the first indication that the velocity of light in a vacuum might be the max imum velocity theoretically possible for any material object. The FitzGerald contraction seemed to go against common sense but with the growth of understanding of the electrical nature of matter, it became less so. Lorentz [839] a little later, independently advanced the same theory and expanded it, so that it is frequently referred to as the Lorentz-FitzGerald contraction. Fitz Gerald did not live to see his contraction
[822] REED
BALFOUR [823] hypothesis become an integral part of a new world system, the relativity theory, first advanced by Einstein [1064] in 1905. [822] REED, Walter American military surgeon Bom: Belroi, Virginia, September 13, 1851 Died: Washington, D.C., Novem ber 23, 1902 Reed, the son of a minister, entered the University of Virginia in 1866, ob taining a medical degree there in 1869 and a second from Bellevue Medical School in New York in 1870. He entered the Army Medical Corps in 1874. He made bacteriology his specialty and in 1893 was appointed professor of bacteri ology in the Army Medical School. The Spanish-American War made the American army more disease conscious than ever before, because in that one sided little conflict, Spanish guns suc ceeded in killing very few American sol diers, but disease felled them in battal ions. Reed headed a commission to study the cause and spread of typhoid fever, one of the epidemic diseases involved. Another was yellow fever, a particu larly dreaded disease, which in 1897 Reed proved was not caused by a certain bacterium on which the blame had been placed. In 1899, the war over, Reed was made head of a commission to travel to Cuba (temporarily an American protec torate), where the disease was particu larly bad. His careful studies led him to believe that the disease was not transmitted by bodily contact, or by clothing, bedding, or anything like that. He returned to an idea that had been advanced earlier, that the germ of yellow fever was transmitted by a mosquito. There was no way of testing this theory on animals and there followed a period of high (and grisly) drama in which the doctors of the com mission allowed themselves to be bitten by mosquitoes to see if they would catch the disease. Some did and one, Jesse William Lazear [955], died, but Reed proved his point. Get rid of the Aedes mosquito by tracking down its breeding sites and de stroying them. Avoid being bitten by using mosquito netting, and you get rid of yellow fever. Havana was indeed rid of the disease in this way. The Panama Canal was built through the adoption by Gorgas [853] of mosquito-killing tech niques. With the focal points of infection in Latin America moderated, the Eastern Seaboard of the United States was freed of the dread of this disease, which peri odically had visited such cities as New York and Philadelphia, slaying tens of thousands. In 1901 Reed proved the causative agent which the mosquitoes carried was a filterable virus of the type discovered by Beijerinck [817] just a few years earlier. Yellow fever thus became the first human disease attributed to a virus. Yellow fever quickly disappeared from Havana, where it had long been en demic. The last yellow fever epidemic the United States has seen struck New Orleans in 1905. Reed did not live to witness it; he had died three years earlier of appendicitis. In 1945 Reed was elected to the Hall of Fame for Great Americans, and the Army General Hos pital in Washington, D.C., is named in his honor. [823] BALFOUR, Francis Maitland Scottish biologist Born: Edinburgh, November 10, 1851
Died: Mont Blanc, Switzerland, July 19, 1882 Balfour’s elder brother, Arthur James, was an important British statesman who held high positions in the government, including that of prime minister from 1902 to 1906. In much less spectacular fashion, Francis Maitland graduated from Cambridge in 1873 and then grew interested in the study of embryology. Through embryos he traced the con nection between different groups of or ganisms, following the exaggerated no tions of Haeckel [707], which were then popular. He noted, for instance, the con nection of the vertebrates generally with certain comparatively primitive creatures that lacked vertebrae. These primitive Download 17.33 Mb. Do'stlaringiz bilan baham: 
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