Local phyicist, James Van Allen, dies

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Local phyicist, James Van Allen, dies

Postby chiggerbit » Thu Aug 10, 2006 9:37 pm

<!--EZCODE AUTOLINK START--><a href="http://news.com.com/Physicist+James+A.+Van+Allen+dead+at+91/2100-11397_3-6104148.html">news.com.com/Physicist+Ja...04148.html</a><!--EZCODE AUTOLINK END--><br><br>James A. Van Allen, the physicist who made the first major scientific discovery of the early space age, the Earth-circling radiation belts that bear his name, and sent spacecraft instruments to observe the outer reaches of the solar system, died Wednesday in Iowa City. He was 91. <br><br>The cause was heart failure, family members said. Van Allen was a longtime professor of physics and astronomy at the University of Iowa, and, with the discovery of the Van Allen belts of intense radiation surrounding Earth, he became a leading figure in the new field of magnetospheric physics, which grew in importance as spacecraft began exploring the planets. <br><br>A legendary lecturer and an inspiration to several generations of budding physicists and astronomers, Van Allen continued to show up at his office-laboratory until a month or so before he died. <br><br>Rapid rise to acclaim<br>James Van Allen, an unassuming but resolute investigator of cosmic rays and other space phenomena, literally rocketed to international acclaim with the launching of Explorer 1, the first successful space satellite of the United States. <br><br>It was on Jan. 31, 1958, in the early days of the space race between the United States and the Soviet Union and almost four months after the Russians stunned Americans with Sputnik 1. The American Explorer 1 may not have been first in space, but a Geiger counter developed by Van Allen sent back data of what would become known as the Van Allen radiation belts. <br><br>The radiation detector recorded two belts of charged particles trapped by Earth's magnetic field. One belt is 400 to 4,000 miles above the surface, and the other is 9,000 to 15,000 miles above the Equator, curving toward the magnetic poles. Further evidence for the encircling radiation was detected with Van Allen's instruments carried aloft aboard Explorer 2 and Explorer 3. <br><br>In the celebration of the Explorer 1 success, Van Allen posed for what became an iconic picture of the early days of spaceflight. He is standing with Wernher von Braun, whose team built the rocket, and William H. Pickering, who directed the spacecraft development, all smiling broadly and holding a model of the spacecraft high over their heads. He was the last of the three to die. <br><br> James Van Allen <br><br><!--EZCODE BOLD START--><strong>For several decades afterward, Van Allen was a staunch advocate of planetary exploration with robotic spacecraft and a critic of big-budget programs for human space flight. Describing himself as "a member of the loyal opposition," he argued that space science could be done better and less expensively when left to remote-controlled vehicles.</strong><!--EZCODE BOLD END--> <br><br>Even before the radiation-belt discovery, Van Allen was heavily involved in early American rocket research. When, on April 16, 1945, a V-2 rocket captured from the Germans was first sent aloft from the White Sands Proving Ground in New Mexico, it carried Geiger counters provided by Van Allen. His goal was to record radiation from space before it was altered by passage through the atmosphere. Such "cosmic rays" had been his lifelong interest, and it had earlier been discovered that they were more intense in outer space. <br><br>It has been said that scientists fall into three categories, thinkers, organizers and doers. Van Allen was a doer. <br><br>He was born on Sept. 7, 1914, in Mount Pleasant, Iowa. A physics professor at Iowa Wesleyan College, near his hometown, recognized the 18-year-old student's skill at tinkering. The professor put him to work, at 35 cents an hour, preparing seismic and magnetic equipment for an expedition to Antarctica. <br><br>It was to be led by Adm. Richard E. Byrd with the physics professor, Thomas Poulter, as second in command. Van Allen wanted to go, but his family thought him too young. He graduated summa cum laude and went to the State University in Iowa City for his graduate work, receiving a doctorate in 1939. <br><br>He worked as a research fellow at the Carnegie Institution of Washington until 1942. He then joined the Navy and worked at the Bureau of Ordnance on the proximity fuse, which was, for the first time, effective against dive bombers. Its strictly kept secret was a tiny radar in the projectile's nose that detonated when it flew past a target. He also served as an assistant staff gunnery officer in the Pacific, winning four combat stars. <br><br>At the Johns Hopkins University Applied Physics Laboratory, from 1946 through 1950, he supervised high-altitude research, promoting development of the Aerobee rocket, which while much smaller and cheaper than the V-2, could lift a small payload almost as high. <br><br>In 1951, he joined the University of Iowa as a professor and head of the department of physics and astronomy. He and his graduate students developed the "rockoon," a rocket lifted by balloon 10 to 15 miles high, where air pressure was low, then fired to soar as high as 85 miles. From icebreakers he supervised rocket shots near both the north and south geomagnetic poles in the belief that Earth's magnetic field there was channeling cosmic ray particles down into the atmosphere, causing the aurora. Such radiation was confirmed by the rockoons. <br><br>Swamped radiation detectors<br>After the successful launching of the Soviet Sputnik and a succession of humiliating failures by the United States Navy's Vanguard launcher, Van Allen was hastily told to refigure the radiation detectors he had designed for Vanguard to fly on the Army's Explorer 1. <br><br>When it was launched, it detected radiation close to the anticipated intensity as it flew over recording stations in the United States. Because it carried no tape recorder, its observations were monitored only as it flew over ground observatories, but when readings began coming in from South America, where high counting rates had been expected, the Geiger counters became strangely silent. <br><br>"Our explanations--both wrong as it turns out," Van Allen said later, "were either that our instruments were faulty or that cosmic rays do not strike the upper atmosphere over the tropics." <br><br>The puzzle was resolved when his group realized that when radiation is extremely intense, such a detector is swamped and becomes silent. Explorer 3 carried a tape recorder, and the vast extent of the radiation belt was detected. Evidence then accumulated for two belts, a more intense inner one and a diffuse outer one. The Pioneer probe to the Moon launched on Oct. 11, 1958, documented the outer part of the belts. <br><br>The same year Van Allen took part in Project Argus, the firing of three atomic bombs 300 miles aloft over the South Atlantic to see if, like the radiation belts, their radioactive particles became trapped by Earth's magnetism. The artificial belts were detected worldwide, producing auroras in both polar regions. <br><br>He also promoted international cooperation in science. On April 5, 1950, one of the most ambitious scientific efforts of all time, the International Geophysical Year, was born in his living room in Silver Spring, Md. <br><br>The guest of honor was Sydney Chapman, a professor of natural philosophy at Oxford and an authority on the link between solar eruptions and magnetic storms on Earth. The assembled scientists agreed that it was time for a global effort to understand the earth and its environment. Chapman became chairman of the committee that organized the 67-nation research program, which was carried out in 1957-58. <br><br>Also in 1958, the year that Sputnik undermined the American ego, Van Allen was chairman of a group of the country's leading space scientists who recommended a manned landing on the Moon by 1968. The group included von Braun, technical director of the Army's Ballistic Missile Agency, and directors of the Smithsonian Astrophysical Observatory and the Jet Propulsion Laboratory. <br><br>They proposed spending $10 billion over the next decade to "establish United States leadership in space research by 1960." They recommended prompt creation of an independent national space establishment. The National Aeronautics and Space Administration was, in fact, established that year. <br><br>Later, however, Van Allen had a change of mind. The Apollo lunar landing project, despite its vast cost, proved meager in revolutionary discoveries. None were comparable to those made by unmanned spacecraft, like the Van Allen belts, but the unmanned programs received lower priority and financing. <br><br>Van Allen said Apollo was of primary value as a television spectacular, rather than for its scientific achievements. <br><br>Ongoing radiation surveys<br>Although he retired from active teaching in 1985, he continued monitoring data being sent to Earth from far out in the solar system. His instruments on Pioneer 10 conducted in 1973 the first survey of Jupiter's radiation belts. Pioneer 11 followed with observations of Saturn's belts. He was also a member of the scientific team for the Galileo mission orbiting Jupiter. <br><br>In 1994, Van Allen received the Kuiper Prize from the Division of Planetary Sciences of the American Astronomical Society "in recognition of his many contributions to the field of planetary science, both through his investigations of planetary magnetospheres and through his advocacy of planetary exploration." <br><br>He was president of the American Geophysical Union from 1982 to 1984, and he received the group's William Bowie Medal in 1977. In 1987, he received the National Medal of Science from President Ronald Reagan, and in 1989 the king of Sweden presented him with the Crafoord Prize of the Royal Swedish Academy of Sciences. <br><br>Van Allen is survived by his wife of more than 60 years, Abigail Fithian Halsey Van Allen; five children, Cynthia Van Allen Schaffner of New York; Margot Van Allen Cairns of Vancouver, British Columbia; Sarah Van Allen Trimble of Washington; Thomas Van Allen of Aspen, Colo.; and Peter Van Allen of Philadelphia; and seven grandchildren. <br><br>In the early space age, Van Allen was often asked the value of space exploration. He sometimes replied with a impish smile, "I make a good living at it." <br><br>Walter Sullivan, science editor of The New York Times, died in 1996.<br><br><br><br> <p></p><i></i>
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Re: Local phyicist, James Van Allen, dies

Postby greencrow0 » Fri Aug 11, 2006 12:42 am

Van Allen Radiation Belts.<br><br>The punch line to the manned lunar voyages.<br><br>GC <p></p><i></i>
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