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发帖数: 4825 | 1 http://www.nytimes.com/2015/01/29/us/charles-h-townes-physicist
Charles H. Townes, a visionary physicist whose research led to the
development of the laser, making it possible to play CDs, scan prices at the
supermarket, measure time precisely, survey planets and galaxies and even
witness the birth of stars, died on Tuesday in Oakland, Calif. He was 99.
His daughter Linda Rosenwein confirmed his death.
In 1964, Dr. Townes and two Russians shared the Nobel Prize in Physics for
their work on microwave-emitting devices, called masers, and their light-
emitting successors, lasers, which have transformed modern communications,
medicine, astronomy, weapons systems and daily life in homes and workplaces.
One of the most versatile inventions of the 20th century, the laser
amplifies waves of stimulated atoms that shoot out as narrow beams of light,
to read CDs and bar codes, guide missiles, cut steel, perform eye surgery,
make astronomical measurements and carry out myriad other tasks, from
transmitting a thousand books a second over fiber optic lines to
entertaining crowds with light shows.
The technological revolution spawned by lasers, laying foundations for much
of the gadgetry and scientific knowledge the world now takes for granted,
was given enormous momentum by the discoveries of Dr. Townes and — because
almost nothing important in science is done in isolation — by the
contributions of colleagues and competitors.
Thus, Dr. Townes shared his Nobel with Nikolai G. Basov and Aleksandr M.
Prokhorov, of the Lebedev Institute for Physics in Moscow, whom he had never
met. It was Dr. Townes and Dr. Arthur L. Schawlow who wrote the 1958 paper
“Infrared and Optical Masers,” describing a device to produce laser light,
and secured a patent for it. A graduate student, R. Gordon Gould, came up
with insights on how to build it, and named it a laser, for light
amplification by stimulated emission of radiation. And it was Dr. Theodore H
. Maiman, a physicist with Hughes Aircraft in California, who built the
first operational laser in 1960.
In a career that spanned six decades, Dr. Townes developed radar bombing
systems and navigation devices during World War II, advised presidents and
government commissions on lunar landings and the MX missile system, verified
Einstein’s cosmological theories, discovered ammonia molecules at the
center of the Milky Way, and created an atomic clock that measured time to
within one second in 300 years.
He moved easily from lab to classroom to government policy-making groups:
with Bell Laboratories for nearly a decade when it was the world’s most
innovative scientific organization; with Columbia University for more than
20 years when he achieved his most important breakthroughs, and with the
Institute for Defense Analyses, a research center that advised the Pentagon
on weapons and defense systems in the Cold War.
Like most scientific researchers delving into unknown realms, Dr. Townes had
not aimed to invent devices that would become laser printers or supermarket
scanners, let alone technologies that would put movies on discs or
revolutionize eye surgery.
Continue reading the main story
He was interested in molecular structures and the behavior of microwaves —
theoretically as a way to measure time with unprecedented accuracy, but more
tangibly because the Pentagon, which partly funded his work at Columbia
University’s Radiation Laboratory, wanted better communications and radar
systems using shorter wavelengths to reach greater distances.
He had an “ah-ha!” moment. Sitting in a park in Washington in 1951,
pondering how to stimulate molecular energy to create shorter wavelengths,
he conceived of a device he called a maser, for microwave amplification by
stimulated emission of radiation. It would use molecules to nudge other
molecules, and amplify their thrust by getting them to resonate like tuning
forks and line up in a powerful beam.
He and two graduate students, James P. Gordon and H. J. Zeigler, built his
maser in 1953 and patented their creation. It was the first device operating
on the principles of the laser, although it amplified microwave radiation
rather than infrared or visible light radiation.
Five years later, Dr. Townes and Dr. Schawlow, who was his brother-in-law
and would receive the 1981 Nobel Prize in Physics for work on laser
spectroscopy, drew a blueprint for a laser. They called it an “optical
maser,” a term that never caught on, and through Bell Laboratories they
secured the first laser patent in 1959, a year before Dr. Maiman’s first
working model.
Despite their patent, they profited little. Both were bound to Bell Labs, Dr
. Schawlow as an employee and Dr. Townes as a consultant. Dr. Gould, the
former graduate student, was denied a laser patent in 1959, but in 1977 he
won a long court fight against the Townes-Schawlow patent and received some
royalties. It was the entrepreneurs, however, who grew rich on laser
products.
Charles Hard Townes was born in Greenville, S.C., on July 28, 1915, one of
six children of Ellen Hard Townes and Henry Townes, a lawyer. Charles, a
brilliant student of wide interests, including entomology and ornithology,
graduated from the local high school in 1931, when he was 15. (Dr. Townes
was honored in Greenville with a statue of him sitting on a park bench.)
At Furman University in Greenville, he majored in physics and modern
languages, was curator of the college museum and a member of the band, glee
club, swimming team and newspaper staff. He graduated valedictorian with two
bachelor’s degrees in 1935 at the age of 19. Focusing on physics, he
earned a master’s degree at Duke University in 1937 and a doctorate at the
California Institute of Technology in 1939.
He joined Bell Laboratories in 1939 at its Murray Hill, N.J., headquarters
and developed wartime radar bombing and navigational systems. Later, he
studied radio astronomy, molecular structures and microwave spectroscopy as
a means of controlling electromagnetic waves.
In 1941, Dr. Townes married Frances Brown. She survives him, as do their
four daughters, Ms. Rosenwein, Ellen Townes-Anderson, Carla Kessler and
Holly Townes; six grandchildren and two great-grandchildren.
Continue reading the main storyContinue reading the main storyContinue
reading the main story
In 1948, he was named executive director of the Radiation Laboratory at
Columbia. Two years later, he became a full professor and from 1952 to 1955
was the head of Columbia’s physics department. He also lectured in France,
Germany, Italy, Japan and India on Guggenheim and Fulbright fellowships.
Dr. Townes was often in the news in the 1950s and ’60s under headlines that
seemed like science fiction: “Bell Shows Beam of ‘Talking’ Light,” “
Man Shines a Light on the Moon,” “Radio Emissions in Space Hint at Birth
of a Planet,” and “Man Listens for Life on Worlds Afar.”
On leave from Columbia, he directed research for the Institute for Defense
Analyses from 1959 to 1961, then became provost and a professor at the
Massachusetts Institute of Technology. In 1967, he joined the University of
California at Berkeley, where he retired in 1986. He and other Nobel
laureates supported a nuclear test ban treaty in 1999, and in 2003 opposed
the United States invasion of Iraq without wide international support.
Besides more than 125 scientific papers, he wrote “Microwave Spectroscopy”
(1955, with Dr. Schawlow), and two memoirs, “Making Waves” (1995) and “
How the Laser Happened: Adventures of a Scientist” (2002).
His accolades included dozens of honorary degrees, the 1982 National Medal
of Science from President Ronald Reagan, and the 2005 Templeton Prize for
contributions to spiritual understanding. Calling himself a Protestant
Christian, he argued that science and religion were compatible, saying there
was little difference between a scientific epiphany, like his 1951 maser
brainstorm, and the religious experience of revelation.
“Understanding the order of the universe and understanding the purpose in
the universe are not identical,” he acknowledged in a paper in 1966, “but
they are not very far apart.” | b******3
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