Chicago Tribune Obituary for John A. Simpson

 
http://www.chicago.tribune.com/news/obituaries/article/0,2669,SAV-0009020086,FF.html


   JOHN SIMPSON, 83, COSMIC RAY PIONEER

   By James Janega
   Tribune Staff Writer
   September 2, 2000

   Somewhere in space above us, and in the white-hot haze around the
   sun, John Alexander Simpson's legacy lives on, bleeping measurements
   relentlessly across the void back toward Earth.

   It is hard even to conceptualize the sheer physical reach of Mr.
   Simpson's contribution to science. A pioneer in the study of cosmic
   rays, his instruments are now orbiting the sun's south pole aboard
   the Ulysses spacecraft, rocketing toward Comet Wild-2 on Stardust,
   and dwindling into deep space aboard Pioneer 10, way out in the
   lonely black, already twice as far from the sun as Pluto.

  Outlived by his experiments, Mr. Simpson, 83, the University of
   Chicago's Arthur H. Compton distinguished service professor emeritus,
   died Thursday, Aug. 31, in the university's Bernard Mitchell Hospital
   of pneumonia following open heart surgery.

   He invented the neutron monitor that allows the measurement of cosmic
   rays, high-energy atomic nuclei spewed out by exploding stars. He
   also was the first to postulate that the Earth's magnetic field had
   an effect on the intensity of cosmic rays pounding the planet's
   surface, and he was the first to collect evidence on how the sun's
   magnetic field influences solar wind in the heliosphere.

   "He was always at the frontier, seeing things for the first time, and
   thereby having the opportunity to interpret and understand things for
   the first time," said Edward C. Stone, director of NASA's Jet
   Propulsion Laboratory and a one-time doctoral student under Mr.
   Simpson.

   "The kind of science he did certainly is consistent with what people
   now call the `smaller, faster, cheaper' model. He started in that
   style of space exploration, and he continued that right to the end of
   his career."

   In person, Mr. Simpson seemed a grandfatherly tinker, somewhat
   reminiscent of a trusted country mechanic. He evinced an
   experimenter's approach to particle physics, of rolling up one's
   sleeves and building things. His creations became complicated wire
   and tubing sculptures, which he would then stick onto space vehicles,
   ultimately to be hurled into space.

   He also was an oft-consulted elder scientist who could presage public
   policy. A scientific group leader for the Manhattan Project, he was
   among the project's scientists to campaign for the peaceful use of
   nuclear power after the United States dropped the bomb on Hiroshima.
   He stated the scientists' case in a 1945 Life magazine article, and
   later that year became an unofficial adviser to U.S. Sen. Brien
   McMahon. McMahon chaired the Senate Special Committee on the Control
   of Atomic Energy.

   Born in Portland, Ore., Mr. Simpson received a bachelor's from Reed
   College in 1940, and his master's and doctorate from New York
   University in 1942 and 1943. He worked on the Manhattan Project until
   1946, when he joined the U. of C. faculty, becoming a full professor
   in 1954, and ultimately moving through a succession of prestigious,
   named professorships at the university. He had been a professor
   emeritus since 1987.

   He was president of the International Commission on Cosmic Radiation
   from 1965 to 1967, was director of the Enrico Fermi Institute from
   1973 to 1978, and held the Smithsonian Institution's Space Science
   History chair in 1987 and 1988. He won awards from physics and
   astronomical societies in the United States, Ireland, the former
   Soviet Union and the United Nations.

   Most of his work centered on cosmic rays, which Mr. Simpson described
   for the Tribune in 1988 as "the Rosetta stones of astronomy."

   "They show how elements were cooked inside of stars. It's like doing
   nuclear physics in space," he said.

   To measure them, Mr. Simpson invented a neutron monitor in 1948,
   setting up monitoring stations from Chicago to Peru by 1951, and
   discovered cosmic ray bombardment was less intense near the equator.

   "John pointed out that this was probably due to magnetic fields
   varying in space," said Eugene Parker, a fellow professor emeritus at
   the U. of C. "They had the effect of somehow eliminating the
   lower-energy cosmic rays here on Earth."

   In 1956, Mr. Simpson's instruments measured a solar flare, and the
   evidence pointed to the fact that the sun's magnetic field probably
   had a big effect on where in the solar system the solar wind blew.
   Scientists think Pioneer 10, launched in 1972, may just now be
   reaching the limits of solar gusts, some 75 times as far from the sun
   as Earth is. Mr. Simpson was still gathering information from Pioneer
   10 last year.

   Another of his inventions, aboard the Cassini spacecraft, will
   collect and analyze dust particles in Saturn's rings. One of his
   instruments was on the Soviet Union's missions to Halley's Comet in
   1986; another mission will rendezvous with Comet Wild-2 in 2004.

   "He was clearly one of the pioneers of the space age," Stone said.
   "And he continued that."

   Mr. Simpson is survived by his wife, Elizabeth; a daughter, Mary Ann
   Smith; a son, John A. Simpson; and three grandchildren. He was
   divorced from his first wife, Elizabeth Hiltz Simpson, in 1977; she
   died in 1990.

   A memorial service was being planned for Mr. Simpson.