John Norris Bahcall, an astrophysicist who found a new way to study the sun and was a major force behind the Hubble Space Telescope, has died. He was 70.
He died Wednesday at New York-Presbyterian Hospital from a rare blood disorder, according to the Institute for Advanced Study in Princeton, N.J., where Bahcall was a faculty member for 35 years.
Bahcall was born in Shreveport, La., in 1934 and considered becoming a rabbi before choosing science. He was educated at Louisiana State University and the University of California at Berkeley and earned a Ph.D. at Harvard in 1961.
In 1964, he was working at the California Institute of Technology when he proposed that scientists could figure out why the sun shines by measuring the number of solar neutrinos —ghostly particles that arrive on Earth.
At the time, collaborator Raymond Davis was trying to catch neutrinos in a chemical tank in a South Dakota gold mine. When too few were found, many thought the experiment was flawed. Bahcall said calculations by physicists — including himself — were flawed and that the tiny particles changed their shape. Experiments in the 1990s finally proved him right.
In 1996, Bahcall wrote about what was learned: "The nuclear reactions that produce the neutrinos also cause the sun to shine."
In the 1970s, he was a leader of the effort to create the Hubble, which was launched in 1990. He pushed for the instrument's survival until the end of his life.
He was president of the American Astronomical Society from 1990 to 2002 and chairman of the National Academy of Sciences panel that wrote a report in 1990 that laid out a plan for the next decade of physics study.
He joined the Institute for Advanced Study, which had been Albert Einstein's academic home, in 1968.
There, he helped train the next generation of scientists. At nearby Princeton University, six of the 12 astrophysics professors had worked with Bahcall.
Bahcall never lost his enthusiasm for what he studied. In a February 2003 interview with The Star-Ledger of Newark, he described the universe as "unattractive, implausible, crazy, but beautiful."
Bahcall received the National Medal of Science from President Clinton in 1998 and won several other major physics awards.
Many scientists expected him to win a Nobel Prize. Longtime collaborator Davis and Japanese neutrino researcher Masatoshi Koshiba shared the prize in 2002, along with another astrophysicist for research in a different field. But Bahcall did not. Friends said he was not bitter about it.
"He had only generous words for Ray Davis and Koshiba," cosmologist Michael Turner told The New York Times.