Dr. John Bahcall (1934-2005)
September 7, 2005
|Dr. John Bahcall
courtesy of Cliff Moore
With the passing of Dr. John Bahcall on August 17, 2005, the entire Spitzer team mourns the loss of a legendary scientist and a great friend. His legacy will live on, in part, in the discoveries of the Spitzer Space Telescope.
Dr. John Norris Bahcall was not an expert in infrared astronomy. However in 1989 when he was asked to chair a committee that would predict the future of astronomy for the 1990s, his leadership led to the eloquent conclusion that the '90s should be a "Decade of the Infrared" and recommended that NASA make a space infrared telescope facility its top priority for the next 10 years.
The high regard that the astronomical community, NASA, and Congress had for the recommendations of Bahcall's committee eventually led to the launch of the Spitzer Space Telescope, 13 years later. Bahcall's leadership and scientific acumen were widely recognized as essential to forging the committee's recommendations and communicating them to the scientific community.
"The thing that you learn about the greats in your field is that they have the breadth and the vision to see where the field should go. John was one of the greats of astronomy, and we who are lucky enough to have been involved in Spitzer have benefited greatly from his vision," said Spitzer Science Center Director, Dr. Thomas Soifer.
The Bahcall Committee
In 1989, the National Research Council of the National Academy of Sciences commissioned a committee of astronomers and astrophysicists to recommend the most important new ground- and space-based initiatives for the coming decade, and asked Bahcall to chair it. The committee was nicknamed "the Bahcall committee."
"John had a very good science instinct... once you explained to him the capabilities of a sensitive infrared telescope, it took him about a millisecond to understand the importance of it," recalls Dr. Charles Beichman, Executive Director of the Michelson Science Center at Caltech.
Beichman worked on the Bahcall committee, which included astronomers with various expertise ranging from solar and planetary science, to theoretical and laboratory astrophysics.
"With a group that large, things have the potential to get very complicated, but decision making went very smoothly," says Beichman. "John was very good at developing a consensus... everyone felt they had a fair hearing, the X-ray scientists felt that they were being heard just as clearly as the infrared advocates."
The group's findings, which listed Spitzer as NASA's top priority and set the stage for astronomy's infrared decade, came to be known as "the Bahcall report."
At Spitzer's inaugural press conference on December 18, 2003, Bahcall called the telescope "a dream come true."
"NASA really got this one right!" He said. "The Spitzer Space Telescope will change the way astronomers do astronomy.... All of us, average citizens and professional astronomers, are interested in the origin of life. All of us are interested in how the universe we inhabit got to be the way it is. We don't yet have the detailed answers. But today thanks to the Spitzer telescope, we are a lot closer than we were before."
Bahcall's Contribution to Spitzer's Legacy
When Soifer began his search for someone to chair a committee to review proposals for Spitzer's Legacy Science Programs before the mission's launch, he was looking for someone who "demanded excellence and would give the projects credibility with the scientific community."
According to Soifer, Bahcall fit these requirements to a tee.
"Bahcall was the most influential person in the astronomical community. People had enormous respect for his theories, vision, and his work in founding the Hubble Space Telescope. That's what you want for the chairman of the first proposal review," says Soifer.
In reporting the results of this proposal selection Bahcall wrote, "...the projects ... represent an exciting usage of NASA's next major astrophysical observatory.... These projects will yield the superb science that we expect of a major investment of time on a NASA Great Observatory."
Since their selection in November 2000, the six Legacy projects have made great strides in the field of astronomy by exploring the Milky Way, searching thick molecular space clouds for infant stars, and peering with infrared eyes through galaxies near and far. In the mission's first year, the projects utilized approximately 3,160 hours of the telescope's observing time.
A Lifelong Quest for Truth
In his lifelong "quest for truth," Bahcall traveled across disciplines and oceans, to Capitol Hill and the edge of the known universe. As an undergraduate, he decided to pursue this quest as an astrophysicist instead of a rabbi, using physics instead of philosophy. By sharing his knowledge as a longtime professor at Princeton's Institute for Advanced Study, Bahcall also proved to be an invaluable source of truth for aspiring astronomers.
"John never had a limited understanding of anything," said Soifer. "Concepts that took him one day of thinking, would take others about a year of thinking."
In a career that spanned five decades, Bahcall published over 500 works and was most famous for his instrumental role in uncovering the process that makes the Sun shine. However, his legacy of universal "truth finding" arguably began in the late 1970s when he stood alongside Dr. Lyman Spitzer and lobbied Congress to fund a large space telescope, which would later become Hubble Space Telescope.
Spitzer first proposed placing a large telescope above the blurring affects of the Earth's atmosphere in 1946, more than a decade before the launching of the Soviet satellite Sputnik in 1957, and the founding of NASA in 1958. With Bahcall's help, Spitzer's dream was realized 44 years later in Hubble.
A true astronomer, Bahcall was always excited by the unknown. Upon Hubble's launch in 1990, he answered a question about the telescope's capabilities by saying, "We often frame our understanding of what the space telescope will do in terms of what we expect to find, and actually it would be terribly anticlimactic if in fact we find what we expect to find... The most important discoveries will provide answers to questions that we do not yet know how to ask and will concern objects we have not yet imagined."
Throughout his prolific career, Bahcall received numerous awards and prizes including the 1998 National Medal of Science from President Clinton; the Hans Bethe Prize of the American Physical Society; the Dan David Prize of Israel; the Gold Medal of the Royal Astronomical Society; the Fermi Award; and the Benjamin Franklin Medal in Physics. He received Honorary Doctorates from University of Pennsylvania, University of Chicago, University of Notre Dame, Hebrew University of Jerusalem, and the University of Milano. He has been a member of the National Academy of Sciences since 1976.
Born in Shreveport, Louisiana, Bahcall began his first year of undergraduate study at Louisiana State University convinced he wanted to study philosophy and possibly become a rabbi. However, like many college students finding their place he soon changed his mind and major. After deciding to pursue physics, he transferred to the University of California at Berkeley, where he received his A.B. in 1956. He received an M.S. from the University of Chicago in 1957, and a Ph.D. from Harvard University in 1961. He was a Research Fellow at Indiana University before joining the faculty at Caltech, where was strongly influenced by leading physics and astronomy luminaries including Richard Feynman, Murray Gell-Mann, and William Fowler.
In addition to his wife Neta and brother Robert, Bahcall is survived by his three children, Safi, Orli, and Dan.