John N. Bahcall

John Norris Bahcall (December 30 1934 – August 17 2005) was an American astrophysicist. He is best known for his contributions to the solar neutrino problem and the development of the Hubble Space Telescope, and for his leadership and development of the Institute for Advanced Study in Princeton.

Early and family life

Bahcall was born in Shreveport, Louisiana. He did not take science classes at high school, and became state tennis champion and a national debate team champion. Bahcall started his university career at Louisiana State University as a philosophy student on a tennis scholarship, and considered becoming a rabbi. He moved to the University of California, Berkeley after one year, still studying philosophy. He took his first physics class as it was a graduation requirement.

He was married to Princeton University professor in astrophysics Neta Bahcall, whom he first met while she was a graduate student at the Weizmann Institute in the 1960s. Together, they had a daughter and two sons. He died in New York from a rare blood disorder.

Academic career

He graduated with an A.B. in Physics from Berkeley in 1956, obtained his M.S. in physics in 1957 from the University of Chicago and his Ph.D. in physics from Harvard in 1961. He became a research fellow in physics at Indiana University in 1960 and then worked at the California Institute of Technology from 1962 to 1970, where he worked alongside Richard Feynman, Murray Gell-Mann, and William Fowler.

He was appointed professor at the Institute for Advanced Study in Princeton in 1971. He became a member of the National Academy of Science in 1976. He was president of the American Astronomical Society from 1990 to 1992, and was president-elect of the American Physical Society at the date of his death.

Bahcall is best known for his work in establishing the Standard Solar Model. He spent much of his life participating in the pursuit of an answer to the solar neutrino problem with physical chemist Raymond Davis, Jr. Together, Davis and Bahcall collaborated on the Homestake Experiment, the creation of an underground detector for neutrinos in a gold mine in South Dakota (essentially a very large tank filled with cleaning fluid). The flux of neutrinos found by the detector was 1/3 the amount predicted by Bahcall, a discrepancy that took over 30 years to resolve. The 2002 Nobel Prize in physics was awarded to Davis and Masatoshi Koshiba for their pioneering work in observing the neutrinos predicted from Bahcall's solar model.

Bahcall's other great contribution was in the development and implementation of the Hubble Telescope, alongside Lyman Spitzer, Jr from the 1970s through to the period after the telescope was launched in 1990. In 1992, he received NASA's Distinguished Public Service Medal for this work.

He also worked in many other areas: the standard model of a galaxy, with a massive black hole surrounded by stars, is known as the Bahcall-Wolf model; the Bahcall-Soneira model was for many years the standard model for the structure of the Milky Way; and he contributed to accurate models of stellar interiors. All together Bahcall published over 600 scientific papers and five books in the field of astrophysics.

Honors

*Helen B. Warner Prize (1970)
*NASA Distinguished Public Service Medal (1992)
*Heineman Prize (1994)
*Hans Bethe Prize (1998)
*National Medal of Science (1998)
*Henry Norris Russell Lectureship (1999)
*Dan David Prize (2003)
*Gold Medal of the Royal Astronomical Society (2003)
*Fermi Award (with Raymond Davis, Jr) (2003)
*Academy of Achievement, Golden Plate Award (2004)

Quotes

* "I know all about neutrinos, and my friend here knows about everything else in astrophysics". --- Bahcall's standard phrase on introducing himself and a colleague to a new acquaintance

External links

* Institute for Advanced Study:
** [http://www.sns.ias.edu/~jnb/ Homepage]
** [http://www.ias.edu/About/faculty/bahcall.php Biography]
** [http://www.ias.edu/Newsroom/announcements/Uploads/view.php?cmd=view&id=290 Press release following his death]
* [http://www.pbs.org/wgbh/nova/neutrino/ PBS Nova: The Ghost Particle]
* [http://www.sns.ias.edu/~jnb/Neta/letter.html Letter from his family after his death]
* [http://www.dandavidprize.com/laureates/future2003.html Dan David Prize] , Dan David Prize laureate 2003

*Obituaries
** [http://www.sns.ias.edu/~jnb/Neta/Natureobituary.pdf Obituary] ("Nature", 1 September 2005) (PDF)
** [http://www.washingtonpost.com/wp-dyn/content/article/2005/08/19/AR2005081901735_pf.html Obituary] ("Washington Post", August 20, 2005)
** [http://www.sns.ias.edu/~jnb/Neta/NYTobituary.doc Obituary] ("New York Times", August 19, 2005) (Microsoft Word,
** [http://www.timesonline.co.uk/article/0,,60-1758833,00.html Obituary] ("The Times", 1 September 2005)