John Norris Bahcall (December 30, 1934 – August 17, 2005) was an American astrophysicist and the Richard Black Professor for Astrophysics at the

Institute for Advanced Study The Institute for Advanced Study (IAS) is an independent center for theoretical research and intellectual inquiry located in Princeton, New Jersey. It has served as the academic home of internationally preeminent scholars, including Albert Ein ...

. He was known for a wide range of contributions to solar, galactic and extragalactic astrophysics, including the

solar neutrino problem The solar neutrino problem concerned a large discrepancy between the flux of solar neutrinos as predicted from the Sun's luminosity and as measured directly. The discrepancy was first observed in the mid-1960s and was resolved around 2002. The fl ...

, the development of the

Hubble Space Telescope The Hubble Space Telescope (HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the Orbiting Solar Observatory, first space telescope, but it is one of the largest and most ...

and for his leadership and development of the Institute for Advanced Study in

Princeton Princeton University is a private Ivy League research university in Princeton, New Jersey, United States. Founded in 1746 in Elizabeth as the College of New Jersey, Princeton is the fourth-oldest institution of higher education in the Unit ...

Early life and education

Bahcall was born into a Jewish family in

Shreveport, Louisiana Shreveport ( ) is a city in the U.S. state of Louisiana. It is the List of municipalities in Louisiana, third-most populous city in Louisiana after New Orleans and Baton Rouge, Louisiana, Baton Rouge. The bulk of Shreveport is in Caddo Parish, Lo ...

on December 30, 1934, and would later describe an early aspiration to become a

Reform Reform refers to the improvement or amendment of what is wrong, corrupt, unsatisfactory, etc. The modern usage of the word emerged in the late 18th century and is believed to have originated from Christopher Wyvill's Association movement, which ...

rabbi A rabbi (; ) is a spiritual leader or religious teacher in Judaism. One becomes a rabbi by being ordained by another rabbi—known as ''semikha''—following a course of study of Jewish history and texts such as the Talmud. The basic form of t ...

. He did not take science classes at high school. In high school he was a state tennis champion and a national debate champion (1952). Bahcall began his university studies at

Louisiana State University Louisiana State University and Agricultural and Mechanical College, commonly referred to as Louisiana State University (LSU), is an American Public university, public Land-grant university, land-grant research university in Baton Rouge, Louis ...

as a

philosophy Philosophy ('love of wisdom' in Ancient Greek) is a systematic study of general and fundamental questions concerning topics like existence, reason, knowledge, Value (ethics and social sciences), value, mind, and language. It is a rational an ...

student on a tennis scholarship, where he considered pursuing the rabbinate. At the end of his freshmen year, he transferred to the

University of California, Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California), is a Public university, public Land-grant university, land-grant research university in Berkeley, California, United States. Founded in 1868 and named after t ...

, still studying philosophy. He took his first

physics Physics is the scientific study of matter, its Elementary particle, fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge whi ...

class to fulfill a graduation science requirement, later saying: Bahcall switched majors to physics, and graduated with an AB in Physics from Berkeley in 1956. He obtained his MS in physics in 1957 from the

University of Chicago The University of Chicago (UChicago, Chicago, or UChi) is a Private university, private research university in Chicago, Illinois, United States. Its main campus is in the Hyde Park, Chicago, Hyde Park neighborhood on Chicago's South Side, Chic ...

and his

PhD A Doctor of Philosophy (PhD, DPhil; or ) is a terminal degree that usually denotes the highest level of academic achievement in a given discipline and is awarded following a course of graduate study and original research. The name of the deg ...

in physics from

Harvard University Harvard University is a Private university, private Ivy League research university in Cambridge, Massachusetts, United States. Founded in 1636 and named for its first benefactor, the History of the Puritans in North America, Puritan clergyma ...

in 1961. He spent a year as a research fellow in physics with Emil Konopinski at

Indiana University Indiana University (IU) is a state university system, system of Public university, public universities in the U.S. state of Indiana. The system has two core campuses, five regional campuses, and two regional centers under the administration o ...

. From 1962 to 1970, he worked with a group led by William Fowler at the Kellogg Laboratory of the

California Institute of Technology The California Institute of Technology (branded as Caltech) is a private research university in Pasadena, California, United States. The university is responsible for many modern scientific advancements and is among a small group of institutes ...

,. first as a research fellow and later as an Assistant and Associate Professor.

Academic career

Bahcall joined the

Princeton, New Jersey The Municipality of Princeton is a Borough (New Jersey), borough in Mercer County, New Jersey, United States. It was established on January 1, 2013, through the consolidation of the Borough of Princeton, New Jersey, Borough of Princeton and Pri ...

in 1968 becoming a professor of natural sciences in 1971 and the Richard Black Professor of Natural Sciences in 1997. Bahcall became a member of the

National Academy of Sciences The National Academy of Sciences (NAS) is a United States nonprofit, NGO, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Engineering (NAE) and the ...

in 1976. He was president of the

American Astronomical Society The American Astronomical Society (AAS, sometimes spoken as "double-A-S") is an American society of professional astronomers and other interested individuals, headquartered in Washington, DC. The primary objective of the AAS is to promote the adv ...

from 1990 to 1992, and was president-elect of the

American Physical Society The American Physical Society (APS) is a not-for-profit membership organization of professionals in physics and related disciplines, comprising nearly fifty divisions, sections, and other units. Its mission is the advancement and diffusion of ...

at the date of his death.

Research

Bahcall published over six hundred scientific papers and wrote or edited nine books on astrophysics. Bahcall is most notable for his work in establishing the standard solar model. He spent much of his life pursuing the

with

physical chemist Physical chemistry is the study of macroscopic and microscopic phenomena in chemical systems in terms of the principles, practices, and concepts of physics such as motion, energy, force, time, thermodynamics, quantum chemistry, statistical mecha ...

Raymond Davis, Jr Raymond Davis Jr. (October 14, 1914 – May 31, 2006) was an American chemist and physicist. He is best known as the leader of the Homestake experiment in the 1960s-1980s, which was the first experiment to detect neutrinos emitted from the Sun; ...

. Together, Davis and Bahcall collaborated on the

Homestake Experiment The Homestake experiment (sometimes referred to as the Davis experiment or Solar Neutrino Experiment and in original literature called Brookhaven Solar Neutrino Experiment or Brookhaven 37Cl (Chlorine) Experiment) was an experiment headed by astr ...

. To test Bahcall's theoretical predictions, Davis created an underground detector for neutrinos in a

South Dakota South Dakota (; Sioux language, Sioux: , ) is a U.S. state, state in the West North Central states, North Central region of the United States. It is also part of the Great Plains. South Dakota is named after the Dakota people, Dakota Sioux ...

gold mine, essentially a large tank filled with cleaning fluid. The flux of neutrinos found by the detector was one-third the amount theoretically predicted by Bahcall, a discrepancy that took over thirty years to resolve. Bahcall's ongoing research in this area resulted in publication of his book, ''Neutrino Astrophysics'' (1989), considered a standard reference on solar neutrinos. The 2002

Nobel Prize The Nobel Prizes ( ; ; ) are awards administered by the Nobel Foundation and granted in accordance with the principle of "for the greatest benefit to humankind". The prizes were first awarded in 1901, marking the fifth anniversary of Alfred N ...

in physics was awarded to Davis and

Masatoshi Koshiba was a Japanese physicist and one of the founders of neutrino astronomy. His work with the neutrino detectors Kamiokande and Super-Kamiokande was instrumental in detecting solar neutrinos, providing experimental evidence for the solar neutrino ...

for their pioneering work in observing the neutrinos predicted from Bahcall's solar model, thereby vindicating Bahcall's prediction. In addition to his work on solar neutrinos, Bahcall collaborated with Eli Waxman on the Waxman-Bahcall bound for high energy neutrinos. This bound sets a limit on high energy neutrino flux based on the observed flux of high energy

cosmic rays Cosmic rays or astroparticles are high-energy particles or clusters of particles (primarily represented by protons or atomic nuclei) that move through space at nearly the speed of light. They originate from the Sun, from outside of the Solar ...

. It was not possible to verify this prediction until after his death, with the construction of neutrino telescopes capable of detecting very high energy neutrinos, such as the

IceCube Neutrino Observatory The IceCube Neutrino Observatory (or simply IceCube) is a neutrino observatory developed by the University of Wisconsin–Madison and constructed at the Amundsen–Scott South Pole Station in Antarctica. The project is a recognized CERN experime ...

. Another contribution of Bahcall to astrophysics was the development and implementation of the

, in collaboration with Lyman Spitzer, Jr., from the 1970s through to the period after the telescope was launched in 1990. In 1992, Bahcall received the

NASA Distinguished Service Medal The NASA Distinguished Service Medal is the highest award that can be bestowed by the National Aeronautics and Space Administration of the United States. The medal may be presented to any member of the federal government, including both milita ...

for this work. He reintroduced the traditional method of star counts, as a quantitative tool for assessing galactic structure. The standard model of a galaxy, with a massive

black hole A black hole is a massive, compact astronomical object so dense that its gravity prevents anything from escaping, even light. Albert Einstein's theory of general relativity predicts that a sufficiently compact mass will form a black hole. Th ...

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 The Milky Way or Milky Way Galaxy is the galaxy that includes the Solar System, with the name describing the #Appearance, galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars in other arms of the galax ...

. He also contributed to accurate astrophysical models of stellar interiors.

Personal life and death

Bahcall married

Princeton University Princeton University is a private university, private Ivy League research university in Princeton, New Jersey, United States. Founded in 1746 in Elizabeth, New Jersey, Elizabeth as the College of New Jersey, Princeton is the List of Colonial ...

astrophysics professor

Neta Bahcall Neta Bahcall (; born 1942) is an Israeli Astrophysics, astrophysicist and Cosmology, cosmologist specializing in dark matter, the structure of the universe, quasars, and the formation of galaxy, galaxies. Bahcall is the Eugene Higgins Professo ...

, whom he met as a graduate student at the

Weizmann Institute The Weizmann Institute of Science ( ''Machon Weizmann LeMada'') is a Public university, public research university in Rehovot, Israel, established in 1934, fourteen years before the State of Israel was founded. Unlike other List of Israeli uni ...

in the 1960s. They had a daughter and two sons (including Safi Bahcall). He died in New York on 17 August 2005 from a rare blood disorder.

Honors

*2006, Exceptional Scientific Achievement Medal (posthumous),

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...

*2004,

Academy of Achievement The American Academy of Achievement, colloquially known as the Academy of Achievement, is a nonprofit educational organization that recognizes some of the highest-achieving people in diverse fields and gives them the opportunity to meet one ano ...

, Golden Plate Award *2004,

Comstock Prize in Physics The Comstock Prize in Physics is awarded by the U.S. National Academy of Sciences "for recent innovative discovery or investigation in electricity, magnetism, or radiant energy, broadly interpreted." Honorees must be residents of North America. ...

from the

*2003,

Gold Medal of the Royal Astronomical Society The Gold Medal of the Royal Astronomical Society is the highest award given by the Royal Astronomical Society (RAS). The RAS Council have "complete freedom as to the grounds on which it is awarded" and it can be awarded for any reason. Past awar ...

*2003, Benjamin Franklin Medal (with Raymond Davis, Jr. and Masatoshi Koshiba) *2003,

Dan David Prize The Dan David Prize is an international group of awards that recognize and support outstanding contributions to the study of history and other disciplines that shed light on the human past. Nine prizes of $300,000 are awarded each year to outstand ...

*2003, Fermi Award (with Raymond Davis, Jr) *2001, Member of the

American Philosophical Society The American Philosophical Society (APS) is an American scholarly organization and learned society founded in 1743 in Philadelphia that promotes knowledge in the humanities and natural sciences through research, professional meetings, publicat ...

*1999,

Henry Norris Russell Lectureship The Henry Norris Russell Lectureship is awarded each year by the American Astronomical Society in recognition of a lifetime of excellence in astronomical research. The idea for the lectureship came from then society President Harlow Shapley in 1945, ...

* 1998,

National Medal of Science The National Medal of Science is an honor bestowed by the President of the United States to individuals in science and engineering who have made important contributions to the advancement of knowledge in the fields of behavioral science, behavior ...

*1998, Hans Bethe Prize *1994, Heineman Prize *1992,

NASA Distinguished Public Service Medal The NASA Distinguished Public Service Medal is an award similar to the NASA Distinguished Service Medal, but awarded to non-government personnel. This is the highest honor NASA awards to anyone who was not a government employee when the service ...

, NASA *1976, Fellow of the

American Academy of Arts and Sciences The American Academy of Arts and Sciences (The Academy) is one of the oldest learned societies in the United States. It was founded in 1780 during the American Revolution by John Adams, John Hancock, James Bowdoin, Andrew Oliver, and other ...

*1970, Helen B. Warner Prize

Early life and education

Academic career

Research

Personal life and death

Honors

References

External links