John Norris Bahcall (December 30, 1934 – August 17, 2005) was an American astrophysicist, best known for his contributions to 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 (often referred to as HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the first space telescope, but it is one of the largest and most vers ...

and for his leadership and development of the

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

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

Early and family life

Bahcall was born into a Jewish family in

Shreveport, Louisiana Shreveport ( ) is a city in the U.S. state of Louisiana. It is the third most populous city in Louisiana after New Orleans and Baton Rouge, respectively. The Shreveport–Bossier City metropolitan area, with a population of 393,406 in 2020, is ...

, and would later describe an early aspiration to become a

Reform Reform ( lat, reformo) means the improvement or amendment of what is wrong, corrupt, unsatisfactory, etc. The use of the word in this way emerges in the late 18th century and is believed to originate from Christopher Wyvill's Association movement ...

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 o ...

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

Louisiana State University Louisiana State University (officially Louisiana State University and Agricultural and Mechanical College, commonly referred to as LSU) is a public land-grant research university in Baton Rouge, Louisiana. The university was founded in 1860 n ...

as a

philosophy Philosophy (from , ) is the systematized study of general and fundamental questions, such as those about existence, reason, knowledge, values, mind, and language. Such questions are often posed as problems to be studied or resolved. ...

student on a tennis scholarship, where he considered pursuing the rabbinate. He transferred to the

University of California, Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California) is a public land-grant research university in Berkeley, California. Established in 1868 as the University of California, it is the state's first land-grant un ...

, still studying philosophy. He took his first

physics Physics is the natural science that studies matter, its 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 which ...

class as a graduation requirement. He was married to

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

astrophysics professor Neta Bahcall, whom he met as a graduate student at the

Weizmann Institute The Weizmann Institute of Science ( he, מכון ויצמן למדע ''Machon Vaitzman LeMada'') is a public research university in Rehovot, Israel, established in 1934, 14 years before the State of Israel. It differs from other Israeli u ...

in the 1960s. They had a daughter and two sons. He died in New York from a rare blood disorder.

Academic career

He graduated with an AB in Physics from Berkeley in 1956, obtained his MS in physics in 1957 from the

University of Chicago The University of Chicago (UChicago, Chicago, U of C, or UChi) is a private research university in Chicago, Illinois. Its main campus is located in Chicago's Hyde Park neighborhood. The University of Chicago is consistently ranked among the b ...

and his

PhD PHD or PhD may refer to: * Doctor of Philosophy (PhD), an academic qualification Entertainment * '' PhD: Phantasy Degree'', a Korean comic series * '' Piled Higher and Deeper'', a web comic * Ph.D. (band), a 1980s British group ** Ph.D. (Ph.D. al ...

in physics from

Harvard Harvard University is a private Ivy League research university in Cambridge, Massachusetts. Founded in 1636 as Harvard College and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of higher le ...

in 1961. He became a research fellow in physics at

Indiana University Indiana University (IU) is a system of public universities in the U.S. state of Indiana. Campuses Indiana University has two core campuses, five regional campuses, and two regional centers under the administration of IUPUI. *Indiana Universi ...

in 1960 and worked at the

California Institute of Technology The California Institute of Technology (branded as Caltech or CIT)The university itself only spells its short form as "Caltech"; the institution considers other spellings such a"Cal Tech" and "CalTech" incorrect. The institute is also occasional ...

from 1962 to 1970, where he worked alongside

Richard Feynman Richard Phillips Feynman (; May 11, 1918 – February 15, 1988) was an American theoretical physicist, known for his work in the path integral formulation of quantum mechanics, the theory of quantum electrodynamics, the physics of the superfl ...

Murray Gell-Mann Murray Gell-Mann (; September 15, 1929 – May 24, 2019) was an American physicist who received the 1969 Nobel Prize in Physics for his work on the theory of elementary particles. He was the Robert Andrews Millikan Professor of Theoretical ...

, and William Fowler. He was appointed professor at the

in 1971. He became a member of the

National Academy of Sciences The National Academy of Sciences (NAS) is a United States nonprofit, 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 Nat ...

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 1990–92, 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 k ...

at the date of his death.

Research

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 mech ...

Raymond Davis, Jr. Together, Davis and Bahcall collaborated on the Homestake Experiment, creating an underground detector for neutrinos in a

South Dakota South Dakota (; Sioux: , ) is a U.S. state in the North Central region of the United States. It is also part of the Great Plains. South Dakota is named after the Lakota and Dakota Sioux Native American tribes, who comprise a large po ...

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. The 2002

Nobel Prize The Nobel Prizes ( ; sv, Nobelpriset ; no, Nobelprisen ) are five separate prizes that, according to Alfred Nobel's will of 1895, are awarded to "those who, during the preceding year, have conferred the greatest benefit to humankind." Alfr ...

in physics was awarded to Davis and Masatoshi Koshiba 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 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 System in our ...

. Bahcall's other contribution 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, he 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. The standard model of a galaxy, with a massive

black hole A black hole is a region of spacetime where gravity is so strong that nothing, including light or other electromagnetic waves, has enough energy to escape it. The theory of general relativity predicts that a sufficiently compact mass can def ...

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 is the galaxy that includes our Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye. ...

. He contributed to accurate astrophysical models of stellar interiors. Bahcall published over six hundred scientific papers and five books in the field of astrophysics.

Honors

* Helen B. Warner Prize (1970) *Fellow of the

American Academy of Arts and Sciences The American Academy of Arts and Sciences (abbreviation: AAA&S) 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, a ...

(1976) * NASA Distinguished Public Service Medal (1992) * Heineman Prize (1994) *

Hans Bethe Prize The Hans A. Bethe Prize, is presented annually by the American Physical Society. The prize honors outstanding work in theory, experiment or observation in the areas of astrophysics, nuclear physics, nuclear astrophysics, or closely related fields ...

(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 and social scienc ...

(1998) * Henry Norris Russell Lectureship (1999) *Member of the

American Philosophical Society The American Philosophical Society (APS), founded in 1743 in Philadelphia, is a scholarly organization that promotes knowledge in the sciences and humanities through research, professional meetings, publications, library resources, and communit ...

(2001) *

Dan David Prize The Dan David Prize is a major international award that recognizes and supports outstanding contributions to the study of history and other disciplines that shed light on the human past. It awards nine prizes of $300,000 each year to outstanding ...

(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) * Fermi Award (with Raymond Davis, Jr) (2003) * Benjamin Franklin Medal (2003) *

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

, 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

(2004)

References

Nature Nature, in the broadest sense, is the physical world or universe. "Nature" can refer to the phenomena of the physical world, and also to life in general. The study of nature is a large, if not the only, part of science. Although humans are ...

'', 1 September 2005) (

PDF Portable Document Format (PDF), standardized as ISO 32000, is a file format developed by Adobe in 1992 to present documents, including text formatting and images, in a manner independent of application software, hardware, and operating systems. ...

) *
Obituary
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Washington Post ''The Washington Post'' (also known as the ''Post'' and, informally, ''WaPo'') is an American daily newspaper published in Washington, D.C. It is the most widely circulated newspaper within the Washington metropolitan area and has a large na ...

'', August 20, 2005) *
Obituary
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New York Times ''The New York Times'' (''the Times'', ''NYT'', or the Gray Lady) is a daily newspaper based in New York City with a worldwide readership reported in 2020 to comprise a declining 840,000 paid print subscribers, and a growing 6 million paid ...

'', August 19, 2005) (

Microsoft Word Microsoft Word is a word processor, word processing software developed by Microsoft. It was first released on October 25, 1983, under the name ''Multi-Tool Word'' for Xenix systems. Subsequent versions were later written for several other pla ...

) *
Obituary
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The Times ''The Times'' is a British daily national newspaper based in London. It began in 1785 under the title ''The Daily Universal Register'', adopting its current name on 1 January 1788. ''The Times'' and its sister paper '' The Sunday Times'' ( ...

'', 1 September 2005) {{DEFAULTSORT:Bahcall, John N. 1934 births 2005 deaths American astronomers California Institute of Technology faculty C. E. Byrd High School alumni Enrico Fermi Award recipients Fellows of the American Academy of Arts and Sciences Harvard Graduate School of Arts and Sciences alumni Indiana University faculty Institute for Advanced Study faculty Louisiana State University alumni Members of the United States National Academy of Sciences National Medal of Science laureates People from Princeton, New Jersey People from Shreveport, Louisiana Recipients of the Gold Medal of the Royal Astronomical Society UC Berkeley College of Letters and Science alumni University of Chicago alumni Jewish American scientists Winners of the Dannie Heineman Prize for Astrophysics Fellows of the American Physical Society Burials at Princeton Cemetery 20th-century American Jews 21st-century American Jews Members of the American Philosophical Society

Early and family life

Academic career

Research

Honors

References

Further reading

External links