Robert Frederick Christy (May 14, 1916 – October 3, 2012) was a Canadian-American
theoretical physicist
Theoretical physics is a branch of physics that employs mathematical models and abstractions of physical objects and systems to rationalize, explain and predict natural phenomena. This is in contrast to experimental physics, which uses experimen ...
and later
astrophysicist who was one of the last surviving people to have worked on the
Manhattan Project
The Manhattan Project was a research and development undertaking during World War II that produced the first nuclear weapons. It was led by the United States with the support of the United Kingdom and Canada. From 1942 to 1946, the project w ...
during
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...
. He briefly served as acting president of
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 ...
(Caltech).
A graduate of the
University of British Columbia
The University of British Columbia (UBC) is a public university, public research university with campuses near Vancouver and in Kelowna, British Columbia. Established in 1908, it is British Columbia's oldest university. The university ranks a ...
(UBC) in the 1930s where he studied physics, he followed
George Volkoff
George Michael Volkoff, (February 23, 1914 – April 24, 2000) was a Russian-Canadian physicist and academic who helped, with J. Robert Oppenheimer, predict the existence of neutron stars before they were discovered.
Early life
He was born ...
, who was a year ahead of him, 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 u ...
, where he was accepted as a graduate student by
Robert Oppenheimer
J. Robert Oppenheimer (; April 22, 1904 – February 18, 1967) was an American theoretical physicist. A professor of physics at the University of California, Berkeley, Oppenheimer was the wartime head of the Los Alamos Laboratory and is often ...
, the leading theoretical physicist in the United States at that time. Christy received his doctorate in 1941
and joined the
physics department of
Illinois Institute of Technology
Illinois Institute of Technology (IIT) is a private research university in Chicago, Illinois. Tracing its history to 1890, the present name was adopted upon the merger of the Armour Institute and Lewis Institute in 1940. The university has prog ...
.
In 1942 he joined the Manhattan Project at 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 ...
, where he was recruited by
Enrico Fermi
Enrico Fermi (; 29 September 1901 – 28 November 1954) was an Italian (later naturalized American) physicist and the creator of the world's first nuclear reactor, the Chicago Pile-1. He has been called the "architect of the nuclear age" and ...
to join the effort to build the first
nuclear reactor
A nuclear reactor is a device used to initiate and control a fission nuclear chain reaction or nuclear fusion reactions. Nuclear reactors are used at nuclear power plants for electricity generation and in nuclear marine propulsion. Heat from nu ...
, having been recommended as a theory resource by Oppenheimer. When Oppenheimer formed the Manhattan Project's
Los Alamos Laboratory
The Los Alamos Laboratory, also known as Project Y, was a secret laboratory established by the Manhattan Project and operated by the University of California during World War II. Its mission was to design and build the first atomic bombs. Ro ...
in 1943, Christy was one of the early recruits to join the Theory Group. Christy is generally credited with the insight that a solid sub-critical mass of plutonium could be explosively compressed into
supercriticality
In nuclear engineering, a critical mass is the smallest amount of fissile material needed for a sustained nuclear chain reaction. The critical mass of a fissionable material depends upon its nuclear properties (specifically, its nuclear fissio ...
, a great simplification of earlier concepts of implosion requiring hollow shells. For this insight the solid-core plutonium model is often referred to as the "
Christy pit".
After the war, Christy briefly joined the University of Chicago Physics department before being recruited to join the Caltech faculty in 1946 when Oppenheimer decided it was not practical for him to resume his academic activities. He stayed at Caltech for his academic career, serving as Department Chair, Provost and Acting President. In 1960 Christy turned his attention to astrophysics, creating some of the first practical computation models of stellar operation. For this work Christy was awarded the
Eddington Medal
The Eddington Medal is awarded by the Royal Astronomical Society for investigations of outstanding merit in theoretical astrophysics. It is named after Sir Arthur Eddington. First awarded in 1953, the frequency of the prize has varied over the year ...
of the
Royal Astronomical Society
(Whatever shines should be observed)
, predecessor =
, successor =
, formation =
, founder =
, extinction =
, merger =
, merged =
, type = NGO ...
in 1967. In the 1980s and 1990s Christy participated in the National Research Council's Committee on Dosimetry, an extended effort to better understand the actual radiation exposure due to the bombs dropped on Japan, and on the basis of that learning, better understand the medical risks of radiation exposure.
Early life
Robert Frederick Cohen was born on May 14, 1916 in
Vancouver, British Columbia
Vancouver ( ) is a major city in western Canada, located in the Lower Mainland region of British Columbia. As the List of cities in British Columbia, most populous city in the province, the 2021 Canadian census recorded 662,248 people in the ...
,
the son of Moise Jacques Cohen, an electrical engineer, and his wife Hattie Alberta née Mackay, a school teacher. He was named Robert after his maternal great uncle Robert Wood, and Frederick after Frederick Alexander Christy, the second husband of his maternal grandmother. He had an older brother, John, who was born in 1913. Moise changed the family surname to Christy by
deed poll
A deed poll (plural: deeds poll) is a legal document binding on a single person or several persons acting jointly to express an intention or create an obligation. It is a deed, and not a contract because it binds only one party (law), party.
Et ...
on August 31, 1918. On November 4, Moise was accidentally electrocuted at work. Hattie died after
goitre
A goitre, or goiter, is a swelling in the neck resulting from an enlarged thyroid gland. A goitre can be associated with a thyroid that is not functioning properly.
Worldwide, over 90% of goitre cases are caused by iodine deficiency. The term is ...
surgery in 1926. Christy and his brother were then cared for by Robert Wood, their grandmother Alberta Mackay, and their great aunt Maud Mackay.
Christy was educated at
Magee High School, and graduated in 1932 with the highest examination score in the province of
British Columbia
British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...
. He was awarded the
Governor General's Academic Medal
The Governor General's Academic Medal is awarded to the student graduating with the highest grade point average from a Canadian high school, college or university program. They are presented by the educational institution on behalf of the Governor ...
, and, importantly in view of his family's limited ability to pay, free tuition to attend the
University of British Columbia
The University of British Columbia (UBC) is a public university, public research university with campuses near Vancouver and in Kelowna, British Columbia. Established in 1908, it is British Columbia's oldest university. The university ranks a ...
(UBC). At the award dinner he met the second-place winner, Dagmar Elizabeth von Lieven, whom he dated while at UBC. He received his
Bachelor of Arts
Bachelor of arts (BA or AB; from the Latin ', ', or ') is a bachelor's degree awarded for an undergraduate program in the arts, or, in some cases, other disciplines. A Bachelor of Arts degree course is generally completed in three or four years ...
(BA) degree in mathematics and physics with first class honors in 1935, and his
Master of Arts
A Master of Arts ( la, Magister Artium or ''Artium Magister''; abbreviated MA, M.A., AM, or A.M.) is the holder of a master's degree awarded by universities in many countries. The degree is usually contrasted with that of Master of Science. Tho ...
(MA) degree in 1937,
writing a thesis on "Electron attachment and negative ion formation in oxygen".
George Volkoff
George Michael Volkoff, (February 23, 1914 – April 24, 2000) was a Russian-Canadian physicist and academic who helped, with J. Robert Oppenheimer, predict the existence of neutron stars before they were discovered.
Early life
He was born ...
, a friend of Christy who was a year ahead of him at UBC, was accepted as a graduate student at 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 u ...
, by
Robert Oppenheimer
J. Robert Oppenheimer (; April 22, 1904 – February 18, 1967) was an American theoretical physicist. A professor of physics at the University of California, Berkeley, Oppenheimer was the wartime head of the Los Alamos Laboratory and is often ...
, who led the most active school of theoretical physics in the United States at that time. This inspired Christy to apply to the University of California as well. He was accepted, and was awarded a fellowship for his first year. At Berkeley he shared an apartment with Volkoff,
Robert Cornog
Robert Alden Cornog (July 7, 1912 – July 17, 1998) was a physicist and engineer who helped develop the atomic bomb and missile systems, and made significant discoveries regarding isotopes of hydrogen and helium.
A native of Portland, Oregon, ...
,
Ken McKenzie
Ken McKenzie (August 19, 1923April 9, 2003) was a Canadian newspaper publisher and sports journalist. He served as publicity director of the National Hockey League (NHL) from 1946 to 1963. In 1947, he published the first NHL press and radio g ...
and McKenzie's wife Lynn McKenzie. For his thesis, Oppenheimer had him look at
mesotrons, subatomic particles called muons today, that had recently been found in
cosmic ray
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 own ...
s. They were so-called because they were more massive than
electron
The electron ( or ) is a subatomic particle with a negative one elementary electric charge. Electrons belong to the first generation of the lepton particle family,
and are generally thought to be elementary particles because they have no kn ...
s but less massive than
proton
A proton is a stable subatomic particle, symbol , H+, or 1H+ with a positive electric charge of +1 ''e'' elementary charge. Its mass is slightly less than that of a neutron and 1,836 times the mass of an electron (the proton–electron mass ...
s. With the help of
Shuichi Kusaka he performed detailed calculations of the particle's
spin
Spin or spinning most often refers to:
* Spinning (textiles), the creation of yarn or thread by twisting fibers together, traditionally by hand spinning
* Spin, the rotation of an object around a central axis
* Spin (propaganda), an intentionally b ...
. He published two papers on mesotrons with Kusaka in the
Physical Review
''Physical Review'' is a peer-reviewed scientific journal established in 1893 by Edward Nichols. It publishes original research as well as scientific and literature reviews on all aspects of physics. It is published by the American Physical S ...
, which formed the basis of his 1941
Doctor of Philosophy
A Doctor of Philosophy (PhD, Ph.D., or DPhil; Latin: or ') is the most common Academic degree, degree at the highest academic level awarded following a course of study. PhDs are awarded for programs across the whole breadth of academic fields ...
(PhD) thesis
Manhattan Project
![Robert F](https://upload.wikimedia.org/wikipedia/commons/8/81/Robert_F._Christy_Los_Alamos_ID.png)
Christy could have graduated in 1940, but could not then be a teaching assistant, and this would have left him jobless and without income. In 1941, Oppenheimer found him a post at the
physics department at
Illinois Institute of Technology
Illinois Institute of Technology (IIT) is a private research university in Chicago, Illinois. Tracing its history to 1890, the present name was adopted upon the merger of the Armour Institute and Lewis Institute in 1940. The university has prog ...
(IIT). In May 1941, he married Dagmar von Lieven. They had two sons: Thomas Edward (Ted), born in 1944, and Peter Robert, born in 1946. IIT paid Christy $200 per month to teach 27 hours per week for 11 months per annum. To keep abreast of developments in physics, he attended seminars at 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 ...
. This brought him to the attention of
Eugene Wigner
Eugene Paul "E. P." Wigner ( hu, Wigner Jenő Pál, ; November 17, 1902 – January 1, 1995) was a Hungarian-American theoretical physicist who also contributed to mathematical physics. He received the Nobel Prize in Physics in 1963 "for his con ...
, who hired him for the same money that IIT was paying him as a full-time research assistant, commencing in January 1942.
Enrico Fermi
Enrico Fermi (; 29 September 1901 – 28 November 1954) was an Italian (later naturalized American) physicist and the creator of the world's first nuclear reactor, the Chicago Pile-1. He has been called the "architect of the nuclear age" and ...
and his team from
Columbia University
Columbia University (also known as Columbia, and officially as Columbia University in the City of New York) is a private research university in New York City. Established in 1754 as King's College on the grounds of Trinity Church in Manhatt ...
arrived at the University of Chicago in January 1942 as part of an effort to concentrate the Manhattan Project's reactor work at the new
Metallurgical Laboratory
The Metallurgical Laboratory (or Met Lab) was a scientific laboratory at the University of Chicago that was established in February 1942 to study and use the newly discovered chemical element plutonium. It researched plutonium's chemistry and m ...
. Fermi arranged with Wigner for Christy to join his group, which was building a
nuclear reactor
A nuclear reactor is a device used to initiate and control a fission nuclear chain reaction or nuclear fusion reactions. Nuclear reactors are used at nuclear power plants for electricity generation and in nuclear marine propulsion. Heat from nu ...
, which Fermi called a "pile", in the
squash
Squash may refer to:
Sports
* Squash (sport), the high-speed racquet sport also known as squash racquets
* Squash (professional wrestling), an extremely one-sided match in professional wrestling
* Squash tennis, a game similar to squash but pla ...
court under
Stagg Field at the University of Chicago. Construction began on November 6, 1942, and Christy was present when
Chicago Pile-1
Chicago Pile-1 (CP-1) was the world's first artificial nuclear reactor. On 2 December 1942, the first human-made self-sustaining nuclear chain reaction was initiated in CP-1, during an experiment led by Enrico Fermi. The secret development of t ...
went
critical
Critical or Critically may refer to:
*Critical, or critical but stable, medical states
**Critical, or intensive care medicine
*Critical juncture, a discontinuous change studied in the social sciences.
*Critical Software, a company specializing in ...
on December 2.
In early 1943, Christy joined Oppenheimer's
Los Alamos Laboratory
The Los Alamos Laboratory, also known as Project Y, was a secret laboratory established by the Manhattan Project and operated by the University of California during World War II. Its mission was to design and build the first atomic bombs. Ro ...
in New Mexico, where he became an
American citizen
Citizenship of the United States is a legal status that entails Americans with specific rights, duties, protections, and benefits in the United States. It serves as a foundation of fundamental rights derived from and protected by the Constituti ...
in 1943 or 1944.
Hans Bethe
Hans Albrecht Bethe (; July 2, 1906 – March 6, 2005) was a German-American theoretical physicist who made major contributions to nuclear physics, astrophysics, quantum electrodynamics, and solid-state physics, and who won the 1967 Nobel Prize ...
, the head of T (Theoretical) Division, detailed his physicists to assist with the projects at the laboratory. With his knowledge of reactors, Christy's assignment was to help
Donald W. Kerst's Water Boiler group. The Water Boiler was an
aqueous homogeneous reactor
Aqueous homogeneous reactors (AHR) are a type of nuclear reactor in which soluble nuclear salts (usually uranium sulfate or uranium nitrate) are dissolved in water. The fuel is mixed with the coolant and the moderator, thus the name "homogeneo ...
intended as a laboratory instrument to test
critical mass
In nuclear engineering, a critical mass is the smallest amount of fissile material needed for a sustained nuclear chain reaction. The critical mass of a fissionable material depends upon its nuclear properties (specifically, its nuclear fissi ...
calculations and the effect of various
tamper materials. It was the first reactor to use
enriched uranium
Enriched uranium is a type of uranium in which the percent composition of uranium-235 (written 235U) has been increased through the process of isotope separation. Naturally occurring uranium is composed of three major isotopes: uranium-238 (238 ...
as a fuel, and the first to use liquid fuel in the form of soluble
uranium sulfate dissolved in water. Christy estimated that it would require of pure
uranium-235
Uranium-235 (235U or U-235) is an isotope of uranium making up about 0.72% of natural uranium. Unlike the predominant isotope uranium-238, it is fissile, i.e., it can sustain a nuclear chain reaction. It is the only fissile isotope that exis ...
, a figure he subsequently revised to . When the reactor went critical on May 9, 1944 with , the accuracy of Christy's figures raised the laboratory's confidence in T Division's calculations.
The discovery by
Emilio Segrè
Emilio Gino Segrè (1 February 1905 – 22 April 1989) was an Italian-American physicist and Nobel laureate, who discovered the elements technetium and astatine, and the antiproton, a subatomic antiparticle, for which he was awarded the Nobel ...
's group in April and May 1944 of high levels of
plutonium-240
Plutonium-240 ( or Pu-240) is an isotope of plutonium formed when plutonium-239 captures a neutron. The detection of its spontaneous fission led to its discovery in 1944 at Los Alamos and had important consequences for the Manhattan Project.
240 ...
in reactor-produced plutonium meant that an
implosion-type nuclear weapon
Nuclear weapon designs are physical, chemical, and engineering arrangements that cause the physics package of a nuclear weapon to detonate. There are three existing basic design types:
* pure fission weapons, the simplest and least technically ...
was required, but studies indicated that this would be extremely difficult to achieve. By August 1944, the calculations had been made of how an ideal spherical implosion would work; the problem was how to make it work in the real world where
jets and
spall
Spall are fragments of a material that are broken off a larger solid body. It can be produced by a variety of mechanisms, including as a result of projectile impact, corrosion, weathering, cavitation, or excessive rolling pressure (as in a ball ...
ing were a problem. Christy worked in
Rudolf Peierls
Sir Rudolf Ernst Peierls, (; ; 5 June 1907 – 19 September 1995) was a German-born British physicist who played a major role in Tube Alloys, Britain's nuclear weapon programme, as well as the subsequent Manhattan Project, the combined Allied ...
's T-1 Group, which studied the theory of implosion. He suggested the possibility of using a solid plutonium core that would form a critical mass when compressed. This was an ultra-conservative design that solved the problem of jets by brute force. It became known as the "
Christy pit" or "Christy gadget", "gadget" being the laboratory euphemism for a bomb. However the solid pit was intrinsically less efficient than a hollow pit, and it required a
modulated neutron initiator
A modulated neutron initiator is a neutron source capable of producing a burst of neutrons on activation. It is a crucial part of some nuclear weapons, as its role is to "kick-start" the chain reaction at the optimal moment when the configuration i ...
to start the chain reaction. Christy worked with
Klaus Fuchs, Paul Stein and Hans Bethe to develop a suitable initiator design, which became known as an "urchin".
The Gadget
Trinity was the code name of the first detonation of a nuclear weapon. It was conducted by the United States Army at 5:29 a.m. on July 16, 1945, as part of the Manhattan Project. The test was conducted in the Jornada del Muerto desert abo ...
used in the
Trinity nuclear test
Trinity was the code name of the first detonation of a nuclear weapon. It was conducted by the United States Army at 5:29 a.m. on July 16, 1945, as part of the Manhattan Project. The test was conducted in the Jornada del Muerto desert abo ...
and the
Fat Man
"Fat Man" (also known as Mark III) is the codename for the type of nuclear bomb the United States detonated over the Japanese city of Nagasaki on 9 August 1945. It was the second of the only two nuclear weapons ever used in warfare, the fir ...
used in the
atomic bombing of Nagasaki used Christy pits.
Later in life, Christy agreed to give a number of both
oral history
Oral history is the collection and study of historical information about individuals, families, important events, or everyday life using audiotapes, videotapes, or transcriptions of planned interviews. These interviews are conducted with people wh ...
and video interviews in which he discussed his role in the Manhattan Project and latter interests.
Later life
![NASA-project-orion-artist](https://upload.wikimedia.org/wikipedia/commons/6/61/NASA-project-orion-artist.jpg)
After the war ended, Christy accepted an
assistant professor
Assistant Professor is an academic rank just below the rank of an associate professor used in universities or colleges, mainly in the United States and Canada.
Overview
This position is generally taken after earning a doctoral degree and general ...
ship at the University of Chicago, at a salary of $5,000 per annum, twice what he had been making before the war. He moved back to Chicago in February 1946, but suitable housing was hard to find in the immediate post-war period, and Christy and his family shared a mansion with
Edward Teller
Edward Teller ( hu, Teller Ede; January 15, 1908 – September 9, 2003) was a Hungarian-American theoretical physicist who is known colloquially as "the father of the hydrogen bomb" (see the Teller–Ulam design), although he did not care fo ...
and his family.
Before the war, Oppenheimer had spent part of each year teaching at
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 ...
(Caltech). Christy was one of Oppenheimer's Berkeley students who made the trip down to
Pasadena, California
Pasadena ( ) is a city in Los Angeles County, California, northeast of downtown Los Angeles. It is the most populous city and the primary cultural center of the San Gabriel Valley. Old Pasadena is the city's original commercial district.
I ...
, each year to continue studying with Oppenheimer. After the war, Oppenheimer decided that with his additional responsibilities he could no longer continue this arrangement. The head of the W. K. Kellogg Radiation Laboratory at Caltech,
Charles Lauritsen
Charles Christian Lauritsen (April 4, 1892 – April 13, 1968) was a Danish/American physicist.
Early life and career
Lauritsen was born in Holstebro, Denmark and studied architecture at the Odense Tekniske Skole, graduating in 1911. In 191 ...
therefore asked Oppenheimer for the name of a theoretical physicist that he would recommend as a replacement. Oppenheimer recommended Christy.
Willy Fowler then approached Christy with an offer of a full-time position at Caltech at $5,400 per annum, and Christy accepted. He remained at Caltech for the rest of his academic career. The drawback to working at Caltech was that neither Lauritsen nor Fowler was a theoretical physicist, so a heavy workload fell on Christy. This was recognised by a pay raise to $10,000 per annum in 1954.
Christy joined Oppenheimer, Lauritsen and
Robert Bacher, who joined the faculty at Caltech in 1949, in Project Vista, a detailed 1951 study on how Western Europe could be defended against the
Soviet Union
The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen national ...
.
Christy was distraught at the outcome of the 1954
Oppenheimer security hearing
The Oppenheimer security hearing was a 1954 proceeding by the United States Atomic Energy Commission (AEC) that explored the background, actions, and associations of J. Robert Oppenheimer, the American scientist who had headed the Los Alamos Lab ...
. When he encountered Teller, who had testified against Oppenheimer, at Los Alamos in 1954, Christy publicly refused to shake Teller's hand. "I viewed Oppenheimer as a god", he later recalled, "and I was sure that he was not a treasonable person."
Asked about his relationship with Teller in 2006, Christy said:
In 1956, Christy was one of a number of scientists from Caltech who publicly called for a ban on atmospheric nuclear testing. The 1963
Partial Nuclear Test Ban Treaty
The Partial Test Ban Treaty (PTBT) is the abbreviated name of the 1963 Treaty Banning Nuclear Weapon Tests in the Atmosphere, in Outer Space and Under Water, which prohibited all test detonations of nuclear weapons except for those conducted ...
that Christy advocated put an end to one of his most unusual projects. He worked with
Freeman Dyson
Freeman John Dyson (15 December 1923 – 28 February 2020) was an English-American theoretical physicist and mathematician known for his works in quantum field theory, astrophysics, random matrices, mathematical formulation of quantum m ...
on
Project Orion, the design of a spacecraft propelled by atomic bombs.
![Heic1323a -1243686232](https://upload.wikimedia.org/wikipedia/commons/a/aa/Heic1323a_-1243686232.jpg)
During a sabbatical year at
Princeton University
Princeton University is a private university, private research university in Princeton, New Jersey. Founded in 1746 in Elizabeth, New Jersey, Elizabeth as the College of New Jersey, Princeton is the List of Colonial Colleges, fourth-oldest ins ...
in 1960, Christy began an investigation of
Cepheid variable
A Cepheid variable () is a type of star that pulsates radially, varying in both diameter and temperature and producing changes in brightness with a well-defined stable period and amplitude.
A strong direct relationship between a Cepheid varia ...
s and the smaller
RR Lyrae variable
RR Lyrae variables are periodic variable stars, commonly found in globular clusters. They are used as standard candles to measure (extra) galactic distances, assisting with the cosmic distance ladder. This class is named after the prototype and ...
s, classes of luminous
variable stars
A variable star is a star whose brightness as seen from Earth (its apparent magnitude) changes with time. This variation may be caused by a change in emitted light or by something partly blocking the light, so variable stars are classified as e ...
. At the time it was a mystery as to why they varied. He used the knowledge of the
hydrodynamics
In physics and engineering, fluid dynamics is a subdiscipline of fluid mechanics that describes the flow of fluids—liquids and gases. It has several subdisciplines, including ''aerodynamics'' (the study of air and other gases in motion) and ...
of implosion gained at Los Alamos during the war to explain this phenomenon. This earned him the
Royal Astronomical Society
(Whatever shines should be observed)
, predecessor =
, successor =
, formation =
, founder =
, extinction =
, merger =
, merged =
, type = NGO ...
's
Eddington Medal
The Eddington Medal is awarded by the Royal Astronomical Society for investigations of outstanding merit in theoretical astrophysics. It is named after Sir Arthur Eddington. First awarded in 1953, the frequency of the prize has varied over the year ...
for contributions to theoretical astrophysics in 1967.
Christy was appointed vice president and
Provost of Caltech in 1970. Under Christy and President
Harold Brown Caltech expanded its
humanities
Humanities are academic disciplines that study aspects of human society and culture. In the Renaissance, the term contrasted with divinity and referred to what is now called classics, the main area of secular study in universities at the t ...
and added
economics
Economics () is the social science that studies the Production (economics), production, distribution (economics), distribution, and Consumption (economics), consumption of goods and services.
Economics focuses on the behaviour and intera ...
to allow (or perhaps to compel—undergrads were required to take 25% of their units in "humanities") students to broaden their education. He had David Morrisroe appointed as vice president for Financial Affairs, and they steered Caltech through the financially stringent 1970s. The first women were admitted as undergraduates in Fall 1970.
When
Jenijoy La Belle
Jenijoy La Belle (born 1943) is an American professor emeritus of English literature at California Institute of Technology. Hired in 1969, she became the first female professor in Caltech history. She is known for her fight to attain tenure in th ...
, who had been hired in 1969 but refused tenure in 1974, filed suit with the
Equal Employment Opportunity Commission
The U.S. Equal Employment Opportunity Commission (EEOC) is a federal agency that was established via the Civil Rights Act of 1964 to administer and enforce civil rights laws against workplace discrimination. The EEOC investigates discrimination ...
, Christy pressed for the case to be settled and La Belle to be given tenure. The EEOC ruled against Caltech in 1977, adding that she had been paid less than male colleagues. La Belle received tenure in 1979.
In 1970 he became romantically involved with
Inge-Juliana Sackman, a fellow physicist 26 years his junior. He divorced Dagmar in early 1971, and married Juliana on August 4, 1973. They had two daughters, Illia Juliana Lilly Christy, born in 1974, and Alexandra Roberta (Alexa) Christy, born in 1976.
Christy briefly became acting President of Caltech in 1977 when Brown left to become
Secretary of Defense. Christy returned to teaching after
Marvin L. Goldberger
Marvin Leonard "Murph" Goldberger (October 22, 1922 – November 26, 2014) was an American theoretical physicist and former president of the California Institute of Technology.
Biography
Goldberger was born in Chicago, Illinois. He went on to re ...
became president in 1978. He became Institute Professor of Theoretical Physics in 1983, and Institute Professor Emeritus in 1986.
Christy died on October 3, 2012. He was survived by his wife Juliana, their two daughters, Illia and Alexa, and his two sons, Peter and Ted.
He was buried at Mountain View Cemetery in
Altadena, California
Altadena () ("Alta", Spanish for "Upper", and "dena" from Pasadena) is an unincorporated area and census-designated place in the Verdugo Mountains region of Los Angeles County, California, approximately 14 miles (23 km) from the downtown ...
.
Notes
References
*
*
*
External links
1983 Audio Interview with Robert Christy by Martin SherwinVoices of the Manhattan Project
*
Interview with Robert F. ChristyCaltech Oral Histories, Caltech Archives, California Institute of Technology.
{{DEFAULTSORT:Christy, Robert
1916 births
2012 deaths
American astrophysicists
American astronomers
Members of the United States National Academy of Sciences
American physicists
Presidents of the California Institute of Technology
Manhattan Project people
University of Chicago faculty
University of British Columbia Faculty of Science alumni
UC Berkeley College of Letters and Science alumni
Fellows of the American Physical Society
Canadian emigrants to the United States