Gerald Maurice Clemence
Encyclopedia
Gerald Maurice Clemence was an American astronomer
. Inspired by the life and work of Simon Newcomb
, his career paralleled the huge advances in astronomy brought about by the advent of the electronic computer. Clemence did much to revive the prestige of the U.S. Nautical Almanac Office.
near Greenville, Rhode Island
, Gerald's parents were Richard R. Clemence and his wife, Lora, née Oatley. Much of his elementary education was at home with his mother, herself a schoolteacher, and he learned about astronomy from his own enthusiastic reading. Clemence attended Brown University
and read mathematics
, achieving a PhB
degree in 1930. In his own words, "as a recreation", he took the civil service examination for the job description
"astronomer" and finished first out of fifty candidates, winning appointment at the United States Naval Observatory
. Taking up the post, he married Edith Melvina Vail, a nurse, in 1929.
, Clemence was assigned to work under H. R. Morgan. George William Hill
had computed the orbit
s of Jupiter
and Saturn
in the nineteenth century and Newcomb has completed the work for the other planet
s of the solar system
. However, there was now almost fifty years of new observational data and Clemence set to recalculate the orbital elements
of Mercury
to provide more accurate
predictions. His results, published in 1943, clearly showed the perihelion precession of Mercury predicted by the general theory of relativity.
Clemence identified systematic errors in the predictions of Mars
' path. The residual
s showed a marked periodicity
and Clemence concluded that the Fourier series
on which the predictions were based was wrong. Clemence set out to derive a new series from scratch using the methods detailed by Hill and Peter Andreas Hansen
in the nineteenth century. The calculations were carried out with "a lead pencil, large sheets of computing paper, [and] a hand-operated Millionaire desk calculator
". Though electronic calculators were available towards the end of the project, the calculations took twelve years.
was appointed as director of the Nautical Almanac Office in 1940 and immediately imported his enthusiasm for using punched card
machines for scientific calculation. Clemence was an early senior appointment to the new regime and soon saw the potential of electronic computation, using it initially on his Mars work but increasingly on the military work whose priority escallated following the entry of the U.S. into World War II
.
Clemence was appointed assistant director in 1942 and was joined on the staff by Paul Herget
. The pair worked on calculating mathematical table
s and developed the optimum-interval technique to construct tables calculated at non-constant intervals and for which linear interpolation
was everywhere legitimate.
In 1945, Eckert left for the IBM
-sponsored computing laboratory at Columbia University
and Herget became director of the Cincinnati Observatory
. Clemence was promoted to director of the Nautical Almanac Office, the post once held by his role-model Newcomb, and proved an able and energetic administrator.
between Clemence's office, Eckert's group at Columbia and Yale University Observatory
, under the direction of Dirk Brouwer
, a former collaborator of Eckert's on punched cards.
, astronomical constant
s and time measurement, as well as collaborating on two text books.
However, Clemence's passion for research ultimately led him to relinquish his managerial roles in 1962, and, in 1963 Brouwer found him a post at Yale. Here, Clemence continued his work on the perturbation theory
of the Earth's orbit but it was interrupted, never to be completed, in 1966 when Brouwer's death demanded that Clemence take over the administration of the department.
He died in Providence, Rhode Island
on November 22, 1974, after an illness of several months.
, accomplished at violin
, piano
and organ
. He was also a keen railfan
.
Astronomer
An astronomer is a scientist who studies celestial bodies such as planets, stars and galaxies.Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using...
. Inspired by the life and work of Simon Newcomb
Simon Newcomb
Simon Newcomb was a Canadian-American astronomer and mathematician. Though he had little conventional schooling, he made important contributions to timekeeping as well as writing on economics and statistics and authoring a science fiction novel.-Early life:Simon Newcomb was born in the town of...
, his career paralleled the huge advances in astronomy brought about by the advent of the electronic computer. Clemence did much to revive the prestige of the U.S. Nautical Almanac Office.
Early life
Born on a farmFarm
A farm is an area of land, or, for aquaculture, lake, river or sea, including various structures, devoted primarily to the practice of producing and managing food , fibres and, increasingly, fuel. It is the basic production facility in food production. Farms may be owned and operated by a single...
near Greenville, Rhode Island
Greenville, Rhode Island
Greenville is a village and census-designated place in the town of Smithfield in Providence County, Rhode Island, United States. The population was 8,626 at the 2000 census...
, Gerald's parents were Richard R. Clemence and his wife, Lora, née Oatley. Much of his elementary education was at home with his mother, herself a schoolteacher, and he learned about astronomy from his own enthusiastic reading. Clemence attended Brown University
Brown University
Brown University is a private, Ivy League university located in Providence, Rhode Island, United States. Founded in 1764 prior to American independence from the British Empire as the College in the English Colony of Rhode Island and Providence Plantations early in the reign of King George III ,...
and read mathematics
Mathematics
Mathematics is the study of quantity, space, structure, and change. Mathematicians seek out patterns and formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proofs, which are arguments sufficient to convince other mathematicians of their validity...
, achieving a PhB
Bachelor of Philosophy
Bachelor of Philosophy is the title of an academic degree. The degree usually involves considerable research, either through a thesis or supervised research projects...
degree in 1930. In his own words, "as a recreation", he took the civil service examination for the job description
Job description
A job description is a list that a person might use for general tasks, or functions, and responsibilities of a position. It may often include to whom the position reports, specifications such as the qualifications or skills needed by the person in the job, or a salary range...
"astronomer" and finished first out of fifty candidates, winning appointment at the United States Naval Observatory
United States Naval Observatory
The United States Naval Observatory is one of the oldest scientific agencies in the United States, with a primary mission to produce Positioning, Navigation, and Timing for the U.S. Navy and the U.S. Department of Defense...
. Taking up the post, he married Edith Melvina Vail, a nurse, in 1929.
Mercury and Mars
After initial work in the Time Service Department, alongside William MarkowitzWilliam Markowitz
William Markowitz was an American astronomer, principally known for his work on the standardization of time....
, Clemence was assigned to work under H. R. Morgan. George William Hill
George William Hill
George William Hill , was an American astronomer and mathematician.Hill was born in New York City, New York to painter and engraver John William Hill. and Catherine Smith Hill. He moved to West Nyack with his family when he was eight years old. After attending high school, Hill graduated from...
had computed the orbit
Orbit
In physics, an orbit is the gravitationally curved path of an object around a point in space, for example the orbit of a planet around the center of a star system, such as the Solar System...
s of Jupiter
Jupiter
Jupiter is the fifth planet from the Sun and the largest planet within the Solar System. It is a gas giant with mass one-thousandth that of the Sun but is two and a half times the mass of all the other planets in our Solar System combined. Jupiter is classified as a gas giant along with Saturn,...
and Saturn
Saturn
Saturn is the sixth planet from the Sun and the second largest planet in the Solar System, after Jupiter. Saturn is named after the Roman god Saturn, equated to the Greek Cronus , the Babylonian Ninurta and the Hindu Shani. Saturn's astronomical symbol represents the Roman god's sickle.Saturn,...
in the nineteenth century and Newcomb has completed the work for the other planet
Planet
A planet is a celestial body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighbouring region of planetesimals.The term planet is ancient, with ties to history, science,...
s of the solar system
Solar System
The Solar System consists of the Sun and the astronomical objects gravitationally bound in orbit around it, all of which formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago. The vast majority of the system's mass is in the Sun...
. However, there was now almost fifty years of new observational data and Clemence set to recalculate the orbital elements
Orbital elements
Orbital elements are the parameters required to uniquely identify a specific orbit. In celestial mechanics these elements are generally considered in classical two-body systems, where a Kepler orbit is used...
of Mercury
Mercury (planet)
Mercury is the innermost and smallest planet in the Solar System, orbiting the Sun once every 87.969 Earth days. The orbit of Mercury has the highest eccentricity of all the Solar System planets, and it has the smallest axial tilt. It completes three rotations about its axis for every two orbits...
to provide more accurate
Accuracy and precision
In the fields of science, engineering, industry and statistics, the accuracy of a measurement system is the degree of closeness of measurements of a quantity to that quantity's actual value. The precision of a measurement system, also called reproducibility or repeatability, is the degree to which...
predictions. His results, published in 1943, clearly showed the perihelion precession of Mercury predicted by the general theory of relativity.
Clemence identified systematic errors in the predictions of Mars
Mars
Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...
' path. The residual
Errors and residuals in statistics
In statistics and optimization, statistical errors and residuals are two closely related and easily confused measures of the deviation of a sample from its "theoretical value"...
s showed a marked periodicity
Frequency
Frequency is the number of occurrences of a repeating event per unit time. It is also referred to as temporal frequency.The period is the duration of one cycle in a repeating event, so the period is the reciprocal of the frequency...
and Clemence concluded that the Fourier series
Fourier series
In mathematics, a Fourier series decomposes periodic functions or periodic signals into the sum of a set of simple oscillating functions, namely sines and cosines...
on which the predictions were based was wrong. Clemence set out to derive a new series from scratch using the methods detailed by Hill and Peter Andreas Hansen
Peter Andreas Hansen
Peter Andreas Hansen was a Danish astronomer, was born at Tønder, Schleswig.-Biography:The son of a goldsmith, Hansen learned the trade of a watchmaker at Flensburg, and exercised it at Berlin and Tønder, 1818–1820...
in the nineteenth century. The calculations were carried out with "a lead pencil, large sheets of computing paper, [and] a hand-operated Millionaire desk calculator
The Millionaire Calculator
The Millionaire calculator was the first commercially successful mechanical calculator that could perform a direct multiplication. It was in production from 1893 to 1935 with a total of about five thousand machines manufactured.- History :...
". Though electronic calculators were available towards the end of the project, the calculations took twelve years.
Nautical Almanac Office
Wallace John EckertWallace John Eckert
Wallace John Eckert was an American astronomer, who directed the Thomas J. Watson Astronomical Computing Bureau at Columbia University which evolved into the research division of IBM.-Life:...
was appointed as director of the Nautical Almanac Office in 1940 and immediately imported his enthusiasm for using punched card
Punched card
A punched card, punch card, IBM card, or Hollerith card is a piece of stiff paper that contains digital information represented by the presence or absence of holes in predefined positions...
machines for scientific calculation. Clemence was an early senior appointment to the new regime and soon saw the potential of electronic computation, using it initially on his Mars work but increasingly on the military work whose priority escallated following the entry of the U.S. into World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
.
Clemence was appointed assistant director in 1942 and was joined on the staff by Paul Herget
Paul Herget
Paul Herget was an American astronomer.Herget taught astronomy at the University of Cincinnati. He was a pioneer in the use of machine methods, and eventually digital computers, in the solving of scientific and specifically astronomical problems .During World War II he applied these same talents...
. The pair worked on calculating mathematical table
Mathematical table
Before calculators were cheap and plentiful, people would use mathematical tables —lists of numbers showing the results of calculation with varying arguments— to simplify and drastically speed up computation...
s and developed the optimum-interval technique to construct tables calculated at non-constant intervals and for which linear interpolation
Linear interpolation
Linear interpolation is a method of curve fitting using linear polynomials. Lerp is an abbreviation for linear interpolation, which can also be used as a verb .-Linear interpolation between two known points:...
was everywhere legitimate.
In 1945, Eckert left for the IBM
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
-sponsored computing laboratory at Columbia University
Columbia University
Columbia University in the City of New York is a private, Ivy League university in Manhattan, New York City. Columbia is the oldest institution of higher learning in the state of New York, the fifth oldest in the United States, and one of the country's nine Colonial Colleges founded before the...
and Herget became director of the Cincinnati Observatory
Cincinnati Observatory
The Cincinnati Observatory, located in Cincinnati, Ohio on top of Mt. Lookout. It consists of two observatory buildings housing an 11 inch and 16 inch aperture refracting telescope. It is the oldest professional observatory in the United States...
. Clemence was promoted to director of the Nautical Almanac Office, the post once held by his role-model Newcomb, and proved an able and energetic administrator.
Research collaboration
In 1947, there began an intense period of cooperative research on celestial mechanicsCelestial mechanics
Celestial mechanics is the branch of astronomy that deals with the motions of celestial objects. The field applies principles of physics, historically classical mechanics, to astronomical objects such as stars and planets to produce ephemeris data. Orbital mechanics is a subfield which focuses on...
between Clemence's office, Eckert's group at Columbia and Yale University Observatory
Yale University Observatory
-History:Yale's first observatory, the Atheneum, was situated in a tower, which from 1830 housed Yale's first and America's largest refractor, a Dollond donated by Sheldon Clark. With this telescope Olmsted and Elias Loomis made the first American sighting of the return of Halley's Comet in 1835....
, under the direction of Dirk Brouwer
Dirk Brouwer
Dirk Brouwer was a Dutch-American astronomer.He received his Ph.D. in 1927 at Leiden University in the Netherlands and then went to Yale University...
, a former collaborator of Eckert's on punched cards.
Later career
In 1958, Clemence was appointed first scientific director of the U.S. Naval Observatory, a post he again addressed with enthusiasm and vigour. His own original research necessarily took a lower profile but he continued to publish on relativityTheory of relativity
The theory of relativity, or simply relativity, encompasses two theories of Albert Einstein: special relativity and general relativity. However, the word relativity is sometimes used in reference to Galilean invariance....
, astronomical constant
Astronomical constant
An astronomical constant is a physical constant used in astronomy. A formal set of constants, along with recommended values, was defined by the International Astronomical Union in 1976, and a new set of recommended values was produced in 1994...
s and time measurement, as well as collaborating on two text books.
However, Clemence's passion for research ultimately led him to relinquish his managerial roles in 1962, and, in 1963 Brouwer found him a post at Yale. Here, Clemence continued his work on the perturbation theory
Perturbation theory
Perturbation theory comprises mathematical methods that are used to find an approximate solution to a problem which cannot be solved exactly, by starting from the exact solution of a related problem...
of the Earth's orbit but it was interrupted, never to be completed, in 1966 when Brouwer's death demanded that Clemence take over the administration of the department.
He died in Providence, Rhode Island
Providence, Rhode Island
Providence is the capital and most populous city of Rhode Island and was one of the first cities established in the United States. Located in Providence County, it is the third largest city in the New England region...
on November 22, 1974, after an illness of several months.
Personality
Clemence was reserved and dignified, conservative in manner and appearance. In writing he was concise and accurate. He was sincere and forthright with a code of ethics inherited from his parents. He was a family man, father of two sons, and always maintained contact with his three brothers and his sister. He was a keen, and self-taught, musicianMusician
A musician is an artist who plays a musical instrument. It may or may not be the person's profession. Musicians can be classified by their roles in performing music and writing music.Also....* A person who makes music a profession....
, accomplished at violin
Violin
The violin is a string instrument, usually with four strings tuned in perfect fifths. It is the smallest, highest-pitched member of the violin family of string instruments, which includes the viola and cello....
, piano
Piano
The piano is a musical instrument played by means of a keyboard. It is one of the most popular instruments in the world. Widely used in classical and jazz music for solo performances, ensemble use, chamber music and accompaniment, the piano is also very popular as an aid to composing and rehearsal...
and organ
Organ (music)
The organ , is a keyboard instrument of one or more divisions, each played with its own keyboard operated either with the hands or with the feet. The organ is a relatively old musical instrument in the Western musical tradition, dating from the time of Ctesibius of Alexandria who is credited with...
. He was also a keen railfan
Railfan
A railfan or rail buff , railway enthusiast or railway buff , or trainspotter , is a person interested in a recreational capacity in rail transport...
.
Offices, awards and honors
- Fellow of the Royal Astronomical SocietyRoyal Astronomical SocietyThe Royal Astronomical Society is a learned society that began as the Astronomical Society of London in 1820 to support astronomical research . It became the Royal Astronomical Society in 1831 on receiving its Royal Charter from William IV...
(UK), (1946); - Honorary member of the Royal Astronomical Society of CanadaRoyal Astronomical Society of CanadaThe Royal Astronomical Society of Canada is a national, non-profit, charitable organization devoted to the advancement of astronomy and related sciences. At present, there are 29 local branches of the Society, called centres, located in towns and cities across the country from St. John's,...
, (1946); - Member of the National Academy of SciencesUnited States National Academy of SciencesThe National Academy of Sciences is a corporation in the United States whose members serve pro bono as "advisers to the nation on science, engineering, and medicine." As a national academy, new members of the organization are elected annually by current members, based on their distinguished and...
, (1952); - Fellow of the American Academy of Arts and SciencesAmerican Academy of Arts and SciencesThe American Academy of Arts and Sciences is an independent policy research center that conducts multidisciplinary studies of complex and emerging problems. The Academy’s elected members are leaders in the academic disciplines, the arts, business, and public affairs.James Bowdoin, John Adams, and...
, (1955); - President American Astronomical SocietyAmerican Astronomical SocietyThe American Astronomical Society is an American society of professional astronomers and other interested individuals, headquartered in Washington, DC...
, (1958–1960); - Gold Medal of the Royal Astronomical SocietyGold Medal of the Royal Astronomical Society-History:In the early years, more than one medal was often awarded in a year, but by 1833 only one medal was being awarded per year. This caused a problem when Neptune was discovered in 1846, because many felt an award should jointly be made to John Couch Adams and Urbain Le Verrier...
, (1965); - Editor of the Astronomical JournalAstronomical JournalThe Astronomical Journal is a peer-reviewed monthly scientific journal owned by the American Astronomical Society and currently published by Institute of Physics Publishing. It is one of the premier journals for astronomy in the world...
, (1969–1974); - James Craig Watson MedalJames Craig Watson Medalthumb|right|400px|James Craig Watson MedalThe James Craig Watson Medal was established by the bequest of James Craig Watson, and is awarded by the U.S. National Academy of Sciences for contributions to astronomy.The recipients have been:-External links:*...
of the National Academy of Sciences, (1975); - AsteroidAsteroidAsteroids are a class of small Solar System bodies in orbit around the Sun. They have also been called planetoids, especially the larger ones...
1919 Clemence1919 Clemence1919 Clemence is an inner main-belt asteroid discovered on September 16, 1971 by Gibson, J. and Carlos Ulrrico Cesco at El Leoncito. It is named for American astronomer Gerald Maurice Clemence.- External links :...
is named for him.