Leland Cunningham
Encyclopedia
| 2211 Hanuman 2211 Hanuman 2211 Hanuman is a main-belt asteroid discovered on November 26, 1951 by Leland E. Cunningham at Mount Wilson.- External links :*... |
November 26, 1951 |
| 6939 Lestone 6939 Lestone 6939 Lestone is a main-belt asteroid discovered on September 22, 1952 by Leland E. Cunningham at Mount Wilson.- External links :*... |
September 22, 1952 |
| (46512) 1951 QD | August 31, 1951 |
| September 23, 1952 |
Leland Erskin Cunningham (born 19 February 1904 in Wiscasset, Maine; died May 31, 1989 in Richmond, California
Richmond, California
Richmond is a city in western Contra Costa County, California, United States. The city was incorporated on August 7, 1905. It is located in the East Bay, part of the San Francisco Bay Area. It is a residential inner suburb of San Francisco, as well as the site of heavy industry, which has been...
) was an American astronomer
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...
. In a career spanning 50 years, he became an authority on orbit theory and on precise measurements of the orbits of comets, planets, satellites, and space probes. He was also an early authority on electronic digital computers and assisted in their construction and use in orbit calculations.
Cunningham began his career as an assistant to astronomer Fred Whipple
Fred Lawrence Whipple
Fred Lawrence Whipple was an American astronomer, who worked at the Harvard College Observatory for over 70 years...
at Harvard University
Harvard University
Harvard University is a private Ivy League university located in Cambridge, Massachusetts, United States, established in 1636 by the Massachusetts legislature. Harvard is the oldest institution of higher learning in the United States and the first corporation chartered in the country...
. In this capacity, he became a driving force in using automated calculating methods for computing celestial orbits.
During 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...
, Cunningham joined the Ballistics Research Laboratory (BRL) at Aberdeen Proving Ground
Aberdeen Proving Ground
Aberdeen Proving Ground is a United States Army facility located near Aberdeen, Maryland, . Part of the facility is a census-designated place , which had a population of 3,116 at the 2000 census.- History :...
in Aberdeen, Maryland
Aberdeen, Maryland
As of the census of 2000, there were 13,842 people, 5,475 households, and 3,712 families residing in the city. The population density was 2,166.2 people per square mile . There were 5,894 housing units at an average density of 922.4 per square mile...
, putting his expertise in number crunching toward the war effort. The computational needs of the BRL revolved around the compilation of artillery
Artillery
Originally applied to any group of infantry primarily armed with projectile weapons, artillery has over time become limited in meaning to refer only to those engines of war that operate by projection of munitions far beyond the range of effect of personal weapons...
firing tables and bombing tables and employed a number of methods, human
Human computer
The term "computer", in use from the mid 17th century, meant "one who computes": a person performing mathematical calculations, before electronic computers became commercially available....
, analog
Analog computer
An analog computer is a form of computer that uses the continuously-changeable aspects of physical phenomena such as electrical, mechanical, or hydraulic quantities to model the problem being solved...
, and digital; the backlog of computation jobs was so overwhelming that a satellite computation center was opened at the University of Pennsylvania
University of Pennsylvania
The University of Pennsylvania is a private, Ivy League university located in Philadelphia, Pennsylvania, United States. Penn is the fourth-oldest institution of higher education in the United States,Penn is the fourth-oldest using the founding dates claimed by each institution...
's Moore School of Electrical Engineering
Moore School of Electrical Engineering
The Moore School of Electrical Engineering at the University of Pennsylvania came into existence as a result of an endowment from Alfred Fitler Moore on June 4, 1923. It was granted to Penn's School of Electrical Engineering, located in the Towne Building...
in Philadelphia, and improved methods of automated computation were sought. Cunningham was present at the June 1943 meeting at which J. Presper Eckert
J. Presper Eckert
John Adam Presper "Pres" Eckert Jr. was an American electrical engineer and computer pioneer. With John Mauchly he invented the first general-purpose electronic digital computer , presented the first course in computing topics , founded the first commercial computer company , and...
, John Mauchly
John Mauchly
John William Mauchly was an American physicist who, along with J. Presper Eckert, designed ENIAC, the first general purpose electronic digital computer, as well as EDVAC, BINAC and UNIVAC I, the first commercial computer made in the United States.Together they started the first computer company,...
, and Lt. Herman Goldstine proposed the construction of the ENIAC
ENIAC
ENIAC was the first general-purpose electronic computer. It was a Turing-complete digital computer capable of being reprogrammed to solve a full range of computing problems....
; the program was agreed upon the same day. Initial plans for the machine called for it to have a precision of 5 decimal digits, but Cunningham's input compelled the inventors to design it with a precision of 10 decimal digits.
From 1945 to 1946, Cunningham served on the BRL's Computations Committee at Aberdeen Proving Grounds in Maryland
Maryland
Maryland is a U.S. state located in the Mid Atlantic region of the United States, bordering Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware to its east...
, a group established as part of the Ballistics Research Laboratory to prepare the ENIAC
ENIAC
ENIAC was the first general-purpose electronic computer. It was a Turing-complete digital computer capable of being reprogrammed to solve a full range of computing problems....
for utilization following its completion the Moore School; the other Computations Committee members were Haskell Curry
Haskell Curry
Haskell Brooks Curry was an American mathematician and logician. Curry is best known for his work in combinatory logic; while the initial concept of combinatory logic was based on a single paper by Moses Schönfinkel, much of the development was done by Curry. Curry is also known for Curry's...
, Derrick Henry Lehmer
Derrick Henry Lehmer
Derrick Henry "Dick" Lehmer was an American mathematician who refined Édouard Lucas' work in the 1930s and devised the Lucas–Lehmer test for Mersenne primes...
, and Franz Alt
Franz Alt (mathematician)
Franz Leopold Alt was an Austrian-born American mathematician who made major contributions to computer science in its early days...
. His duties included supervision of the laboratory's shop of 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...
punched card calculating equipment, which was busy calculating ballistics trajectories, and writing sample problem specifications for benchmark
Benchmark (computing)
In computing, a benchmark is the act of running a computer program, a set of programs, or other operations, in order to assess the relative performance of an object, normally by running a number of standard tests and trials against it...
ing the ENIAC.
In 1946, Cunningham followed Lehmer to Berkeley
Berkeley, California
Berkeley is a city on the east shore of the San Francisco Bay in Northern California, United States. Its neighbors to the south are the cities of Oakland and Emeryville. To the north is the city of Albany and the unincorporated community of Kensington...
where the latter was a professor, joining the Department of Astronomy at the University of California, Berkeley
University of California, Berkeley
The University of California, Berkeley , is a teaching and research university established in 1868 and located in Berkeley, California, USA...
(a department that had 10 members in 1964–1965), and at one point serving as the department's chair. With Lehmer, Cunningham planned the construction of the California Digital Computer (CALDIC
CALDIC
CALDIC was an electronic digital computer built with the assistance of the Office of Naval Research at the University of California, Berkeley between 1951 and 1955 to assist and enhance research being conducted at the university with a platform for high-speed computing.CALDIC was designed to be...
).
Working with the Leuschner Observatory
Leuschner Observatory
Leuschner Observatory, originally called the Students' Observatory, is an observatory operated by the University of California, Berkeley. The observatory was built in 1886 on the Berkeley campus. For many years, it was directed by Armin Otto Leuschner, for whom the observatory was renamed in 1951...
in the 1950s and 1960s, Cunningham performed and published calculations of the orbits of comets. In particular, he showed that Comet Pereyra
Comet Pereyra
Comet Pereyra was a bright comet which appeared in 1963. It was a member of the Kreutz Sungrazers, a group of comets which pass extremely close to the Sun.- Discovery :...
and Comet Ikeya-Seki
Comet Ikeya-Seki
Comet Ikeya–Seki, formally designated C/1965 S1, 1965 VIII, and 1965f, was a long-period comet discovered independently by Kaoru Ikeya and Tsutomu Seki...
were sungrazers
Sungrazing comet
A sungrazing comet is a comet that passes extremely close to the Sun at perihelion – sometimes within a few thousand kilometres of the Sun's surface. While small sungrazers can be completely evaporated during such a close approach to the Sun, larger sungrazers can survive many perihelion passages...
similar to comets seen in 1668, 1843, 1880, and 1882.
Cunningham died on May 31, 1989, at the age of 85.