Grace Brewster Hopper (néeMurray; December 9, 1906 – January 1, 1992) was an Americancomputer scientist,mathematician, andUnited States Navyrear admiral.[1] She was a pioneer of computer programming. Hopper was the first to devise the theory of machine-independent programming languages, and used this theory to develop theFLOW-MATIC programming language andCOBOL, an earlyhigh-level programming language still in use today. She was also one of the first programmers on theHarvard Mark I computer. She is credited with writing the first computer manual, "A Manual of Operation for the Automatic Sequence Controlled Calculator."
Before joining the Navy, Hopper earned a Ph.D. in both mathematics and mathematical physics fromYale University and was a professor of mathematics atVassar College. She left her position at Vassar to join theUnited States Navy Reserve during World War II. Hopper began her computing career in 1944 as a member of the Harvard Mark I team, led byHoward H. Aiken. In 1949, she joined theEckert–Mauchly Computer Corporation and was part of the team that developed theUNIVAC I computer. At Eckert–Mauchly she managed the development of one of the firstCOBOL compilers.
She believed that programming should be simplified with an English-based computer programming language. Her compiler converted English terms intomachine code understood by computers. By 1952, Hopper had finished her programlinker (originally called acompiler), which was written for theA-0 System.[2][3][4][5] In 1954, Eckert–Mauchly chose Hopper to lead their department for automatic programming, and she led the release of some of the first compiled languages likeFLOW-MATIC. In 1959, she participated in theCODASYL consortium, helping to create a machine-independent programming language calledCOBOL, which was based on English words. Hopper promoted the use of the language throughout the 60s.
Grace Brewster Murray was born inNew York City. She was the eldest of three children. Her parents, Walter Fletcher Murray and Mary Campbell Van Horne, were ofScottish andDutch descent, and attendedWest End Collegiate Church.[12] Her great-grandfather, Alexander Wilson Russell, an admiral in the US Navy, fought in theBattle of Mobile Bay during theCivil War.[12]: 2–3
Grace was very curious as a child; this was a lifelong trait. At the age of seven, she decided to determine how an alarm clock worked and dismantled seven alarm clocks before her mother realized what she was doing (she was then limited to one clock).[13] Later in life, she was known for keeping a clock that ran backward; she explained, "Humans are allergic to change. They love to say, 'We've always done it this way.' I try to fight that. That's why I have a clock on my wall that runs counterclockwise."[14] For herpreparatory school education, she attended theHartridge School inPlainfield, New Jersey. Grace was initially rejected for early admission toVassar College at age 16 (because her test scores in Latin were too low), but she was admitted the next year. She graduatedPhi Beta Kappa from Vassar in 1928 with a bachelor's degree in mathematics and physics and earned her master's degree atYale University in 1930.
In 1930, Grace Murray marriedNew York University professor Vincent Foster Hopper (1906–1976); they divorced in 1945.[15][16] She did not marry again and retained his surname.
In 1934, Hopper earned a Ph.D. in mathematics from Yale[17] under the direction ofØystein Ore.[15][18] Herdissertation, "New Types of Irreducibility Criteria",[19] was published that year.[20] She began teaching mathematics at Vassar in 1931, and was promoted to associate professor in 1941.[21]
Hopper's name on a duty roster for the Bureau of Ships Computation Project at Harvard, which built and operated theMark I
Hopper tried to be commissioned in the Navy early inWorld War II, however she was turned down. At age 34, she was too old to enlist and her weight-to-height ratio was too low. She was also denied on the basis that her job as a mathematician and mathematics professor at Vassar College was valuable to the war effort.[22] During the war in 1943, Hopper obtained a leave of absence from Vassar and was sworn into the United States Navy Reserve; she was one of many women who volunteered to serve in theWAVES.[citation needed]
She had to get an exemption to be commissioned; she was 15 pounds (6.8 kg) below the Navy minimum weight of 120 pounds (54 kg). She reported in December and trained at the Naval Reserve Midshipmen's School atSmith College inNorthampton, Massachusetts. Hopper graduated first in her class in 1944, and was assigned to theBureau of Ships Computation Project atHarvard University as a lieutenant, junior grade. She served on theMark I computer programming staff headed byHoward H. Aiken.[citation needed]
Hopper and Aiken co-authored three papers on the Mark I, also known as the Automatic Sequence Controlled Calculator. Hopper's request to transfer to the regular Navy, out of WAVES, at the end of the war was denied due to being two years older than the cutoff age of 38. She continued to serve in the Navy Reserve. Hopper remained at the Harvard Computation Lab until 1949, turning down a full professorship at Vassar in favor of working as a research fellow under a Navy contract at Harvard.[23]
In 1949, Hopper became an employee of theEckert–Mauchly Computer Corporation as a senior mathematician and joined the team developing theUNIVAC I.[21] Hopper also served as UNIVAC director of Automatic Programming Development for Remington Rand. The UNIVAC was the first known large-scale electronic computer to be on the market in 1951.[24]
When Hopper recommended the development of a new programming language that would use entirely English words, she "was told very quickly that [she] couldn't do this because computers didn't understand English." Still, she persisted. "It's much easier for most people to write an English statement than it is to use symbols", she explained. "So I decided data processors ought to be able to write their programs in English, and the computers would translate them into machine code."[25]
Her idea was not accepted for three years. In the meantime, she published her first paper on the subject, compilers, in 1952. In the early 1950s, the company was taken over by theRemington Rand corporation, and it was while she was working for them that her originalcompiler work was done. The program was known as the A compiler and its first version wasA-0.[26]: 11
In 1952, she had an operational link-loader, which at the time was referred to as a compiler. She later said that "Nobody believed that", and that she "had a running compiler and nobody would touch it. They told me computers could only do arithmetic."[27]
In 1954 Hopper was named the company's first director of automatic programming.[21] Beginning in 1954, Hopper's work was influenced by theLaning and Zierler system, which was the first compiler to accept algebraic notation as input.[28] Her department released some of the first compiler-based programming languages, includingMATH-MATIC andFLOW-MATIC.[21]
Hopper said that her compilerA-0, "translated mathematical notation into machine code. Manipulating symbols was fine for mathematicians but it was no good for data processors who were not symbol manipulators. Very few people are really symbol manipulators. If they are, they become professional mathematicians, not data processors. It's much easier for most people to write an English statement than it is to use symbols. So I decided data processors ought to be able to write their programs in English, and the computers would translate them into machine code. That was the beginning ofCOBOL, acomputer language for data processors. I could say 'Subtract income tax from pay' instead of trying to write that in octal code or using all kinds of symbols.COBOL is the major language used today in data processing."[29]
In the spring of 1959, computer experts from industry and government were brought together in a two-day conference known as the Conference on Data Systems Languages (CODASYL). Hopper served as a technical consultant to the committee, and many of her former employees served on the short-term committee that defined the new languageCOBOL (an acronym forCOmmonBusiness-OrientedLanguage). The new language extended Hopper's FLOW-MATIC language with some ideas from theIBM equivalent,COMTRAN. Hopper's belief that programs should be written in a language that was close to English (rather than inmachine code or in languages close to machine code, such asassembly languages) was captured in the new business language, and COBOL went on to be the most ubiquitous business language to date.[30] Among the members of the committee that worked on COBOL wasMount Holyoke College alumnaJean E. Sammet.[31]
From 1967 to 1977, Hopper served as the director of the Navy Programming Languages Group in the Navy's Office of Information Systems Planning and was promoted to the rank ofcaptain in 1973. She developed validation software for COBOL and its compiler as part of a COBOL standardization program for the entire Navy.[23]
In the 1970s, Hopper advocated for the Defense Department to replace large, centralized systems with networks of small, distributed computers. Any user on any computer node could access common databases on the network.[26]: 119 She developed the implementation ofstandards for testing computer systems and components, most significantly for earlyprogramming languages such asFORTRAN and COBOL. The Navy tests for conformance to these standards led to significant convergence among the programming language dialects of the major computer vendors. In the 1980s, these tests (and their official administration) were assumed by the National Bureau of Standards (NBS), known today as theNational Institute of Standards and Technology (NIST).[citation needed]
Hopper being promoted to the rank of commodore in 1983
In accordance with Navy attrition regulations, Hopper retired from the Naval Reserve with the rank ofcommander at age 60 at the end of 1966.[32] She was recalled to active duty in August 1967 for a six-month period that turned into an indefinite assignment. She again retired in 1971 but was again asked to return to active duty in 1972. She was promoted tocaptain in 1973 byAdmiralElmo R. Zumwalt Jr.[33]
After a career that spanned more than 42 years, Hopper retired from the Navy on August 14, 1986.[40] At the time, she was the oldest serving member of the Navy. At a celebration held in Boston on theUSS Constitution to commemorate her retirement, Hopper was awarded theDefense Distinguished Service Medal, the highest non-combat decoration awarded by the Department of Defense.[41]
At the time of her retirement, she was the oldest active-duty commissioned officer in the United States Navy (79 years, eight months and five days), and had her retirement ceremony aboard the oldest commissioned ship in the United States Navy (188 years, 9 months, 23 days).[42]
After her retirement from the Navy, Hopper was hired as a senior consultant toDigital Equipment Corporation (DEC). Hopper was initially offered a position by Rita Yavinsky, but she insisted on going through the typical formal interview process. She then proposed in jest that she would be willing to accept a position which made her available on alternating Thursdays, exhibited at their museum of computing as a pioneer, in exchange for a generous salary and unlimited expense account. Instead, she was hired as a full-time Principal Corporate Consulting Engineer, a tech-track SVP-equivalent. In this position, Hopper represented the company at industry forums, serving on various industry committees, along with other obligations.[43] She retained that position until her death at age 85 in 1992.
At DEC Hopper served primarily as a goodwill ambassador. She lectured widely about the early days of computing, her career, and on efforts that computer vendors could take to make life easier for their users. She visited most of Digital's engineering facilities, where she generally received a standing ovation at the conclusion of her remarks. Although no longer a serving officer, she always wore her Navy full dress uniform to these lectures contrary to U.S. Department of Defense policy.[44] In 2016 Hopper received the Presidential Medal of Freedom, the nation's highest civilian honor, in recognition of her remarkable contributions to the field of computer science.
"The most important thing I've accomplished, other than building the compiler," she said, "is training young people. They come to me, you know, and say, 'Do you think we can do this?' I say, 'Try it.' And I back 'em up. They need that. I keep track of them as they get older and I stir 'em up at intervals so they don't forget to take chances."[45]
Log book showing the "bug" found caught in a Mark II relay
Throughout much of her later career, Hopper was much in demand as a speaker at various computer-related events. She was well known for her lively and irreverent speaking style, as well as a rich treasury of early war stories. She also received the nickname "Grandma COBOL".[46]
While Hopper was working on aMark II Computer at Harvard University in 1947,[47] her associates discovered amoth that was stuck in arelay and impeding the operation of the computer. Upon extraction, the insect was affixed to a log sheet for that day with the notation, "First actual case of bug being found". While neither she nor her crew members mentioned the exact phrase, "debugging", in their log entries, the case is held as a historical instance of "debugging" a computer and Hopper is credited with popularizing the term in computing. For many decades, the term "bug" for a malfunction had been in use in several fields before being applied tocomputers.[48][49] The remains of the moth can be found taped into the group's log book at theSmithsonian Institution'sNational Museum of American History inWashington, D.C.[47]
Hopper became known for hernanoseconds visual aid. People (such as generals and admirals) used to ask her whysatellite communication took so long. She started handing out pieces of wire that were just under one foot long—11.8 inches (30 cm)—the distance that light travels in onenanosecond. She gave these pieces of wire themetonym "nanoseconds".[38] She was careful to tell her audience that the length of her nanoseconds was actually the maximum distance the signals would travel in a vacuum in a nanosecond, and that signals would travel more slowly through the actual wires that were her teaching aids. Later she used the same pieces of wire to illustrate why computers had to be small to be fast. At many of her talks and visits, she handed out "nanoseconds" to everyone in the audience, contrasting them with a coil of wire 984 feet (300 meters) long,[50] representing amicrosecond. Later, while giving these lectures while working for DEC, she passed out packets of pepper, calling the individual grains of ground pepperpicoseconds.[51]
Jay Elliot described Hopper as appearing to be"'all Navy', but when you reach inside, you find a 'Pirate' dying to be released".[52]
1964: Hopper was awarded theSociety of Women Engineers Achievement Award, the Society's highest honor, "In recognition of her significant contributions to the burgeoning computer industry as an engineering manager and originator of automatic programming systems."[57] In May 1950, Hopper was one of the founding members of theSociety of Women Engineers.[58]
1986: Received the Defense Distinguished Service Medal at her retirement.
1986: Received an Honorary Doctor of Science from Syracuse University.[66]
1987: She became the firstComputer History Museum Fellow Award Recipient "for contributions to the development of programming languages, for standardization efforts, and for lifelong naval service."[67]
1991:National Medal of Technology "For her pioneering accomplishments in the development of computer programming languages that simplified computer technology and opened the door to a significantly larger universe of users."[69][70]
2013: Google made theGoogle Doodle for Hopper's 107th birthday an animation of her sitting at a computer, using COBOL to print out her age. At the end of the animation, a moth flies out of the computer.[79][80]
2016: On November 22, 2016, Hopper was posthumously awarded aPresidential Medal of Freedom for her accomplishments in the field of computer science.[81]
Brewster Academy, a school inWolfeboro, New Hampshire, United States, dedicated their computer lab to her in 1985, calling it the Grace Murray Hopper Center for Computer Learning.[33] The academy bestows a Grace Murray Hopper Prize to a graduate who excelled in the field of computer systems.[94] Hopper had spent her childhood summers at a family home in Wolfeboro.
An administration building on Naval Support Activity Annapolis (previously known as Naval Station Annapolis) in Annapolis, Maryland is named the Grace Hopper Building in her honor.[33]
Hopper Hall isNaval Academy's newest academic building that houses its cyber science department, among others. It is the first building at any service academy named after a woman.[96]
The US Naval Academy also owns a Cray XC-30 supercomputer named "Grace", hosted at the University of Maryland-College Park.[97]
Building 1482 aboard Naval Air Station North Island, housing the Naval Computer and Telecommunication Station San Diego, is named the Grace Hopper Building, and also contains the History of Naval Communications Museum.[98]
The street outside of the Nathan Deal Georgia Cyber Innovation and Training Center in Augusta, Georgia, is named Grace Hopper Lane.[100]
Grace Hopper Academy is a for-profit immersive programming school in New York City named in Grace Hopper's honor. It opened in January 2016 with the goal of increasing the proportion of women in software engineering careers.[101][102]
Grace Hopper Hall, a community meeting hall in Orlando, Florida, on the site of the former Orlando Naval Training Center, is named for her.[105]
The United States Naval Academy dedicated Hopper Hall, their cyber, computer science, and computer engineering building, to RDML Hopper in 2020, and it opened to midshipmen in the spring of 2021.
Women atMicrosoft Corporation formed an employee group called Hoppers and established a scholarship in her honor.[106]
Beginning in 2015, one of the nine competition fields at theFIRST Robotics Competition world championship is named for Hopper.[107]
A named professorship in the Department of Computer Sciences was established at Yale University in her honor.Joan Feigenbaum was named to this chair in 2008.[108]
In 2020,Google named its newundersea network cable'Grace Hopper'. The cable connects the US, UK and Spain and it was estimated to be completed by 2022.[109] Nonetheless, The Grace Hopper cable was completed in 2021, and it stretches 3,900 miles.[110]
Her legacy was an inspiring factor in the creation of theGrace Hopper Celebration of Women in Computing.[113] Held yearly, this conference is designed to bring the research and career interests of women in computing to the forefront.[114]
^"Grace Hopper".womenshistory.org. National Women's History Museum. RetrievedJuly 11, 2018.
^Though some books, including Kurt Beyer'sGrace Hopper and the Invention of the Information Age, reported that Hopper was the first woman to earn a Yale Ph.D. in mathematics, the first of ten women before 1934 was Charlotte Cynthia Barnum (1860–1934).Murray, Margaret A. M. (May–June 2010). "The first lady of math?".Yale Alumni Magazine. Vol. 73, no. 5. pp. 5–6.ISSN0044-0051.
^Murray Hopper, Grace (1934)."New Types of Irreducibility Criteria"(PDF).American Mathematical Society (Thesis). New Haven, CT: Yale University.Archived(PDF) from the original on February 18, 2020.
^abWilliams, Kathleen Broome (2001).Improbable Warriors: Women Scientists and the U.S. Navy in World War II. Annapolis, Maryland: Naval Institute Press.ISBN978-1-55750-961-1.
^"Rear Admiral Grace Murray Hopper, USNR, (1906–1992) Informal Images taken during the 1980s".Biographies in Naval History. United States Navy Naval Historical Center. Archived fromthe original on December 11, 2013. RetrievedJuly 2, 2013.Commodore Grace M. Hopper, USNR. receives congratulations from President Ronald Reagan, following her promotion from the rank of Captain to Commodore in ceremonies at the White House, 15 December 1983
^ab"Historic Images of Ronald Reagan". U.S. Defense Department. Archived fromthe original on October 19, 2013. RetrievedMarch 7, 2016.President Ronald Reagan greets Navy Capt. Grace Hopper as she arrives at the White House for her promotion to Commodore, Dec. 15, 1983. Hopper was a computer technology pioneer
^ab"Late Night with David Letterman".Late Night with David Letterman. Season 5. Episode 771. New York City. October 2, 1986.NBC."[to President Ronald Reagan on her promotion] Sir ... I'm older than you are ... YouTube title: Grace Hopper on Letterman
^Edison to Puskas, November 13, 1878, Edison papers, Edison National Laboratory, U.S. National Park Service, West Orange, N.J., cited in Thomas P. Hughes,American Genesis: A History of the American Genius for Invention, Penguin Books, 1989,ISBN0-14-009741-4, on page 75.
^"First Ladies".SWE Philadelphia Section. Archived fromthe original on August 6, 2019. RetrievedMarch 27, 2020.
^"The Founders"(PDF).SWE Magazine of the Society of Women Engineers: 34. Spring 2015.ISSN1070-6232.Archived(PDF) from the original on March 20, 2020.Gathering at theCooper Union's Green Engineering Camp on a spring weekend, the following women founded the Society of Women Engineers on May 27, 1950, known as Founders' Day: ...Mary Blade ...Beatrice Alice Hicks ...Grace M. Hopper
Beyer, Kurt W. (2009).Grace Hopper and the Invention of the Information Age. Cambridge, Massachusetts: MIT Press.ISBN978-0-262-01310-9.
Marx, Christy (2003).Grace Hopper: the first woman to program the first computer in the United States. Women hall of famers in mathematics and science. New York: Rosen Publishing Group.ISBN978-0-8239-3877-3.
Williams, Kathleen Broome (2004).Grace Hopper: Admiral of the Cyber Sea. Annapolis, Maryland: Naval Institute Press.ISBN978-1-55750-952-9.
Williams, Kathleen Broome (2001).Improbable Warriors: Women Scientists and the U.S. Navy in World War II. Annapolis, Maryland: Naval Institute Press.ISBN978-1-55750-961-1. Williams' book focuses on the lives and contributions of four notable women scientists:Mary Sears (1905–1997);Florence van Straten (1913–1992); Grace Murray Hopper (1906–1992);Mina Spiegel Rees (1902–1997).
Ignotofsky, Rachel (2017).Women in Science: 50 fearless pioneers who changed the world. London: Wren & Rook.ISBN978-1-9848-5615-9.
Williams, Kathleen Broome (1999). "Scientists in Uniform: The Harvard Computation Laboratory in World War II".Naval War College Review.52 (3):90–110.JSTOR44643011.
Tietjen, Jill (2022). "Amazing Grace - Computer Pioneer Admiral Grace Murray Hopper". In Smith, Alice (ed.).Women in Computational Intelligence: Key Advances and Perspectives on Emerging Topics. Springer Nature. pp. 1–20.ISBN9783030790912.
Tietjen, Jill (2025). "Chapter 17: Admiral Grace Murray Hopper". In Craig, Cecilia; Teig, Holly; Kimberling, Debra; Williams, Janet; Tietjen, Jill; Johnson, Vicki (eds.).Women Engineering Legends 1952-1976: Society of Women Engineers Achievement Award Recipients. Springer Cham.ISBN9783032002235.
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