Donald Ervin Knuth (born January 10, 1938) is an American computer scientist and mathematician. He is a retired professor at Stanford University. He received the ACM Turing Award in 1974, which is often called the Nobel Prize of computer science. Knuth is known as the "father of the analysis of algorithms."
Knuth wrote a multi-volume book titled The Art of Computer Programming. He helped develop methods to study how efficiently algorithms solve problems and organized mathematical techniques for this work. He also introduced the use of asymptotic notation. In addition to his work in computer science, Knuth created the TeX typesetting system, the METAFONT font language, and the Computer Modern typefaces.
As a writer and scholar, Knuth designed the WEB and CWEB programming systems to support literate programming. He also created the MIX/MMIX instruction set architectures. He strongly disagrees with the granting of software patents and has shared his views with the United States Patent and Trademark Office and the European Patent Organisation.
Biography
Donald Knuth was born in Milwaukee, Wisconsin, to Ervin Henry Knuth and Louise Marie Bohning. He described his heritage as "Midwestern Lutheran German." His father owned a small printing business and taught bookkeeping. While a student at Milwaukee Lutheran High School, Knuth thought of creative ways to solve problems. For example, in eighth grade, he entered a contest to find how many words could be made from the letters in "Ziegler's Giant Bar." The judges found 2,500 words. Knuth used a complete dictionary and checked each entry to see if it could be made from the letters in the phrase. He found over 4,500 words, winning the contest. As prizes, the school received a new television and enough candy bars for all his classmates.
Knuth received a physics scholarship to the Case Institute of Technology (now part of Case Western Reserve University) in Cleveland, Ohio, and enrolled in 1956. He also joined the Beta Nu Chapter of the Theta Chi fraternity. While studying physics at Case, Knuth was introduced to the IBM 650, an early computer. After reading the computer's manual, Knuth decided to rewrite the assembly and compiler code for the machine used at his school because he believed he could improve it.
In 1958, Knuth created a program to help his school's basketball team win games. He assigned "values" to players to estimate how likely they were to score points. This idea was reported by Newsweek and CBS Evening News.
Knuth was one of the founding editors of the Case Institute's Engineering and Science Review, which won a national award as the best technical magazine in 1959. He then switched from physics to mathematics and received two degrees from Case in 1960: a Bachelor of Science and a Master of Science by a special award from the faculty, who considered his work outstanding.
At the end of his senior year at Case in 1960, Knuth proposed to Burroughs Corporation to write an ALGOL compiler for the B205 for $5,500. The proposal was accepted, and he worked on the ALGOL compiler between graduating from Case and going to Caltech.
In 1963, with mathematician Marshall Hall as his adviser, Knuth earned a PhD in mathematics from the California Institute of Technology, with a thesis titled Finite Semifields and Projective Planes.
In 1963, after receiving his PhD, Knuth joined Caltech's faculty as an assistant professor.
While at Caltech and after the success of the Burroughs B205 ALGOL compiler, he became a consultant to Burroughs Corporation, joining the Product Planning Department. At Caltech, he worked as a mathematician, but at Burroughs, he worked as a programmer, collaborating with people he considered to have written the best software at the time: the ALGOL compiler for the B220 computer (a successor to the B205).
Knuth turned down a $100,000 contract to write compilers at Green Tree Corporation, choosing instead to continue working at Caltech and Burroughs. He received a National Science Foundation Fellowship and a Woodrow Wilson Foundation Fellowship, but these required him to study full-time as a graduate student, which would have prevented him from working as a consultant for Burroughs. He declined the fellowships and continued with Burroughs. In summer 1962, he wrote a FORTRAN compiler for Univac but later said, "I sold my soul to the devil" to write a FORTRAN compiler.
After graduating, Knuth returned to Burroughs in June 1961 but did not tell them he had graduated with a master's degree instead of the expected bachelor's degree. Impressed by the ALGOL syntax chart, symbol table, recursive-descent approach, and the separation of the scanning, parsing, and emitting functions of the compiler, Knuth suggested an extension to the symbol table: that one symbol could stand for a string of symbols. This idea became the basis of the DEFINE in Burroughs ALGOL, later adopted by other languages. However, some people disliked the idea and wanted DEFINE removed. The last person to strongly oppose it was Edsger Dijkstra during a visit to Burroughs.
Knuth worked on simulation languages at Burroughs, producing SOL, a language called "Simulation Oriented Language," which improved upon the state of the art. He co-designed SOL with J. McNeeley. In May 1967, he attended a conference in Norway organized by the creators of the Simula language. Knuth influenced Burroughs to use Simula. Knuth had a long association with Burroughs as a consultant from 1960 to 1968 until he moved into more academic work at Stanford in 1969.
In 1962, Knuth accepted a commission from Addison-Wesley to write a book on computer programming language compilers. While working on this project, he decided he could not adequately cover the topic without first developing a fundamental theory of computer programming, which became The Art of Computer Programming. He originally planned to publish this as a single book but later concluded that six volumes, and then seven, were needed to fully cover the subject. He published the first volume in 1968.
Just before publishing the first volume of The Art of Computer Programming, Knuth left Caltech to accept employment with the Institute for Defense Analyses' Communications Research Division, located on the Princeton campus. This division performed mathematical research in cryptography to support the National Security Agency.
In 1967, Knuth attended a Society for Industrial and Applied Mathematics conference. When asked what he did, he explained that computer science was divided into three areas: numerical analysis, artificial intelligence, and programming languages. Based on his studies and The Art of Computer Programming, Knuth decided the next time someone asked he would say, "Analysis of algorithms."
In 1969, Knuth left his position at Princeton to join the Stanford University faculty. He became Fletcher Jones Professor of Computer Science in 1977. In 1990, he became Professor of The Art of Computer Programming and has been an emeritus professor since 1993.
Writings
Knuth is both a writer and a computer scientist.
In the 1970s, Knuth said computer science was a new field without a clear identity. Many published papers had errors. He wanted to correct these mistakes and improve how the field was described.
Between 1972 and 1973, Knuth worked at the University of Oslo with Ole-Johan Dahl. He planned to write the seventh book in his series, but focused on the third volume instead. He finished the third volume after returning to Stanford in 1973.
Concrete Mathematics: A Foundation for Computer Science began as an expansion of the math section in Volume 1 of TAoCP. Knuth realized he needed more math tools for Volume 1 and created a course for students. The course notes became a book in 1988, co-authored with Ronald Graham, Oren Patashnik, and others. A second edition was published in 1994.
By 2011, Volume 4A of TAoCP had been published. In April 2020, Knuth said Volume 4 would include parts A through F. Volume 4B was published in October 2022.
Knuth wrote Surreal Numbers, a book explaining a number system created by John Horton Conway. The book shows how math ideas develop, helping students do original research.
In 1995, Knuth wrote the introduction for the book A=B. He also writes puzzles for Word Ways: The Journal of Recreational Linguistics.
Knuth has written about recreational mathematics. He started writing for the Journal of Recreational Mathematics in the 1960s and was recognized for his work.
Knuth appears in videos on YouTube, talking about topics like Surreal Numbers and his use of email.
Knuth suggested the term "algorithmics" as a better name for computer science.
Knuth, a Lutheran, wrote 3:16 Bible Texts Illuminated. He analyzed a specific Bible verse from each book and had artists create calligraphy for each verse. He gave lectures at MIT about religion and computer science, which were published in a book called Things a Computer Scientist Rarely Talks About.
Knuth opposes patents for simple software solutions but has more complex views on non-simple solutions like the interior-point method of linear programming. He has shared these views with the United States Patent and Trademark Office and the European Patent Organisation.
Programming
In the 1970s, the publishers of TAOCP stopped using Monotype and chose phototypesetting instead. Knuth was very frustrated because the new system could not match the quality of earlier books, which had been made using the older system. This frustration led him to work on digital typesetting, and he created TeX and Metafont.
While creating TeX, Knuth developed a new way of writing computer programs. He called this method "literate programming" because he believed programs should be treated like written works of literature.
Knuth used the WEB system to show his idea of literate programming. The same WEB source file was used to create a TeX file and a Pascal source file. These files then produced a readable explanation of the program and a working version of the program, respectively. A later version of the system, called CWEB, replaced Pascal with C, C++, and Java.
Knuth used WEB to write TeX and Metafont. He published both programs as books, which were released in the same year: TeX: The Program (1986) and Metafont: The Program (1986). Around the same time, Leslie Lamport created LaTeX, a widely used tool based on TeX. He published the first user manual for LaTeX in 1986.
Personal life
Donald Knuth married Nancy Jill Carter on June 24, 1961, while he was a graduate student at the California Institute of Technology. They have two children: John Martin Knuth and Jennifer Sierra Knuth.
Knuth gives lectures that are not formal a few times each year at Stanford University. He calls these lectures "Computer Musings." He taught as a guest professor at the Oxford University Department of Computer Science in the United Kingdom until 2017. He was also honored as an Honorary Fellow of Magdalen College.
Knuth is an organist and a composer. He and his father played the organ for Lutheran congregations. Knuth and his wife own a 16-rank organ at their home. In 2016, he completed a musical piece for the organ called Fantasia Apocalyptica. He describes this piece as "a translation of the Greek text of the Revelation of Saint John the Divine into music." The piece was first performed in Sweden on January 10, 2018.
Knuth’s Chinese name is Gao Dena (simplified Chinese: 高德纳; traditional Chinese: 高德納; pinyin: Gāo Dénà). He was given this name in 1977 by Frances Yao before she traveled to China. In the 1980 Chinese edition of The Art of Computer Programming (simplified Chinese: 计算机程序设计艺术; traditional Chinese: 計算機程式設計藝術; pinyin: Jìsuànjī chéngxù shèjì yìshù), Knuth explained that he chose to use his Chinese name so that Chinese computer programmers could recognize him. In 1989, his Chinese name was printed on the cover of the Journal of Computer Science and Technology. Knuth said this made him feel connected to Chinese people, even though he cannot speak their language.
Knuth used to pay $2.56 for each typographical error or mistake found in his books. He called this amount "one hexadecimal dollar" because 256 pennies equal one hexadecimal dollar. He also paid $0.32 for "valuable suggestions." According to an article in the Massachusetts Institute of Technology’s Technology Review, these reward checks are "among computerdom’s most prized trophies." Knuth stopped sending real checks in 2008 due to bank fraud. Now, he gives each error finder a "certificate of deposit" from a public balance in his fictional "Bank of San Serriffe."
Knuth once warned a correspondent, "Beware of bugs in the above code; I have only proved it correct, not tried it."
Knuth published his first "scientific" article in a school magazine in 1957. The article was titled "The Potrzebie System of Weights and Measures." In it, he defined the basic unit of length as the thickness of Mad No. 26. He also named the basic unit of force "whatmeworry." Mad published the article in issue No. 33 (June 1957).
To explain the idea of recursion, Knuth intentionally made the index of The Art of Computer Programming, Volume 1, refer "Circular definition" and "Definition, circular" to each other.
The preface of Concrete Mathematics includes the following paragraph:
At the TUG 2010 Conference, Knuth announced a humorous XML-based version of TeX called "iTeX" (pronounced [iː˨˩˦tɛks˧˥⸨bell⸩], said while ringing a bell). This version would support features such as units based on irrational numbers, 3D printing, input from seismographs and heart monitors, animation, and stereophonic sound.
Awards and honors
In 1971, Knuth won the first ACM Grace Murray Hopper Award. He has also received other awards, such as the Turing Award, the National Medal of Science, the John von Neumann Medal, and the Kyoto Prize.
In 1980, Knuth was chosen as a Distinguished Fellow of the British Computer Society (DFBCS) because of his important work in computer science.
In 1990, he was given a special academic title called Professor of The Art of Computer Programming. Later, this title was changed to Professor Emeritus of The Art of Computer Programming.
Knuth was elected to the National Academy of Sciences in 1975. In 1981, he was chosen as a member of the National Academy of Engineering for organizing large areas of computer science so they are easier for everyone in the computing field to understand. In 1992, he became an associate of the French Academy of Sciences. That same year, he stopped working regularly at Stanford University to complete his book, The Art of Computer Programming. In 1996, he received the degree of Doctor Honoris Causa in Mathematical Sciences from Masaryk University in Brno. In 2003, he was elected a Foreign Member of the Royal Society.
In 2009, Knuth was chosen as a Fellow (first class of Fellows) of the Society for Industrial and Applied Mathematics for his excellent work in mathematics. He is also a member of the Norwegian Academy of Science and Letters. In 2012, he became a fellow of the American Mathematical Society and a member of the American Philosophical Society. Other awards and honors include:
Publications
A short list of his published works includes:
The Art of Computer Programming
Computers and Typesetting (all books are hardcover unless stated otherwise):
Collected works: