Saunders Mac Lane facts for kids

Quick facts for kids Saunders Mac Lane
Born	(1909-08-04)4 August 1909 Taftville, Connecticut, U.S.
Died	14 April 2005(2005-04-14) (aged 95) San Francisco, California, U.S.
Nationality	United States
Alma mater	Yale University University of Chicago University of Göttingen
Known for	Category theory Mac Lane set theory
Awards	Chauvenet Prize (1941) Leroy P. Steele Prize (1986) National Medal of Science (1989)
Scientific career
Fields	Mathematics (Mathematical logic Algebraic number theory Algebraic topology)
Institutions	Harvard University Cornell University University of Chicago Columbia University
Doctoral advisor	Hermann Weyl Paul Bernays
Doctoral students	Steve Awodey David Eisenbud William Howard Irving Kaplansky Roger Lyndon Michael D. Morley Anil Nerode Robert Solovay John G. Thompson

Saunders Mac Lane (born August 4, 1909 – died April 14, 2005) was an American mathematician. He is famous for helping to create something called category theory with his friend and colleague, Samuel Eilenberg.

Early Life and Education

Saunders Mac Lane was born in Norwich, Connecticut. His family lived nearby in Taftville, Connecticut. His birth name was "Leslie Saunders MacLane," but his parents didn't like "Leslie." So, he stopped using it. Later, he added a space to his last name, making it "Mac Lane." This was because his first wife found it easier to type that way.

Saunders was the oldest of three brothers. His brother, Gerald MacLane, also became a math professor. Their father and grandfather were both ministers. His mother, Winifred, went to Mount Holyoke College. She taught English, Latin, and mathematics.

Discovering a Love for Math

In high school, Saunders really liked chemistry. After his father passed away, his grandfather took care of him. His uncle wanted him to go to Yale University, where many of his family members had studied. His uncle paid for him to attend Yale starting in 1926.

As a freshman, Saunders didn't enjoy chemistry as much. But his math teacher, Lester S. Hill, helped him prepare for a math competition. Saunders won the competition, which helped him decide to focus on mathematics. He studied both math and physics at Yale. He graduated with a bachelor's degree in 1930. During this time, he even published his first science paper in physics.

Graduate Studies and New Ideas

In 1929, Saunders met Robert Maynard Hutchins, the new president of the University of Chicago. Hutchins encouraged him to study there for his advanced degrees. Saunders received a scholarship and began his graduate studies. He studied different math topics like set theory and number theory.

In 1931, after earning his master's degree, he received a special fellowship. This allowed him to study at the University of Göttingen in Germany. He was one of the last Americans to study there before the Nazi party caused problems. His main teachers there were Paul Bernays and Hermann Weyl. He finished his doctorate degree in 1934. Soon after, he married Dorothy Jones and returned to the U.S.

Career and Achievements

From 1934 to 1938, Saunders Mac Lane worked at several universities. These included Yale University, Harvard University, Cornell University, and the University of Chicago. In 1938, he got a permanent teaching job at Harvard, where he stayed until 1947.

Working with Samuel Eilenberg

In 1941, while giving lectures at the University of Michigan, he met Samuel Eilenberg. This meeting was very important. They started working together on how algebra and topology connect. Their teamwork led to new ideas in mathematics.

During World War II, in 1944 and 1945, Mac Lane also helped with the war effort. He directed a group at Columbia University that worked on math for fire-control systems. These systems helped aim weapons.

Leadership in Mathematics

In 1947, he moved back to the University of Chicago. Many other famous scientists were also moving there. He traveled to Switzerland as a Guggenheim Fellow in 1947–1948. There, he worked with another important mathematician, Heinz Hopf. Saunders Mac Lane became the head of the math department at Chicago in 1952 and served for six years.

Mac Lane held many important positions in the world of mathematics. He was a vice president of the National Academy of Sciences and the American Philosophical Society. He also served as president of the American Mathematical Society. In the 1950s, he led efforts to improve how modern mathematics was taught. He advised the American government on science and even led a group of mathematicians to China in 1976. In 1989, he received the National Medal of Science, a very high honor.

Contributions to Mathematics

Saunders Mac Lane's early work was in mathematical logic and other areas of algebra. He started working on group extensions in 1942. In 1943, he began research on what are now called Eilenberg–MacLane spaces. This work helped develop a field called group cohomology.

Creating Category Theory

In 1945, Mac Lane and Samuel Eilenberg created category theory. This is one of his most important contributions. Category theory is a way to study mathematical structures and the relationships between them. It uses "diagrams" with arrows connecting different mathematical "objects." This way of thinking about math, using diagrams, became very popular because of Mac Lane's work. He also named the Yoneda lemma, which is a key idea in category theory.

Influential Books

Mac Lane was dedicated to writing clear and easy-to-understand math books. In 1941, he co-wrote A Survey of Modern Algebra with Garrett Birkhoff. This book was very important because it made modern algebra understandable for college students. His book, Categories for the Working Mathematician, is still a top guide for learning category theory.

Saunders Mac Lane also guided many students who went on to become important mathematicians themselves. Some of his notable students include David Eisenbud, Irving Kaplansky, and John G. Thompson.

Selected Works

• 1997 (1941). A Survey of Modern Algebra (with Garrett Birkhoff). A K Peters. ISBN: 1-56881-068-7
• 1995 (1963). Homology, Springer (Classics in Mathematics) ISBN: 978-0-387-58662-5
• 1999 (1967). Algebra (with Garrett Birkhoff). Chelsea. ISBN: 0-8218-1646-2
• 1998 (1972). Categories for the Working Mathematician, Springer (Graduate Texts in Mathematics) ISBN: 0-387-98403-8
• 1986. Mathematics, Form and Function. Springer-Verlag. ISBN: 0-387-96217-4
• 1992. Sheaves in Geometry and Logic: A First Introduction to Topos Theory (with Ieke Moerdijk). ISBN: 0-387-97710-4
• 2005. Saunders Mac Lane: A Mathematical Autobiography. A K Peters. ISBN: 1-56881-150-0

Images for kids

• 

  Mac Lane and Samuel Eilenberg at a conference in July 1992

See also

In Spanish: Saunders Mac Lane para niños