Michael Darwin Morley (September 29, 1930 – October 11, 2020) was an American

mathematician A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, mathematical structure, structure, space, Mathematica ...

. At his death in 2020, Morley was professor emeritus at

Cornell University Cornell University is a Private university, private Ivy League research university based in Ithaca, New York, United States. The university was co-founded by American philanthropist Ezra Cornell and historian and educator Andrew Dickson W ...

. His research was in

mathematical logic Mathematical logic is the study of Logic#Formal logic, formal logic within mathematics. Major subareas include model theory, proof theory, set theory, and recursion theory (also known as computability theory). Research in mathematical logic com ...

and

model theory In mathematical logic, model theory is the study of the relationship between theory (mathematical logic), formal theories (a collection of Sentence (mathematical logic), sentences in a formal language expressing statements about a Structure (mat ...

, and he is best known for

Morley's categoricity theorem In mathematical logic, a theory is categorical if it has exactly one model ( up to isomorphism). Such a theory can be viewed as ''defining'' its model, uniquely characterizing the model's structure. In first-order logic, only theories with a fi ...

, which he proved in his PhD thesis ''Categoricity in Power'' in 1962.

Early life and education

Morley was born in

Youngstown, Ohio Youngstown is a city in Mahoning County, Ohio, United States, and its county seat. It is the List of municipalities in Ohio, 11th-most populous city in Ohio with a population of 60,068 at the 2020 United States census, 2020 census. The Mahoning ...

, on September 29, 1930. He obtained his BS in mathematics from

Case Institute of Technology Case Western Reserve University (CWRU) is a Private university, private research university in Cleveland, Ohio, United States. It was established in 1967 by a merger between Western Reserve University and the Case Institute of Technology. Case ...

in 1951 and his PhD in mathematics from the

University of Chicago The University of Chicago (UChicago, Chicago, or UChi) is a Private university, private research university in Chicago, Illinois, United States. Its main campus is in the Hyde Park, Chicago, Hyde Park neighborhood on Chicago's South Side, Chic ...

in 1962. Morley's formal PhD advisor at the University of Chicago was

Saunders Mac Lane Saunders Mac Lane (August 4, 1909 – April 14, 2005), born Leslie Saunders MacLane, was an American mathematician who co-founded category theory with Samuel Eilenberg. Early life and education Mac Lane was born in Norwich, Connecticut, near w ...

, but he completed his thesis under the guidance of Robert Vaught at the

University of California, Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California), is a Public university, public Land-grant university, land-grant research university in Berkeley, California, United States. Founded in 1868 and named after t ...

. His dissertation was titled ''Categoricity in Power''.

Career

Morley was an assistant professor at the

University of Wisconsin–Madison The University of Wisconsin–Madison (University of Wisconsin, Wisconsin, UW, UW–Madison, or simply Madison) is a public land-grant research university in Madison, Wisconsin, United States. It was founded in 1848 when Wisconsin achieved st ...

from 1963 to 1967. He joined the faculty at

in 1967 as an associate professor, was promoted to professor in 1970, and became a professor emeritus in 2003. He served as president of the

Association for Symbolic Logic The Association for Symbolic Logic (ASL) is an international organization of specialists in mathematical logic and philosophical logic. The ASL was founded in 1936, and its first president was Curt John Ducasse. The current president of the ASL ...

from 1986 to 1989. Morley received the 2003 Leroy P. Steele Prize for Seminal Contribution to Research from the

American Mathematical Society The American Mathematical Society (AMS) is an association of professional mathematicians dedicated to the interests of mathematical research and scholarship, and serves the national and international community through its publications, meetings, ...

for his 1965 paper "Categoricity in Power". This paper, his doctoral dissertation, introduced

Morley rank In mathematical logic, Morley rank, introduced by , is a means of measuring the size of a subset of a model theory, model of a theory (logic), theory, generalizing the notion of dimension in algebraic geometry. Definition Fix a theory ''T'' with a ...

and proved

Personal life

Morley died on October 11, 2020, in Sayre, Pennsylvania.

Selected publications

References

External links