Michael J. T. Guy (born 1 April 1943) is a British computer scientist and

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, structure, space, models, and change. History On ...

. He is known for early work on computer systems, such as the

Phoenix Phoenix most often refers to: * Phoenix (mythology), a legendary bird from ancient Greek folklore * Phoenix, Arizona, a city in the United States Phoenix may also refer to: Mythology Greek mythological figures * Phoenix (son of Amyntor), a ...

system at the

University of Cambridge The University of Cambridge is a public collegiate research university in Cambridge, England. Founded in 1209 and granted a royal charter by Henry III in 1231, Cambridge is the world's third oldest surviving university and one of its most pr ...

, and for contributions to

number theory Number theory (or arithmetic or higher arithmetic in older usage) is a branch of pure mathematics devoted primarily to the study of the integers and integer-valued functions. German mathematician Carl Friedrich Gauss (1777–1855) said, "Mat ...

, computer algebra, and the theory of

polyhedra In geometry, a polyhedron (plural polyhedra or polyhedrons; ) is a three-dimensional shape with flat polygonal faces, straight edges and sharp corners or vertices. A convex polyhedron is the convex hull of finitely many points, not all on ...

in higher dimensions. He worked closely with

John Horton Conway John Horton Conway (26 December 1937 – 11 April 2020) was an English mathematician active in the theory of finite groups, knot theory, number theory, combinatorial game theory and coding theory. He also made contributions to many branches ...

, and is the son of Conway's collaborator Richard K. Guy.

Mathematical work

With Conway, Guy found the complete solution to the

Soma cube The Soma cube is a solid dissection puzzle invented by Danish polymath Piet Hein in 1933 during a lecture on quantum mechanics conducted by Werner Heisenberg. Seven pieces made out of unit cubes must be assembled into a 3×3×3 cube. The pie ...

of Piet Hein. Also with Conway, an enumeration led to the discovery of the

grand antiprism In geometry, the grand antiprism or pentagonal double antiprismoid is a uniform 4-polytope (4-dimensional uniform polytope) bounded by 320 cells: 20 pentagonal antiprisms, and 300 tetrahedra. It is an anomalous, non-Wythoffian uniform 4-polytope ...

, an unusual

uniform polychoron In geometry, a uniform 4-polytope (or uniform polychoron) is a 4-dimensional polytope which is vertex-transitive and whose cells are uniform polyhedra, and faces are regular polygons. There are 47 non-prismatic convex uniform 4-polytopes. There ...

in four dimensions. The two had met at

Gonville and Caius College, Cambridge Gonville and Caius College, often referred to simply as Caius ( ), is a constituent college of the University of Cambridge in Cambridge, England. Founded in 1348, it is the fourth-oldest of the University of Cambridge's 31 colleges and one of t ...

, where Guy was an undergraduate student from 1960, and Conway was a graduate student. It was through Michael that Conway met Richard Guy, who would become a co-author of works in

combinatorial game theory Combinatorial game theory is a branch of mathematics and theoretical computer science that typically studies sequential games with perfect information. Study has been largely confined to two-player games that have a ''position'' that the player ...

. Michael Guy with Conway made numerous particular contributions to geometry, number and game theory, often published in problem selections by Richard Guy. Some of these are

recreational mathematics Recreational mathematics is mathematics carried out for recreation (entertainment) rather than as a strictly research and application-based professional activity or as a part of a student's formal education. Although it is not necessarily limited ...

, others contributions to discrete mathematics. They also worked on the

sporadic group In mathematics, a sporadic group is one of the 26 exceptional groups found in the classification of finite simple groups. A simple group is a group ''G'' that does not have any normal subgroups except for the trivial group and ''G'' itself. The ...

s. Guy began work as a research student of J. W. S. Cassels at

Department of Pure Mathematics and Mathematical Statistics Department may refer to: * Departmentalization, division of a larger organization into parts with specific responsibility Government and military *Department (administrative division), a geographical and administrative division within a country, ...

(DPMMS), Cambridge. He did not complete a Ph.D., but joint work with Cassels produced numerical examples on the

Hasse principle In mathematics, Helmut Hasse's local–global principle, also known as the Hasse principle, is the idea that one can find an integer solution to an equation by using the Chinese remainder theorem to piece together solutions modulo powers of eac ...

for

cubic surface In mathematics, a cubic surface is a surface in 3-dimensional space defined by one polynomial equation of degree 3. Cubic surfaces are fundamental examples in algebraic geometry. The theory is simplified by working in projective space rather th ...

Computer science

He subsequently went into computer science. He worked on the filing system for Titan, Cambridge's Atlas 2, being one of a team of four in one office including

Roger Needham Roger Michael Needham (9 February 1935 – 1 March 2003) was a British computer scientist. Early life and education Needham was born in Birmingham, England, the only child of Phyllis Mary, ''née'' Baker (''c''.1904–1976) and Leonard Wi ...

. In working on

ALGOL 68 ALGOL 68 (short for ''Algorithmic Language 1968'') is an imperative programming language that was conceived as a successor to the ALGOL 60 programming language, designed with the goal of a much wider scope of application and more rigorously d ...

, he was co-author with Stephen R. Bourne of

ALGOL 68C ALGOL 68C is an imperative computer programming language, a dialect of ALGOL 68, that was developed by Stephen R. Bourne and Michael Guy to program the Cambridge Algebra System (CAMAL). The initial compiler was written in the Princeton Syntax ...

.ALGOL 68C
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Bibliography

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Notes

References

{{DEFAULTSORT:Guy, Michael J. T. 1940s births Living people 20th-century British mathematicians Alumni of Gonville and Caius College, Cambridge Recreational mathematicians Mathematics popularizers British computer scientists