Bonnie Stewart


Bonnie Madison Stewart was a professor of mathematics at Michigan State University from 1940 to 1980. He earned his Ph.D. from the University of Wisconsin–Madison in 1941, under the supervision of Cyrus Colton MacDuffee.

Contributions

Number theory

In 1952, the first edition of his book, Theory of Numbers, was published.
Stewart's contributions to number theory also include a complete characterization of the practical numbers in terms of their factorizations, which he published in 1954, a year before Wacław Sierpiński's independent discovery of the same result.

Geometry

In 1970 he published a book, Adventures among the toroids. A study of orientable polyhedra with regular faces, in which he discussed what are now called Stewart toroids. The book was handwritten in calligraphy with many formulas and illustrations. Like the Platonic solids, Archimedean solids, and Johnson solids, the Stewart polyhedra have regular polygons as faces. The first three categories are all convex, whereas Stewart toroids have polygonal-faced tunnels.

Selected publications