Stanley Tennenbaum

Stanley Tennenbaum (1927 or 1928 to 2005) was an American mathematical logician, best remembered for Tennenbaum's theorem, which says that no countable nonstandard model of Peano arithmetic can be recursive, a result he announced in 1959 but never published a proof of. He grew up in Cincinnati, entered the University of Chicago at sixteen and took his doctorate there in 1956. His career moved between the University of Michigan, the University of Pennsylvania, the University of Rochester, the Institute for Advanced Study and New Mexico State University. In 1963 he proved the relative consistency of the negation of Suslin's hypothesis using an early form of forcing, and in 1965 he and Robert Solovay proved the relative consistency of Suslin's hypothesis. He also studied computably enumerable sets and found a short geometric proof that the square root of 2 is irrational.