George Whitelaw Mackey (February 1, 1916 in St. Louis, Missouri – March 15, 2006 in Belmont, Massachusetts) was an American mathematician. Mackey earned his bachelor of arts at Rice University (then the Rice Institute) in 1938 and obtained his Ph.D. at Harvard University in 1942 under the direction of Marshall H. Stone. He joined the Harvard University Mathematics Department in 1943, was appointed Landon T. Clay Professor of Mathematics and Theoretical Science in 1969 and remained there until he retired in 1985.

Mackey's main areas of research were in the areas of representation theory, ergodic theory, and related parts of functional analysis. Earlier in his career Mackey did significant work in the duality theory of locally convex spaces, which provided tools for subsequent work in this area, including Alexander Grothendieck's work on topological tensor products.

Mackey was one of the pioneer workers in the intersection of quantum logic, the theory of infinite-dimensional unitary representations of groups, the theory of operator algebras and noncommutative geometry. A central role in Mackey's work, both in the theory of group representations and in mathematical physics, was played by the concepts of system of imprimitivity and induced representation. This idea led naturally to an analysis of the representation theory of semi-direct products in terms of ergodic actions of groups and in some cases a complete classification of such representations. Mackey's results were essential tools in the study of the representation theory of nilpotent Lie groups using the method of orbits developed by Alexandre Kirillov in the 1960s. His notion of "virtual subgroup", introduced in 1966 using the language of groupoids, had a significant influence in ergodic theory.

James "Jim" (or "Jimmy") Clark, Jr OBE (4 March 1936 – 7 April 1968) was a British Formula One racing driver from Scotland, who won two World Championships, in 1963 and 1965.

Clark was a versatile driver who competed in sports cars, touring cars and in the Indianapolis 500, which he won in 1965. He was particularly associated with the Lotus marque.

He was killed in a Formula Two motor racing accident in Hockenheim, Germany in 1968. At the time of his death, he had won more Grand Prix races (25) and achieved more Grand Prix pole positions (33) than any other driver. The Times recently placed Clark at the top of a list of the greatest Formula One drivers.

James Clark Jr was born into a farming family at Kilmany House Farm, Fife, the youngest child of five, and the only boy. In 1942 the family moved to Edington Mains Farm, near Duns, Berwickshire, in the Borders. He was educated at primary schools, first in Kilmany and then in Chirnside, and then following three years of preparatory schooling at Clifton Hall School near Edinburgh he was sent to Loretto School in Musselburgh, near Edinburgh.