born Feb. 23, 1924, Johannesburg, S.Af.
died May 7, 1998, Winchester, Mass., U.S.
South African-born U.S. physicist.
After doing research on the interaction of subatomic particles, he became interested in the problem of X-ray imaging of soft tissues or layers of tissue of differing densities and established the mathematical and physical foundations of computerized scanning. With Godfrey Hounsfield (b. 1919), he was awarded a 1979 Nobel Prize for his work in developing computed axial tomography .