Allan M. Cormack is a physicist whose theoretical analysis and experiments in the fields of nuclear and particle physics, computer tomography and math led to his invention of a mathematical technique for computer-assisted X-ray tomography. Computerized axial tomography, otherwise known as the CAT scan, is a process by which X rays can be concentrated on specific sections of the human body at a variety of angles. Once this information is analyzed by a computer, it is combined to reproduce images of internal structures previously unviewable by medical technology. It is considered the most revolutionary development in the field of radiography since the discovery of the X ray by Wilhelm Conrad Röntgen in 1895. Cormack was the first to analyze the possibility of such an examination of a biological system, in 1963 and 1964, and to develop the equations needed for computer-assisted X-ray reconstruction of pictures of the human brain...