About the Author
Hans A. Bethe took his Ph.D. in Munich in 1928. In 1935, he came to Cornell University, where he is now Professor Emeritus. In 1967, he received the Nobel Prize in Physics, primarily for his explanation of the processes by which stars produce their energy. His early scientific work was mainly in the theory of atoms, of the solid state, and of atomic collisions. Later he concentrated on nuclear physics. His explanation of stellar energy grew out of his work in nuclear theory. Recently, he has worked on neutron stars and supernova stars. Roman Jackiw has been professor of physics at the Massachusetts Institute of Technology since 1969, after spending three years as a Junior Fellow with Harvard University's Society of Fellows. His primary research area is theoretical physics and he has contributed to particle, condensed matter, and gravitational physics. Recently he received the Dannie Heineman Prize for mathematical physics from the American Physical Society and the American Institute of Physics.