Before World War II came along, J. Robert Oppenheimer worked on a number of physics questions, including astrophysics. As written by Mark Paris in Physics Today, Oppenheimer “ used the equations of general relativity to trace the collapsing mass of a neutron star. That theoretical work predicted black holes. Oppenheimer’s mathematical predictions, of course, have in recent years been borne out by scientific observation of the once-speculative phenomenon.”
Ethan Siegel argues that “[Oppenheimer’s] most lasting contribution to the world, from a scientific perspective, is an astrophysical one: developing the method for theoretically understanding the upper mass limit that defines the border between a neutron star and a black hole.”
Stephen Hawking himself, in Chapter 6 of his famous A Brief History of Time, mentions Oppenheimer and his work, including noting that WWII derailed much of what Oppenheimer was doing scientifically in the late 1930s:
Chandrasekhar had shown that the exclusion principle could not halt the collapse of a star more massive than the Chandrasekhar limit, but the problem of understanding what would happen to such a star, according to general relativity, was first solved by a young American, Robert Oppenheimer, in 1939. His result, however, suggested that there would be no observational consequences that could be detected by the telescopes of the day. Then World War II intervened and Oppenheimer himself became closely involved in the atom bomb project. After the war the problem of gravitational collapse was largely forgotten as most scientists became caught up in what happens on the scale of the atom and its nucleus. In the 1960s, however, interest in the large-scale problems of astronomy and cosmology was revived by a great increase in the number and range of astronomical observations brought about by the application of modern technology. Oppenheimer’s work was then rediscovered and extended by a number of people. The picture that we now have from Oppenheimer’s work is as follows…
It was Hawking, along with others, that picked up on many of the theoretical conclusions Oppenheimer had made. How fitting that Stephen Hawking gave the J. Robert Oppenheimer Memorial Lecture at UC Berkeley in 2007.
Learn more about Oppenheimer the man and Oppenheimer the film.
