Abstract
During the 100 years that astrophysics has been recognized as a separate discipline, there has been progress in interpreting observations of stars and galaxies using the principles of modern physics. Here we review some of the highlights, including the evolution of stars driven by nuclear reactions in their interiors, the emission of detectable neutrinos by the sun and by a supernova, the rapid and extremely regular rotation of neutron stars, and the accretion of matter onto black holes. A comparison of the observed Universe with the predictions of general relativity is also given.