Thirty-threeyears have passed since the ?rst edition of Astrophysical Concepts - peared. During this time astrophysics has undergone major revolutions. We have gained new perspectives on the Universe with the aid of powerful gamma-ray, - ray, and infrared telescopes, whose sensitivitiescould not have been imagined three decades earlier. We have become expert at snaring neutrinos to gain insight on - clear processes at work in the Sun and supernovae. We have direct evidence for the existence of neutron stars and gravitationalwaves, and persuasive arguments for the detection of black holes on...

Thirty-threeyears have passed since the ?rst edition of Astrophysical Concepts - peared. During this time astrophysics has undergone major revolutions. We have gained new perspectives on the Universe with the aid of powerful gamma-ray, - ray, and infrared telescopes, whose sensitivitiescould not have been imagined three decades earlier. We have become expert at snaring neutrinos to gain insight on - clear processes at work in the Sun and supernovae. We have direct evidence for the existence of neutron stars and gravitationalwaves, and persuasive arguments for the detection of black holes on...

At 8:15 A.M., August 6, 1945, the Enola Gay released her load. For forty three seconds, the world's first atomic bomb plunged through six miles of clear air to its preset detonation altitude. There it exploded, destroying Hiroshima and eighty thousand of her citizens. No war had ever seen such instant devastation. Within nine days Japan surrendered. World War II was over and a nuclear arms race had begun. Fifty years later, the National Air and Space Museum was in the final stages of preparing an exhibition on the Enola Gay's historic mission when eighty-one members of Congress angrily...

Astrophysicist and scholar Martin Harwit examines how our understanding of the Cosmos advanced rapidly during the twentieth century and identifies the factors contributing to this progress. Astronomy, whose tools were largely imported from physics and engineering, benefited mid-century from the U.S. policy of coupling basic research with practical national priorities. This strategy, initially developed for military and industrial purposes, provided astronomy with powerful tools yielding access at virtually no cost to radio, infrared, X-ray, and gamma-ray observations. Today, astronomers are...