Offshoots from basic research in nuclear physics have profoundly changed our daily lives. Nuclear energy and, by extension, nuclear weapons have had a deep impact on society. The uses of radioisotopes and magnetic resonance imaging in medicine are so widespread that rarely are they associated any longer with their origins in nuclear research. In these areas and in many others, inventions of new practical applications are ongoing—new radioisotopes and radiation detectors allow positron-emission tomography (PET) imaging of the human brain's functions, neutron beams serve as bomb detectors and scan for explosives, and accelerator-based mass spectrometry permits ultrasensitive detection of trace elements.
Proton and heavy-ion beams provide effective forms of cancer therapy. Accelerators developed by nuclear physicists for basic research are used extensively in materials studies. New concepts of fission reactors may create much safer and more efficient power reactors, and heavy-ion beams may move us a step closer to an inexhaustible supply of energy through inertial fusion reactors. Even in its seemingly esoteric mission for basic research, nuclear physics trains the technical manpower that invents, implements, and operates such applications in industry, medicine, and government, including national defense. Nuclear physics is one of the cornerstones of the nation's technological edifice.