Word: nuclei
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...universe is controlled by four basic forces: gravity, the glue that holds the cosmos together; electromagnetism, which keeps electrons from breaking away from the rest of the atom; the strong force, which holds together the atomic nucleus; and the weak force, which controls the gradual disintegration of some nuclei, the process at work in radioactivity...
...things we see that actually reside in the comet's nucleus." The most stunning observational feat came when the big, 1,000-ft. radio telescope in Arecibo, PR., managed to bounce radar waves off the fleeting object and perhaps settled the old argument over whether cometary nuclei are gaseous or solid. Said Harvard's Fred Whipple, dean of American comet watchers and chief proponent of the dirty-snowball theory: "The radar proves to my satisfaction that there is a solid object in the center of the comet...
...reactions, even human metabolism. But there are two other less well-known agencies at work within the nucleus of the atom: the so-called strong force, which binds the nucleus' protons and neutrons, and the weak force, which shows its hand in the disintegration, or "decay," of certain nuclei, like those of uranium 235. Post-Einstein theorists in the late 1960s succeeded in finding a unity between electromagnetism and the weak force. Their "electroweak" theory postulated the existence of a family of three particles called intermediate vector bosons (after the Indian physicist S.N. Bose...
...nuclear energy; in Bethesda, Md. More than 50 years ago, Tuve noted that short-pulse radio waves reflected off the ionosphere, which provided the theoretical underpinning for radar. In 1933 he confirmed the existence of the neutron and was also able to measure the bonding forces in atomic nuclei. During World War II, he organized development of the proximity fuse for antiaircraft shells, enabling defenders to increase greatly their accuracy in combating German V-1 buzz bombs and Japanese kamikaze plane attacks...
...bombs. Articles have been written about the subject. The key ingredient for both the bombs and the reactors is the same: fissile material such as uranium or plutonium, whose atoms can readily split, scattering tiny, fast-moving particles called neutrons. When neutrons score bull's-eyes on the nuclei of neighboring atoms, they split them as well, unleashing still more neutrons, which in turn cause more breakups, all of which release energy...