WHITE HOLES

Will our galaxy turn into a quasar? Are quasars stages on the cosmic way to becoming galactic nuclei? Are quasars in fact white holes—"cosmic gushers"—compact objects powered by gravitation and spewing out clouds of material from their highly energetic cores? Astrophysicist Gribbin abounds with heady speculations and Lewis Carroll-like conundrums as he reports on present-day theorizing about the origins and destiny of the universe and about holes, white, black, and worm. He describes theory-spinning at this level of imperfect information as "entertainment"—but entertainment with the potential for substantial gains in understanding. The novice had better tread lightly here. Gribbin assumes reasonable familiarity with cosmological theories, relativity, and essential laws of physics. His frequent allusions to science fiction plots to illustrate points are a help, however, as well as a demonstration of his observation that science is even stranger than science fiction. An essay, "Is Our Sun a Normal Star," added as an appendix, is a little marvel of provocative suggestions, tease, and, yes, entertainment.