The Hole Shebang Black holes and galaxies may be entwined from birth One of the great accomplishments of astronomy over the past century has been to explain stars. Despite their amazing variety, stars all go through the same basic life cycle, driven by a few basic processes such as gravitational collapse and nuclear fusion. Now astronomers are on the verge of a similar synthesis for galaxies.
Black holes are notoriously destructive, but their creative potential has gradually come to light.
The pace of discovery has accelerated lately, helped along by the ultrahigh resolution of the Hubble Space Telescope and the Very Long Baseline Array radio telescope. The count of supermassive holes is now up to 34, and two remarkable trends have emerged. First, supermassive black holes appear not just in quasar or quasarlike galaxies but in unostentatious ones, too. Completely flat galaxies lack large holes. Holes weigh in at 0.15 percent of the mass of their elliptical galaxies or bulges.