In contrast to his earlier, all-encompassing expositions on the universe (Search for a Supertheory, 1987; Creation, 1988), the Idaho State physicist-astronomer focuses here on galaxies, those ""island universes"" Kant foresaw to be composed of stars like our own Milky Way. Not until the 1920's was there convincing evidence (thanks to the work of Edwin Hubble) that there are indeed worlds beyond worlds made up of billions of stars. What followed was a taxonomy of galaxies (spirals, ellipticals, and ""peculiars"") and much theorizing about their evolution and destiny. The study of galaxies took off after WW II, when radio astronomy came into its own and it was discovered that ""active"" as opposed to inactive galaxies had cores that transmit intense synchrotron radiation at radio frequencies and often at higher frequencies as well. The source? Supernova remnants. . .black holes. . .quasars. . .colliding galaxies: case-by-case analyses are offered here. The idea of colliding galaxies is particularly intriguing, given their myriad numbers and their huge spread in space. (Yet the probability of individual stars colliding is nfl since the stars are so far apart.) The advent of supercomputers has made it possible to model collisions as well as mergers of galaxies and leads Parker to final conjectures on how clusters and superclusters of galaxies have formed. An image of the universe as soapsuds emerges, with the soap bubbles being voids surrounded by chains of galaxy superclusters. As always, Parker tempers the heady theorizing with portraits of personalties and the promise that more and better technology will resolve current debates. We believe him.