Perfect symmetry

"This book is divided into four parts. The first part, 'Herschel's Garden,' {aims to} give the reader an overview of the dynamic universe discovered by astronomers--the stars, white dwarfs, neutron stars, black holes, interstellar gas and dust, quasars, galaxies, their distribution in space as clustersand superclusters of galaxies, and the cosmos as a whole. . . . The second part, 'The Early Universe,' {seeks to} describe the . . . picture of the universe when it was only seconds and minutes old. . . . The third part of the book, 'Wild Ideas,' . . . speculates about the nature of that universe before the first nanosecond {one-billionth of a second}. . . . There is a short fourth part, 'Reflections,' which expresses my opinions and attitudes."