Light from the Depths of Time

1. Anatomy of the Milky Way.- Cosmic Yardsticks.- Herr Meyer Solves a Riddle.- Approaching the Milky Way.- In the Virgo Cluster.- The Stars of the Milky Way Make Their Appearance.- Inside the Milky Way.- The Centre of the Milky Way.- 2. Light.- Waves in Empty Space.- Herr Meyer Dreams About the Electromagnetic Spectrum.- The Spectrum.- How the Spectral Lines Are Formed.- Hydrogen as a Radio Transmitter.- Thermal Radiation.- Spectra from the Depths of Space.- A Millionth of a Gramme of Light.- Radiation into Matter; Matter into Radiation.- Energy in Light and Matter.- 3. Speeding Up the Milky Way.- Novae and Supernovae.- The Rotating Disk.- Two Populations.- Motion Revealed by Light and Radio Waves.- Herr Meyer and His Bicycle.- The Doppler Effect.- The Pattern of Movement Within the Milky Way.- 4. Plumbing the Depths of the Milky Way.- Stellar Proper Motions.- Radial Velocities.- Star Streams.- The Hyades Cluster.- Beyond the Hyades Farther Out into Space.- Pulsating Stars and the Cosmic Distance Scale.- How Far Away Are the Globular Clusters?.- Harlow Shapley Ousts Us from the Galactic Centre.- The Hyades Stars Determine the Size of the Universe.- 5. The Island Universe Debate.- The Problem of the Nebulae.- Stars Erupt in the Nebulae.- "Secondary Nuclei" Within the Andromeda Nebula.- The 26th of April 1920.- Walter Baade Increases the Distance of the Andromeda Nebula.- 6. The Universe Is Expanding.- The High Velocities of the Spiral Nebulae.- Are We in the Centre of the Universe?.- Expansion and Olbers' Paradox.- When Did It Begin?.- Galaxies That Are Approaching.- Doubts About the Expansion.- What Lies Farther Out?.- 7. The Big Bang in Flatland.- Herr Meyer's Dream of Flatland.- The World of the Flatmen.- A Two-Dimensional World's Astronomy.- Geometry inFlatland.- True Curved Surfaces.- Is Our Three-Dimensional Space Curved?.- Ghosts from the Fourth Dimension.- 8. Expansion and Gravity.- It Is the Same Everywhere in the Universe as It Is Here.- Which Curved Universe Do We Inhabit?.- The Expansion Slows Down.- Expanding Flat Universes.- From Flatland to Our Universe.- Gravitational Repulsion?.- Which Came First, the Chicken or the Egg?.- The Russian Balloonist and Einstein's Mistakes.- The Theory of the Steady-State Universe.- 9. The Realm of the Nebulae.- Galaxies Rotate.- The Invisible Material.- The Zoo of Galaxies.- Galactic Nuclei.- Seyfert Galaxies.- Clusters of Galaxies.- Cannibalism Among Galaxies.- Clusters of Clusters.- 10. The Radio Sky.- The Birth of Radio Astronomy.- Radio Waves from the Milky Way.- The Story of Cygnus A.- Radio Galaxies.- The Twin Exhaust Model.- "Tadpole" Galaxies and Aperture Synthesis.- 11. The Mysterious Quasars.- The Classification of Radio Sources.- Stars That Are Utterly Unlike Anything Ever Seen Before.- The Recession Velocities of Radio Stars.- Are Quasars Really Distant?.- Black Holes in Quasars?.- The Absorption Lines in Quasars.- The Problem of Superluminal Velocities.- Herr Meyer and the Firework Display.- A Counter-Example.- Are There Quasars in the Centres of Galaxies?.- The Double Quasar.- 12. ... and There Was Light.- Radio Emission from Our Bodies.- Searching for Faint Radiation from the Milky Way.- The Radiation Remaining from the Big Bang.- Cold Radiation from the Hot Big Bang.- Our Slipstream in Space.- The Cosmic Mixture of Matter and Radiation.- Cosmic Material in the Laboratory.- When Radiation and Matter Separated.- Radiation Becomes Dominant.- Where Is the Antimatter?.- The First Chemical Elements.- Are Neutrinos Sufficient to Close the Universe?.- OurUniverse's Luminous Boundary.- Olbers' Paradox, for the Last Time.- 13. The Intelligent Universe.- Where Did Galaxies and Quasars Come from?.- Why Is the Universe so Smooth?.- We Are Here Because the Universe Is Uniform.- What Came Before?.- At the Origin of Time.- When the Universe Was Tossed into Physics.- Do Natural Laws Determine the Form of the Universe?.- A Time-Lapse Film of the Universe.- Appendices.- A. Frequency and Wavelength.- B. How the Distance of the Hyades Is Determined.- C. The Space Telescope and Stellar Parallaxes.- D. Distances by Dead Reckoning.- Author and Subject Index.