How Old Is the Universe?

Chapter 1 Introduction: 13.7 Billion Years 1


PART I. The Age of Objects in Our Solar System
Chapter 2 4004 bce 9
Chapter 3 Moon Rocks and Meteorites 16
Chapter 4 Defying Gravity 27


PART II. The Ages of the Oldest Stars
Chapter 5 Stepping Out 43
Chapter 6 Distances and Light 55
Chapter 7 All Stars Are Not the Same 61
Chapter 8 Giant and Dwarf Stars 78
Chapter 9 Reading a Hertzsprung-Russell (H-R) Diagram 94
Chapter 10 Mass 101
Chapter 11 Star Clusters 111
Chapter 12 Mass Matters 126
Chapter 13 White Dwarfs and the Age of the Universe 133
Chapter 14 Ages of Globular Clusters and the Age of the Universe 159


PART III. The Age of the Universe
Chapter 15 Cepheids 175
Chapter 16 An Irregular System of Globular Clusters 191
Chapter 17 The Milky Way Demoted 202
Chapter 18 The Trouble with Gravity 209
Chapter 19 The Expanding Universe 217
Chapter 20 The Hubble Age of the Universe 235
Chapter 21 The Accelerating Universe 245
Chapter 22 Dark Matter 261
Chapter 23 Exotic Dark Matter 282
Chapter 24 Hot Stuff 301
Chapter 25 Two Kinds of Trouble 319
Chapter 26 The WMAP Map of the CMB and the Age of the Universe 333
Chapter 27 A Consistent Answer 360
Index 365