Intelligent Life in the Universe (eBook)

Preface to the Second Edition 6
Preface to the First Edition 8
Table of Contents 10
Planets 15
1 Stars, Galaxies, and the Origin of Chemical Elements 16
1.1 The History of the Universe 16
1.2 Molecular Clouds 19
1.3 The Pre-Main Sequence Evolution of Stars 21
1.4 The Post-Main Sequence Evolution of Stars 24
1.5 Element Composition and Dating 26
2 Planet Formation 32
2.1 Accretion Disks and Planetesimal Formation 32
2.2 Terrestrial Planets 34
2.3 Jovian Planets and Kuiper Belt Objects 37
2.4 The Migration of Jovian Planets 38
2.5 The T-Tauri Stage 39
2.6 Asteroids 41
2.7 Comets 44
2.8 Meteorites 46
2.9 Early History of the Solar System 47
3 The Earth 52
3.1 Planetological History of the Early Earth 52
3.2 Formation of the Moon 53
3.3 Ocean-Vaporizing Impacts 55
3.4 The End of the Heavy Bombardment 57
3.5 The Environment on the Early Earth 58
3.6 Seismology and the Earth’s Interior Structure 62
3.7 Volcanism and the Composition of Rocks 65
3.8 The Earth’s Core and Mantle 69
3.9 The Earth’s Magnetic Field and Sea-Floor Spreading 71
3.10 Convection, Hot Spots and Plate Tectonics 73
3.11 Mountain Building and the Evolution of Continents 79
3.12 Plate Tectonics on Mars and Venus? 84
4 The Search for Extrasolar Planets 86
4.1 The Recently Discovered Planets 86
4.2 Direct Search Methods for Planets 89
4.3 Indirect Search Methods 89
4.4 Circumstellar Disks 92
4.5 New Search Strategies 93
5 Planets Suitable for Life 99
5.1 Habitable Zones 99
5.2 Planetary Mass and the Evaporation of the Atmosphere 103
5.3 The Lifetimes of the Stars 106
5.4 Tidal Effects on Planets 107
5.5 The Increase in Solar Luminosity and the Continuously Habitable Zone 109
5.6 Instabilities of the Planetary Atmosphere 110
5.7 Axis Variations of the Planets 115
5.8 Biogenic Effects on Planetary Atmospheres 117
5.9 Proterozoic Glaciations and Snowball Earth 119
5.10 The Requirements for Continuous Habitability 121
5.11 The Drake Formula 121
5.12 The Number of Habitable Planets 123
Life 126
6 Life and its Origin on Earth 127
6.1 What is Life? 127
6.2 The Special Role of Organic Chemistry 128
6.3 The Elements of Biochemistry 128
6.4 Cells and Organelles 137
6.5 Sequencing and the Classification of Organisms 139
6.6 Geological Traces of Life 145
6.7 The Stage for the Appearance of Life 146
6.8 Abiotic Chemical Evolution and the Theories of How Life Formed 153
7 Evolution 158
7.1 Darwin’s Theory 158
7.2 The Development of Eukaryotes and Endosymbiosis 160
7.3 Oxygen as an Environmental Catastrophe 162
7.4 The Cell Nucleus and Mitosis 163
7.5 Sexuality and Meiosis 164
7.6 Genetic Evolution 166
7.7 Multicellularity, the Formation of Organs, and Programmed Cell Death 168
7.8 Problems of Life on Land 171
7.9 The Great K/T Boundary Event 182
7.10 The Tertiary and the Evolution of Mammals 186
7.11 Primate Evolution 187
7.12 DNA Hybridization 196
7.13 Brain Evolution and Tool Use 197
7.14 Stone Tool Culture 199
7.15 Diet and Social Life 201
7.16 The Logic of the Human Body Plan 202
7.17 Evolution, Chance, and Information 205
7.18 Cultural Evolution 208
8 The Search for Extraterrestrial Life 209
8.1 Life in the Solar System 209
8.2 Europa’s Ocean 210
8.3 Life on Mars 212
8.4 The Early Atmosphere of Mars 218
8.5 Future Mars Missions 220
8.6 Life Outside the Solar System 222
8.7 UFOs 224
Intelligence 227
9 The Future of Mankind 228
9.1 Predicting Mankind’s Future 228
9.2 Settlement of the Solar System 229
9.3 Interstellar Travel 243
9.4 Mastering the Biological World 244
9.5 Androids and Miniaturization 247
9.6 Connected Societies 248
9.7 Fear of the Future 249
9.8 The Dangers for Mankind 249
9.9 Survival Strategies 259
10 Extraterrestrial Intelligent Life 261
10.1 Does Extraterrestrial Intelligent Life Exist? 261
10.2 What is the Hypothetical Nature of the Extraterrestrials? 263
10.3 The Drake Formula, the Number of Extraterrestrial Societies 266
10.4 The Lifetime of an Extraterrestrial Civilization 268
10.5 Distances to the Extraterrestrial Societies 269
10.6 SETI, the Search for Extraterrestrial Intelligent Life 271
10.7 The Fermi Paradox: Where are the Extraterrestrials? 278
10.8 The Zoo Hypothesis 282
References 284
Author Index 301
Subject Index 307