John Gribbin 
Alone in the Universe 
Why Our Planet Is Unique

Preface: The Only Intelligent Planet xiii

Introduction: One in a Trillion 1
Across the Milky Way; Hot jupiters; Planets in profusion; Dusty beginnings; Cosmic chemistry; The life of Gaia; Searching for other Gaias

1. Two Paradoxes and an Equation 26
The cosmic lottery and the Drake equation; The inspection paradox and the Copernican principle; Panspermia and the Fermi paradox; Probing for an answer

2. What’s So Special about Our Place in the Milky Way? 55
Making galaxies; Making metals; Mixing metals in the Milky Way; Our place in the Milky Way; The Galactic Habitable Zone; Catastrophic comets

3. What’s So Special about the Sun? 80
The narrow zone of life; The Sun is not an average star; Perturbing partners; Blasts from the past; The mystery of solar metallicity; Until the Sun dies; Postponing Doomsday

4. What’s So Special about the Solar System? 100
Too hot to handle; The geography of the Solar System; Making planets; Making the Solar System; Making the Earth; The special one

5. What’s So Special about the Earth? 126
Like a diamond in the sky; A planetary jigsaw puzzle; Creating continents; A fi eld of force; Venus and Mars; A planetary stabilizer; Plate tectonics and life

6. What’s So Special about the Cambrian Explosion? 151
I. Contingency and Convergence
The Cambrian explosion; The Burgess Shale; Contingency; Convergence; The third way

7. What’s So Special about the Cambrian Explosion? 167
II. Hothouse Venus/Snowball Earth
After the deep freeze; Tipping the balance; From without or within?; The archetypal impact; Cosmic clouds and comet dust; Diamond dust and a facelift for a goddess

8. What’s So Special about Us? 184
Chance, necessity and the decimal system; The molecular clock; The trigger for change; The pacemaker of human evolution; The fate of technological civilization; The fate of the Earth; No second chance

Further Reading 206

Index 211