سیاره خوش‌شانس: چرا زمین استثنایی است و این چه معنایی برای زندگی در جهان دارد

Humankind has long fantasized about life elsewhere in the universe. And as we discover countless exoplanets orbiting other stars—among them, rocky super-Earths and gaseous Hot Jupiters—we become ever more hopeful that we may come across extraterrestrial life. Yet even as we become aware of the vast numbers of planets outside our solar system, it has also become clear that Earth is exceptional. The question is: why? In Lucky Planet , astrobiologist David Waltham argues that Earth’s climate stability is one of the primary factors that makes it able to support life, and that nothing short of luck made such conditions possible. The four-billion-year stretch of good weather that our planet has experienced is statistically so unlikely, he shows, that chances are slim that we will ever encounter intelligent extraterrestrial others. Describing the three factors that typically control a planet’s average temperature—the heat received from its star, how much heat the planet absorbs, and the concentration of greenhouse gases in the atmosphere—Waltham paints a complex picture of how special Earth’s climate really is. He untangles the mystery of why, although these factors have shifted by such massive measures over the history of life on Earth, surface temperatures have never fluctuated so much as to make conditions hostile to life. Citing factors such as the size of our Moon and the effect of an ever-warming Sun, Waltham challenges the prevailing scientific consensus that other Earth-like planets have natural stabilizing mechanisms that allow life to flourish. A lively exploration of the stars above and the ground beneath our feet, Lucky Planet seamlessly weaves the story of Earth and the worlds orbiting other stars to give us a new perspective of the surprising role chance plays in our place in the universe. Why Earth's life-friendly climate makes it exceptional#x97;and what that means for the likelihood of finding intelligent extraterrestrial life We have long fantasized about finding life on planets other than our own. Yet even as we become aware of the vast expanses beyond our solar system, it remains clear that Earth is exceptional. The question is: why? In Lucky Planet, astrobiologist David Waltham argues that Earth's climate stability is what makes it uniquely able to support life, and it is nothing short of luck that made such conditions possible. The four billion year-stretch of good weather that our planet has experienced is statistically so unlikely that chances are slim that we will ever encounter intelligent extraterrestrial others. Citing the factors that typically control a planet's average temperature#x97;including the size of its moon, as well as the rate of the Universe's expansion#x97;Waltham challenges the prevailing scientific consensus that Earth-like planets have natural stabilizing mechanisms that allow life to flourish. A lively exploration of the stars above and the ground beneath our feet, Lucky Planet seamlessly weaves the story of Earth and the worlds orbiting other stars to give us a new perspective of the surprising role chance plays in our place in the universe Science tells us that life elsewhere in the Universe is increasingly likely to be discovered. But in fact the Earth may be a very unusual planet - perhaps the only one like it in the entire visible Universe. In Lucky Planet David Waltham asks why, and comes up with some surprising and unconventional answers. Recent geological, biological, and astronomical discoveries are bringing us closer to understanding whether we might be alone in the Universe, and this book uses these to question the conventional wisdom and suggest, instead, that the Earth may have had 'four billion years of good weather' purely by chance. Contents Prologue: A Tale of Two Planets 1. Almost Too Good to Be True 2. Mediocrity 3. Rarely Earth 4. Constant Change 5. Air Conditioning 6. Snowballs and Greenhouses 7. Staggering Through Time 8. Music of the Spheres 9. Force of Nature 10. Pond Weeds and Daisies 11. Life's Big Bang 12. Eclipse 13. The Dark Side of the Moon 14. Gaia or Goldilocks? Epilogue: Siblings Further Reading Acknowledgments Index