Alone in the Universe

Why Our Planet is Unique

John Gribbin

Gribbin gives a lot of qualitative overview of astronomy, and coming from a good writer with a long background in astronomy, I would do well to carefully review my astronomy content in HyperPhysics in light of it.

Preface

xiii Introduces super comet and Venus collision as a possibility. "we know that something catastrophic happened to both Venus and Earth at the same time." Hasn't said yet how we know that.

xiv Discusses Copernican hypothesis, Gaia and Jim Lovelock, concedes liklihood of simple life elsewhere than the Earth but suggests that intelligent life like Earth may be unique.

xv "the only witnesses with an understanding of the origin and nature of the universe itself."

Introduction: One in a Trillion

p1 Describes observable universe like a bubble with 13.7 Glyr radius, but "this does not mean that we are at the center of the universe any more than a sailor out of signt of land is at the center of the ocean."

p2 Rounds off to a trillion stars in our galaxy and a trillion galaxies in the universe

p3 Brief summary of importance of 4.5gyr age to collect heavy elements

p3 Qualitative description of spiral arms

p5 Maybe half the stars have planets.

p5 Check out comment on neutron stars having ~10km diameter and ~a solar mass.

p6 Description of planets around pulsar - data on them for one pulsar, detected by change in pulsar rate. Discussion of planet formation from debris since any planets would have been destroyed by supernova, so a clue that all planet formation is from the debris.

p6 Planet 51 Pegasi, doppler discovery, hot Jupiter

p8 Discussion of transit measurement, Kepler satellite launched 2009 for planet studies.

p10 Story of Gliese 581 with planets 1.9M_E,7M_E

p14-16 Review of chemistry of life

p16 Half the mass of all biological matter on Earth is in form of amino acids.

1. Two Paradoxes and an Equation

2. What's So Special about Our Place in the Milky Way?

3. What's So Special about the Sun?

4. What's So Special about the Solar System?

5. What's So Special about the Earth?

6. What's So Special about the Cambrian Explosion I?

7. What's So Special about the Cambrian Explosion II?