I believe that many people, perhaps most, are interested in the big questions this book has touched on, questions such as ‘Why are we here?’ and ‘Are we alone?’ I personally also find these questions interesting because they are covered by areas of science that are filled by controversy and passionate argument; and I do enjoy a good argument. This is a rapidly moving field which, as I hope this book has shown, is currently experiencing a dramatic influx of hard data concerning both the very ancient history of life on Earth and the existence of strange worlds beyond our cosy solar system. At present, there is no scientific consensus about what this data is telling us and, inevitably, I’ve put my own cast on the subject. But I passionately believe that, whatever the topic, alternative views must always be listened to, and so I’d like to spend the last pages of Lucky Planet suggesting where you might go to explore a wider range of opinions.
Your first port of call should be James Kasting’s excellent How to Find a Habitable Planet (Princeton University Press, 2010), which is, to a considerable extent, a riposte to the equally engaging Rare Earth (Copernicus Books, 2000) by Peter Ward and Donald Brownlee. Rare Earth, like my own book, supports the view that the Earth may be special but it takes a much broader look well beyond the issue of climate stability that I have concentrated on. How to Find a Habitable Planet takes very much the opposite view and presents many cogent arguments suggesting that life may, after all, be common in the Universe. I suggest you read both books and make your own mind up.
That covers what could be described as the main controversy I’ve looked at in this book, but in fact almost every chapter of Lucky Planet discusses issues that cause heated debate among the experts studying them. A good example of this concerns the history of Earth’s climate itself. Did those snowball Earth episodes really happen or has there been massive over-interpretation of very limited data? What about the cooling trend over billions of years: Is it real or an artefact of poor data? To read more about the Earth’s climate history you could not do better than read The Goldilocks Planet (Jan Zalasiewicz and Mark William, Oxford University Press, 2012). I can also thoroughly recommend Frozen Earth: The Once and Future Story of Ice Ages by Doug MacDougal (University of California Press, 1994). When it comes to Gaia and climate, you must read On Gaia (Toby Tyrrell, Princeton University Press, 2013), which is an in-depth critique of the Gaia hypothesis. For a more positive assessment take a look at Revolutions that Made the Earth by Tim Lenton and Andrew Watson (Oxford University Press, 2011), whose main subject is an unmatched exploration of the most important events in the evolution of life on Earth.
On the cosmological side of my story there are many excellent texts available, since this is a very well covered area in popular science books. My personal favourite is Leonard Susskind’s The Cosmic Landscape (Hachette Book Group, 2006) but I’d also suggest Steven Manly’s Visions of the Multiverse (The Career Press, 2011) and The Goldilocks Enigma by Paul Davies (Penguin Books, 2006), which are, perhaps, a little more accessible for those new to the subject. If, like me, you find that a little mathematics enlightens rather than obscures, then have a go with Barbara Ryden’s Introduction to Cosmology (Addison Wesley, 2003), which, as a non-expert in this area, I found enormously helpful.
Finally, for the technical references I have used in my work, you will need to go to my published scientific papers on the subject. Links to these can be found at www.davidwaltham.com, where you should select the Lucky Planet menu.