David Waltham believes that the Earth is a peculiar place, ‘perhaps the only highly habitable planet we will ever find’; a view at odds with the prevailing opinion that the Earth is ‘small, insignificant and lost in the immensity of the Universe’.
This latter school of thought emerged recently, as astronomers discovered exoplanets – planets that orbit stars other than the Sun – and Waltham acknowledges that it’s almost inevitable that vast numbers of near-twins to Earth exist in deep space, separated by billions of light years. Indeed, as he describes the various events that, on a bad day, might have ensured Earth’s uninhabitability – such as the interplanetary collision that resulted in our moon, or the factors that might have changed the Earth’s temperature by hundreds of degrees centigrade – he admits that ‘experts would argue over almost every one of the details’.
Ultimately, the question he’s asking is: are the physical laws of the Universe we inhabit contrived in such a way as to make the emergence of life on our planet inevitable? Not everyone will agree with his answers, but it’s difficult not to be charmed by his analysis of lunar motifs in Peppa Pig cartoons.
LUCKY PLANET: Why Earth is Exceptional – and What that Means for Life in the Universe by David Waltham, Icon Books, £14.99