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A short history of nearly everythingFrom his deck, Evans supposes he can see between 50,000 and 100,000 galaxies, each containing tens of billions of stars. These are of course respectable numbers, but even with so much to take in, supernovae are extremely rare. A star can burn for billions of years, but it dies just once and quickly, and only a few dying stars explode. Most expire quietly, like a campfire at dawn. In a typical galaxy, consisting of a hundred billion stars, a supernova will occur on average once every two or three hundred years. Finding a supernova therefore was a little bit like standing on the observation platform of the Empire State Building with a telescope and searching windows around Manhattan in the hope of finding, let us say, someone lighting a twenty-first-birthday cake. So when a hopeful and softspoken minister got in touch to ask if they had any usable field charts for hunting supernovae, the astronomical community thought he was out of his mind. At the time Evans had a ten-inch telescope-a very respectable size for amateur stargazing but hardly the sort of thing with which to do serious cosmology-and he was proposing to find one of the universeБЂ™s rarer phenomena ...» |
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