WHEN THE SKIES are clear and the Moon is not tht, the Reverend Robert Evans, aquiet and cheerful man, lugs a bulky telescope onto the back deck of his home in the BlueMountains of Australia, about fifty miles west of Sydney, and does araordinary thing. Helooks deep into the past and finds dying stars.
Looking into the past is of course the easy part. Gla the night sky and what you see ishistory and lots of it—the stars not as they are now but as they were when their light leftthem. For all we know, the North Star, our faithful panion, might actually have bur last January or in 1854 or at any time sihe early fourteenth tury and news of it justhasn』t reached us yet. The best we say— ever say—is that it was still burning on thisdate 680 years ago. Stars die all the time. What Bob Evans does better than anyone else whohas ever tried is spot these moments of celestial farewell.
By day, Evans is a kindly and now semiretired minister in the Uniting Chur Australia,who does a bit of freelance work and researches the history of eenth-tury religiousmovements. But by night he is, in his unassuming way, a titan of the skies. He huntssupernovae.
Supernovae occur when a giant star, one much bigger than our own Sun, collapses and theacularly explodes, releasing in an instant the energy of a hundred billion suns, burningfor a time brighter than all the stars in its galaxy. 「It』s like a trillion hydrogen bombs going offat once,」 says Evans. If a supernova explosion happened within five hundred light-years of us,we would be goners, acc to Evans—「it would wreck the show,」 as he cheerfully puts it.
But the universe is vast, and supernovae are normally much too far away to harm us. In fact,most are so unimaginably distant that their light reaches us as no more than the faiwinkle. For the month or so that they are visible, all that distinguishes them from the otherstars in the sky is that they occupy a point of space that wasn』t filled before. It is theseanomalous, very occasional pricks in the crowded dome of the night sky that the ReverendEvans finds.
To uand what a feat this is, imagine a standard dining room table covered in a blacktablecloth and someohrowing a handful of salt across it. The scattered grains bethought of as a galaxy. Now imagine fifteen hundred more tables like the first one—enough tofill a Wal-Mart parking lot, say, or to make a single liwo miles long—each with a randomarray of salt across it. Now add one grain of salt to any table a Bob Evans walk amongthem. At a glance he will spot it. That grain of salt is the supernova.
Evans』s is a talent so exceptional that Oliver Sacks, in An Anthropologist on Mars, devotesa passage to him in a chapter on autistic savants—quickly adding that 「there is no suggestionthat he is autistic.」 Evans, who has not met Sacks, laughs at the suggestion that he might beeither autistic or a savant, but he is powerless to explain quite where his talent es from.
「I just seem to have a knaemorizing star fields,」 he told me, with a franklyapologetic look, when I visited him and his wife, Elaine, in their picture-book bungalow on atranquil edge of the village of Hazelbrook, out where Sydney finally ends and the boundlessAustralian bush begins. 「I』m not particularly good at other things,」 he added. 「I don』tremember names well.」
「Or where he』s put things,」 called Elaine from the kit.
He nodded frankly again and grihen asked me if I』d like to see his telescope.