A short history of nearly everything - Bill Bryson [15]
To understand what a feat this is, imagine a standard dining room table covered in a black tablecloth and someone throwing a handful of salt across it. The scattered grains can be thought of as a galaxy. Now imagine fifteen hundred more tables like the first one—enough to fill a Wal-Mart parking lot, say, or to make a single line two miles long—each with a random array of salt across it. Now add one grain of salt to any table and let Bob Evans walk among them. 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, devotes a passage to him in a chapter on autistic savants—quickly adding that “there is no suggestion that he is autistic.” Evans, who has not met Sacks, laughs at the suggestion that he might be either autistic or a savant, but he is powerless to explain quite where his talent comes from.
“I just seem to have a knack for memorizing star fields,” he told me, with a frankly apologetic look, when I visited him and his wife, Elaine, in their picture-book bungalow on a tranquil edge of the village of Hazelbrook, out where Sydney finally ends and the boundless Australian bush begins. “I'm not particularly good at other things,” he added. “I don't remember names well.”
“Or where he's put things,” called Elaine from the kitchen.
He nodded frankly again and grinned, then asked me if I'd like to see his telescope. I had imagined that Evans would have a proper observatory in his backyard—a scaled-down version of a Mount Wilson or Palomar, with a sliding domed roof and a mechanized chair that would be a pleasure to maneuver. In fact, he led me not outside but to a crowded storeroom off the kitchen where he keeps his books and papers and where his telescope—a white cylinder that is about the size and shape of a household hot-water tank—rests in a homemade, swiveling plywood mount. When he wishes to observe, he carries them in two trips to a small deck off the kitchen. Between the overhang of the roof and the feathery tops of eucalyptus trees growing up from the slope below, he has only a letter-box view of the sky, but he says it is more than good enough for his purposes. And there, when the skies are clear and the Moon not too bright, he finds his supernovae.
The term supernova was coined in the 1930s by a memorably odd astrophysicist named Fritz Zwicky. Born in Bulgaria and raised in Switzerland, Zwicky came to the California Institute of Technology in the 1920s and there at once distinguished himself by his abrasive personality and erratic talents. He didn't seem to be outstandingly bright, and many of his colleagues considered him little more than “an irritating buffoon.” A fitness buff, he would often drop to the floor of the Caltech dining hall or other public areas and do one-armed pushups to demonstrate his virility to anyone who seemed inclined to doubt it. He was notoriously aggressive, his manner eventually becoming so intimidating that his closest collaborator, a gentle man named Walter Baade, refused to be left alone with him. Among other things, Zwicky accused Baade, who was German, of being a Nazi, which he was not. On at least one occasion Zwicky threatened to kill Baade, who worked up the hill at the Mount Wilson Observatory, if he saw him on the Caltech campus.
But Zwicky was also capable of insights of the most startling brilliance. In the early 1930s, he turned his attention to a question that had long troubled astronomers: the appearance in the sky of occasional unexplained points of light, new stars. Improbably he wondered if the neutron—the subatomic particle that had just