## the man who loved numbers (3) it is one

Mathematicians, other scientists, no laboratory equipment - Archimedes, after out of his bath and rubbing himself with olive oil, discovered the principles of geometry by using his fingernails to trace figures on his oily skin. A Japanese restaurant, apparently, is as good a place as to do mathematics. All that mathematicians need is peace of and, occasionally, paper and pencil.

Anne Davenport, the widow of one of Erdös's English collaborators, remembers a time at Trinity College, in the Thirties. "Erdös and my husband, Harold, sat thinking in a place for more than an hour without saying a word. Then Harold the long silence by saying: 'It is not nought. It is one.' There was huge and joy. Everyone around them thought they were mad. Of course, they were."

Before Erdös died in 1996, at the age of 83, he had to think about more problems than any other mathematician in history. He wrote or co-authored 1,475 academic papers, many of them monumental and all of them substantial. in his seventies, there were years when Erdös published 50 papers, which is more than most good mathematicians write in a .

Erdös (pronounced "air-dish") structured his life to maximise the of time he had for mathematics. He had no wife or children, no job, no hobbies, not even a home, to him down. He lived out of a suitcase and a drab orange plastic bag from a large department store in Budapest.