Erdős number

I was just reading the news of stepping down of Stephan hawking from the Lucasian professor of Mathematics in Cambridge University.I also came to know that Hawking has a Erdos number of 4. This evoked my interest to know more about Paul Erdos the great Hungarian mathematician.

Paul Erdos ,an immensely prolific mathematician has wrote around 1,475 mathematical articles in his lifetime, mostly with co-authors. This made his colleagues to coin the term Erdos number which indicates the collaborative distance between a person and Erdős, as measured by authorship of mathematical papers.Erdos has a number of 0 his co-authors has number of 1 and their co-authors will have number of 2 and so on.

The origin of this term won't be astonishing if you come to know more about Paul Erdos and his contributions .He stands only next to Euler in terms of the volume of mathematical work.Erdos also known to be of exceptional character for whom possessions meant nothing and spent most of his life as a vagabond.He has once told "You don't have to believe in God, but you should believe in The Book".The Book is an imaginary book that Erdos believes in which God had written down the best and most elegant proofs for mathematical theorems.See the wikipedia article and related links on Paul Erdos for more details.
Reference
Wikipedia