Hawking's final paper outlines universe theory

The final research paper submitted by Stephen Hawking days before his death suggests our universe might be one of an endless supply of very similar universes created by the Big Bang.

In the 1980s, Hawking, who died on March 14 at age 76 after years of battling motor neurone disease, worked with US physicist James Hartle on a new theory on the beginning of the universe.

Their theory resolved a difficulty with Albert Einstein's, which put an estimated age on the universe but did not explain how it had come into being.