Stephen Hawking's final work may contain clues on how we could find parallel universes.
The Sunday Times reports the cosmologist's final paper, A Smooth Exit from Eternal Inflation, could be his pièce de résistance.
"These ideas offer the breathtaking prospect of finding evidence for the existence of other universes," Carlos Frenk, professor of cosmology at Durham University, told the paper.
Prof Hawking died last week aged 76, after living with the debilitating effects of ALS for more than five decades. While it slowly wrecked his body, it seems Prof Hawking's mind was as sharp as ever - he submitted the paper just two weeks before he died.
It reportedly tries to patch holes in a previous theory he came up with, which predicted an infinite number of big bangs creating an infinite number of universes - apparently a mathematical paradox, and completely untestable.
"We wanted to transform the idea of a multiverse into a testable scientific framework," said Thomas Hertog, professor of theoretical physics at KU Leuven University, who collaborated with Prof Hawking on the paper.
Even in fiction, few have imagined how an infinite number of multiverses could work. Star Trek has its 'Mirror Universe' where all the good guys are bad guys, but otherwise sticks to the same cosmos.
"This was Stephen: to boldly go where Star Trek fears to tread," Prof Hertog told the Sunday Times. "He has often been nominated for the Nobel and should have won it. Now he never can."
Prof Hawking's work might not just pave the way for humanity to find other universes, but give us motivation to.
Every universe will end in cold darkness when its stars run out of energy, according to his final work. That idea isn't new - it's called the heat death of the universe, and current estimates put it about 10^10^10^56 years in the future - so many, there aren't enough atoms in the universe to write it down.
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Others have predicted the universe's constant inflation will tear it apart, perhaps in only a few billion years; others suggest the expansion will slow, with everything falling back together in a 'big crunch'.
Prof Hawking's new research may in time, put an end to those theories.
Despite being an atheist, Prof Hawking will be remembered in a service with prayers and hymns at Westminster Abbey, according to reports.