Right before he died, Stephen Hawking submitted his final paper that might lay out the math needed to prove the existence of other universes — as well as how ours might fade out.
The working paper, submitted for publication two weeks before his death, according to the U.K.’s Sunday Times, may turn out to be a culmination of the renowned physicist’s life’s work. In his research, Hawking sought to solve problems he’d been pondering for the past 35 years — ever since he published his theory of how the universe expanded following the Big Bang.
The paper proposes that evidence of a multiverse is detectable in the background radiation of our own universe — and that that evidence could, in theory, be found and measured. If we do, in fact, live in a “multiverse,” our own cosmos is just one of many universes out there. Taken together, the multiverse, made up of all its individual universes, would comprise all of space, time, matter, and energy.
Though Hawking’s last paper could provide optimism for those hoping to test for the existence of multiple universes, his research also includes a bleak prediction: Our universe will eventually go dark once all its stars run out of energy.
The paper, titled “A Smooth Exit from Eternal Inflation,” is under peer review for publication in an unnamed major scientific journal.
In 1983, Hawking and his colleague Jame Hartle co-authored a paper describing the inflation that took place after the Big Bang — the rapid expansion of space that created the universe. The theory relied on the existence of other universes, formed at the same time as ours during the Big Bang. The theory, however, couldn’t be tested.
But testing the idea through experimentation was exactly what Hawking sought to do. “We wanted to transform the idea of a multiverse into a testable scientific framework,” said Thomas Hertog, the co-author of the paper and Hawking’s mentee, according to the Sunday Times. If Hawking were still alive, the paper might have even won him his first Nobel Prize, other researchers said. The award, however, isn’t given posthumously.
But not everyone agrees the working paper’s findings are groundbreaking.
“His very last paper sought to rescue some predictiveness, but the arguments are as yet unconvincing,” said Professor Neil Turok, director of Canada’s Perimeter Institute and a friend of Hawking, told U.K.’s The Times.
Hawking died peacefully in his home on March 14 at the age of 76 due to complications associated with the neurodegenerative disease he’d fought for most of his adult life, amyotrophic lateral sclerosis.
Correction 3/20: Due to an editing error, this post incorrectly said Hawking submitted his final paper on March 14. He submitted the paper two weeks earlier.
Cover image: Professor Stephen Hawking arrives for the Interstellar Live show at the Royal Albert Hall in central London on March 30, 2015. (Photo by Joel Ryan/Invision/AP, File)