Soft hair: Stephen Hawking’s final theory explained
Late cosmologist’s last work tackles enduring mystery of ‘information paradox’
Stephen Hawking’s final scientific paper has been released by physicists who worked with the late cosmologist in his decades-long effort to understand what happens to information that falls into black holes.
The work - written up and posted online by his former Harvard and Cambridge university colleagues - tackles what theoretical physicists call the “information paradox”. It was completed just days before Hawking died, in March.
Malcolm Perry, Cambridge professor and co-author of the paper, titled Black Hole Entropy and Soft Hair, said the information paradox was “at the centre of Hawking’s life” for more than 40 years. Put simply, the idea that a black hole, and any information that has fallen into it, can evaporate away to nothing is at odds with the rules of quantum mechanics that demand that information is never lost.
Subscribe to The Week
Escape your echo chamber. Get the facts behind the news, plus analysis from multiple perspectives.
Sign up for The Week's Free Newsletters
From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox.
From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox.
“The difficulty is that if you throw something into a black hole it looks like it disappears,” Perry told The Guardian. “How could the information in that object ever be recovered if the black hole then disappears itself?”
At its core, the theory addresses the problematic nature of black holes, which Albert Einstein believed had only three features - mass, charge and spin.
Hawking later asserted that they also had a temperature and so obeyed the laws of thermodynamics. As such, black holes “must inevitably burn themselves out into nothing as they lose energy”, explains the London Evening Standard.
Hawking “tried to reconcile this with the competing theory that no information - meaning physical information in objects - can ever be lost”, the newspaper continues.
He reasoned that, at least in part, the information that enters a black hole goes into “soft hair” - a haze of photons at the event horizon, the outer periphery of a black hole and its point of no return.
That theory is being explored by fellow scientists including Perry, who told the Guardian: “We think it’s a pretty good step but there is a lot more work to be done. We still don’t have the technology to verify Stephen Hawking’s big ideas.”
Among the unknowns that Perry and his colleagues must try to explain are how information “is physically stored in soft hair and how that information comes out of a black hole when it evaporates”, says news site Tech2.
Create an account with the same email registered to your subscription to unlock access.
Sign up for Today's Best Articles in your inbox
A free daily email with the biggest news stories of the day – and the best features from TheWeek.com
-
'A direct, protracted war with Israel is not something Iran is equipped to fight'
Instant Opinion Opinion, comment and editorials of the day
By Harold Maass, The Week US Published
-
Today's political cartoons - April 17, 2024
Cartoons Wednesday's cartoons - political anxiety, jury sorting hat, and more
By The Week US Published
-
Arid Gulf states hit with year's worth of rain
Speed Read The historic flooding in Dubai is tied to climate change
By Peter Weber, The Week US Published
-
Stephen Hawking’s voice to be beamed into black hole
Speed Read Satellite will broadcast “message of peace and hope” after Westminster Abbey memorial service
By The Week Staff Published
-
Should we be worried about artificial intelligence?
In Depth In Depth: the rise of AI robots could make or break mankind’s future
By The Week Staff Published