The latest scientific article by Stephen Hawking, which he was finishing just before his death, was published.
Black Hole Entropy and Soft Hair were the last work of the professor of cosmology and physicist and were finalized by his closest colleagues.
The paper opens its long-standing battle with the theoretical physics of the "information paradox" and what happens to the information when objects fall into a black hole.
He had completed his work on the theory in March just before dying and his work had been written by his colleagues at Cambridge and Harvard University.
Co-author Malcolm Perry, a professor of theoretical physics in Cambridge, said the information paradox was "at the center of Hawking's life" for more than 40 years.
"We still do not have the technology to check Stephen Hawking's great ideas," he told The Guardian.
You can read the paper here.
The theory addresses the problematic nature of black holes which, according to Einstein, had only three characteristics: mass, charge, and rotation. But Professor Hawking thought that they also had a temperature and thus obeyed the laws of thermodynamics.
They must therefore inevitably wear out when they lose energy. Hawking has therefore tried to reconcile this with the competing theory that no information – which means physical information in objects – can be lost.
"The problem is that if you throw something into a black hole, it seems like it's going away," said Professor Perry. "How could the information contained in this object be recovered if the black hole disappears on its own?"
The document shows how at least some information can be preserved because the object will also affect the physical forces of the black hole.
And the reference to "soft hair" in the title refers to the corona of photons surrounding the edge of the black hole at the event horizon.
Stephen Hawking Scientist – In Pictures
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Nelson Mandela meets with Professor Hawking in Johannesburg in 2008
AFP / Getty Images
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Professor Hawking and his second wife Elaine Mason attend the International Book Fair in Frankfurt, Germany, in 2005
Getty Images
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Professor Hawking gives a lecture at the Bloomfield Science Museum in Jerusalem in 2006
AFP / Getty Images
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Hawking, his daughter Lucy and French physicist Christophe Galfard in 2007
AFP / Getty Images
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Professor Stephen Hawking during his graduation at Oxford
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Stephen Hawking with his son Robert in 1967
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Stephen Hawking with his wife
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Stephen Hawking with his wife Jane and their children
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Professor Stephen Hawking at the wedding ceremony with his former nurse Elaine Mason in 1995
Pennsylvania
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Stephen Hawking and Nobel laureate Dorothy Hodgkin with their portraits unveiled at the National Portrait Gallery in London
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A brief history of time by Stephen Hawking
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Outgoing President Barack Obama Presents Professor Hawking Medal Freedom in 2009
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Queen Elizabeth II meets Professor Hawking at the Palais Saint-James in 2014
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Professor Stephen Hawking and Eddie Redmayne attend the British premiere of "The Theory Of Everything" at Odeon Leicester Square
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George Osborne and Stephen Hawking attend the "1000: London's Most Influential People" from the London Evening Standard at the Francis Crick Institute
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Stephen Hawking in The Simpsons
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Stephen Hawking with David Beckham
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Professor Stephen Hawking unveils a scientific formula to predict England's chances of success at the World Cup in Cambridge
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ill Gates (L), accompanied by Professor Alec Broers, Vice Chancellor of the University, meets Professor Stephen Hawking visiting the University of Cambridge
REUTERS
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Stephen Hawking floats on a weightless jet in 2007
AP
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Pope Benedict XVI welcomes British Professor Stephen Hawking at a meeting of science academics at the Vatican in 2008
Reuters
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Professor Hawking visits Cap Finestre, Spain, in 2008
AFP / Getty Images
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Professor Stephen Hawking in Futurama
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Stephen Hawking has starred in several episodes of "The Big Bang Theory".
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Hawking: Leaders and scientists from around the world pay tribute to the famous physicist
Pennsylvania
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Professor Hawking photographed in London in 2014
AFP / Getty Images
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British physicist Stephen Hawking sits in the Olympic Stadium at the Opening Ceremony of the London 2012 Paralympic Games on August 29, 2012. REUTERS / Toby Melville (BRITAIN – Tags: OLYMPIC SPORTS)
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David Walliams, Professor Stephen Hawking and Catherine Tate for Red Nose Day 2015
Rex Features
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Stephen Hawking with Jane Wilde and guests attend the EE British Academy Awards at the Royal Opera House in 2015
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Stephen Hawking and Felicity Jones Present Special Effects Award at the 2015 British Academy Film Award at EE BAFTA
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Pope Francis welcomes physicist Stephen Hawking at a hearing bringing participants to a plenary session of the Academy of Pontifical Sciences at the Vatican in 2016
AP
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Professor Stephen Hawking presents the trophy at Balliol College of Oxford, winner of 190 points against 140-140, against Wolfson College Cambridge (left) in 2017
Pennsylvania
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Professor Stephen Hawking is presented with his illuminated scroll of freedom by London Chamberlain Peter Kane at the City of London's Freedom of Honor Ceremony at a ceremony at the London Guildhall in 2017
AP
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Nelson Mandela meets with Professor Hawking in Johannesburg in 2008
AFP / Getty Images
2/33
Professor Hawking and his second wife Elaine Mason attend the International Book Fair in Frankfurt, Germany, in 2005
Getty Images
3/33
Professor Hawking gives a lecture at the Bloomfield Science Museum in Jerusalem in 2006
AFP / Getty Images
4/33
Hawking, his daughter Lucy and French physicist Christophe Galfard in 2007
AFP / Getty Images
5/33
Professor Stephen Hawking during his degree at Oxford
6/33
Stephen Hawking with his son Robert in 1967
COLLECTION
7/33
Stephen Hawking with his wife
8/33
Stephen Hawking with his wife Jane and their children
9/33
Professor Stephen Hawking at the wedding ceremony with his former nurse Elaine Mason in 1995
Pennsylvania
10/33
Stephen Hawking and Nobel laureate Dorothy Hodgkin with their portraits unveiled at the National Portrait Gallery in London
Pennsylvania
11/33
A brief history of time by Stephen Hawking
Amazon
12/33
Outgoing President Barack Obama Presents Professor Hawking Medal Freedom in 2009
Getty Images
13/33
Queen Elizabeth II meets Professor Hawking at the Palais Saint-James in 2014
Getty Images
14/33
Professor Stephen Hawking and Eddie Redmayne attend the British premiere of "The Theory Of Everything" at Odeon Leicester Square
Getty Images
15/33
George Osborne and Stephen Hawking attend the "1000: London's Most Influential People" from the London Evening Standard at the Francis Crick Institute
16/33
Stephen Hawking in The Simpsons
17/33
Stephen Hawking with David Beckham
18/33
Professor Stephen Hawking unveils a scientific formula to predict England's chances of success at the World Cup in Cambridge
19/33
ill Gates (L), accompanied by Professor Alec Broers, Vice Chancellor of the University, meets Professor Stephen Hawking visiting the University of Cambridge
REUTERS
20/33
Stephen Hawking floats on a weightless jet in 2007
AP
21/33
Pope Benedict XVI welcomes British Professor Stephen Hawking at a meeting of science academics at the Vatican in 2008
Reuters
22/33
Professor Hawking visits Cap Finestre, Spain, in 2008
AFP / Getty Images
23/33
Professor Stephen Hawking in Futurama
24/33
Stephen Hawking has starred in several episodes of "The Big Bang Theory".
25/33
Hawking: Leaders and scientists from around the world pay tribute to the famous physicist
Pennsylvania
26/33
Professor Hawking photographed in London in 2014
AFP / Getty Images
27/33
British physicist Stephen Hawking sits in the Olympic Stadium at the Opening Ceremony of the London 2012 Paralympic Games on August 29, 2012. REUTERS / Toby Melville (BRITAIN – Tags: OLYMPIC SPORTS)
28/33
David Walliams, Professor Stephen Hawking and Catherine Tate for Red Nose Day 2015
Rex Features
29/33
Stephen Hawking with Jane Wilde and guests attend the EE British Academy Awards at the Royal Opera House in 2015
30/33
Stephen Hawking and Felicity Jones Present Special Effects Award at EE BAFTA British Academy Film Award 2015
31/33
Pope Francis welcomes physicist Stephen Hawking at a hearing bringing participants to a plenary session of the Academy of Pontifical Sciences at the Vatican in 2016
AP
32/33
Professor Stephen Hawking presents the trophy at Balliol College of Oxford, winner of 190 points against 140-140, against Wolfson College Cambridge (left) in 2017
Pennsylvania
33/33
Professor Stephen Hawking is presented with his illuminated scroll of freedom by London Chamberlain Peter Kane at the City of London's Freedom of Honor Ceremony at a ceremony at the Guildhall, in London. London in 2017
AP
"It's really a step forward," added Professor Perry. "We think it's a good step forward, but there is still a lot of work to be done."