The Thorne–Hawking–Preskill bet was a public bet on the outcome of the

black hole information paradox The black hole information paradox is a puzzle that appears when the predictions of quantum mechanics and general relativity are combined. The theory of general relativity predicts the existence of black holes that are regions of spacetime from wh ...

made in 1997 by physics theorists

Kip Thorne Kip Stephen Thorne (born June 1, 1940) is an American theoretical physicist known for his contributions in gravitational physics and astrophysics. A longtime friend and colleague of Stephen Hawking and Carl Sagan, he was the Richard P. F ...

and Stephen Hawking on the one side, and

John Preskill John Phillip Preskill (born January 19, 1953) is an American theoretical physicist and the Richard P. Feynman Professor of Theoretical Physics at the California Institute of Technology The California Institute of Technology (branded as Caltech ...

on the other, according to the document they signed 6 February 1997, as shown in Hawking's ''

The Universe in a Nutshell ''The Universe in a Nutshell'' is a 2001 book about theoretical physics by Stephen Hawking. It is generally considered a sequel and was created to update the public concerning developments since the multi-million-copy bestseller '' A Brief Histo ...

''.

Overview

Thorne & Hawking argued that since

general relativity General relativity, also known as the general theory of relativity and Einstein's theory of gravity, is the geometric theory of gravitation published by Albert Einstein in 1915 and is the current description of gravitation in modern physics ...

made it impossible for black holes to radiate, and lose information, the mass-energy and information carried by

Hawking radiation Hawking radiation is theoretical black body radiation that is theorized to be released outside a black hole's event horizon because of relativistic quantum effects. It is named after the physicist Stephen Hawking, who developed a theoretical a ...

must be "new", and must not originate from inside the black hole

event horizon In astrophysics, an event horizon is a boundary beyond which events cannot affect an observer. Wolfgang Rindler coined the term in the 1950s. In 1784, John Michell proposed that gravity can be strong enough in the vicinity of massive compact ob ...

. Since this contradicted the idea under

quantum mechanics Quantum mechanics is a fundamental theory in physics that provides a description of the physical properties of nature at the scale of atoms and subatomic particles. It is the foundation of all quantum physics including quantum chemistr ...

of microcausality, quantum mechanics would need to be rewritten. Preskill argued the opposite, that since quantum mechanics suggests that the information emitted by a black hole relates to information that fell in at an earlier time, the view of black holes given by general relativity must be modified in some way. The winning side of the bet would receive an encyclopedia of their choice, "from which information can be retrieved at will". In 2004, Hawking announced that he was conceding the bet, and that he now believed that black hole horizons should fluctuate and leak information, in doing so providing Preskill with a copy of ''Total Baseball, The Ultimate Baseball Encyclopedia''. Comparing the useless information obtainable from a black hole to "burning an encyclopedia", Hawking later joked, "I gave John an encyclopedia of baseball, but maybe I should just have given him the ashes." Thorne, however, remained unconvinced of Hawking's proof and declined to contribute to the award. Hawking's argument that he solved the paradox has not yet been wholly accepted by the scientific community, and a consensus has not yet been reached that Hawking provided a strong enough argument that this is in fact what happens. Hawking had earlier speculated that the singularity at the centre of a black hole could form a bridge to a "baby universe", into which the lost information could pass; such theories have been very popular in science fiction. But according to Hawking's new idea, presented at the 17th International Conference on General Relativity and Gravitation, on 21 July 2004 in

Dublin Dublin (; , or ) is the capital and largest city of Ireland. On a bay at the mouth of the River Liffey, it is in the province of Leinster, bordered on the south by the Dublin Mountains, a part of the Wicklow Mountains range. At the 2016 c ...

, black holes eventually transmit, in a garbled form, information about all matter they swallow:

Earlier Thorne–Hawking bet

An older bet from 1974 – about the existence of black holes – was described by Hawking as an "insurance policy" of sorts: In the updated and expanded edition of ''A Brief History of Time'', Hawking states, "Although the situation with Cygnus X-1 has not changed much since we made the bet in 1975, there is now so much other observational evidence in favour of black holes that I have conceded the bet. I paid the specified penalty, which was a one year subscription to '' Penthouse'', to the outrage of Kip's liberated wife." While Hawking described the bet as having been made in 1975, the written bet itself—in Thorne's handwriting, with his and Hawking's signatures—bears witness signatures under the legend "Witnessed this tenth day of December 1974". Thorne confirmed this date on the 10 January 2018 episode of '' Nova'' on

PBS The Public Broadcasting Service (PBS) is an American public broadcaster and non-commercial, free-to-air television network based in Arlington, Virginia. PBS is a publicly funded nonprofit organization and the most prominent provider of educat ...

References

{{DEFAULTSORT:Thorne-Hawking-Preskill Bet Black holes Stephen Hawking Wagers 1997 in science February 1997 events

Overview

Earlier Thorne–Hawking bet

See also

References