[Paleopsych] IOP: Stephen Hawking presents new black hole theory
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Wed Jul 21 17:55:32 UTC 2004
Stephen Hawking presents new black hole theory
The Institute of Physics
Wednesday 21 July 2004
One of the most intriguing problems in theoretical physics has been
solved by Professor Stephen Hawking of the University of Cambridge. He
presented his findings at GR17, the 17th International Conference on
General Relativity and Gravitation, in Dublin on Wednesday 21st July.
Black holes are often thought of as being regions of space into which
matter and energy can fall, and disappear forever. In 1974, Stephen
Hawking discovered that when one fused the ideas of quantum mechanics
with those of general relativity, it was no longer true that black
holes were completely black. They emitted radiation, now known as
Hawking radiation. This radiation carried energy away from the black
hole, which meant that the black hole would gradually shrink and then
disappear in a final explosive outburst.
These ideas led to a fundamental difficulty, the information paradox,
the resolution of which is to be revealed in Dublin. The basic problem
is that black holes, as well as eating matter, also appear to eat
quantum mechanical information. Yet the most fundamental laws of
physics demand that this information be preserved as the universe
evolves. The information paradox was explored and formalised by
Hawking in 1975. Since then, many have tried to find a solution.
Whilst most physicists think that there must be a resolution of the
paradox, nobody has really produced a believable explanation. In fact,
seven years ago the issue prompted Hawking, together with Kip Thorne
of Caltech, to make a wager against John Preskill also of Caltech,
that the information swallowed by black holes could never be
Hawking has now conceded that he has lost the bet!
The way his new calculations work is to show that the event horizon,
which is the surface of the black hole, has quantum fluctuations in
it. These are the same uncertainties in position that were made famous
by Heisenberg's uncertainty principle and are central to quantum
mechanics. The fluctuations gradually allow all the information inside
the black hole to leak out, thus allowing us to form a consistent
picture. The information paradox is now unravelled.
A complete description of this work will be published in professional
journals and on the web in due course.
Prof. Hawking's lecture forms part of the 17th International
Conference on General Relativity and Gravitation (GR17). This lecture
forms part of the scientific programme of the conference, and is not
open to the public.
However, the conference programme also includes two public lectures.
On Monday 19th at 8pm, Prof. Kip Thorne delivered a lecture entitled
"Probing the Universe and Black Holes with Gravitational Waves", while
on Friday 23rd, also at 8pm, Prof. Sir Roger Penrose will speak on
"Fashion, Faith, and Fantasy in Modern Physical Theories". Tickets for
Prof. Penrose's lecture will be available at the door. The lectures
take place in the Concert Hall of the RDS (Merrion Road entrance).
The weeklong GR17 conference is taking place in the RDS Conference
Centre, Dublin. It is being attended by upwards of 600 scientists from
48 different countries. As well as Prof. Hawking, GR17 is being
attended by such renowned scientists as Sir Roger Penrose, Kip Thorne
and Sir Martin Rees. The conference was officially inaugurated on
Monday 19th by Her Excellency Mrs Mary McAleese, President of Ireland.
GR17 is the latest edition in a triennial series held under the
auspices of the International Society on General Relativity and
Gravitation. This conference series constitutes the principal
international meetings in the areas of relativity, gravitation and
The subject matter of the conference is all areas of general
relativity and gravitation, including Gravitational Waves: Detection
and Generation, Astrophysics of Black Holes, the Early Universe,
String Theory, and Quantum Gravity.
See the GR17 web site for more information about the conference.
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