Einstein's Theory 'Improved'? (Forwarded)

Press Office
University of St Andrews
Fife, U.K.

Contact:
Gayle Cook, Press Officer
01334 467227 / 462529

13 Feb 2006

Einstein's Theory 'Improved'?

Research from the University of St Andrews has revealed that a 'simple'
fine-tuning in Einstein's theory of gravity could solve a dark mystery
in galaxies that has baffled astrophysicists for three- quarters of a
century.

By refining the law of gravity, Chinese astronomer Dr HongSheng Zhao and
his Belgian collaborator Dr Benoit Famaey of the Free University of
Brussels (ULB), aim to improve Einstein's theory and prove whether the
mysterious Dark Matter actually exists in galaxies.

Theories of the physics of gravity were first developed by Isaac Newton
in 1687 and refined by Albert Einstein's general theory of relativity in
1905 so that the speed of gravity is equal to the speed of light. While
it is the earliest-known force, gravity is still very much a mystery
with theories still unconfirmed by astronomical observations in space.

The 'problem' with the golden laws of Newton and Einstein is that they
do not explain the accelerations of stars in galaxies where there is
more gravity observed than predicted.

Legend has it that Newton began thinking about gravity when an apple
fell on his head, but according to Dr Zhao: "It is not obvious how an
apple would fall in a galaxy. Mr Newton's theory would be off by a large
margin; his apple would fly out of the galaxy."

Astronomers believe that these stars move so fast they would fly apart
if they were not being held together by the gravitational attraction of
a huge amount of unseen material, first noted by Fritz Zwicky in 1933
and now commonly referred to as Dark Matter (or DM).

Though astronomers cannot detect Dark Matter directly because it emits
no light or radiation, it is thought to account for up to 90% of the
Universe. Not all scientists believe in the DM theory however, with some
preferring to believe the theory proposed by Moti Milgrom in 1983 (and
backed up by Jacob Bekenstein in 2004) that a boost in the gravity of
ordinary matter is the cause of this acceleration.

Dr Zhao, a lecturer at the School of Physics and Astronomy at St Andrews
and member of the Scottish Universities Physics Alliance (SUPA),
continued: "Efforts to restore the apple on a nice orbit around the
galaxy has over the years led to two schools of thoughts: Dark Matter
versus non-Newtonian gravity. There has always been a fair chance that
astronomers might rewrite the law of gravity. We have tested a new
formula for gravity, which allows gravity to be boosted gradually from
the Einstein/Newtonian prediction further away from the solar system.

"Our 'simple formula', which is actually a refinement of Bekenstein's,
is consistent with galaxy data so far, and if further verified for solar
system and cosmology, it could solve the Dark Matter mystery. We may be
able to answer common questions such as whether Einstein's theory of
gravity is right and whether the so-called Dark Matter actually exists
in galaxies.

"A non-Newtonian gravity formula is now fully specified on all scales by
a smooth continuous function; it is ready for fellow scientists to
falsify. It is time to keep an open mind while we continue our search
for Dark Matter."

The new formula will be presented to an international audience of
experts at Edinburgh's Royal Observatory in April, which will be given
the opportunity to test and debate the reworked theory. Drs Zhao and
Famaey will demonstrate their new formula to an audience of Dark Matter
and gravity experts from ten different countries.

Dr Famaey commented: "It is possible that neither the modified gravity
theory, nor the DM theory, as they are formulated today, will solve all
the problems of galactic dynamics or cosmology.

"The truth could in principle lie in between, but it is very plausible
that we are missing something fundamental about gravity, and that a
radically new theoretical approach will be needed to solve all these
problems.

"Nevertheless, our formula is so attractively simple that it is tempting
to see it as part of a yet unknown fundamental theory. All galaxy data
seem to be explained effortlessly."

The results are published in the US-based Astrophysical Journal Letters.

ENDS

NOTE TO EDITORS:

THE RESEARCHERS ARE AVAILABLE FOR INTERVIEW:

UK – HongSheng Zhao, University of St Andrews
01334 463135

Belgium - Benoit Famaey , Université Libre de Bruxelles (ULB)
+32-2-6502833

Dr Zhao is a PPARC (Particle Physics and Astronomy Research Council)
Advanced Fellow. For further info contact: Julia Maddock, Tel 01793 442094

Dr. Zhao also holds a NSF Overseas Outstanding Young Scholarship from
National Astronomical Observatory of China (contact Dr. B. Qin at
Beijing Observatory, qinbo @ bao.ac.cn)

The paper is available on line at:

http://adsabs.harvard.edu/cgi-bin/np...pJ...638L...9Z

IMAGE CAPTION:
[http://calvin.st-andrews.ac.uk/exter...%5Fsmall%2Ejpg
(8KB)]
HongSheng Zhao and the 'simple formula'. CREDIT: Tim Fitzpatrick.

The press release says the paper is available online.
I followed the link and read the abstract, but can't
figure out how to get the whole article. Can I get it
for free? If so, how?

-- Jeff, in Minneapolis

In message .com, Jeff
Root writes
The press release says the paper is available online.
I followed the link and read the abstract, but can't
figure out how to get the whole article. Can I get it
for free? If so, how?

-- Jeff, in Minneapolis

Well, you can get the Arxiv e-print at
http://arxiv.org/abs/astro-ph/0512425 but the Astrophysical Journal
version is understandably restricted to subscribers.
BTW, I'm a biologist and the free e-print phenomenon hasn't really hit
the life science journals yet. How do physics journals survive?

"JS" == Jonathan Silverlight writes:

JS BTW, I'm a biologist and the free e-print phenomenon hasn't really
JS hit the life science journals yet. How do physics journals
JS survive?

I think through a variety of factors. At least some of the
astronomical journals charge "page charges," i.e., ask the authors to
cover part of the cost of publishing in the journal. In some cases
professional societies also subsidize, at least partially, journals
that they own or publish. One thing many astronomical journals do not
do is take advertising. It is still a bit jarring to me to pick up
journals in other fields that are filled with advertisements.

--
Lt. Lazio, HTML police | e-mail:
No means no, stop rape. | http://patriot.net/%7Ejlazio/
sci.astro FAQ at http://sciastro.astronomy.net/sci.astro.html

In article ,
Jonathan Silverlight writes:
BTW, I'm a biologist and the free e-print phenomenon hasn't really hit
the life science journals yet. How do physics journals survive?

The commercial ones rely mostly on library subscriptions. Many of
them are having trouble, though the "must have" publications such as
_Nature_ seem to be doing all right. The main astronomy journals in
the US are run by non-profit scientific societies and rely on
(mostly) volunteer labor from editors and referees. Production costs
are paid by a combination of page charges and library subscriptions.
I understand European journals are subsidized directly by their
equivalents of the NSF as a substitute for page charges. They also
benefit from library subscriptions.

If the editing and refereeing process fails to add value (as
perceived by the users) at least equal to the production costs, the
journals will indeed go out of business.

--
Steve Willner Phone 617-495-7123
Cambridge, MA 02138 USA
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