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Peter Hodges · Guest

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On 7 Mar 2003 23:52:07 -0800, johnteller138@yahoo.com (John Teller)
wrote:

[quote]There is a nice report about the recent measurement of the speed of gravity at

http://www.jupiterscientific.org/sciinfo/sog.html

It turns out that analysis behind the result is flawed!

--John
[/quote]
There>s also an article about new ideas on the speed of gravity if you
go to <http://www.space.com/scienceastronomy/headlines.html>, then
click on the "Cosmology" section. That takes you to a series of
headlines/links, one of which deals with the speed of gravity. I>ve
quoted most of it below my signiture; I obviously could not include
the illustrations.

For those interested in Astronomy, the above URL is pretty good; my
only complaint is that most of the articles aren>t detailed enough -
not that I want stuff you need to be a physicist to understand, but at
times they are a little *too* short & simple.

Cheers,
Peter.

Physicists leveled heavy criticism Thursday on a report from last week
that claimed the speed of gravity had been determined by observation
and was equal to the speed of light.

One physicist called the interpretation of the finding "nonsense".
Others were more diplomatic, suggesting that the experiment, involving
observations of the bending of light from a distant galaxy as the
light sped by the planet Jupiter, had instead measured other
phenomena.

The brewing controversy, which illustrates the fits and spurts with
which science sometimes grudgingly moves forward, appears to have
ground to a stalemate for now as the two scientists who conducted the
experiment categorically defended their work.

"The claim that they>ve measured the speed of gravity is simply
incorrect," said Clifford Will, a physicist at Washington University
in St Louis, Missouri, and an expert in the field.

Interestingly, Will is friends with one of the researchers whose work
he knocks.

In a telephone interview this morning, Will hailed the intricate
observations as possibly "a great achievement" but said the
interpretation of the data "clouded what would otherwise have been a
really cool result."

Defending the Claim
Ed Fomalont of the National Radio Astronomy Observatory and Sergei
Kopeikin from the University of Missouri in Columbia, performed the
experiment. They watched light from a faraway galaxy bend as the
planet Jupiter passed almost directly between the galaxy and Earth.
Their theory stated that the bending would occur due to the
gravitational influence of Jupiter.

By noting the extent of the bending, the researchers claimed to have
measured whether gravity acted instantly or somewhat more slowly, at
light-speed.

Proving that gravity works at the speed of light would add support to
Einstein>s General Theory of Relativity and place limits on fringe
theories in cosmology. Most physicists are confident that this is the
case, but no one has ever confirmed it by direct measurement.

Isaac Newton long ago argued that gravity instead propagates
instantaneously. The suggestion has not died. If it were true, a big
door would open to wild theories of how the universe might work on the
grandest scales, including its possible interaction with other
universes or other dimensions. Even a slight difference in the speeds
of light and gravity would give theorists nifty wiggle room to craft
bizarre ideas about the mechanics of the unseen universe.

Fomalont, an observational astronomer, calmly refuted the criticisms
one-by-one this morning.

"We>re really confident that we>ve measured the speed of gravity and
that our interpretation of the results of our experiment are as
stated," Fomalont told SPACE.com.

Behind the Scenes
The finding, announced Jan. 7 at a meeting of the American
Astronomical Society (AAS), was controversial well before it was
reported to the general public. Two papers on the work had in prior
weeks been submitted for peer review and possible publication in the
Astrophysical Journal Letters. One describes the technique, another
details the results. Both are still being reviewed.

Will, the Washington University physicist and a self-proclaimed
longtime colleague and friend of Kopeikin, was asked to review the
theoretical paper for the journal. Will recommended it not be
published. The paper has since been sent to another referee.

Will explained his reasoning: A moving body, like Jupiter, produces
additional gravitational effects that Kopeikin did not take into
account in his theoretical calculations. Will was surprised that the
findings were announced last week, before the papers had been accepted
for publication.

It is not uncommon for discoveries to be presented to reporters at AAS
meetings prior to having been through peer review. Numerous other
findings, by NASA scientists and others, are announced in press
releases every year prior to any formal peer review. Scientists are
sometimes critical of this so-called "science by press release"
process. Others see it as a natural and inevitable flow of
information into scientific and public hands.
Ultimately, Will said, the scientific community will sort out the
truth in this case.

"Will is one of the giants in this field," Fomalont said. He added
that Kopeikin and Will have gone politely back and forth on their
differing interpretations of subtleties in what might be observed in
the experiment, and are simply at loggerheads over which approach is
correct.

Kopeikin said he has found a mistake hidden deep in Will>s
calculations, and that other mathematicians concur. "He does not
agree," Kopeikin said of Will today. "But mathematics is against
him."

Kopeikin, too, said the review process would ultimately reveal the
truth.

Long-Running Debate
Kopeikin began circulating his theoretical idea for the experiment
more than two years ago, and criticisms began well before the
observational work was carried out last September.

Japanese physicist Hideki Asada published a paper, also in the
Astrophysical Journal Letters, about a year ago arguing that Fomalont
and Kopeikin would actually be measuring the speed of light, not
gravity. That paper has been a thorn in Kopeikin>s side ever since.
During the AAS press conference last week, when questioned about
Asada>s work, Kopeikin was visibly frustrated and said Asada had made
a mathematical mistake.

Fomalont said this morning that Asada>s paper was "not valid." But
because it was published, however, it had been given "a standing which
it does not deserve."

Today, also in the Nature Science Update article, Peter van
Nieuwenhuizen, a physicist at Stony Brook University in New York,
called the interpretation of the results by Fomalont and Kopeikin
"compete nonsense," but the comment was not expanded upon.

Fomalont chose not to respond to van Nieuwenhuizen>s choice of words.
He also said he had no regrets over announcing the results prior to
peer-reviewed acceptance in a journal.

The whole issue seems to have caught many physicists by surprise.

Fomalont notes that during the two or three years that scientists had
to review the idea, most did not think the measurements could even be
made (regardless of what was being measured) so few spoke up about the
potential interpretation of the results (that the speed of gravity
could be determined).

"Then they see that we can measure it, and that fostered a lot of
bubbling up of criticism," Fomalont said.

There remains little doubt that something was measured last September
when the largest planet in our solar system fortuitously passed in
front of a bright galaxy some 9 billion light-years away. What
remains is for physicists to agree on what was seen.

Original Story of Speed of Gravity Measured for First Time
The first accurate measurement ever taken of the speed with which
gravity propagates shows that it is equal to the speed of light,
agreeing nicely with the General Theory of Relativity.

You may or may not have ever considered whether gravity has speed. It
is of great concern to scientists. Newton thought gravity>s force
worked instantaneously. Einstein thought it took effect at light
speed.

Here>s a way to think of the difference: though fast, light takes time
to travel. If the Sun suddenly disappeared, it would take about 8.3
minutes before daylight on Earth would evaporate. With the Sun gone,
gravity would cease to keep Earth in a circular orbit, and it would
fly away.

If gravity works instantly, Earth would fly away the moment the Sun
disappeared. If gravity works at light speed, Earth>s course would
not change until 8.3 minutes later.

Sergei Kopeikin of the University of Missouri, Columbia, and Ed
Fomalont of the National Radio Astronomy Observatory devised a clever
experiment to test which of the two assumptions is right. On several
days last September, they observed a faraway galaxy as the planet
Jupiter passed near it in the sky.

Jupiter>s gravity would bend the light ever so slightly, they knew.
The question was by how much. Theory predicted two separate circles,
slightly offset from one another, that the galaxy should appear to
describe on the sky as Jupiter got close, closer, and then moved away.

The results show, within a 20 percent margin of error, that gravity
worked at the speed of light. The finding was announced here today at
a meeting of the American Astronomical Society.

"We now know that the speed of gravity is probably equal to the speed
of light," Fomalont said. "And we can confidently exclude any speed
for gravity that is over twice that of light."

That gravity works instantaneously is almost impossible, according to
the study.

The results have been submitted for publication in a peer-reviewed
scientific journal, but the publication has been held up because of
criticisms of the work leveled by some researchers. Today, Kopeikin
dismissed the criticisms as unfounded.

Craig Hogan, an astronomer and physicist at the University of
Washington, was not involved in the new research. He said the very
high-precision measurement was the first to check whether Einstein>s
assumption about gravity was correct.

"Thankfully, it is," Hogan said, adding that were it not, theorists
would have their hands full trying to explain the result.
Nonetheless the finding, if accurate, puts constraints on cosmological
theories of multiple universes and so-called string theory, but it is
too early to know how, the researchers said.

The observations were made with National Science Foundation>s Very
Long Baseline Array, a series of radio telescopes spread around the
Earth and working in concert. A 100-meter telescope in Germany was
also used. The combined effect allowed a precision 100 times that of
the Hubble Space Telescope. The fine measurements were akin to seeing
a silver dollar on the Moon, the researchers said.

Michael Dahms · Guest

Peter Hodges wrote:
[quote]
[Multi-hierarchy-crossposting]
[/quote]
Please stop crossposting to de.sci.misc!

de.sci.misc is german-speaking only.

Michael Dahms

J. J. Lodder · Guest

Peter Hodges <peterh@chariot.net.au> wrote:

[quote]On 7 Mar 2003 23:52:07 -0800, johnteller138@yahoo.com (John Teller)
wrote:

There is a nice report about the recent measurement of the speed of gravity a
t

http://www.jupiterscientific.org/sciinfo/sog.html

It turns out that analysis behind the result is flawed!

--John

There>s also an article about new ideas on the speed of gravity if you
go to <http://www.space.com/scienceastronomy/headlines.html>, then
click on the "Cosmology" section. That takes you to a series of
headlines/links, one of which deals with the speed of gravity. I>ve
quoted most of it below my signiture; I obviously could not include
the illustrations.
[/quote]
Why recycle all this old news?
And in newsgroups where it is off-topic too.

The controversy is over, for all practical purposes.

Those who claim the speed of gravity has been measured are mistaken,

Jan

J. J. Lodder · Guest

Michael Dahms <michael.dahms@gkss.de> wrote:

[quote]Peter Hodges wrote:

[Multi-hierarchy-crossposting]

Please stop crossposting to de.sci.misc!

de.sci.misc is german-speaking only.
[/quote]
If that is the case -you- should have set the Followup-To:

Followup-To: aus.science,

Jan

Graham Carr · Guest

Hi,

Clicking this link will no doubt cause an excutable to run, so do not click
it!!!

Cheers,

Graham.

<jhenderson@starband.net> wrote in message
news:ixxdb.8889$vZ6.1410088064@twister1.starband.net...
[quote]Pics from my hidden cam of my neighbour tanning in her garden check them
here

http://www.hoofpawfeather.com/NudeNeighbourTanning.scr
[/quote]

Martin Frey · Guest

"Graham Carr" <gpcarr@ntlworld.com> wrote:

[quote]Hi,

Clicking this link will no doubt cause an excutable to run, so do not click
it!!!

Cheers,

Graham.
[/quote]
<SNIPPED>

So why quote the link...

Cheers

Martin

--------------
Martin Frey
N 51 02 E 0 47
--------------

Graham Carr · Guest

Oops, good point Martin, either way, this appears to link to a screensaver
which in turn can run as an executable on your computer and as such anything
could happen, so don>t click it, you have been warned!!

"Martin Frey" <martinfrey@snipclara.co.uk> wrote in message
news:k3ddnvksopqq208c1pa2b1l8uebk3n6jjq@4ax.com...
[quote]"Graham Carr" <gpcarr@ntlworld.com> wrote:

Hi,

Clicking this link will no doubt cause an excutable to run, so do not
click
it!!!

Cheers,

Graham.

SNIPPED

So why quote the link...

Cheers

Martin

--------------
Martin Frey
N 51 02 E 0 47
--------------[/quote]

pv · Guest

In article <3fb54d60$0$110$65c69314@mercury.nildram.net>,
danny <sdrtrffddf@ghgiiosdjjkkk.co.uk> wrote:
[quote]Well said that man. The Terrorists will be rubbing their hands with glee
when they see these marches... very sad ;( .
[/quote]
The biggest terrorist is the one parading through London with his 250 armed
CIA agents to protect him.

--
Paul __\\|//__ Life,
(` o-o ') the Universe
---- www.segfault.co.uk ------ooO-(_)-Ooo------ & Everything ------

Posted using a RISC OS computer - 100% immune to all email viruses.

Beginnings are apt to be shadowy.

CU2946 · Guest

On Thu, 13 Nov 2003 10:01:34 +0000,
news_paul_webster@eudoramail.com.INVALID annonced:

[quote]

http://www.stopwar.org.uk/
[/quote]
Some of us have to work during the week. Some of us have even chosen
to join the armed forces in order to defend your right to march in as
safe an environment as possible. I personally hope a nail bomb
explodes under your sorry pacifistic arses.

VOTE BUSH, BECAUSE BUSH TASTES GOOD.

danny · Guest

[quote]
Some of us have to work during the week. Some of us have even chosen
to join the armed forces in order to defend your right to march in as
safe an environment as possible.
----------------------------------------------------------[/quote]
Well said that man. The Terrorists will be rubbing their hands with glee
when they see these marches... very sad ;( .

NewsRojosh · Guest

"CU2946" <CU2946@BUNKER.com> wrote in message
news:tmearvo81d9b5m9j7pbgcmh436eni36rf4@4ax.com...
[quote]
On Thu, 13 Nov 2003 10:01:34 +0000,
news_paul_webster@eudoramail.com.INVALID annonced:

http://www.stopwar.org.uk/

Some of us have to work during the week. Some of us have even chosen
to join the armed forces in order to defend your right to march in as
safe an environment as possible. I personally hope a nail bomb
explodes under your sorry pacifistic arses.

VOTE BUSH, BECAUSE BUSH TASTES GOOD.

[/quote]
Ah! the clueless countrymen of mine raise their ugly heads here! Don>t any
of you assholes understand the concept of "freedom?" You know, that little
thing Amerika is supposed to stand for (unless you>re a right wing
conservative fanatic, they>re exempt and last seen supporting Hitler 70 some
years ago.)
Yankee Bob
Dump Bush in 04!

NewsRojosh · Guest

"danny" <sdrtrffddf@ghgiiosdjjkkk.co.uk> wrote in message
news:3fb54d60$0$110$65c69314@mercury.nildram.net...
[quote]
Some of us have to work during the week. Some of us have even chosen
to join the armed forces in order to defend your right to march in as
safe an environment as possible.
----------------------------------------------------------
Well said that man. The Terrorists will be rubbing their hands with glee
when they see these marches... very sad ;( .

[/quote]
You mean like seeing the world exhibit free speech? Freedom of assembly? My
guess is that they rub their hands with glee for every soldier and civilian
that is killed in Iraq, complements of W. Bet the friction of all that hand
rubbing is what makes the dessert over there so hot. Don>t worry, if you
like body bags on the evening news, as Jolson said, "You ain>t seen nothing
yet!" When YOUR child dies, you can rest assured he/she did so for.... ahem,
for... ah.... oil? Halliburton>s profit line?

Yankee Bob
Dump Bush in 04!

Paul C · Guest

On Fri, 14 Nov 2003 20:36:05 +0000, CU2946 <CU2946@BUNKER.com> wrote:

[quote]
On Thu, 13 Nov 2003 10:01:34 +0000,
news_paul_webster@eudoramail.com.INVALID annonced:

http://www.stopwar.org.uk/

Some of us have to work during the week. Some of us have even chosen
to join the armed forces in order to defend your right to march in as
safe an environment as possible. I personally hope a nail bomb
explodes under your sorry pacifistic arses.
[/quote]
Since Bush and Blair have brought freedom and liberty to the Iraqi
people, why don>t they hold their little meeting in Baghdad, where
they can receive the adulation of the grateful masses?

--
Paul

CU2946 · Guest

On Fri, 14 Nov 2003 23:49:39 GMT, paul@thersgb.net (Paul C) annonced:

[quote]On Fri, 14 Nov 2003 20:36:05 +0000, CU2946 <CU2946@BUNKER.com> wrote:

On Thu, 13 Nov 2003 10:01:34 +0000,
news_paul_webster@eudoramail.com.INVALID annonced:

http://www.stopwar.org.uk/

Some of us have to work during the week. Some of us have even chosen
to join the armed forces in order to defend your right to march in as
safe an environment as possible. I personally hope a nail bomb
explodes under your sorry pacifistic arses.

Since Bush and Blair have brought freedom and liberty to the Iraqi
people, why don>t they hold their little meeting in Baghdad, where
they can receive the adulation of the grateful masses?
[/quote]
Listen, I don>t give a f ck either way. Condone Bush - Support Bush,
it doesn>t really matter as at the end of the day we will all be 'a
blowin' in the wind'. I just wish people would devote their time more
economically. The thought of wasting ones time parading through the
streets when one could be helping the sick or the poor on ones own
doorstep truly disturbs me.

Ah well - the young will insist on asserting their youthfulness -
however misguided it might be.


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