Gravitational anomalies: An invisible hand?

From The Economist print edition ^ | Aug 19th 2004

[PatrickHenry]

Thanks for that link. We can now return to where we were before the “Allais effect” was noticed:

"When the moon hits your eye like a big pizza pie ... that's amore!"

[edwin hubble]

"If the change in the rate is due to a distortion of spacetime, I don't see why an atomic clock wouldn't measure the effect far more accurately."

(I was in Munich to film the eclipse in 1999, but I certainly didn't have an atomic clock)

On the Behaviour of Atomic Clocks during the 1999 Solar Eclipse over Central Europe
Article http://www.mpq.mpg.de/~haensch/eclipse/full.html

No evidence found of time distortion during eclipse
--abstract from article -
Previous reports on detected influences of solar eclipses on atomic clocks and the movement of pendulums have brought up speculations that some yet undetected gravitational shielding effect exists. We have compared the relative pace of three types of atomic clocks, based on the ground state hyperfine transitions of hydrogen, rubidium and cesium during the total solar eclipse on 11th of August 1999 over central Europe. In our experiment, no anomalous changes in the relative clock rates correlated with the eclipse were found, at a level much smaller than previously reported.

[Physicist]

By Van Flandern, no less! LOL

But waaaaaait, wait wait waitaminute...

I thought there was supposed to be a global academic conspiracy to keep Van Flandern out of the pages of reputable journals, and here he is in Phys. Rev. D! Things that make you go "Hmmm..."

[swilhelm73]

A finite amount of air (or steel, or water, or whatever) has a given mass, no matter what temperature it may be.

Density can be consider to be the measure of the amount of matter within a given area. The ambient temperature is the primary determinate of the density of air. Cold air is denser the warmer air. As such, there are more "air" molecules in the area around the pendulum if the air is cooled.

So, cold air does indeed generate a stronger gravitational pull then warmer air.

However, as I pointed out originally this effect would be very very small.

[RadioAstronomer]

By Van Flandern, no less! LOL

I noticed that too. :-)

[RadioAstronomer]

We have compared the relative pace of three types of atomic clocks, based on the ground state hyperfine transitions of hydrogen, rubidium and cesium during the total solar eclipse on 11th of August 1999 over central Europe. In our experiment, no anomalous changes in the relative clock rates correlated with the eclipse were found, at a level much smaller than previously reported.

Would have been fun to have been involved with that experiment! :-)

I am anxiously awaiting the results from the Gravity Probe B.

[steve in DC]

One might suggest that the differential in mass might place more air molecules in closer proximity to the pendulum, but overall, the mass of air in the atmosphere has to be considered static for these purposes.

Regarding a change in proximal mass, and its discernable impact in the speed of the pendulum, I would suggest that the near transit of a heavy truck would have more significant gravitational impact than a slight change in air temperature, no matter how swiftly that change in temperature might occur.

(But I am too poorly schooled and too lazy to perform the calculations to support my statement:-)

[RightWhale]

Majorana shielding. This eponymous theory is that large masses (such as the moon) partially block the gravitational force from more distant objects

Thus explaining why the force of gravity increases. ??????

MOND is more interesting.

[mvpel]

It's conclusion is chock full of "mights" and "mays" - basically calling the experiments that detected it poorly controlled. I don't think this is a definitive explanation.

[swilhelm73]

I would suggest that the near transit of a heavy truck would have more significant gravitational impact than a slight change in air temperature, no matter how swiftly that change in temperature might occur.

That's exactly why I have to believe that the reporter meant air resistance, not air's gravitational effect. ;)

[boris]

Someone said, "If you cannot say it in numbers you don't understand it," or words to that effect.

So let's see some equations and confirming calculations, please--otherwise you are blowing hot air.

--Boris

[boris]

AAARGH! Van Flandern! My brain is exploding.

Amazing he got published in Phys Rev D. He is the fellow who continues to claim that gravity propagates at infinite velocity...

[longshadow]

>I noticed that too. :-)<

Perhaps he upped his medication.....

[Doctor Stochastic]

When the Moon hits your eye like a big pizza pie...that's a movie.

[Old Professer]

Are the pendula in question oriented in some respect to the line of earth, moon, sun?

[aruanan]

This is a very silly post. The Allais effect is only puzzling to someone who fails to view the Earth, the moon, and the sun as a single system.

When the moon is on the opposite side of the earth from the sun, the center of mass of that system is slightly farther away from the observer on the surface of the earth, than if the moon is in line between the earth and the sun.

And you're saying this about astronomers and physicists. Ha ha ha. You're comparing the gravitational attraction of the moon on an object on earth with relationship to the sun, the object being either between the sun and the moon or the moon being between the object and the sun. This difference in gravitational pull isn't what the difference noted in the Allais effect is talking about. The Allais effect is a change in the period of the pendulum that is observed during the period of totality and only within the zone of totality. The change begins and ends with that short period of totality.

[aruanan]

If so, then the effect should also be observed whenever the moon is more-or-less in line with the sun (ie, once every month), rather than exclusively being seen during an eclipse

No, if there's shielding going on, the zone of totality would be the place where the effect would be the greatest.

[aruanan]

Here's something related. Ron Koczor was doing some work several years ago with the Allais pendulum effect, but I've misplaced all my email correspondence with him about it.

[aruanan]

Here's another one more directly on the subject from NASA about the work Ron Koczor was doing.

[freedumb2003]

"That's not a moon, it's a sattelite!!