An angularly accelerated superconductive ring induces non-Newtonian gravitational fields in its neibourghood.
Posted on 03/25/2006 11:13:27 AM PST by PatrickHenry
Scientists funded by the European Space Agency have measured the gravitational equivalent of a magnetic field for the first time in a laboratory. Under certain special conditions the effect is much larger than expected from general relativity and could help physicists to make a significant step towards the long-sought-after quantum theory of gravity.
Just as a moving electrical charge creates a magnetic field, so a moving mass generates a gravitomagnetic field. According to Einstein's Theory of General Relativity, the effect is virtually negligible. However, Martin Tajmar, ARC Seibersdorf Research GmbH, Austria; Clovis de Matos, ESA-HQ, Paris; and colleagues have measured the effect in a laboratory.
Their experiment involves a ring of superconducting material rotating up to 6 500 times a minute. Superconductors are special materials that lose all electrical resistance at a certain temperature. Spinning superconductors produce a weak magnetic field, the so-called London moment. The new experiment tests a conjecture by Tajmar and de Matos that explains the difference between high-precision mass measurements of Cooper-pairs (the current carriers in superconductors) and their prediction via quantum theory. They have discovered that this anomaly could be explained by the appearance of a gravitomagnetic field in the spinning superconductor (This effect has been named the Gravitomagnetic London Moment by analogy with its magnetic counterpart).
Small acceleration sensors placed at different locations close to the spinning superconductor, which has to be accelerated for the effect to be noticeable, recorded an acceleration field outside the superconductor that appears to be produced by gravitomagnetism. "This experiment is the gravitational analogue of Faraday's electromagnetic induction experiment in 1831.
It demonstrates that a superconductive gyroscope is capable of generating a powerful gravitomagnetic field, and is therefore the gravitational counterpart of the magnetic coil. Depending on further confirmation, this effect could form the basis for a new technological domain, which would have numerous applications in space and other high-tech sectors" says de Matos. Although just 100 millionths of the acceleration due to the Earth’s gravitational field, the measured field is a surprising one hundred million trillion times larger than Einstein’s General Relativity predicts. Initially, the researchers were reluctant to believe their own results.
"We ran more than 250 experiments, improved the facility over 3 years and discussed the validity of the results for 8 months before making this announcement. Now we are confident about the measurement," says Tajmar, who performed the experiments and hopes that other physicists will conduct their own versions of the experiment in order to verify the findings and rule out a facility induced effect.
In parallel to the experimental evaluation of their conjecture, Tajmar and de Matos also looked for a more refined theoretical model of the Gravitomagnetic London Moment. They took their inspiration from superconductivity. The electromagnetic properties of superconductors are explained in quantum theory by assuming that force-carrying particles, known as photons, gain mass. By allowing force-carrying gravitational particles, known as the gravitons, to become heavier, they found that the unexpectedly large gravitomagnetic force could be modelled.
"If confirmed, this would be a major breakthrough," says Tajmar, "it opens up a new means of investigating general relativity and it consequences in the quantum world."
The results were presented at a one-day conference at ESA's European Space and Technology Research Centre (ESTEC), in the Netherlands, 21 March 2006. Two papers detailing the work are now being considered for publication. The papers can be accessed on-line at the Los Alamos pre-print server using the references: gr-qc/0603033 and gr-qc/0603032.
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Special Relativity and Gravity...are you certain?
Yup. Massive gov't spending on science began during WW II. By a massive coincidence, American pre-eminence in science began during WW II. Private spending on science is the way it was done before, when America was not pre-eminent in science.
For Women: gravity on butt and boobs=age
In this case, yes. Acceleration and gravity have the same effect on clocks. The principle of equivalence. If I'm wrong, I expect that one of the heavyweights will correct me.
It is kind of second-order weird when people like Hawking bet on a theoretical result and they are the one doing the theoretical calculation and they lose the bet.
Thanks for the ping!
I would have expected Special Relativity to deal with the kinematic effect, but that General Relativity would have dealt with the Gravitational effect.
I don't mean to be dense, but how do we know that it is not the other way around?
BTW: Thanks for the interesting posts, I'm on my way out for a while.
Things that make you go "hhhhhhhhhhhhhhummmmmmmmmmmmmmmmmnnnnnn....."
Of course we should use whichever coordinate system seems most workable. For gravitational fields we have Riemannian space, and that seems handy enough. If time fields use the same kind of field, it would not matter as a practical thing. Whichever is convenient and attracts funding is the way to go.
I agree.
I'm not sure how Bob Forward's Mass Detector worked but I thought he was looking for gravitational waves and never actually found them.
These guys must be using some sort of mass detector that shows a deflection from the vertical in the presence of mass. And that deflection changes when the superconducting ring is accelerated. I'm just guessing but that's what it sounds like to me.
SR can only deal with the kinematics of constant velocities. When accelerations or gravitational fields are involved, GR is needed; and in its framework, an accelerating reference frame and gravitational field are equivalent, just as PH stated.
Not to pick nits, but you better make that at least a million feet.
< ]8^0)
Better check twice which clock will be lagging, too.
Was GR or SR cited in that post by PatrickHenry?
I didn't think of using the Earth's rotation at different heights to do the experiment. Pretty constant v for each clock...
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