First real challenge to General Relativity?, (and not from Gravity Probe-B) Options

[Guest_BruceMoomaw_*]

...in the form of what may be an accidentally discovered artificial gravity generator, with possible practical applications!:
http://www.esa.int/SPECIALS/GSP/SEM0L6OVGJE_0.html

If this effect is real, it's fully 1/10,000 G -- which is not to be sneezed at, and might conceivably lead us to Bigger Things.

[Guest_Richard Trigaux_*]

The Lens-Thiring effect, or magnetogravitationnal field, is the exact equivalent to gravitation and mass of what the magnetic field is to electric field and charge.

This is because the two domains mostly obey to the same equations.

When electric charges move, for instance rotate in a transformer coil (say to simplify a ring) they produce a magnetic field, with a north pole at one side of the ring, and a south pole at the other side. This magnetic field can in turn induce an electric field and a current into a secondary ring (coil).
Similarly, a ring of matter rotating produces a magnetogravitationnal field, which can in turn induce the rotation of a secondary ring besides the first.
This is a known consequence of the relativity. At a pinch, that relativity predicts the existence of the magnetogravitationnal field makes that it predicts too... the magnetic field, which is thus a BIG consequence of relativity at human scale.

Alas for us, the gravitomagnetic field is so weak that any human scale test is still unable to detect it, only at space scale the gravity probe B could detect it (results please?). But it may play an important role in the realm of neutron stars and black holes, for instance the rotation energy of a black hole could be extracted to accelerate an accretion disk. (and for instance produce jets)

What is new with this experiment is that a magnetogravitationnal field is said to result from electromagnetic effects alone, a thing hich is not predicted by relativity and is said (in the paper) to result from the violation of a basic physical symmetry.

If it is true, it may be a breakthrough into our understanding of the relation between relativity and the quantum world. But I wait for others reproducing the results before inflating imagination.

Anyway the gravitationnal field resulting from a Lens-Thiring field is ROTATING, so that it cannot be used to produce anti-gravitation or any propulsive gravitationnal field. At least not directly. At a pinch two Lens-Thiring rings repell each other, if they show both the same pole to the other. But it is much more complicated than using simply the magnetic properties of superconducting rings. And we are still far of producing a 1 G effect, if we need for this a rotation at 64 MILLIONS RPM...

So the thing is anyway to follow carefully, as soon as the primary results are reproduced.

[Marz]

The Lens-Thiring effect, or magnetogravitationnal field, is the exact equivalent to gravitation and mass of what the magnetic field is to electric field and charge.

This is because the two domains mostly obey to the same equations.

When electric charges move, for instance rotate in a transformer coil (say to simplify a ring) they produce a magnetic field, with a north pole at one side of the ring, and a south pole at the other side. This magnetic field can in turn induce an electric field and a current into a secondary ring (coil).
Similarly, a ring of matter rotating produces a magnetogravitationnal field, which can in turn induce the rotation of a secondary ring besides the first.
This is a known consequence of the relativity. At a pinch, that relativity predicts the existence of the magnetogravitationnal field makes that it predicts too... the magnetic field, which is thus a BIG consequence of relativity at human scale.

Alas for us, the gravitomagnetic field is so weak that any human scale test is still unable to detect it, only at space scale the gravity probe B could detect it (results please?). But it may play an important role in the realm of neutron stars and black holes, for instance the rotation energy of a black hole could be extracted to accelerate an accretion disk. (and for instance produce jets)

What is new with this experiment is that a magnetogravitationnal field is said to result from electromagnetic effects alone, a thing hich is not predicted by relativity and is said (in the paper) to result from the violation of a basic physical symmetry.

If it is true, it may be a breakthrough into our understanding of the relation between relativity and the quantum world. But I wait for others reproducing the results before inflating imagination.

Anyway the gravitationnal field resulting from a Lens-Thiring field is ROTATING, so that it cannot be used to produce anti-gravitation or any propulsive gravitationnal field. At least not directly. At a pinch two Lens-Thiring rings repell each other, if they show both the same pole to the other. But it is much more complicated than using simply the magnetic properties of superconducting rings. And we are still far of producing a 1 G effect, if we need for this a rotation at 64 MILLIONS RPM...

So the thing is anyway to follow carefully, as soon as the primary results are reproduced.

Ok... um... duh.... I don't even have a Mr. Wiz level of understanding of these concepts. It's the first time I've ever heard the word 'magnetogravity', and I'm not happy about it. :-p

I always thought Einstein's view of a Gravitational "Field" was a literal distortion of space-time. That's why I thought quantum-gravity is, from where I sits, crazy! (If gravity is in discrete quanta, then that must mean time AND space can be defined in discrete quanta - please tell me this ain't so!)

The idea that a gravitational "field" can rotate means really stupid things to me, like time & space must rotate with it?
For instance, if ya'll are already speculating on rotating mass to create "negative" gravity, then why not "negative" space-time too?

Um... check please!

[nprev]

Ok... um... duh.... I don't even have a Mr. Wiz level of understanding of these concepts. It's the first time I've ever heard the word 'magnetogravity', and I'm not happy about it. :-p

I always thought Einstein's view of a Gravitational "Field" was a literal distortion of space-time. That's why I thought quantum-gravity is, from where I sits, crazy! (If gravity is in discrete quanta, then that must mean time AND space can be defined in discrete quanta - please tell me this ain't so!)

The idea that a gravitational "field" can rotate means really stupid things to me, like time & space must rotate with it?
For instance, if ya'll are already speculating on rotating mass to create "negative" gravity, then why not "negative" space-time too?

Um... check please!

Well, there is such a thing as the Planck-Wheeler wavelength, which is basically the point at which spacetime becomes discontinuous, so broadly speaking this is the fundamental unit of spacetime. Bruce alluded to "foaminess", and this is probably an indirect reference to Misner, Thorne, and Wheeler's classic Gravitation; what it seems to mean is that the physical universe is a second-order side effect of the considerably greater potential mass/energy "background" of virtual particle production, known in some circles as the zero-point field. (Research note: There is a LOT of marginal pseudoscience that has arisen from these apparently well-established and uncontroversial principles; I urge anyone investigating this material on the Net to maintain a healthy level of skepticism and employ full-strength critical thinking at all times!) .

[Guest_Richard Trigaux_*]

(Research note: There is a LOT of marginal pseudoscience that has arisen from these apparently well-established and uncontroversial principles; I urge anyone investigating this material on the Net to maintain a healthy level of skepticism and employ full-strength critical thinking at all times!) .

Good caution. But it may happen that the solution lies in a domain or idea considered as fringe today.

What is important with non-standard idea, is not to make "alternative" dogmas of them, but to study them with caution and method. Of course many fringe ideas would not pass even the very first step of any serious study, but who knows. Perhaps it is a flaw into the science method itself which prevents us of understanding the truth.

As for me I do not make categories such as "standard" or "fringe". I just consider likeliness or usefulness of ideas. of course standard theories are in the best position (it is why they are standard theories, and the only good reason for them to be standard theories) while many fringe theories quickly appear as ignorant speculations or confusions. But who knows, maybe a new Einstein is breeding somewhere...