Evidences that the theory of general relativity is "wrong"

[Pyrrho]

http://derrenbrown.co.uk/blog/2010/02/t ... ity-wrong/

Apparently the gravitomagnetic field is larger than predicted.

[GenesForLife]

I'm guarded, but if this is true I wonder how much the foundations of physics will be shaken up, and if, with the demise of general relativity, quantum mechanics will no longer need any concillation/reconcillation.

[Gawdzilla Sama]

"Einstein is dead, long live Einstein!"

Or something.


I blame Darwin.

[newolder]

Has this been confirmed? Derren's blog's linked report at softpedia is from 2006.

"If confirmed, this would be a major breakthrough," says Tajmar

[Pyrrho]

Has this been confirmed? Derren's blog's linked report at softpedia is from 2006.

"If confirmed, this would be a major breakthrough," says Tajmar

Argh. Why I should never rely on secondary sources.

[GenesForLife]

I wonder if this http://www.sciencedaily.com/releases/20 ... 104855.htm was a riposte to that...

[Nautilidae]

The "results" that showed that the gravitomagnetic effect was larger than expected have never been reproduced. It is not currently possible to produce an artificial gravitational field in the laboratory. The superconductor experiment is nothing more than fringe physics.

For real results pertaining to gravitomagnetism, please visit the website for Gravity Probe B.

http://einstein.stanford.edu/

[feign_ignorence]

I don't get it... so what happens to all the maths that were done to do work out what was going on in deep space and with black holes?

Doesn't wrongness mean the actual theory is ineffective to describe the all the physical phenomena attributed to it, not just some pieces? I'm confused.

[Salviati]

General relativity DOES seem to be wrong, because it is apparently inconsistent with quantum mechanics. In quantum mechanics, an atom can exist in a superposition of various energy eigenstates, so that it doesn't really have one particular energy, but exists in a kind of "superposition" of different states of energy. According to general relativity, however, energy is a frame-dependent quantity -- a component of a larger object, called the stress-energy tensor. The components transform as we switch to a different frame of reference.

So far this is a feature, not a bug. The real problem is that in general relativity, there is no yet conceivable way of accommodating superpositions of different stress-energy tensors. This is a serious and fundamental difficulty, and something (probably GR) has got to give.

As for the thing in this thread. Ever since the theory's inception we've known it's possible that the Einstein field equations, which determine how matter causes space to curve, are possibly approximately wrong. The derivation given by Einstein relies on somewhat subjective criteria, such as simplicity. (Hilbert's derivation is an improvement, but it still remains that there are other possible field equations which square with all the known facts.)

Anyway, don't trust Derren Brown.

[josephtamis]

Hi,

I don't know why anyone would be surprised that Einstein's theory could be wrong. He was only a man and each man's work is just a stepping stone to the next discovery of truth. Theories are just that, theories! How can you progress if you believe everything that you are taught is accurate? Besides, after helping create the Atomic bomb, I wouldn't be surprised if he intentionally damaged his work to prevent man from creating another weapon. Imagine if the centrifugal force of a spinning superconductor could be directed up or down in the Y plane by way of an external coil. The effect would be similar to a jet engine or gravity repulsion and attraction.

[Nautilidae]

Hi,

I don't know why anyone would be surprised that Einstein's theory could be wrong. He was only a man and each man's work is just a stepping stone to the next discovery of truth. Theories are just that, theories! How can you progress if you believe everything that you are taught is accurate? Besides, after helping create the Atomic bomb, I wouldn't be surprised if he intentionally damaged his work to prevent man from creating another weapon. Imagine if the centrifugal force of a spinning superconductor could be directed up or down in the Y plane by way of an external coil. The effect would be similar to a jet engine or gravity repulsion and attraction.

None of those effects have been reproduced in the laboratory. There is NO reason why rotating a superconductor would create artificial gravity waves. We don't claim that Einstein isn't wrong. However, observations tell us that he wasn't wrong. This superconductor experiment shows us nothing.

[lpetrich]

Those experimenters claim to have observed an effect that is 1020 times what one would expect from general relativity.

However, if GR was so grossly wrong about gravitomagnetism, we ought to be able to see that effect elsewhere, like in the Moon's orbit. This effect would mean some extra precession of the Moon's orbit, and we can estimate how big the bounds are.

The line of nodes, where the Moon passes the ecliptic, precesses backwards with a period of 18.5996 years
The line of apsides, which connects the Moon's closest and farthest points relative to the Earth, precesses forward with a period of 8.8504 years

Nearly all of that effect is due to Newtonian-limit effects, mostly the Sun's. However, the Earth-Moon system can be interpreted as a large gyroscope, and the Sun makes it precess with gravitomagnetism. This effect is about 2 seconds of arc per century, and it's been measured to an accuracy of 0.6%.

Source: 3.7 Other tests of post-Newtonian gravity in The Confrontation between General Relativity and Experiment -- a very nice article, though a very technical one.


There was recently an extremely sensitive experiment for searching for gravitomagnetism: Gravity Probe B: Testing Einstein's Universe It involved spinning four extremely precisely-machined glass spheres inside a spacecraft, then following their precession. There were two types of expected gravitomagnetic effects:

Spin-orbit, from the spacecraft's orbit (geodetic) -- 6606 milliarcseconds/year
Spin-spin, from the Earth's rotation (frame dragging) -- 39 milliarcseconds/year

At last report, their measurement of the spin-spin effect agrees with GR predictions to within about 14% (5 marcsec/year). This is better than 0.1% for the spin-orbit effect.


We can quantify the agreement with GR and similar theories by considering the "parametrized post-Newtonian formalism", a way of expressing departures from Newtonian gravity. It contains 10 fudge factors or PPN parameters that different theories of gravity have predictions for. To date, all of them are very close to their GR-predicted values, to within typically 10-3 - 10-4. This rather strongly constrains alternatives to GR.


So the experiment mentioned in the OP has some flaw somewhere in it.