[aculeus]

Two super-dense neutron stars circling each other [1] are expected to emit gravitational waves that move out at the speed of light At GEO 600, a high-powered laser [2] is fired at a 'beam splitter' - a semi-transparent mirror - which divides the beam down two vacuumed tunnels Mirrors [a+b] at the far ends bounce the light back; more mirrors [c+d] extend the measuring distance, and still more [e+f] are used to recycle the power and enhance the signal The light paths from the separate arms are recombined and sent to a photodetector. If a gravitational wave has passed though the observatory, it will have changed the length of the arms and the signal should be evident when analysed by computer

[AntiGuv]

graviton ping!

[aculeus]

Corrected caption in reply #1 follows ...


HOW A LASER INTERFEROMETER CAN CATCH THE ELUSIVE WAVES


Two super-dense neutron stars circling each other [1] are expected to emit gravitational waves that move out at the speed of light At GEO 600, a high-powered laser [2] is fired at a 'beam splitter' - a semi-transparent mirror - which divides the beam down two vacuumed tunnels Mirrors [a+b] at the far ends bounce the light back; more mirrors [c+d] extend the measuring distance, and still more [e+f] are used to recycle the power and enhance the signal The light paths from the separate arms are recombined and sent to a photodetector. If a gravitational wave has passed though the observatory, it will have changed the length of the arms and the signal should be evident when analysed by computer

[keithtoo]

It will be interesting to see just how fast these waves propogate. It may be faster than the speed of light.

[Blood of Tyrants]

This won't tear a hole in the space-time continuium and end all life as we know it, will it?

[Southack]

If you want to investigate Gravity waves, start with the tides of our oceans.

Carefully note the precise lag between the tide rising compared to the overhead orbital position of our Moon. That lag helps indicate the propagation speed of Gravity.

[Iris7]

Looks like Michelson - Morley without the mercury bearing.

Looks like it would pick up any ground born vibration down to a fly landing or a gust of wind to small to feel. A fantastically noisy signal.

[thoughtomator]

Cheap shot incoming....

Any moving mass will send gravitational waves radiating outwards at the speed of light; but only truly massive bodies, such as exploding stars and coalescing neutron stars, can disturb space-time sufficiently for our technology to pick up the signal.

Alternate test subjects:

[theDentist]

Bump to read again when I have more time to follow/understand the physics behind it.

[R. Scott]

Something else to keep up on. Thanks.

[Sam Cree]

*

[E. Pluribus Unum]

Reminiscent of the Michelson Interferometer.

[GSlob]

But wouldn't the passing gravitational wave change not only the spatial length but also everything in that space, light wavelength included?

[skinkinthegrass]

"The displacement sensitivity of GEO 600 is one three-thousandth of the diameter of a proton," explains Professor Karsten Danzmann, from the Albert Einstein Institute and Hanover University..."Put another way, it's equivalent to measuring a change of one hydrogen atom diameter in the distance from the Earth to the Sun."....Careful refinement and tuning of the instrumentation has moved the installation very close to the required sensitivity

KEWL! ...Picometer range?.. :)

[doc30]

World's biggest interferrometer?

[Bigh4u2]

I have always felt that gravity was a constant.

Sort of like the ocean where any 'movement' of the waters is really the 'effect' of passing through it.

I'm just using the ocean as a rough example.

Since I have no real scientific background to test this, then I also have no way to prove it either.

[MonroeDNA]

I thought that they proved that gravity travels at the speed of light when it was first observed that the relative position of an orbiting body (like the sun) tacked the gravitational pull of the orbit around it (like the earth).

8 minute delay in both cases.

[GallopingGhost]

bookmark

[RightWhale]

Interferometers are amazing. They don't work in the hoped for way when the ether itself is warping. Alexander Graham Bell's experiment came up empty, so Fitzgerald and Einstein had to figure out something else.

Whatever theory you might have, it is a special case of the more general theory yet to come. This statement is an article of what passes for faith in science.

[MonroeDNA]

OK, for an Art Bell moment (arrgh...!)

I had a dram the other night, that there are more dimensions to travelling waves, and that the fastest waves depend on a boundary layer, wether in 3-space or more space.

My dream said that creating a wave in water involved some kind of force, let's say a palm striking downward in a pool, from the air. The initial strike transfers an impact force to the water, travelling at the speed of sound in the water. The "smack" is a square wave type, and travels at the speed of sound by compression and reaction of the components of water.

The "follow through" is when the palm continues, generating a much, much slower wave at the boundary layer between the water and air.

I can't much remember the dream, other than it explains heat transfer, and that EM waves are similar to the second type of reaction, the "follow through." As in you have to move an electric or magnetic field a relatively long distance to create EM waves.

My dream said that if you even start to move an electric or magnetic field, it would be like the first instance, the "smack," square wave thing, that would propagate immensely faster. Just the start of such an incident would cause instantaneous reaction elsewhere, according to our current "speed of light" based measuring tools. There is a delay, just not measurable with our current tools.

As soon as you start to move whatever, the initial "smack" motion propagates at far beyond light speeds.

Then my dream said it explained quantum twin reactions, where "twin" particles knew where each was, and knew what each was doing, way beyond the speed of light.

Yeah, then I woke up.

[zeugma]

Excellent stuff!

BUMP