Measuring gravitational waves

[Mordred]

On 11/12/2017 at 8:25 AM, DParlevliet said:

Is a gravity wave also a natural expansion/contraction, but now in ~~sinus schape?

Or: what is the difference?

 no it is not sinuoidal that is a dipole wave, the quadrupole wave has 4 distinc polarity states two of which are 45 degrees out of phase with the other two. This is why the LIGO detector uses two arms in an L shape.

Edited December 13, 2017 by Mordred

[swansont]

Is shape referring to the amplitude or the spatial variation?

[StringJunky]

11 hours ago, Mordred said:

 no it is not sinuoidal that is a dipole wave, the quadrupole wave has 4 distinc polarity states two of which are 45 degrees out of phase with the other two. This is why the LIGO detector uses two arms in an L shape.

But it can be viewed sinusoidally, just using two points, can't it?

 

Edited December 13, 2017 by StringJunky

[Mordred]

yes like two sine waves both simulatneous.

[StringJunky]

20 minutes ago, Mordred said:

yes like two sine waves both simulatneous.

Cool. Is it emitted from merging black holes in a polar, conical fashion, like a GRB, or concentrically through 360^o in all planes, or just in one plane? Popsci animations seem to show it radiating all around in one plane.

[swansont]

Animations can only show what is happening along some path, or in one location over time. 

[StringJunky]

6 minutes ago, swansont said:

Animations can only show what is happening along some path, or in one location over time. 

Right.

[DParlevliet]

I think this part of a publication gives the answer. Only free masses will follow the gravity wave, with solid mass the atomic forces prevent this mostly (except elastic):

[DParlevliet]

On 12/11/2017 at 12:51 PM, Strange said:

Gravitational waves travel through space, independently of the presence of mass.

In the new exibition of the museum Boerhave in Leiden (Netherlands) I saw the MiniGRAIL, a gravitational wave measuring device which prooved to be not sensitive enough. It was based on mechanical resonance in a copper ball. So gravitational waves loose energy in mass.