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, 20178 yr by Mordred

Is shape referring to the amplitude or the spatial variation?

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, 20178 yr by StringJunky

yes like two sine waves both simulatneous.

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.

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

6 minutes ago, swansont said:

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

Right.

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):

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.