Brain hurts... I'm at the bleeding edge of what I can kinda understand.
Wouldn't a spherical or point source of gravity, the monopole falls by uh... square of the distance?
And a quadrapole gravitational waves fall off by the fourth power of the distance?
THAT puts the massive power of that event LIGO recorded into perspective, above/beyond the "All the stars in the universe if it was light" analogies.
No, I mean it like this: (IIRC, it's been a while)
A light wave is a dipole wave, I.e. The electric field vector oscillates in a plane, and there isn't a cross-component (of the electric field), so a point charge experiences a force up and down in that plane.
A gravity wave is a quadrupole wave, meaning at any point there is a contraction in one direction perpendicular to its propagation, and an expansion in the other perpendicular direction, so a point mass doesn't experience a force in any one direction, but rather a compression in one direction and expansion in the other (note that these are space time effects, since the force acts on all particles in the mass at once).
The LIGO detector works best if the direction of the wave is perpendicular to the legs of the L, so one leg gets shorter, and the other gets longer, and that effect oscillates back and forth. A wave traveling in the plane of the detector would only affect one leg.
Again, if I remember correctly.
So the conventional wave analog doesn't really hold...