Clarify something for me.
If we were observing from a stable angle normal to the plane of their mutual orbit, we would not be able to detect the gravitational waves, right? (At least with our current instrument.)
We can only detect them if we are observing from an angle more parallel to their mutual orbit, right?
The best observations would occur if we were exactly parallel to (in line with, on the same plane as) their mutual orbit, right?
If this is the case, and the tops of the observed curves are nice and smooth (sinusoidal), this would imply that gravity waves can not only penetrate a black hole, but could get through it and back out again on its opposite side.... right?
If not, the tops of the curves would have a slight dip as the two black holes aligned with each other in our line of sight. The nearer one would occlude the gravity field of the other, and we could not detect any summation with the farther black hole's gravity at that particular point in their mutual orbit. Hence the "dip" I postulated above.
Going back to "If this is the case," above, this would further imply that gravity waves either can't have any particle-like characteristics, or if they do, the particle's velocity must be high enough to exceed the escape velocity of the black hole as they emerge from the opposite side.
Terry
My guess is that the shared orbiting plane between merging black holes, the gravity waves would be the strongest edge-on to Earth, but they would emanate spherically in all directions to some degree or another with more twisty filaments of space-time along the poles or their mutual axis of revolution.
Even single black-holes will twist up space-time with their rotation in a region near the event-horizon called the ergosphere. But that's more like twisting up spaghetti on a fork than waves created in water or air.
Gravity on the small scale is kinda/sorta like photons, that in a ham-fisted analogy has a wave-particle duality. At least theoretically, on the quantum scale there is a graviton, massless with characteristics of other force particles. But it has a fundamental problem of not being directly detectable, because you've got a kind of chicken-n-egg catch-22 problem of what to see it with. But if we can, or someone figures out a scientifically rigorous way to detect them it would go a long way to getting a handle on superunification, quantum-gravity, or "theory of everything".
But on the macro-scale, gravity is like a wave, or at least can be modulated wave-like, but instead of an EM wave, it's more akin to sound-waves in air, they're like density waves (again, ham-fisted analogies here) in space-time itself, in the rubber-sheet model how gravity is a curvature of space-time drawing mass/energy together because they follow the path of least resistance into the "dip" or "hole". The waves don't pass through the black holes on a 2D simulation, it's like the waves coming off of two pencils being dragged around each other in a circle in a pool of water.
Space-time itself goes all the way into the black holes, so the idea if the waves can pass through black holes or not might be kind of moot, It's like asking if waves can pass through a whirlpool, but the water goes into the whirlpool, the whirlpool is the water... In the rubber-sheet analogy, it gets so steep, like it's being poked down with a long pin, that it's almost vertical. What happens in the singularity, does it "poke through" into "somewhere else" or what?... possibly unknowable. Because physical laws and constants break down there and a meaningful frame of reference might not be possible.
And a very sensitive laser interferometer like LIGO can see the waves, because as the waves pass us by, space actually shrinks and stretches a tiny bit, and the lasers bouncing back and forth have a little bit longer or shorter distance to go, and the interference pattern acts like a very powerful magnifying glass allowing us to see that.
Discussing this is really hard though, because when physicists say "I can't really explain it without the math" they're not lying, because the way things on the particle scale behave, or the higher dimensional nature of space-time, things simply don't act in the way our human-scale brains that process the regular 3-D Newtonian world can really imagine.
