I had somehow never made the connection that the gravitational inverse square law has the same physical explanation as visible light fall-off [1] -- energy being distributed over a larger area with increasing distance from a point source (with which I'm intimately familiar from computer graphics and vision).
Does anyone with a physics background know: is there any evidence of absorption, reflection, or occlusion of gravitational energy in the same way that we experience with light (and sound)?
Not really. The big difference between electro-magnetism and gravity is, that you have positive and negative charge for EM and only positive charge for gravity. So you can not shield gravity, because the shielding can only add to the gravitational force, not subtract from it. A gravity occlusion in a similar way as most things are opaque does therefore not exist.
Reflection is tied to the electric properties of the reflecting material. [1] So there is no electric field in a conductor, otherwise the electrons would move around until there is no longer a electric field. This means that the field on the surface has also to be zero. So if a electro magnetic wave, light, hits the conductor it has to be reflected, since the energy has to go somewhere and it can not enter the conductor.
Refraction of gravitational waves, well that could be interesting. [2] In non-conductors a passing EM wave induces a EM field in the material, so called polarization. [3] This can be traced back to the large wave length of light compared to the length scale in the crystal lattice. It could well be, that you could generate interference patterns of gravitational waves, if the gravitational waves would pass through a similar arrangement of point masses. ( But this would likely need hundreds of stars aligned on scales much smaller than a light second. )
[1] I am not sure, if the following is fully general. But it covers at least metal mirrors.
[2] I am basing my reasoning on a formal analogy between linearized gravity and the Poisson equation, it may be that it would turn out that refraction can not exist via a more subtle argument, like any such device would collapse into a black hole or something.
Thanks for the explanation! I've spent so long using the aforelinked diagrams to visualize how much light falls onto a surface that thinking about gravity that way brought up a few bizarre possibilities. Thanks for clearing things up -- much appreciated.
Does anyone with a physics background know: is there any evidence of absorption, reflection, or occlusion of gravitational energy in the same way that we experience with light (and sound)?
[1] http://hyperphysics.phy-astr.gsu.edu/hbase/forces/isq.html