Christian, et al,
I found your essay clear, well written and nice to read and interesting too. I knew Einstein had changed his mind on GW's (and many things) but not quite how much! OK the links with the topic were a touch homeopathic, but frankly I blame the topic, pregnant with quintupletaly poor assumptions and able to link to anything in physics!
On GW's. I agree they exist and further that they are indeed a 'no brainer' and, this may shock, but I long ago designed a detector which still works perfectly. You tell me if you think it's flawed; I use water but must point out your analogy IS flawed as in space there's no 'surface' or medium interface on which the waves may form. I was then a bit disappointed you didn't get into what GW's 'ARE', which I consider best described simply as 'fluctuations in gravitational potential' due to positional changes (normally orbital) of the massive bodies. Do say if you think that's wrong, but I found definition important for detection.
The set up? It uses the 'large elephant' scenario; There's always a large elephant in the room nobody has noticed; So practically; take a large volume of fluid with a long 'arm' length, then pass a massive body above it, slowly and repeatedly. Sure enough I find a detectable change in level and even a 'flow' corresponding to the motions. Using TWO massive bodies, together, opposite or orthogonally, and at different distances modifies the level and flow in a predictable manner. I have sets of 'tidal prediction' tables, not always precise but very good approximations. You can get copies here; gravity wave tidal predictions.
The large set up and gauge is outside my office, with a max height range of 5.8m when in conjunction and peak flow of 3.1knots. It did need bodies the size of a star and small moon and the liquid volume of the North Sea and Atlantic to get that scale of change, but smaller works too. In the Med the max is some 1.5m (which Venitians are thankful for!)
What I'm pointing out is that this really is exactly the SAME effect as the fluctuating potentials from two BINARY AGN's (or 'black holes' in old money). It's just so familiar and BIG it becomes invisible as we habitually don't apply fully evolved brain power to seeing it!
In fact rather like the classical derivation of QM predictions in my essay!
If you fancy collaborating on a paper I'm up for it, but it may be too shocking for the LIGO lot! Anyway very well written and thank you for the greater definition of history. Another top score coming to counter the non-reader trolling with 1's (I've now reached double figures!)
Very Best
Peter