Some RG Researcher in 2015: "One way to prove that gravity is a true force is if a gravitational field can be shown to possess energy density." Me:
It is easy. The resulting E is true scalar. The energy is linked with it's use. Before Einstein's discovery E = m c^2 were was little useful energy. So, please specify the receiver (gravity wave detector) of energy, then insert them all over the spacetime. So, You get the field E = E(t,x,y,z), which is physical. Thus, is independent of the coordinate system. What do you think? Yes, the field of receivers will modify the gravity wave and spacetime, making the result E useless. Then, one can use following philosophy. The E will be not the actual energy, but the "conditional" energy: "the value, which would get single receiver, if you put it there at t and in the point x,y,z during 1 second". All rights reserved: please include my name in your authors' list and tell me publication story.
So, there is local energy harvesting. What? You say, that Dr. Fred Cooperstock has proved, that receiver do not harvest the energy (Wikipedia: "Energy Localization Hypothesis")? The doctor has used the Quantum Mechanics of Niels Bohr, but in the Quantum Mechanics of David Bohm the detector gets the energy: [my peer-reviewed, certificated paper in IJSER, March 2015, http://www.ijser.org/research-paper-publishing-march-2015_pageU.aspx].
For sure, the energy does not come from the gravity wave: the continuity law is not applied there. Indeed, as already Dr. Cooperstock has written, the gravitational wave does not contain the energy: its energy-momentum tensor is simply zero. This drop of the law has caused much headache and, thus, much (useless?) gravity pseudo-tensors were derived together with impossibility of local energy harvesting: "no energy scalar, then no objective energy there". Latter is wrong, as you could believe after my contribution to the research topic.
Then what happens? The temperature of detector gets increased, because it is affected of the gravity wave. Hereby the gravity wave, which has passed the detector may loose its ability to increase temperature in an other detector on its way. It all looks, like the gravity wave carries the energy throughout cosmos. But it does not. It simply increases level of energy in some object (receiver), or decreases energy in the emitter of wave. Such is the philosophical consequence. Do you see, that scientific philosophy very well can be alive, despite the S. Hawking wrote?
All rights are reserved: include my name in your paper as co-author and tell me the publication details.