I would like to humbly suggest that gravity can't be unified with the current generally accepted theoretical framework. I believe that there is a fundamental error that remains unidentified. This error probably crept into things early in the 20th century and has made resolution of some fundamental questions impossible. I do not say this as a physicist, but only as an interested observer. When the mathematical framework has to be expanded to ten or eleven dimensions and cosmic inflation must be introduced to keep from wrecking the theory, I have to believe we've gotten off track.

I've gone to sleep thinking about gravity more times than I can remember. I have come to the conclusion that most, if not all, particles of matter are actually spread across the entire universe - a sort of quantum smear. What we are able to perceive or measure as the particle is only the most concentrated portion. The "dark matter" that is so sought after to produce the desired amount of gravity is the undetected part of each and every particle. I imagine that this idea would require cosmologists to rewrite a lot of theory, but it has some potential advantages. The Higg's field (or aether, if you prefer) would be understood as the undetected soup that exists in "empty" space. This is the thinned out part of all the particles. The uncertainty principle becomes clearer because all particles really are everywhere. Gravity then becomes each particles complete envelope covering the entire universe. This opens the possibility that gravity is actually an effect of interaction between particles, not a quality of fundamental particles themselves, i.e. a particle in a vacuum has no gravity.