Wizofoz
Fair enough. Concerning
what gravity IS, not just what it DOES,
there is much to choose from, e.g.
http://www.imsc.res.in/~iagrg/IagrgSite/Activities/IagrgMeetings/25th_Iagrg/VRtalk.pdf or
http://arxiv.org/abs/1001.0785 and many others besides.