You'll forgive me if I haven't read all 11 pages of this thread, I'm sure, but assuming no one has gotten around to answering the original question yet, it's my understanding, so to speak, that we don't actually know what gravity is. We basically know how it works, but not what it is, although we're pretty sure it's something. I don't think we've figured out exactly what dust is either. Despite my spiritual views, or lack of them, or perhaps because of them or not, I'm open to correction.
