I'm quoted you there here. Heh
Hashi Lebwohl wrote:The "center of gravity" for any given object is an attractor, with the size of the basin of attraction being based on the amount of mass present. Of course, this doesn't answer why mass is an attractor, only describing that it is one.
The fact that gravity has infinite reach means that the attractive force we know as gravity is somehow linked to one of those higher dimensions (we have 11 of them, remember?) where "distance" as we know it has no meaning. I once read someone's speculation that "gravity" is actually the "spillover" of that force from that dimension into the four we experience. *shrug*
There was a fringe science site I saw some years ago that talked about people's experiments into trying to induce acceleration vectors, which would directly lead to the ability to accelerate an object by manipulating local space-time. There were no conclusive results at the time, of course, but if such a thing were possible then interstellar travel becomes a possibility. It might still take 100 years to reach nearby systems but at least it would be possible.
All I know about this stuff is from Brian Greene. Particularly his
Ted Talk on String Theory. Which paints a very different picture of the extra dimensions than whatever it is you're talking about. He says the others are "tiny, curled up dimensions, curled up so small, even though they're all around us, that we don't see them." They are "deeply tucked into the fabric of space itself". Ten dimensions of space, and one dimension of time. These tiny dimensions "have a very rich, intertwined geometry." They might form what's known as a Calabi-Yau shape. (The idea is that the Strings can vibrate a certain number of ways within the allowable geometry of these intertwined dimensions. And these certain ways explain the very specific numbers that science has determined are so delicately tuned to allow our universe's existence. Exact strength of the electromagnetic force; strong and weak nuclear forces; mass of the elementary particles; etc. But I digress. We're talking about gravity.)
So what do you mean by "higher dimensions?"
Wikipedia's entry on String theory says that, in Einstein's general theory of relativity, "the phenomenon of gravity is viewed as a consequence of the geometry of spacetime." I think this is the answer that I'm looking for. There isn't anything that "grabs and pulls", or is a lasso, or however we might think of it. Maybe without any matter, spacetime is a perfect lattice of x, y, and z axes, in straight lines. And maybe that perfect lattice does not cause movement. Maybe something sitting in warped spacetime
must move. One bit of matter in that lattice would warp spacetime around it, but it would just sit where it is, because it is at the center of the warp-shape, the gravity well, it produces. (Of course, without another thing to measure it's position, we couldn't know if it was moving or not. But I hope you know what I mean anyway.) But a second mass would also warp spacetime. Now that our first mass is not sitting in a lattice warped only by (and to) itself, it moves. It
must move, because it is simply a property of spacetime that, if it is warped, anything within that warp must move toward the point of the greatest warp - the center of the gravity well.
I have no idea if I'm explaining what I mean. And, most definitely, I have no idea if that's what general relativity is saying. But if, as you say in the post above (not the one I quoted), gravity is not carried by particles (They've given up on gravitons?), then maybe this is what they're saying?
[And if we figure out how to warp spacetime through other means, we'll be able to make artificial gravity.]