Visualizing General Relativity

This is a bit different than the usual rubber-sheet visual.

Visualizing General Relativity

Yes, I love seeing new explanations of gravity. Gravity remains one of the most puzzling aspects of the universe, since "instantaneous action at a distance" isn't supposed to be possible without the exchange of some fundamental particle (the 'graviton') to transmit it.

I'm not sure this visualization adds much. Basically it just takes the 2-dimensional rubber sheet visualization and makes it into a 3-dimensional rubber sheet, with the grid lines falling into the gravitational body. In the same way that you can't explain gravity by saying that items "fall into the gravity well due to gravity," you can't really say "gravity works by items falling into the contracting space by gravity." There's still something ineffable about gravity that remains unexplained.

Coincidentally, I'm reading a couple books about atomic bombs, and the incredible energy contained inside atoms. Considering the universe arose spontaneously from nothing, the fact that 'matter is condensed energy' of such incredibly high density indicates a background energy in the universe which is unimaginably huge. I'm sure gravity is somehow tied to this concept, but I'm not smart enough to work out the connection.

At one point in the visualization presented, the author says "you can see how the surface of the Earth is continuously expanding against the contracting space around it." This reminds me of a pamphlet I bought in high school, called "The Einstein Gravity Monster" where the author, a fevered junior physics student, postulated that the Earth (and all gravitational bodies) are expanding, and their expansion is accelerating -- acceleration being indistinguishable from gravity. It makes sense on one level, until you begin contemplating the dynamics of constant acceleration, not just expansion. With everything expanding equally, interstitial space becomes hard to define.