Brian Greene knocked this whole space-time thing out of the park.
First of all, kudos to Greene for putting together a very accessible explanation of the “fabric” of space. Sure, I’ve already read enough Isaac Asimov and Philip Pullman to have a good understanding of the basic concepts (or at least the basic concepts as they’re applied in science fiction and fantasy books … I was an English major, folks), but learning about the actual experiments that proved some of these concepts was fascinating. That it took 40 years to mount a few gyroscopes on the top of a satellite and see if they’d be thrown off kilter by the folding matter of empty space is amazing on a few different levels (good news – they were, indeed, thrown off kilter. Whew!). Plus, I’ve never had a better explanation of why the speed of light is always constant, even if it should speed up when it’s being pushed by something else. I’m not sure I can totally wrap my head around this idea of elastic space-time, but I at least could explain it at a cocktail party now.
But the finish is what really got me. You guys are mostly engineers, so you probably already heard about this theory, but I was pretty thrown by this recently put-forward theory that the universe doesn’t actually have a third dimension. In fact, this theory goes, the third dimension is just a kind of illusion, like a hologram is an illusion, created by the largest-imaginable sphere that contains the universe. Really, the math says, the universe is contained in the 2 dimensions that make up the surface of that sphere (or maybe “sphere” is being too specific). Apparently, this makes sense because the space inside the center of a black hole, and the space that comprises the edges and surface of the black hole, are exactly the same. Or, put another way, all of the “data” it would require to describe this 3D space could exist in 2D. Or something. That might have been near the end of the glass of vodka.
But, in simple terms, I guess those of us in the 3D data capture industry are hosed. We’re simply documenting the reality of an illusion. How depressing.
(Just kidding. And this rather lucid post from io9 says we’re probably not a giant hologram after all. Which is comforting.)