I'm also curious to learn the answer to your question. The way I've always seen space-time modeled in illustrations, and now this video, is like a single plane.

I'm also curious to learn the answer to your question. The way I've always seen space-time modeled in illustrations, and now this video, is like a single plane. I've always imagined that plane as one of infinite planes that form a sphere surrounding the mass whose gravity is warping the space-time. If I'm wrong, I'd appreciate being corrected.