Spacetime, warped

http://www.spacetelescope.org/videos/html/hst15_blackhole_grid.html
European Space Agency

Astronomy 10 learning goal Q10.1

Short movie clip illustrating how the mass of a black hole and the masses of stars "warp" a two-dimensional model of spacetime.   This "warpage" is what is experienced as gravity--no gravitational forces, spacetime is "smooth," stronger and stronger gravitational forces correspond to stronger and stronger "distortions" in spacetime.