Visualize a Black Hole at the Event Horizon

This cute little animation shows the causal structure around a classical black hole in an interesting way. The perspective is that of a body orbiting just outside the event horizon:

Animation credit: Robert Nemiroff.
Nemiroff's paper discussing this kind of visualization is available on ArXiv.org.

For more animations of spacetimes with screwy causal structures, visit Virtual Trips to Black Holes & Neutron Stars.