Fall into a black hole on a real free fall orbit. All distortions of images are real, both general relativistic from the gravitational bending of light, and special relativistic from the near light speed orbit.

A simple derivation of Einstein's theory of relativity which is widely taught to undergraduate physics students. The mathematics required though make this easy for anyone to understand.

A set of notes outlining general relativity and its applications, including modern theories of FTL travel and wormholes.

A very thorough introduction, studies the Schwarzschild, Reissner-Nordstrom, and Kerr solutions using a variety of coordinate systems. Additional topics include gravitational collapse, horizons, singularities, Carter-Penrose diagrams (aka conformal compactification), Hawking radiation and black hole thermodynamics

Includes lecture notes and question sheets.

some basic background covering how mathematical models of space and time have evolved since ancient times, from the Pythagorean Rule to Newtonian mechanics, Special Relativity and General Relativity.

An introduction to general relativity

A complete online course in tensors and relativity

undergraduate course notes include both special relativity (e.g., spacetime, Lorentz invariance, various "paradoxes") and general relativity (e.g., equivalence principle, black holes, gravitational waves, experimental tests of gtr). Apparently a survey course for non-majors, with little math but some very nice graphics.

Detailed steps on how to Linearize Einstein's field equations of general relativity.