Relativity: a very short introduction

Special relativity. The principle of relativity and the speed of light ; Time dilation ; The twin paradox ; Length contraction ; Loss of simultaneity ; Space-time diagrams ; Four-dimensional spacetime ; The ultimate speed ; E = mc[superscript 2]

General relativity ; The equivalence principle ; The effects on time of acceleration and gravity ; The twin paradox revisited ; The bending of light ; Curved space ; Black holes ; Gravitational waves ; The universe.