Relativity: The Special And The General Theory,... [ Official ]

This section expands relativity to include gravity. Einstein describes gravity not as a force between objects, but as a curvature of spacetime caused by mass and energy. He uses the "Principle of Equivalence" to show that being in a gravitational field is indistinguishable from accelerating.

A full audio version is hosted by LibriVox for listening on the go. Relativity: The Special and General Theory Relativity: The Special and the General Theory,...

Einstein's Relativity: The Special and the General Theory is one of the most significant works in scientific history, written specifically to explain his revolutionary ideas to the general public. Originally published in German in 1916, it remains a primary text for anyone looking to understand the universe through the eyes of its creator. This section expands relativity to include gravity

The text is famous for its "Gedankenexperimenten" (thought experiments), such as observers on moving trains and flashes of light, to make abstract concepts concrete. A full audio version is hosted by LibriVox

Because the original work is in the public domain, you can find it for free or as high-quality reprints:

Read the full text at the Project Gutenberg or Marxists Internet Archive.