Einstein: On Aether and Relativity

"Aether and the Theory of Relativity" by Albert Einstein

-- Based on the lecture given by Einstein at the University of Leiden, the Netherlands, in 1920.

-- New Modern English translation - 2025!

In this lecture, Einstein first provides a brief history of the concept of space and aether, since the time of Newton, and then he explains why "space" is necessary, and what exactly it is, in the context of general relativity. Space and time still remain to be the two most important unsolved mysteries of nature.

This short book is a must-read for the Einstein enthusiasts, scientists and philosophers, and any serious physics students who are interested in understanding space and time on their own way (some day).

Note: This article, "Aether and the Theory of Relativity", by Einstein and the Translator's notes are also included in the book, "Einstein's Seven Essays on Relativity, Geometry, and Scientific Methods" (2025).