Einstein wrote this book for people who are interested in understanding the Theory of Relativity but aren't experts in scientific and mathematical principles. I'm sure many people have heard about Einstein's Theory of Relativity, but most of them don't really know what it is all about. This book gives them a chance to know more about this very famous theory without the need to take a Physics course first. This book is divided into three parts. The first part explains what special relativity is all about...

Sidelights on Relativity contains ETHER AND THE THEORY OF RELATIVITY, an address delivered on May 5th, 1920, in the University of Leyden; and GEOMETRY AND EXPERIENCE, an expanded form of an address to the Prussian Academy of Sciences in Berlin on January 27th, 1921. (Intro from Project Gutenberg)