Relativity
The Special and General Theory

from the reader difficulties which are inherent to the subject. On the other hand, I have purposely treated the empirical physical foundations of the theory in a "step-motherly" fashion, so that readers unfamiliar with physics may not feel like the wanderer who was unable to see the forest for the trees. May the book bring some one a few happy hours of suggestive thought!

A. EINSTEIN
December, 1916

[1] The mathematical fundaments of the special theory of relativity are to be found in the original papers of H. A. Lorentz, A. Einstein, H. Minkowski published under the title Das Relativitätsprinzip (The Principle of Relativity) in B. G. Teubner’s collection of monographs Fortschritte der mathematischen Wissenschaften (Advances in the Mathematical Sciences), also in M. Laue’s exhaustive book Das Relativitätsprinzip--published by Friedr. Vieweg & Son, Braunschweig. The general theory of relativity, together with the necessary parts of the theory of invariants, is dealt with in the author’s book Die Grundlagen der allgemeinen Relativitätstheorie (The Foundations of the General Theory of Relativity)--Joh. Ambr. Barth, 1916; this book assumes some familiarity with the special theory of relativity.