Resolving a paradox.

This was six years after the publication of Einstein's special theory of relativity, but several years before the general theory, and in his book he includes Langevin's original account in English translation. Benguigui himself is strongly of the opinion that the acceleration must be involved, and that this involves considerations of general relativity. The author of the present book, Lucien Benguigui, recounts this and traces the original tale back to a talk by the French physicist Paul Langevin in 1911. There are few topics in physics that have excited so many different contrary opinions as Einstein's so-called "Twin Paradox", otherwise known as the "Clock Paradox". [Extracted from the article]