Selection of free books in pdf

Books are free when copyright expire. Here we are a selection of free books, Digital, ready to download. In pdf format. And also articles, papers, famous writers. SOME FREE BOOKS 1 Fundamental ideas and problems of the theory of relativity (in english) Albert Einstein 2 Does the inertia of a body depend upon its energy-content? (in english) […]

Gravitational waves

It is said that the gravitational waves are a consequence of the  theory of relativity, of   Albert Einstein, but it is difficult to find texts in which they argue why this relationship, except that they are arising from the study of the Einstein field equations. Let’s try to apply a little logic and some knowledge of relativity […]