First published in 1916, 'Relativity: The Special and the General Theory' is regarded as the most significant work in modern physics. This book gives an insight into the scientific theory about the relationship between space and time, the theory of gravitation and the universe. The author using minimum mathematical terms and implementing basic principles and ideas of the theory tells how it helped shaping the present world. The book is divided into three parts which deal respectively with the special theory of relativity, with the general theory of relativity, and with considerations on the universe as a whole. The special theory deals with the physics of elementary particles while the general theory is concerned with the force of gravity and its effect on the other forces of nature. These two theories, while exceptional in their explanations of their particular focus, are inconsistent with each other, and it has long been an aim of the science of physics to help resolve these inconsistencies.