‘When you are courting a nice girl an hour seems like a second. When you sit on a red-hot cinder a second seems like an hour. That's relativity.’Dealing with the theory of relativity—special relativity and general relativity—and the considerations on the universe as a whole, this book gives an insight into the scientific theory about the relationship between space and time, the theory of gravitation and the universe.A Nobel laureate, Einstein’s research and theories changed the world. First published in 1916, Relativity: The Special and the General Theory is regarded as the most significant work in modern physics. It continues to remain popular and highly influential.