Albert Einstein described Relativity as a "popular exposition" of his famous theory. He wrote: "The author has spared himself no pains in his endeavor to present the main ideas in the simplest and most intelligible form." Written in 1916, Relativity introduced the lay audience to the remarkable perspective which had overturned theoretical physics. Einstein's genius was to express this perspective in understandable terms. Concepts of Time and Space could now relate intrinsically in a relativistic viewpoint that stretched the imagination. Einstein prefaced Relativity with this simple desideratum: "May the book bring someone a few happy hours of suggestive thought!"