Introduction to Astrophysics/Albert Einstein< Introduction to Astrophysics
Albert Einstein, a rare genius, has something that changes the whole way of looking to the heavens. He developed the theory of relativity, one of the most important discoveries of the 20th century. This deals with very large objects, such as planets and galaxies. The Special Theory pertains to motion without a gravitational field, and the General Theory pertains to motion with a gravitational field.