Imagination is more important than knowledge.
Einstein contributed more than any other scientist since Sir Isaac Newton to our understanding of physical reality. Einstein worked at the patent office in Bern, Switzerland from 1902 to 1909. During this period he completed an astonishing range of theoretical physics publications, written in his spare time, without the benefit of close contact with scientific literature or colleagues. He based his new theory on the principle that the laws of physics are in the same form in any frame of reference. As a second fundamental hypothesis, Einstein assumed that the speed of light remained constant in all frames of reference.