The aberration of light (or astronomical or stellar aberration) is a tiny seasonal displacement of the fixed stars of about . First observed in late 1600s by astronomers searching for stellar parallax, it was clearly demonstrated by James Bradley in 1727, who also provided a classical explanation in terms of the Earth's orbital motion and the finite speed of light. In the early 1900s the phenomenon played an important role in Albert Einstein's development of the theory of special relativity. This Demonstration enhances the seasonal stellar displacements by letting you set the Earth's velocity to any value less than the speed of light . You can compare the predictions of the classical and relativistic theories with the positions of stars at .