If the idea of stellar aberration -- celestial objects making small ellipses in the sky over the course of a year -- you might want to start with Carl. https://

If the idea of stellar aberration -- celestial objects making small ellipses in the sky over the course of a year -- you might want to start with Carl. https://www.youtube.com/watch?v=RXXekZA_vZg#t=02m25s https://www.youtube.com/watch?v=RXXekZA_vZg#t=02m25s