This document provides an outline on the topic of physics. It begins with an introduction defining physics as the branch of science concerned with the nature and properties of matter and energy. It then lists and briefly describes the main branches of physics, including astronomy, astrophysics, atomic physics, geophysics, high energy physics, and nuclear physics. It provides a comparison of astronomy and astrophysics, noting their differences. Finally, it discusses the contributions of the Muslim scientist Ibn al-Haitham, including his work developing early theories and laws of optics, the structure and workings of the eye, and the reflection of light.