The following outline is provided as an overview of and topical guide to physics: Physics – natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves. What type of subject is physics? Physics can be described as all of the following: An academic discipline – one with academic departments, curricula and degrees; national and international societies; and specialized journals. A scientific field (a branch of science) – widely recognized category of specialized expertise within science, and typically embodies its own terminology and nomenclature. Such a field will usually be represented by one or more scientific journals, where peer-reviewed research is published. A natural science – one that seeks to elucidate the rules that govern the natural world using empirical and scientific methods. A physical science – one that studies non-living systems. A biological science – one that studies the role of physical processes in living organisms. 'See Outline of biophysics.' Branches of physics Astronomy – studies the universe beyond Earth, including its formation and development, and the evolution, physics, chemistry, meteorology, and motion of celestial objects (such as galaxies, planets, etc.) and phenomena that originate outside the atmosphere of Earth (such as the cosmic background radiation). Astrodynamics – application of ballistics and celestial mechanics to the practical problems concerning the motion of rockets and other spacecraft. Astrometry – the branch of astronomy that involves precise measurements of the positions and movements of stars and other celestial bodies. Astrophysics – the study of the physical aspects of celestial objects Celestial mechanics - the branch of theoretical astronomy that deals with the calculation of the motions of celestial objects such as planets. Extragalactic astronomy – the branch of astronomy concerned with objects outside our own Milky Way Galaxy Galactic astronomy – the study of our own Milky Way galaxy and all its contents. Physical cosmology – the study of the largest-scale structures and dynamics of the universe and is concerned with fundamental questions about its formation and evolution. Planetary science – the scientific study of planets (including Earth), moons, and planetary systems, in particular those of the Solar System and the processes that form them. Stellar astronomy – natural science that deals with the study of celestial objects (such as stars, planets,