<P> The study of the principles of the universe has a long history and largely derives from direct observation and experimentation . The formulation of theories about the governing laws of the universe has been central to the study of physics from very early on, with philosophy gradually yielding to systematic, quantitative experimental testing and observation as the source of verification . Key historical developments in physics include Isaac Newton's theory of universal gravitation and classical mechanics, an understanding of electricity and its relation to magnetism, Einstein's theories of special and general relativity, the development of thermodynamics, and the quantum mechanical model of atomic and subatomic physics . </P> <P> The field of physics is extremely broad, and can include such diverse studies as quantum mechanics and theoretical physics, applied physics and optics . Modern physics is becoming increasingly specialized, where researchers tend to focus on a particular area rather than being "universalists" like Isaac Newton, Albert Einstein and Lev Landau, who worked in multiple areas . </P> <P> This discipline is the science of celestial objects and phenomena that originate outside the Earth's atmosphere . It is concerned with the evolution, physics, chemistry, meteorology, and motion of celestial objects, as well as the formation and development of the universe . </P> <P> Astronomy includes the examination, study and modeling of stars, planets, comets, galaxies and the cosmos . Most of the information used by astronomers is gathered by remote observation, although some laboratory reproduction of celestial phenomena has been performed (such as the molecular chemistry of the interstellar medium). </P>

Is anatomy and physiology considered a natural science