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 [[Law of universal gravitation|theory of universal gravitation]] and [[classical mechanics]], an understanding of [[electricity]] and it's relation to [[magnetism]], [[Albert Einstein|Einstein]]'s theories of [[special relativity|special]] and [[general relativity]], the development of [[thermodynamics]], and the [[quantum mechanics|quantum mechanical]] model of atomic and subatomic physics. | 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 [[Law of universal gravitation|theory of universal gravitation]] and [[classical mechanics]], an understanding of [[electricity]] and it's relation to [[magnetism]], [[Albert Einstein|Einstein]]'s theories of [[special relativity|special]] and [[general relativity]], the development of [[thermodynamics]], and the [[quantum mechanics|quantum mechanical]] model of atomic and subatomic physics. |