Physics is the branch of science that studies the physical world, including objects as small as subatomic particles and as large as galaxies. While it is true that many physics classes focus on the eq...Physics is the branch of science that studies the physical world, including objects as small as subatomic particles and as large as galaxies. While it is true that many physics classes focus on the equations, it is important to remember that the purpose of physics is less about the problems and more about using equations, laws, and theories to understand the world we live in.