Physics (from the Greek, φυσικός (physikos), "natural", and φύσις (physis), "nature") is the science of the natural world, which deals with the fundamental constituents of the universe, the forces they exert on one another, and the results of these forces. Sometimes, in modern physics, a more sophisticated approach is taken that incorporates elements of the three areas listed above; it relates to the laws of symmetry and conservation, such as those pertaining to energy, momentum, charge, and parity.[1] Physicists study a wide range of physical phenomena spanning all length scales: from the subatomic particles of which all ordinary (i.e., baryonic) matter is made (particle physics) to the behavior of the material universe as a whole (cosmology).