Laws of conservation
Many of the regularities (or symmetries) observed in science may be expressed as the laws of conservation, each of which states that a particular measurable property (or quantity) of an isolated physical system does not change (i.e., is constant) during the course of time. These laws are perhaps the most powerful tools of analysis in physics and classical mechanics.
Another important function of the laws of conservation is that they make possible the prediction of the macroscopic behavior of a system without necessarily delving into the microscopic details of the system and its behavior.
- Gerald J. Holton and Stephen G. Brush (2001). Physics, the Human Adventure: From Copernicus to Einstein and Beyond, 3rd Edition. Rutgers University Press. ISBN 0-8135-2908-5.
- William M. Gibson and Brian R. Pollard (1976). Symmetry Principles in Elementary Particle Physics, 1st Edition. Cambridge University Press. ISBN 0-521-20787-8.
- At one time, it was thought that the law of conservation of mass and the law of conservation of energy were separate and distinct. However, in the early 20th century, the German-born physicist Albert Einstein showed that mass can change into energy and that energy can change into mass. This made necessary a restatement of the laws of conservation of mass and energy, namely that the total amount of mass plus energy before and after a change remains constant.