Principle of least action
The principle of least action was first formulated by Pierre-Louis Moreau de Maupertuis, who said that "Nature is thrifty in all its actions". See action (physics). Others who developed the idea included Euler and Leibniz. It should be said that, from the point of view of the calculus of variations, a principle of stationary action is a more accurate formulation.
Earlier, Pierre de Fermat had introduced the ideas that rays of light, in optical conditions such as refraction and reflection, followed a principle of least time: see Fermat's principle.
The principle of least action led to the development of the Lagrangian and Hamiltonian formulations of classical mechanics. Although they are at first more difficult to grasp, they have the advantage that their world-view is more transferable to the frameworks of relativistic and quantum-mechanical physics than that of Newton's laws.
This has caused some people to think that this principle is a "deep" principle of physics.
See also
- Action (physics)
- Variational principle
- Calculus of variations
- Functional integral
- Fermat's principle