History of variational principles in physics involves integrals over an interval of time and (for fields) extended region of space. Moreover, in the usual formulation of classical action principles, the initial and final states of the system are fixed, e.g., In particular, the fixing of the "final" state appears to give the action principle a teleological character which has been controversial historically. This apparent teleology is eliminated in the quantum mechanical version of the action principle. History of variational principles in physics A variational principle in physics is an alternative method for determining the state or dynamics of a physical system, by identifying it as an
Deflection (physics) interaction, some energy must be converted into alternative forms of energy or is absorbed by the deformation of the objects involved in the collision. Deflection (physics) A deflection, in physics, refers to the change in an object's velocity as a consequence of contact (collision) with a surface or the influence of a field. Examples of the former include a ball bouncing off the ground or a bat; examples of the latter include a beam of electrons used to produce a picture, or the relativistic bending of light due to gravity. An object's deflective efficiency can never equal or surpass 100%,