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
Physics (American Physical Society magazine) Physics (American Physical Society magazine) Physics is an open access online publication containing commentaries on the best of the peer-reviewed research published in the journals of the American Physical Society. The editor-in-chief of "Physics" is Jessica Thomas. It highlights papers in "Physical Review Letters" and the "Physical Review" family of journals. The magazine was established in 2008. "Physics" contains three types of commentaries on research papers: journalistic articles ("Focus"), in depth pieces written by active researchers ("Viewpoints"), and short summaries of a research paper ("Synopsis") written by editorial staff. Readers get free access to the underlying research papers on which