Equations · equation
Principle of Least Action
Classical Field Theory · 1744
- Equation
- δS = 0, S = ∫L dt
- Field
- Classical Field Theory
- Named After
- Pierre Louis Maupertuis · Leonhard Euler · Joseph-Louis Lagrange
- Year
- 1744
Symbols
S the action, a single number scoring an entire history · L the Lagrangian, kinetic minus potential energy · δS = 0: the true path is the one small changes can't improve
Significance
Nature doesn't push things step by step — it picks, among all conceivable histories, the one that makes the action stationary. Every classical law on this shelf can be rewritten as a choice of L; Feynman's path integral later explained why: all paths are tried, and this one is where the phases agree.
Referenced by
equation
theory
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