The Lagrangian

The Lagrangian is a mathematical tool used in physics to describe how a system evolves over time. It captures the difference between the system's kinetic energy (energy of motion) and potential energy (stored energy). By analyzing the Lagrangian, scientists can derive the equations that predict how objects move or how fields interact. It provides a unified way to understand dynamics across different systems, from planets to particles, making it fundamental for studying the laws of nature in a concise and systematic manner.