Zustandsgrößen

Zustandsgrößen, also known as state variables or state quantities, are measurable physical properties that define the state of a system at a given time. These quantities are independent of the path taken to reach that state and depend only on the current condition of the system. Common examples include pressure, temperature, volume, and internal energy in thermodynamics. In mechanics, position and momentum are considered state variables. The values of state variables are sufficient to completely describe the system's equilibrium state. Changes in state variables are directly observable and are used to characterize thermodynamic processes. For instance, a change in temperature or pressure indicates a change in the system's state. The concept of state variables is fundamental to understanding physical systems, particularly in fields like thermodynamics, statistical mechanics, and chemistry, as they allow for a systematic analysis of system behavior without needing to track every microscopic detail. They form the basis for defining thermodynamic potentials and formulating laws of physics.