Free energy

Free energy may refer to:

Science

• Free energy perturbation, a method based on statistical mechanics used in computational chemistry
• Free energy principle, a variational formulation of self-organisation in biological systems, applied in particular to neuroscience
• Free-energy relationship, a relationship in physical organic chemistry
• Principle of minimum energy, a thermodynamic formulation based on the second law
• Thermodynamic free energy, the energy in a physical system that can be converted to do work, including:
  • Gibbs free energy
  • Landau free energy (also known as grand potential)
  • Helmholtz free energy
• Variational free energy, a construct from information theory that is used in variational Bayesian methods

Pseudoscience

• Free energy device, a hypothetical perpetual motion device that is supposedly capable of drawing energy from a hidden free energy field, which is unknown in science
• Free energy suppression conspiracy theory, in which advanced energy technologies are suppressed by governments or special interest groups
• History of perpetual motion machines, history of devices supposedly capable of drawing unlimited energy

Other uses

• In economics, energy from sources that do not require an input which has to be paid for (usually a sub-set of renewable energy)
• Free Energy (band), a 5-piece rock band on DFA Records