free energy

• Concept théorique désignant l'énergie pouvant être extraite de l'environnement sans coût, souvent associé au mouvement perpétuel ou aux sources d'énergie alternatives ; en thermodynamique, énergie dans un système disponible pour effectuer un travail.

A theoretical concept referring to energy that can be extracted from the environment at no cost, often associated with perpetual motion or alternative energy claims; in thermodynamics, it refers to the energy in a system available to do work.

1. Thermodynamic potentialC1formal

   In physics and chemistry, the energy in a system that is available to do useful work, often referring to Gibbs free energy or Helmholtz free energy.

   Énergie libre

   • The change in Gibbs free energy determines whether a reaction is spontaneous.
   • Helmholtz free energy is used to analyze systems at constant volume.
   • Calculating free energy helps predict chemical equilibrium.

2. Perpetual motion conceptB2informal

   A hypothetical, often pseudoscientific, concept of obtaining energy from a source that supposedly requires no input and is not subject to the laws of thermodynamics.

   énergie libre (pseudo-scientifique)

   • Many online videos claim to demonstrate free energy devices, but they are usually hoaxes.
   • The idea of free energy violates the first law of thermodynamics.
   • Scientists dismiss most free energy claims as pseudoscience.