[The fluctuation-dissipation theorem (FDT) is a] fundamental result in statistical physics which links microscopic (thermal) fluctuations with the macroscopic property that creates a drag force on a particle in a medium.

— by Zap

— Thu May 09 2002 at 16:48:10

— Everything2

The fluctuation-dissipation theorem (FDT) is a powerful tool in statistical physics for predicting the behavior of non-equilibrium thermodynamical systems. These systems involve the irreversible dissipation of energy into heat from their reversible thermal fluctuations at thermodynamic equilibrium.

— Wikipedia on *Fluctuation-dissipation Theorem*

2013.06.28 Friday ACHK