Work from fluctuations

  Can asymmetry and ratchet forces be used to extract energy from fluctuations?

This is clearly not possible in thermal equilibrium (time reversal symmetry).

Non-equilibrium fluctuations can indeed generate force and motion

• Random motion of bacteria:                                   
• Whether any form of "active matter" leads to ratchet motion is ongoing activity.
• Feynman's ratchet and pawl:  (youtube)                

 Nonequilibrium fluctuations + asymmetry can potentially lead to motive force

 Radiative heat transfer as source of nonequilibrium fluctuations

Next (Fluctuational QED) Outline Equilibrium force Active Force Work extraction Fluctuational QED Engine Dynamic phenomena Summary