One of these devices “flashing” between tilted flat and sawtooth potentials exhibits Parrondo’s paradox, in which alternating two losing strategies eventually wins. These devices name the effect where directed transport (-5[1])arises in driven, asymmetric periodic potentials, making them useful models for molecular motors. A 1962 lecture updated a thought experiment in which one of these devices in a heat bath is connected to a paddle wheel in a different heat bath. (10[1])That one of these devices appears to violate the second law of (10[1])thermodynamics, (10[2]-5[2])but doesn’t actually (10[1])rotate (-5[1])because thermal fluctuations also affect the pawl and cause the gear to slip. Socket wrenches (-5[1])are alternatively named (10[1])for these mechanisms. (10[2])For 10 points, (10[2])Feynman (-5[1])popularized a “Brownian” example (-5[1])of what mechanisms (10[1])that only allow (10[1])motion (10[2])in one direction? (10[2])■END■ (10[5]0[7])