Key up the musicThe Outer Limits…the theme from the Outer Limits.    Drs. Toyabe and Sano (Chuo and Tokyo Universities) (in concert with Drs. Sagawa, Ueda and Muneyuki) have found a means to harness Maxwell’s Demon.  For those of you who don’t recall your physics lesson,  this demon was proposed by James Maxwell right about the time that MIT was founded (both are 150 years old).  Maxwell postulated that, despite the second law of thermodynamics, one can separate cold and hot water into two compartments, by letting those molecules that exceed the average temperature to pass through a trap door between the two compartments. Maxwell averred that the mixed water was of higher entropy than the separated water (true), so his demon – using only the knowledge which molecules were cold and hot- could convert a system from disorder to order. Once it was demonstrated that the demon would have to expend some energy (Leo Szilard), it was clear that the laws of thermodynamics would not be violated. Nevertheless, no one ever proved the experiment.  Until now…
Toyabe and Sano (described in a letter to Nature Physics)  developed a spiral staircase (micro-miniature) employing electric fields.  Due to their thermal energy, the molecules could move in random directions.   The molecule had “free motion” as long as the molecule moved up the staircase; an electric field (basically an invisible wall) precluded the molecules from going down the staircase.  Since the molecule moved UP the staircase, its potential energy was augmented (it was moving to a position of greater potential). However, Toyabe and Sato never did any work or imparted energy to the molecule.  (The electric field “wall” was not imparting energy to the molecule.)  Only the information (knowledge of which direction the molecule moved) was used to insure its continued upward motion.
The only problem with this experiment is that – at least right now- it has no practical application.  As stated, energy is needed to provide the invisible wall. That is more energy than is gained by the molecule as it moves up the staircase.  (This is akin to nuclear fusion experiments- they work, but require apparati expended far more energy than the nuclear fusion process provides in return).

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