Editing Maxwell's demon (section)

== Applications ==
Real-life versions of Maxwellian demons occur, but all such "real demons" or [[molecular demon]]s have their entropy-lowering effects duly balanced by increase of entropy elsewhere.<ref name="c543N">{{Cite book|title=Physics in mind : a quantum view of the brain|last=Loewenstein|first=Werner R.|isbn=9780465029846|publisher=Basic Books|location=New York|oclc=778420640|date=2013-01-29}}</ref> Molecular-sized mechanisms are no longer found only in biology; they are also the subject of the emerging field of [[nanotechnology]]. Single-atom traps used by particle physicists allow an experimenter to control the state of individual quanta in a way similar to Maxwell's demon.

If hypothetical [[mirror matter]] exists, Zurab Silagadze proposes that demons can be envisaged, "which can act like perpetuum mobiles of the second kind: extract heat energy from only one reservoir, use it to do work and be isolated from the rest of ordinary world. Yet the Second Law is not violated because the demons pay their entropy cost in the hidden (mirror) sector of the world by emitting mirror photons."<ref name="1aEYK">{{Cite journal|arxiv=physics/0608114|title=Maxwell's demon through the looking glass|journal=Acta Physica Polonica B|volume=38|issue=1|pages=101–126|year=2007|last1=Silagadze|first1=Z. K|bibcode=2007AcPPB..38..101S}}</ref>