The term "perpetual motion" has been ascribed to any scheme that purports to be able to extract useful energy from an apparently energy free environment. There are two entirely different reasons why this should be impossible: the First and Second Laws of Thermodynamics. The first law says you cannot extract useful work from nothing. The second says you cannot extract useful work from the heat of the environment. It is most unfortunate that the same term should be used to stigmatize two fundamentally different approaches.

Attempts to violate the 1st law of thermodynamics have been discredited by both theory and experience. However, unlike the 1st law, the 2nd Law of thermodynamics is a complex and poorly understood law. There are many reasons why it might be possible to violate it, but little attempt has been made. In particular, an objection put forward by one of its very architects, Maxwell, points the way. He recognized that there was a theoretical way that the law could be violated by a mechanism that has become to be known as his "demon".

This group is for those who are interested in the subject and want to explore possible practical ways of implememting Maxwell's Demon.