Perpetual motion

work continuously done without an external supply of energy

lowest possible energy of a quantum system or field

thought experiment

German inventor

thought experiment and instance of a perpetual motion machine of the second kind

Steorn Ltd () was a small, private technology development company based in Dublin, Ireland. In August 2006, it announced that it had developed a technology to provide "free, clean, and constant energy" via an apparent perpetual motion machine, something which is contrary to the law of conservation of energy, a fundamental principle of physics.

Bulgarian physicist, dissident (1931-1997)

dates at least back to the Middle Ages

hypothetical perpetual motion machine

treatise by John Wilkins published 1648