By David Grossman
Jun 7, 2017
Among impossible machines, perpetual motion is in a class of its own. The idea of creating unlimited energy has burned through humanity for centuries, that somehow a device could work forever without a power source.
Of course, a perpetual motion machine is impossible because it violates not just one, but two rules of thermodynamics. Entropy and conservation of energy are universal concepts, applying both to the battery in your cellphone and celestial bodies like the Sun. Different scales apply, of course, but the same principles work throughout.
Ted-Ed gives a rundown of some of the more notable attempts to subvert these laws.
Some say that the recently discovered time crystals, which never have an equilibrium, may hold the key to perpetual motion. If that turns out to be the case, then entire physics textbooks would have to be rewritten from scratch, with an emphasis on early innovators like Bhakshara and Robert Boyle as early trailblazers.
Don't hold your breath.
