Time crystals could behave almost like perpetual motion machines
Monday, February 20, 2012 - 16:30
in Physics & Chemistry
(PhysOrg.com) -- As every young science student knows, moving objects have kinetic energy. But just how much energy does something need to move? In a new study, a pair of physicists has shown that its theoretically possible for a system in its lowest energy state, or ground state, to exhibit periodic motion. This periodically moving system can be thought of as the temporal equivalent of a crystal, which is defined by its spatial periodicity. Whats even more intriguing about these "time crystals" is that, by exhibiting motion at their state of lowest energy, they break a fundamental symmetry called time translation symmetry and become "perilously close" to looking like perpetual motion machines.