Brady here, For everyone demanding more (or not complete lay term) information on Time Crystals I present Fizicks, PhD:
It's actually really cool shit. Most of Wilczek's work came in the field of theoretical particle physics and quantum field theories. But quantum field theories also apply to condensed matter systems: systems with large numbers of particles that exhibit intricate quantum behaviors. There are degrees of freedom to any system -- ways that it can change or adjust -- both classical or quantum. The idea of a time crystal, in both classical and quantum versions, is that it should repeat its configuration, so long as it stays in its ground state, periodically in time. Just as a normal crystal repeats its configured molecular/atomic pattern periodically in space, a time crystal should have this same property except for time.
The obvious problem was that if you're moving from one state to another to another, and then back to your initial state, that would appear to indicate some type of perpetual motion, which shouldn't be possible due to the conservation of energy. In fact, there's even a theorem forbidding this behavior for classical systems, and it's been thought to be strictly forbidden for quantum ones as well.
As it turned out, though a team in 2016 (maybe late 2015...can't recall), came up with a scheme where the creation of these time crystals actually seemed possible. Instead of a closed, constant system, he proposed taking the system out-of-equilibrium. By driving the system externally -- making it an "open" instead of a "closed" system -- they realized that, at least in theory, there were some physical conditions under which this time-translation-symmetry could be broken.
The two things that needed to be varied in the model were the Ising interaction strength, which represents the dipole moments of the atomic spins, and spin-echo pulse imperfections, which represents the external driving of the crystal. For certain classes of combinations, this should yield a time crystal
I'm pretty sure this was verified a couple of times by Harvard researchers actually.
Driving a system isn't a very common term outside the physics world but it essentially means that you send a "spin-flip pulse" of a particular strength through the system. And what you get is a periodic response that's directly proportional to the time at which you're pulsing the system.
Still, time crystals as Wilczek originally envisioned them -- in systems in thermal equilibrium -- really do appear to be impossible. You have to have an open system, and the system needs to be driven at a periodic frequency with imperfections that aren't too large. Over-drive it, and the crystal will "melt," losing the properties that made it so interesting in a periodic fashion. We still haven't crystallized time, and likely never will. But the ability to make a system, that when all you do is pulse it in a particular way, returns, periodically, to a uniform state over and over again, is fucking amazing.
Someday in the not-too-distant future, there may be a Nobel Prize handed out for this.
WOW Thank-you Fizicks for helping us digest this amazing new discovery!