Crystals are structures in which a pattern of atoms or molecules repeats in space. Now, two teams of researchers have figured out that crystals’ repeating patterns can also exist through time. These “time crystals,” detailed in a new paper in Physical Review Letter, are an entirely new kind of matter, one that can never reach equilibrium.
To create the time crystals, researchers at University of Maryland hooked together 10 ytterbium atoms and hit them with two lasers multiple times to keep them out of equilibrium. Though the atoms did settle into a pattern, they could not reach equilibrium, meaning that the crystals perpetually remain in motion, though they don’t contain any energy. Almost all of physics is based in studying matter that is at equilibrium, so the ability to create these non-equilibrium crystals is a huge deal for the future of physics.
The researchers say that time crystals resemble Jell-O. When you tap Jell-O, it jiggles. The only difference is that the crystals are jiggling without using any energy, without any tap. By definition, time crystals can never stop oscillating, no matter how little energy they contain.
Articles like this, which attempt to describe some new scientific discovery in terms a layman can understand, often make me scratch my head. On the one hand, this sounds very cool. On the other hand, it doesn’t make a lot of sense to me, so how would I know?
Take the observation that these “crystals perpetually remain in motion, though they don’t contain any energy.” I don’t remember much from my high school physics class, but I do remember that perpetual motion is supposed to be impossible. Have these researches just done the impossible? I gather not, since that would be a pretty big deal, and the author doesn’t really milk it. (I imagine a headline like “Scientific Consensus Shattered!” might do the trick in today’s environment, where appeals to consensus have replaced the scientific method as the arbiter of truth.)
I’m not sure what it means that the crystals “don’t contain any energy.” Doesn’t everything contain energy? I assume these things are made of molecules, meaning they’ve got electrons and the like bouncing all around inside of them. Isn’t that energy? I assume these crystals have mass. Again, I’m weak on my science, but I thought Einstein showed us that mass and energy are the same thing.
By the time I read through an article like this, the “cool factor” has often melted away for me. I still have sense that something cool, perhaps very cool, went down, but that I somehow missed it. (I never was one of the cool kids. See what I did there?)
And I’m never quite sure why I missed it. Maybe I’m not smart enough, or don’t have the scientific foundation to understand what’s going on. Or maybe the author is a poor writer, or can’t explain it well because she doesn’t understand it herself. Maybe the scientist she interviewed didn’t explain it well. It can be tough to reduce complex things to layman’s terms.
It could be any, or all of these things, but whatever the case, I feel a little bummed. Because damn that sounds cool, and I missed it!