"...
What defines any bog-standard crystal—such as a diamond, an emerald, or even an ice cube—is that the crystal’s atoms are somehow arranged in repeating patterns in space. There’s three dimensions of space—and a fourth dimension, time. So physicists wondered if a crystal’s atoms could be arranged in repeating patterns in time.

In practice, that works something like this. You create a crystal whose atoms start in one state. If you blast that crystal with a finely tuned laser, those atoms might flip into another state—and then flip back—and then flip again—and so forth, all without actually absorbing any energy from the laser.

If you step back, what you’ve just created is a state of matter that’s perpetually in motion, indefinitely, without taking in any energy.

That’s no small feat. It beats against one of classical physics’ most sacred tenets: the second law of thermodynamics. ..."

#physics #time #entropy #quantum #computing #math

https://www.popsci.com/science/what-is-time-crystal-physics/