# Maybe explain like I’m 1 years old… Just read an article on a team of researchers who recently created a video of a Space-Time crystal. Pls can someone explain in the most basic way possible what a time crystal is? I’ve read previous posts on this and I still don’t understand :(

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In: Physics

From my understanding this is basically a metronome.

It’s a crystal that moves on the atomic level in a patterns at regular intervals.

So this could be used to measure time extremely accurately.

A lot of times you see that a watch has quartz in it and that is because quartz is a crystal that is used for measuring time.

A crystal is a material whose internal structure is a highly ordered geometric pattern. So, like a regular crystal’s atomic structure repeats in space, a “time crystal” is an atomic structure that repeats in *time*. It’s a set of atoms that seem to go change between several different configurations and do so in a loop that repeats forever.

I really don’t know how that works, at all

This isn’t a simple subject so don’t worry if you don’t fully understand it. Most people probably don’t.

Simply put it is a structure which in its ground state oscillates in time instead of space.

To start simply a crystal is basically a structure with a repeating pattern. As you move through the structure you come across pieces of it at regular intervals. So a crystal repeats in space, a time crystal repeats in time. It is able to change regularly between different configurations or arrangements of its structure while in its lowest energy state. Lowest energy state means the energy isn’t able to be used for work, meaning you can’t use the energy or withdraw it from the crystal. When these crystals are acted upon by an outside frequency, let’s say an energy pulse hits it, they resonate, or change configuration of the structure, repeatedly back and forth between these configurations, but not in the expected symmetric way. They break symmetry. For example instead of one pulse of energy repeating back through the crystal as one pulse, back and forth between configurations, it may repeat as a fractional pulse, the value of which depends on the structure of the crystal. In a perfect time crystal the changing back and forth should likely continue indefinitely. I don’t think they can make perfect ones though.

How I understand it is 6 mirrors all looking at each other (north south east west, up and down) and it creates some sort of infinite loop where it’s just endless

Try thinking of it as a theoretical model. It´s a concept for describing a mathematical tool, more or less, not meant to be seen as an actual object as such. Same with particles / atoms.

Think slinky escalator https://youtu.be/5UP_njBPpZ4?t=126. The slinky is changing constantly but repeating periodically