[_8091149529]

For anyone struggling to make sense of this: I have a physics PhD, I have spent most of my career in fundamental research, I have read the Wikipedia article and other references multiple times, and attended several talks, and I still don't understand what qualifies as a time crystal. All I know that it seems to have something to do with subharmonic response.

[systemvoltage]

The more deeper you get in a particular field, the more you realize how no one else has a clue. It's time we put credentials aside, I found this amusing: https://en.wikipedia.org/wiki/Michael_Crichton#GellMannAmnes...

[boibombeiro]

The irony is that this applies to hacker news.

[WildParser]

I don't really know what those people in physics do, but as a mathematician my definition of a time-crystal would be a 4-dimensional discrete structure. You have some 4-dimensional symmetries.

Just rotating in 3D is a bit boring. Interesting symmetries would be where you get the time-axis involved.

4D is most likely a bit boring - having more dimensions and more time-dimensions helps greatly to get more symmetries to work with...