4D Crystals (yes, they do actually exist)

[DiTBho]

Will be used in quantum computers? Probably Yes

Wait ... What? Why? How? .... 

Well, in her last YouTube video, Physics Girl tries to answer some questions:

[PlainName]

So you have this stuff and it changes back and forth when you feed it some energy? Sounds a bit like a crystal.

[tszaboo]

When she was first describing time crystals, I was saying: "sure, I have them in almost every device I make, and buy them at digikey"
I'm still not sure why it is important, sounds like it changes spin every time you shoot laser at it? Not sure what gives it the time property. I dont think it can even be used for timing purposes, it sounds to me more like a counter.

[TimFox]

Isaac Asimov, as usual, was way in advance of his time.
He described "thiotimoline", a molecule with interesting temporal properties, in several spoof scientific articles and used it in some SF stories.
https://gizmodo.com/the-fake-chemical-compound-isaac-asimov-invented-to-pun-5887014

[AndyBeez]

Define the fourth dimension. Is it time or just the next higher geometric level? The fourth dimensional cube in 3D space https://en.m.wikipedia.org/wiki/Tesseract