A time crystal has been created using common screen materials.
Why it is true
Researchers created a classical time crystal using liquid crystals, the same type of material used in smartphone and television screens. The time crystal repeats patterns in time, not in space, and remained stable for over 24 hours.
Source: Nature Communications
Would you rather be asked first?
This is the reading side of the site, so the answer is in the sentence above — that is the whole point of it. Test yourself works the other way round: the question comes on its own, and the fact and the explanation only appear once you have answered.