|coins, 2 sides|
DW News offers a short “Time Crystals: A new phase of matter, and breakthrough for quantum competing?” The cover title is “4D Matter”.
The illustration is a glass of ice water where the ice melts and refreezes back into floating cubes.
There is an illustration of shaking subway tokens, and seeing them be heads or tails about evenly. But if it were 4F matter, they might all be heads or tails alternating. Imagine playing poker this way.
In a sense a refrigerator cycle (somewhat audible in a smaller apartment or condo) seems like a time crystal.