Deck

this order has never existed. anywhere. ever.

shuffle once — hold a cosmically unique object

There are roughly 8×10⁶⁷ possible orderings of a standard deck of cards, so many that the overwhelming majority of shuffles in history, including this one, land on an arrangement nobody has produced before. It says less about the deck in your hands and more about how fast factorial growth outpaces anything physical, even the count of atoms in the galaxy.

Concepts: probability, combinatorics.

An interactive you play with one thumb, on Wundr.