It has nothing to do with Alfred Einstein. In this case, einstein tile comes from the German words for “one stone.

Roger Penrose held the record until recently. He discovered two tiles that together could "tile" the plane forever with patterns that never repeat, and without gaps. In November, 2022 David Smith of Yorkshire England discovered one stone with 13 sides that can do it.

I made the files from 23mm hexagons and share them with the world here. It might be one of the most unique shapes that will ever be discovered. Fun for DIY projects!