Dimensions 2 and 3
The special cases of 2D (wallpaper groups) and 3D (space groups) are most heavily used in applications, and we can treat them together.
Read more about this topic: Crystallographic Restriction Theorem
Famous quotes containing the word dimensions:
“It seems to me that we do not know nearly enough about ourselves; that we do not often enough wonder if our lives, or some events and times in our lives, may not be analogues or metaphors or echoes of evolvements and happenings going on in other people?—or animals?—even forests or oceans or rocks?—in this world of ours or, even, in worlds or dimensions elsewhere.”
—Doris Lessing (b. 1919)