Crossing number may refer to:
- Crossing number (knot theory) of a knot is the minimal number of crossings in any knot diagram for the knot.
- The average crossing number is a variant of crossing number obtained from a three-dimensional embedding of a knot by averaging over all two-dimensional projections.
- Crossing number (graph theory) of a graph is the minimal number of edge intersections in any planar representation of the graph.
Famous quotes containing the words crossing and/or number:
“This was charming, no doubt: but they shortly found out
That the Captain they trusted so well
Had only one notion for crossing the ocean,
And that was to tingle his bell.”
—Lewis Carroll [Charles Lutwidge Dodgson] (1832–1898)
“Nothing ever prepares a couple for having a baby, especially the first one. And even baby number two or three, the surprises and challenges, the cosmic curve balls, keep on coming. We can’t believe how much children change everything—the time we rise and the time we go to bed; the way we fight and the way we get along. Even when, and if, we make love.”
—Susan Lapinski (20th century)