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, my first [bicycle] had an intrinsic beauty. And it opened for me an era of all but flying, which roads emptily crossing the airy, gold-gorsy Common enhanced. Nothing since has equalled that birdlike freedom.”
—Elizabeth Bowen (1899–1973)
“If we remembered everything, we should on most occasions be as ill off as if we remembered nothing. It would take us as long to recall a space of time as it took the original time to elapse, and we should never get ahead with our thinking. All recollected times undergo, accordingly, what M. Ribot calls foreshortening; and this foreshortening is due to the omission of an enormous number of facts which filled them.”
—William James (1842–1910)