  We prove a variant of the Sylvester-Gallai theorem for cubics (algebraic
curves of degree three): If a finite set of sufficiently many points in
$\mathbb{R}^2$ is not contained in a cubic, then there is a cubic that contains
exactly nine of the points. This resolves the first unknown case of a
conjecture of Wiseman and Wilson from 1988, who proved a variant of
Sylvester-Gallai for conics and conjectured that similar statements hold for
curves of any degree.
