This false-color map of a random light field includes a large number of a feature called C points, described below. The colors reflect the electric field's polarization, and the circles and triangles—visible when you zoom—mark C points, where polarization is undefined. The white C points have a positive index and the black C points have a negative index. In light of this, they went back to the beginning and created a new theoretical model of C points in two dimensions. The similarities between the behavior of C points and charged particles could point to a deeper insight on the nature of charge and its relationship to light.