Full box cube-root-of-total-volume scale factor a_eff(t) evolution fortop: , middle: , bottom: , for N = 256³ particles; where h_eff is written as h to reduce clutter. The scales are labelled, increasing in length from top to bottom within any panel. Cosmic variance is visible as non-uniformity in the dependence of the separation of the curves. Online: a fixed scale is shown with the same colour in all panels in this and later figures (for example, is purple).