Extended Data Fig. 1: Asymmetry of the disk.
a, b, Degree of asymmetry with respect to 180° rotation around the disk centre (‘Point symmetry’; a) and that with respect to reflection in the plane perpendicular to the disk mid-plane (‘Reflection symmetry’; b). The colour (see scale at right) denotes [I(x,y) − I(−x,−y)]/I(x,y) and [I(x,y) − I(x,−y)]/I(x,y) in a and b, respectively, where I(x,y) denotes the intensity at position (x,y). Here the Cartesian coordinates x and y are set along the disk minor and major axes, respectively.
