Magnetic field lines. The box on the left has dimensions 10 AU on each side, while the box on the right has dimensions 100 AU. The dashed lines represent the flux-freezing model, while the solid lines show the same field lines for the model including non-ideal MHD effects for a grain size a_gr = 0.038 μm. In both cases, the second core has just formed and is on the left axis midplane. The field lines straighten out significantly on small scales in the non-ideal model compared to the flux-frozen model.