Within the DM paradigm the Tully-Fisher law must arise from galaxy formation since it connects luminosity of baryonic matter with a dynamical property, rotation, which is seen as dominated by the DM halo. But it has not been easy to derive Tully-Fisher from any natural connection between the two components. And as R. H. Sanders has pointed out, the messiness of galaxy formation is hardly the natural backdrop for such a sharp correlation between galaxy properties. The sharpness needs a dynamical reason as opposed to an evolutionary one.

What It Means

This is a placeholder explanation generated by the low-overhead model. It interprets "Within the DM paradigm the Tully-Fisher law must arise from galaxy formation since it connects luminosity of baryonic matter with a dynamical property, rotation, which is seen as dominated by the DM halo. But it has not been easy to derive Tully-Fisher from any natural connection between the two components. And as R. H. Sanders has pointed out, the messiness of galaxy formation is hardly the natural backdrop for such a sharp correlation between galaxy properties. The sharpness needs a dynamical reason as opposed to an evolutionary one." in the context of "(21 January 2010), "Alternatives to dark matter: Modified gravity as an alternative to dark matter", arXiv preprint arXiv:1001.3876" to mean that wisdom is timeless.