  The standard picture for the formation of disk galaxies has come to face a
number of problems related to angular momentum. Numerical simulations produce
disks that are too small, and analytical models predict too much low angular
momentum compared to observations. In addition, angular momentum distributions
of proto-galaxies in numerical simulations reveal large mass fractions with
negative specific angular momentum, which implies that the gas cannot conserve
its detailed distribution of specific angular momentum when cooling to form the
disk. This crumples one of the main pillars of our standard picture, and
indicates that a new spin on the angular momentum acquisition of disk galaxies
may be required.
