The Stellar Population of the Thin Disk
  We discuss recent observations of stars located close to the symmetry plane
of the Milky Way, and examine them in the context of theories of Galaxy
formation and evolution. The kinematics, ages, and compositions of thin disk
stars in the solar neighborhood display complex patterns, and interesting
correlations. The Galactic disk does not seem to pose any unsurmountable
obstacles to hierarchical galaxy formation theories, but a model of the Milky
Way able to reproduce the complexity found in the data will likely require a
meticulous study of a significant fraction of the stars in the Galaxy. Making
such an observational effort seems necessary in order to make a physics
laboratory out of our own galaxy, and ultimately ensure that the most relevant
processes are properly understood.
