  This article is based on the talk with the same title at the Blaubeuren
meeting. First we discuss briefly the importance of time and time keeping,
explaining the basic functioning of clocks in general and atomic clocks in
particular, which rely on Ramsey interferometry. The usefulness of cold atoms
is discussed as well as their limits in Bose-Einstein condensates. An
alternative that we study is a different cold-atom regime: the Tonks-Girardeau
(TG) gas of tightly confined and strongly interacting bosons. The TG gas is
reviewed and then generalized for two-level atoms. Finally, we explore the
combination of Ramsey interferometry and TG gases.
