Scientific development allows us to work today with gas at temperatures far below the 10-6 K . These gases are obtained by optical cooling techniques and need to be characterized for their thermodynamic properties. Among these properties is the temperature measurement. We show in a tutorial how low temperatures are measured using techniques called time of flight. These techniques combine basic knowledge of mechanics, thermodynamics, among other topics conventionally studied in the basic physics course.
atomic physics; cold atoms; atomic clock
