Exploring buoyancy and thermal equilibration with a Galileo thermometer

Galileo thermometers are often used to demonstate buoyancy and density. In this article, a Galileo thermometer is used as the basis of a classroom activity which extends beyond Archimedes’ principle. Observations were made during cooling and localised heating of the thermometer which provide opportunities to discuss measurement range, thermal equilibration, response time, and non-equilibrium behaviour. Photographs and supplementary videos are provided and applications in classroom activities are discussed. The activity may be implemented in introductory thermal physics and fluid dynamics teaching.