Levitation, oscillations, and wave propagation in a stratified fluid

We present an engaging levitation experiment that students can perform at home or in a simple laboratory using everyday objects. A cork, modified to be slightly denser than water, is placed jug containing tap water and coarse kitchen salt delivered the bottom without stirring. The gradually diffuses determines stable density stratification of layers being top ones. During dissolution salt, cork slowly rises increasing height, where any instant its balanced by surrounding water. If gently pushed off temporary equilibrium position, it experiences restoring force starts oscillate. Students many different measurements phenomena involved tackle non-trivial physical issues related behaviour macroscopic body immersed stratified fluid. Despite simplicity, this allows introduce various theoretical concepts relevance for physics atmosphere stars offers opportunity getting acquainted with system serve as model understand complex such oscillations Brunt-V\"{a}is\"{a}l\"{a} frequency propagation internal gravity waves medium.