RT instability

The Rayleigh-Taylor instability (RT instability) occurs at the interface between two fluids of different density when the less dense fluid is "below" the more dense fluid (within a gravitational field). When any bit of the lighter fluid happens to rise slightly, pushing the boundary at that location, it will continue to rise through buoyancy. This instability is the trigger for convection, which occurs in astrophysical phenomena such as stellar structure, supernovae, and the interstellar medium and star formation. The instability is named for Lord Rayleigh and Geoffrey Ingram Taylor.