Poking holes in a piece of foil, senior Erich Heinricher allows convection currents to form. “I thought the lab demonstrated how convection currents worked and showed us the different densities of water depending on temperature,” junior Angela Ahern said. APES students used food coloring, different temperature water, foil, and pepper to illustrate the use of convection currents. The warmer water flowed along the surface, displacing the pepper floating on top of the colder water, and the colder water flowed at the bottom of the tank.