WARNING: Be careful with the boiling water.
Theory: The rate at which heat is radiated from an object depends on its emissivity. Black objects both absorb and emit heat at a higher rate than do shiny objects.
Description: Pour boiling water into both cans, filling them. Cap, and insert a thermometer into each through the cap. Monitor the temperature as the cans cool. The black can should cool significantly faster than the silver can.
Setup time: 10 minutes, including time for the water to boil.
References: (available in the demo room)