Try This at Home
In this experiment you will build your own cold lava lamp! Regular (hot) lava lamps work by heating up wax inside a glass bottle that also has water in it. The hot wax expands a little and becomes less dense than the water, so it floats to the top in large blobs. When it cools back down, it becomes denser and sinks back to the bottom to be heated up again. You can recreate this same effect at home using a different principle and easy-to-find materials!