Convection Experiment

Science experiments have always been a favorite of the Artist's. Late in the summer I gave the kids a little box of light-related experiments and it provided them several hours of fun and cooperation in the last couple of weeks before school started. I think that whetted the Engineer's taste for experiments too.

This year in science both kids will be studying earth science and astronomy. The Artist's book included a convection experiment demonstrating how convection currents move in air, in water, or in magma.

First, we put cooking oil into a clear (as clear as I had) pot. Then we added food coloring drops. The book encouraged trying different colors to see if they behave differently. We added some blue and some green.

Then the pot was propped up above candle (two in this case, because I know these pots can take a looooong time to heat up). Then the watching and waiting begins.
The first thing they noticed was a little condensation on the outside of the pot. The oil was cold from being stored in the refrigerator. Then we could see heat waves wafting through the oil, but the water-based food coloring was not affected yet.
The suddenly, rapidly and with loud pops reminding us of volcanic explosions, the green food coloring blob released small bubbles of itself into the oil. The floated up and out to the sides staying close to the edge of the pot. Then they cooled and fell just as suddenly to the bottom.