Of all the labs for CPO Earth Science, 3A: Convection in Earth's Atmosphere was the most daunting to contemplate using a homemade system. The text calls for a "GeoBox" with a special fitted lid that contains two chimneys. Meet my GeoBox-----an old Rubbermaid box (the size larger than a shoebox), an even older cardboard document box lid that had gone through several moves, and two clear plastic cups left from a party. The other necessary supplies were a tealight candle and a cone of incense, plus a long lighter or fireplace matches and a heat-proof holder for the incense. We live in a university town with a ready supply of incense LOL:
The ever-resourceful Mike cut out the bottoms of the plastic cups using a Dremel attachment:
Then I inserted the cups into holes cut into the cut-down cardboard lid. Unfortunately, I inserted them upside down compared to the official GeoBox chimneys, but it still worked just fine.
I attached the lid assembly to the plastic box with packing tape. The lid wasn't perfectly flat so this helped to create a better seal for the eventual smoke.
As you can see, we needed help from our lab assistant (who was working from home) to keep the lid pushed down. The smoke wanted to escape out the edges instead of through the left chimney.
We smartened up and used index card packs to hold down the lid. I had a hard time photographing the smoke. If you look carefully at the left chimney, you can see a column of smoke exiting there. What you cannot see is the smoke re-entering the GeoBox through the right chimney. The smoke moves from the smoldering incense (cough, cough) toward the candle's warmth, rises as it warms and becomes less dense (exiting), then cools, becomes more dense and sinks back into the box through the right chimney. The smoke enables one to observe the convection currents in action.
Did you enjoy our geeking-out?
