The kind folks at the Boise WaterShed Environmental Education Center invited me to speak with their visitors today. It was a wonderful crowd of young children and their parents.
I did my best to answer their questions and also gave them a tour of the night sky using the sky simulator stellarium.
Among the displays at the education center was a tray full of sand. As you dragged your hand through the sand, a computer projected topographic contours onto the sand that were updated in real-time to show how water would flow. Apparently, this set-up is called an “Augmented Reality Sandbox“. The video above shows how it works.