Essential Science For Everyday Life part I

One day in the ninth grade in my little rural junior high school in Boston, Indiana, I saw a demonstration in the science class that has stuck with me ever since. When we came into class, the science teacher had an aquarium set up on the front table. The aquarium had a glass divider which fit down into two channels to keep what was in once side separate from the other. We came in and got quiet. Well, okay, we came in and mostly sat in the chairs behind our tables. When we were sort of paying attention the science teacher poured one side full of cold blue water, then poured the other side full of warm red water. He reminded us to watch what happened when he pulled the divider straight up out of the water. At first nothing happened, but within five or ten seconds, the cool blue water began to spread across the bottom of the aquarium while the warm red water rose in the tank and spread the other way across the top. I was transfixed. Before a minute was up, the top half of the aquarium was all red and the bottom half was all blue. The water didn't even mix much.