The only word I can really use for this experiment is mesmerizing. I will have to admit that I found myself staring long after the kids had moved on to something else. I was also amazed how simple this experiment was. All you need is: a glass or see through bottle, vegetable oil, water, food coloring and some effervescent tablets, like alkaseltzer. Fill the bottle 1/3 of the way with oil, then fill the rest with water leaving a little room at the top. Next add about 10 drops of food coloring, we used blue which worked well but I would like to try it again with other colors. Then take turns breaking the alkaseltzer in half and dropping the half's into the bottle. When the alkaseltzer hits the bottle it starts to fizz causing the oil and coloring to bubble up like a lava lamp. We have played with this multiple times, just putting the lid back on when we are finished. It is so cool to look at and the girls love putting the tablets in to start the reaction!