Ocean in a bottle

Create an ocean snow globe with your child by following the instructions below:

1. Fill the plastic bottle one-third to one-half full with water.
2. Add drops of food coloring to the water until you reach a desired color. A combination of blue and green make the traditional color of the sea. However, your child might want to make a red, orange, or even hot pink "ocean." Use this time to discuss colors and what happens when different colors are mixed (yellow + red = orange, blue + red = purple, yellow + blue = green).
3. If you have any extra colorful items (glitter, marbles, buttons, plastic figures), add them to the colored water.
4. Using a funnel to prevent a mess, fill the remainder of the bottle with oil, leaving a couple of inches at the top. This is necessary to simulate the rolling of waves.
5. Screw the lid on tightly and secure it with heavy duct tape or glue.
6. Turn the bottle over and watch what happens!

The principle behind the "ocean" is that because oil and water do not mix, the movement of the two separate liquids within the bottle gives the illusion of waves. Try different colors and make a rainbow of oceans!