What to Do
Fill the bowl with water. Pour the cooking oil into the paper cup. Add four drops of each food coloring color. Mix the oil and colors thoroughly with the spoon. Pour the colored oil mixture into the water in the bowl. Observe for ten minutes.
What Happens
Small pools of oil spotted with tiny spheres of color float to the surface of the water, exploding outward and creating flat circles of color on the surface of the water. Long streamers of color then sink down through the water, like a fireworks display.
Why It Works Oil and water are immisciblemeaning they do not mix, but separate into layers because of the different polarity of their molecules. The oil rises to the surface because it is less dense than the water. Since the water-based food coloring does not dissolve in oil, it remains in tiny spheres throughout the oil on the waters surface, then sinks through the oil layer and dissolves in the water below, creating long streamers of color.
Bizarre Facts
In the tenth century, the Chinese discovered that three common kitchen ingredientssaltpetre, sulfur, and charcoalwere explosive when combined. When packed into a bamboo tube and ignited, the mixture rocketed skyward and exploded, lighting up the sky.
In fireworks, sodium compounds produce yellow light, strontium and lithium salts emit red light, copper gives blue light, and barium creates green light.
In 1988, the world's longest fireworks displaymeasuring 18,777 feet long, consisting of 3,338,777 firecrackers and 1,468 pounds of gunpowderwas ignited in Johor, Malaysia, and burned for nine hours and twenty-seven minutes.
On July 15, 1988, the world's largest fireworkweighing 1,543 pounds and measuring 1,354.7 inches in diameterwas exploded over Hokkaido, Japan, bursting to a diameter of 3,937 feet.
Flying Toast
Chinese inventor Wan-hu attempted to fly by building a plane made from two kites, a chair, and forty-two rocket-like fireworks. When the firecrackers were ignited, Wan-hu and his contraption went up in flames.