Add bubble fun to your summer and learn about surface tension and evaporation at the same time. Last month, I tried a new bubble solution recipe that called for sugar. Now, you can get some fun bubbles from combining water with dishwashing liquid. Adding a little bit of sugar and letting the solution sit overnight leads to big, long-lasting bubbles! Plus, the bubble mixture was just right for blowing bubbles inside other bubbles. Sound impossible?
- Add 1 tablespoon of granulated sugar to 8 ounces of water and stir until it dissolves. (Warm water will make it dissolve more quickly.)
- Add 2 tablespoons of dishwashing liquid to the water, stirring slowly—you don’t want to make it foamy. Cover the solution and leave it to age overnight before using.
- Dampen a 10” circle on a smooth surface with some of the solution.
- Dip a drinking straw in the bubble solution so it is wet about halfway up the straw.
- Gently blow a large bubble inside the damped circle.
- Dip the straw in the bubble solution again.
- Carefully push it into the first bubble, blowing another bubble inside it.
- Repeat this until the bubbles pop.
How many bubbles can you blow inside the first one?
Bubbles are pockets of soap and water that are filled with air. When soap and water are mixed together and air is blown into the mixture, the soap forms a thin skin or wall and traps the air, creating a bubble.
Soap makes the surface tension of water weaker than normal and forms a very thin skin that is more flexible than water. When air gets trapped under the surface of the soap and water mixture, the flexible skin stretches into a spherical or round shape, making a bubble.
Bubbles only last as long as the water in them lasts. As the dry air around a bubble soaks up the water in it—as evaporation occurs, the skin of the bubble gets thinner and thinner until it pops! The soap and sugar or glycerin help slow the evaporation of the water molecules so that bubbles can last longer. But evaporation isn’t the only thing that pops bubbles. Gravity makes the film and water in the bubble move downward until the film gets so thin that it can’t hold together. Oil or dirt particles also break through or dissolve the soap film in bubbles. And anything dry can pop them.
For more information on the science of bubbles: