Shaving Cream Rain Clouds Science Experiment


Shaving Cream Rain Clouds

Shaving cream rain clouds are a funny and easy science project that illustrates key science concepts, such as density, mixing, and how clouds work. Once you master the basics, turn the project into a science experiment by tweaking the materials and methods.

Materials

All you need are a few basic materials from home:

  • Shaving cream
  • Water
  • Food coloring
  • Glass or jar

Let’s Make Shaving Cream Clouds!

  1. Fill the glass mostly full of cold water. Why use cold water? The reason is because warmer water more readily degrades the shaving cream and also disperses the food coloring.
  2. Dispense a “cloud” of shaving cream on top of the water. Don’t make the layer too think or else the food coloring won’t make it all the way to the water.
  3. Add drops of food coloring to the top of the clouds. Blue is the traditional color for rain, but you can explore color theory if you get creative.
  4. Watch as the food coloring “rain” falls from the shaving cream “cloud”.

The Science Behind Shaving Cream Rain Clouds

Shaving cream floats on water because it has a lower density than water. Similarly, clouds float in the atmosphere, even though the average cumulus cloud weighs over one million pounds. It hardly seems possible that a cloud doesn’t just sink to the ground! Keep two facts in mind. First, clouds are huge, so they rest on top of a gigantic air column. Second, clouds kind of do fall, when you think about it.

When a nimbus cloud (the type of cloud that produces precipitation) holds more water than the air can support, the excess falls as rain, snow, or sometimes hail. Similarly, when you drip food coloring onto shaving cream, it is heavier than the foam and falls through the fake cloud. Eventually it enters the water (the “atmosphere” in this project).

The food coloring consists of pigment and water. It readily mixes with the water. If two different colored drops come into contact or mix together in the water, you get new colors.

Turn the Science Project Into a Science Experiment

Performing the shaving cream rain clouds project fulfills the first step of the scientific method, which is making observations. From your observations, think of things you can change about the project and make a prediction about the effect of this change. In other words, form a hypothesis and conduct an experiment that tests this hypothesis. Finally, evaluate the results of your experiment and decide whether you accept or reject your hypothesis. Often, this process gives you ideas for new experiments.

Here are some ideas:

  • Examine the effect of water temperature on cloud stability and “rain” formation.
  • Can you replace the shaving cream with another material? Examples might include whipped cream or egg whites.
  • What happens if you introduce another layer between the water and shaving cream? For example, do you get “rain” if there is a thin layer of vegetable oil on top of the water? (Hint: This is the basis for the fireworks in a glass project.)
  • What happens if you use paint, colored sugar, or ink instead of food coloring?
  • Does changing the size or shape of the container affect the outcome?
  • Predict what happens if you replace water with another liquid, such as oil or milk.

References

  • Burroughs, William James; Crowder, Bob (2007). Weather. San Francisco: Fog City Press. ISBN 978-1-74089-579-8.
  • Freud, E.; Rosenfeld, D. (2012). “Linear relation between convective cloud drop number concentration and depth for rain initiation”. Journal of Geophysical Research. 117 (D2). doi:10.1029/2011JD016457
  • Jaramillo, A.; Mesa, O. (June 19, 2017). “On the relative density of clouds.” Quarterly Journal of the Royal Meterological Society. Vol. 144; Iss. 707, pp. 2650-2653. doi:10.1002/qj.3099
  • Young, Hugh D.; Freedman, Roger A. (2012). University Physics with Modern Physics. ISBN 978-0-321-69686-1.