Written By Pranavi Kondam Edited By Francesca-Lauren Seguin
We all remember playing with bubbles. The perfect accompaniment to a bright sunny day and a picnic, bubbles are magical. However, while they might appear to be mythical creations, they’re actually just a feat of soap, water and air. You can even make bubbles yourself, and there's more on that later!
The science behind it is quite simple. A bubble is just air trapped between a layer of water which is shielded by soap.
When you blow a bubble through a bubble wand, you create a pocket of air in between soap and water. The reason why this is able to happen is because soap molecules (tiny particles that make up soap) are really stretchy and water molecules are super bendy.
Because of the properties of water and soap, you are able to make perfectly round bubbles every time! If you’ve ever played with bubbles, you might have wondered why they are round. Do you think it would be possible for bubbles to be another shape? Maybe star shaped or triangles?
While heart shaped bubbles would be perfect for Valentine’s Day, bubbles can only be round. The reason for this is because of surface tension. Surface tension is the stretchy force of liquids. Some liquids, like water, are more stretchy than others. Some insects can even walk on water because of surface tension! When you blow air through the bubble wand, the water and soap molecules that surround the air stretch and form a sphere. Spheres are one of the strongest shapes and would be the most effective shape for the bubble because of surface tension and geometry! So, in nature, only round bubbles can exist.
We’ve talked quite a bit about soap and water molecules. Why do we even use soap and water to make bubbles? Well, we use water because water has surface tension. Surface tension, like we mentioned before, is very important to make bubbles because it forms the shape of the bubble. But without soap, it would be impossible to make bubbles! Because of the surface tension of water, water molecules tend to stick together. When you add soap, something magical (and scientific!) happens. The water molecules are separated by the soap molecules. One side of soap molecules pull water closer while the other side pushes it away. This creates separation, and when you blow through the bubble wand, the soap and water separates, allowing for many different bubbles!
Want to make your own bubbles and explore all of these scientific topics some more? Here’s a recipe below! Make sure you have an adult helper with you to help with the measurements and mixing.
Bubble Recipe
Ingredients:
4 cups of warm water (make sure it isn’t too hot!)
1 cup of dish soap
3 tablespoons of glycerin
Materials:
Mixing bowl
Jar
Spoon
Instructions:
Add the warm water to your mixing bowl
Add your dish soap slowly. Add half of it first, mix, then add your other half.
Carefully stir in your glycerin. Try adding one tablespoon at a time.
Pour your mixture into a jar.
That’s it, your bubbles are ready to use! While you can use them right away, they tend to make stronger bubbles if the bubble mixture is left alone for 2-3 days. This is because the ingredients used will make a stronger mixture and make your bubbles less likely to pop as easily. Once you’re done, go out and play!
References:
Surface Tension, https://www.chem.purdue.edu/gchelp/liquids/tension.html. Accessed 20 March 2024.
“Amazing Bubble Science Facts for Kids of all Ages.” Children's Museum of Sonoma County, 14 June 2022, https://www.cmosc.org/the-science-of-bubbles-for-kids/. Accessed 20 March 2024.
“Easy Bubble Recipe - giant bubbles, bubble activities & more.” Red Ted Art, https://www.redtedart.com/bubble-recipe/. Accessed 20 March 2024.
“The science behind - The Science Behind Bubbles: How Bubbles Work.” KiwiCo, 7 May 2023, https://www.kiwico.com/blog/the-science-behind/the-science-behind-bubbles. Accessed 20 March 2024.