Bubbles! We all know how fascinating they are, evoking happy memories of blowing and chasing the mystical orbs with our friends. A bubble’s fragile nature, beautiful rainbow colors, and ability to soar through the sky make them universally fascinating among kids.

A bubble is just air wrapped in soap film. Soap film is made from soap and water (or other liquid). The outside and inside surfaces of a bubble consist of soap molecules. A thin layer of water lies between the two layers of soap molecules, sort of like a water sandwich with soap molecules for bread. They work together to hold air inside.

Bubbles are round because, just like balloons, they are what scientists call ‘minimal surface structures’. What this means is that bubbles hold the air enclosed inside them in the least possible surface area that they can. Out of all the geometric shapes such as cubes, or pyramids, the geometric form with the least surface area is a round sphere! So sadly, it isn’t possible to make square-shaped bubbles.