Curiosity Corner: Why do bubbles always look round?

Have you noticed how bubbles always tend to be round, regardless of how large or small they are? It could be soap bubbles drifting in the air or bubbles forming in a glass of water; you will find that they are always round. The reason behind bubbles always taking the round shape has something to do with science and nature's balanced nature. The mystery of bubbles can now be unravelled as we dig into why they tend to be round. The key here is understanding how forces interact in nature in creating the most round shape possible.

Nature favours the smallest surface area
Bubbles are created when air gets trapped between a thin layer of liquid solution consisting of soap and water. It is a known fact that the surfaces of all substances tend to minimise in order to occupy the least possible area. Amongst all shapes and sizes, a sphere has the least surface area among all shapes for a given volume. That is why the bubble immediately turns spherical in shape.

The role of surface tension

"Surface tension is the unseen force that holds a bubble together. It attracts the fluid on all sides evenly, like an elastic skin. When a force attracts simultaneously on all sides, there is a symmetry. A bubble provides a perfect point where surface tension balances itself. Had there been a square or oval shape, surface tension would have forced it back to being spherical."

Air pressure acts from the inside

The force inside the bubble acts equally in all directions. The result of the force helps keep the bubble round and spherical in shape. The bubble does not have an edge or a corner where the force inside the bubble can act or escape, causing the force to act uniformly on the surface of the bubble. The two opposing forces cause the bubble to float in the air in a round manner.

Why do bubbles change shape sometimes

Even though bubbles are spherical in shape, sometimes they extend or wobble when they come into contact with other objects or when two bubbles collide with each other. In such situations, external forces affect the balance of bubbles. But after the effect is over, bubbles return to their spherical shape instantly. This clearly reveals how strongly nature favours the spherical shape.

The perfect lesson in everyday science

Bubbles may appear like a toy, but actually, these objects unveil many scientific concepts. The spherical shape of a bubble can help children become familiar with optimisation, balance, and natural forces. The next time you see some bubbles drifting before your eyes, remember that these objects do not possess a random shape but a shape that nature finds most optimal.

Get the latest lifestyle updates on Times of India, along with Happy New Year wishes, messages and quotes !