Why Do Soap Bubbles Have Rainbow Swirls? | Colorful Bubbles

Why is Soap Bubbles Rainbow Colored?

Rainbow bubbles are not simply pretty to seem at, Isaac Newton was able to make an interesting discovery from this phenomenon. Even if the soap bubbles typically last for less than a few seconds before bursting, either on their own or on contact with another object.

What Happens to the Soap Bubbles?

When light shines onto a bubble it seems to change color. Not like those seen during a rainbow, that arises from differential refraction, the colors are seen during a soap bubble that arises from interference of light reflecting off the front and back surfaces of the thin film. Depending on the thickness of the film, totally different colors interfere constructively and destructively.


It is the phenomenon during which there is a superimposition of the waves. The resulting wave might have a bigger or lower wave.

The interference happens due to light reflecting off the front of the thin soap films and back surface of the thin soap films. Some wavelengths (colors) cancel each other out, whereas others are reinforced. The bubble wall is a thin film of water, protected against collapsing by a layer of detergent molecules on both sides.

How the Color-Changing Method Take Place?

The colors gradually change as the water films drain below gravity. Isaac Newton noticed a similar thing one day, when taking a shower and turned the observation to sensible use by setting up an experiment where all of the water eventually drained from the top of the bubble.

It left a black spot (now known as a ‘Newton black film’) consisting of simply the two layers of detergent molecules.

By following the change within the colors, Newton was able to calculate the size of the detergent molecules, and that was a truly remarkable achievement.