Iridescence

It can be seen in a simple soap bubble that a scale of colors can be seen inside. These are the colors of the rainbow and this example illustrates a phenomenon of nature, iridescence . This phenomenon that occurs with some frequency, an example with oil stains on wet floors, when colors are reflected in thin films of water, the wings of a butterfly, iridescent pearls, opals, also when we observe the feathers of a peacock or simply when we see the sky after a storm and the rainbow appears.

Origin of the term

The word iridescent comes from the Greek word iris, which means light. This has its origin in Greek mythology (in the Iliad Iris is a divinity who acts as one of the messengers of the gods). About 300 years ago this phenomenon began to be understood.

The English scientist Isaac Newton in a parallel experiment mixed all colors and thus created white light. Thus, when a prism refracts light, its particular shape causes the light to be divided into colors. This is an optical phenomenon that depends on the angle of illumination and the angle of observation.

It occurs when two or more light waves are grouped or superimposed to create a wave with a different amplitude.

Meanings and approaches

Light is explainable in scientific language but at the same time has a unique semantic value. We can say that it serves as a metaphor to explain ideas and feelings (we say about someone we love that they are our light or we compare the idea of ​​God with a divine light). In a similar sense, an iridescent person is one who has a special light. We also use this adjective to refer to people with many dimensions in their life.

For followers of apocalyptic doctrines, clouds with an iridescent color have a special message: they announce the proximity of a planetary catastrophe.

In the universe of art there are many examples related to this optical phenomenon: there are oil pastels and iridescent pigments with which it is possible to create original visual effects, photographs that imitate the action of the rainbow, decorative geometric figures, etc. In these cases we could affirm that art imitates nature.

Nowadays, iridescent is used as an adjective to metaphorically refer to a person who is different because they reflect many colors instead of one. The adjective was popularized by the movie Flipped in its phrase: “Some of us have a matte finish, others satin, others enamel. But every once in a while you meet someone who is iridescent, and when it happens, there is nothing comparable.”

What causes iridescence?

The cause of iridescence (irisation) has a different role in the formation of rainbows and halos. Iridescence (irisation) is not a rare phenomenon, although it is less known, it occurs when a curtain of small water drops or small ice crystals produce solar diffraction. It is observed in Cumulus, Cirrocumulus, Altocumulus , lenticular clouds and more rarely in Cirrus clouds.

The curtain of small diffracting bodies must be thin enough for a light ray to be scattered by a single fragment of water or ice. This way the effect is seen in semi-transparent clouds or on the edges of thick clouds, as you can see in the video below.

Diffraction iridescence can be observed in umbrella fabrics. The observer holding the umbrella (black), facing the sun with a clear sky, will observe, in the light that passes through the fine mesh of the fabric, the appearance of the colors of the rainbow.

This phenomenon began to be understood about 300 years ago

In one of his experiments, English scientist Isaac Newton focused a beam of light on a prism and observed that white light is made up of different colors.

In a parallel experiment, he mixed all the colors and thus created a white light. In this way, when a prism refracts light, its particular shape causes the light to be divided into colors. It is an optical phenomenon that depends on the angle of illumination and the angle of observation.

Iridescence occurs when two or more light waves are grouped or overlapped to create a wave of distinct amplitude.

The coloration of the animal and plant kingdom is related to this optical phenomenon. In this sense, the color of the elements is the result of the action of light on the structure of matter (the color of a living being is not always due to the pigments it has, but rather to its internal structure).