In May 2021, residents of Bengaluru saw a spectacular halo around the sun. The halo was evenly spread around the sun, and it looked splendid. Twitter was abuzz that day with people posting photos of this halo. So what exactly was that halo? It resulted from light getting reflected and refracted through ice crystals in the clouds.
These ice crystals act like prisms. This is what we call the Kaleidoscope effect. Since the radius of tha halo from the sun (or moon) remains around 22 degrees, the phenomenon is also known as the 22 Degree halo.
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All About the Kaleidoscope Effect
The Kaleidoscope Effect is the phenomenon of the formation of a halo-like ring around the sun with a radius of 22 degrees. To know how these mystical halos are formed, you need to understand three things-
- At an altitude of 20,000-43,000 feet, a type of cloud forms which is known as cirrostratus cloud. These clouds are generally very thin. This means light can enter the cloud and escape from the other side.
- These clouds can have ice crystals that can work as prisms. They are hexagonal in shape.
- When sunlight passes through these thin clouds, the light is bent because of the crystals in the cloud.
- The halo depends on how the crystals are placed and what their shape is. The way the light is refracted defines the shape of the halo.
Since the Kaleidoscope Effect has to meet so many conditions, you will rarely see the formation of such halos. There can be many halos or semi-halos around the sun. However, to see an evenly spread 22-degree halo is a treat to the eyes because of its rarity.
Kaleidoscope Effect Is Not a Rainbow
Although the halo made by the Kaleidoscope effect can display colours, it should not be confused with a rainbow. A rainbow occurs because the sunlight is reflected by the water droplets. On the other hand, the 22-degree halo occurs because the ice crystals work like prisms and refract and reflect the sunlight.
When the light gets out of the cloud, the red spectrum of the light is refracted at an angle of 21.54 degrees and the blue spectrum of the light at 22.37 degrees. This is why the outer portion of such halos tends to appear bluish while the inner portion is reddish.
Kaleidoscope Effect and the Weather
It is often believed that when a 22-degree halo forms over an area, it indicates that the area will experience rainfall/or storms within one or two days. This is because the Kaleidoscope Illustrator happens mostly when there is the presence of cirrostratus clouds in the sky. And these clouds form a few days before rainfall or storm occurs. However, you can’t rely on 22-degree halos for weather forecasts because it’s not every time rainfall or storm follows after the formation of the halo.
The Kaleidoscope Effect can be an extremely interesting thing to observe. However, there is nothing mystical or superstitious about this natural phenomenon. It can be explained with Physics and can even be recreated in your school’s laboratory.
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Frequently Asked Questions on the Kaleidoscope Effect
What is a Kaleidoscope Effect?
The Kaleidoscope Effect is a natural phenomenon that happens when the sunlight or moonlight is refracted and reflected by hexagonal ice crystals present in cirrostratus clouds. Due to the refraction, the light gets bent and forms a circular halo around the sun. The halo has a radius of 22 degrees from the perspective of the observer. Hence, it is also known as the 22-degree halo.
What is refraction?
When light from one medium passes through another, its speed can change because of the difference in density between the two mediums. As a result of this change in speed, the light bends or changes its direction. This change of direction is what we call refraction.
Why is the Kaleidoscope Effect so rare in India?
The formation of the Kaleidoscope Effect depends on whether there are ice crystals in the cirrostratus clouds. Since India is a tropical country, the overall climate here is warm. As a result, cirrostratus clouds rarely have ice crystals in them. This is why it is uncommon for a 22-degree halo to form in India. However, in recent years, we have seen such formations in Bengaluru, Jharkhand, Telangana, and West Bengal.