What Is A Mirage?
A mirage is an image that looks real but is not really there. This phenomenon is called an Optical Illusion.
Mirages are usually formed by layers of air at different temperatures and thicknesses close to a surface like the ground or a water body.
When light passes through these different layers of air, it bends. This bending is called “refraction” and causes distant objects to be reflected, causing false images.
Types Of Mirages
There are two types of mirages.
- Inferior Mirage
- It occurs when the air near the surface is much hotter than the air above it.
- The light bends upwards at the point where the two layers of air meet.
- Distance objects like the blue sky are reflected on the ground.
- Example: Mirage of an oasis in the desert.
- Superior Mirage
- It occurs when the air near the surface is cooler than the air above it.
- The light bends downwards at the point where the two layers of air meet.
- Objects appear elevated or floating above their position.
- Example: Distant islands floating above the sea when observed from a ship.
Here are some interesting facts about optical illusions or phenomena:
- “Fata Morgana” is a mirage that occurs in the Arctic. In 1818, an expedition crew saw towering mountains in the Arctic, which they called the Croker Mountains.
- A Brocken Spectre is a special kind of shadow that appears on clouds or fog when someone stands on a high mountain or hill. When the sun is behind them, their shadow can appear huge and surrounded by a colorful halo.
- A Sundog is an optical phenomenon in which bright spots appear on either side of the sun at the same altitude. The spots are seen during sunrise or sunset.
- Solar pillars occur when sunlight reflects off the surfaces of horizontally oriented ice crystals in the atmosphere.
Let’s quickly recap what we learned about mirages:
- How should two layers of air close to a surface differ for a mirage to be formed? Differ in Temperature and Density
- What is the bending of light that passes through different layers of air called? Refraction
- What type of mirage forms when the air near the surface is much hotter than the air above it? Inferior Mirage
- What type of mirage forms when the air near the surface is cooler than the air above it? Superior Image