Mirage

Sometimes you see things that are not there.

This is called a mirage. It is a trick of light.

Light rays can bend as they move through the air. This happens when air is not the same temperature.

On a hot road, the air near the ground is very warm. This makes the sky look like a pool of water.

Sometimes the air is cold near the ground. This can make things look very high in the sky. You might even see a ship that is far away.

These tricks are real. They are not just in your head.

A mirage is a real trick of light. It is not a dream or a hallucination. You can even catch a mirage on a camera.

Mirages happen because light rays bend. This bending is called refraction. It occurs when light moves through air of different temperatures.

An inferior mirage happens when the ground is very hot. This often happens on roads or in deserts. The hot air stays near the ground. The cool air stays above it. Light from the sky bends as it hits the warm air. This makes the sky look like a pool of water on the ground.

A superior mirage is different. It happens when the air near the ground is cold. This is called a temperature inversion. This can happen in cold, polar regions. In this case, the light bends down. This makes objects look much higher than they really are.

Some mirages can even show objects that are below the horizon.

There is also a special kind called Fata Morgana. This is a complex superior mirage. It can change very fast. It makes images look stretched or squished.

A mirage is a real trick of light. It is not a dream or a hallucination. You can actually catch a mirage on a camera. This happens because of refraction. Refraction is when light rays bend as they move. The word mirage comes from the Latin word mirari. This means to look at or to wonder at.

Mirages can look very strange to our eyes. They can make things appear in the wrong place. They can also make objects look much bigger or smaller. Scientists group them into different types based on where they appear.

An inferior mirage appears below the real object. This often happens on very hot days. The ground or road gets very hot from the sun. This hot air stays near the surface. Cooler air stays above the hot layer. Light rays from the sky bend as they hit this warm air. This makes the blue sky look like a puddle of water on the ground.

People often call this a highway mirage on roads. It can also be a desert mirage in sandy places. These images are usually upside-down. They can also look like they are vibrating or shaking. This happens because the hot air layers mix together.

A superior mirage is the opposite kind. It appears above the real object. This happens during a temperature inversion. An inversion is when the air near the ground is colder than the air above it. This is common in polar regions with lots of ice. The light rays bend downward toward the observer. This can make a distant shoreline look much taller. It might even look like it is closer than it really is.

Sometimes these mirages show things that are actually below the horizon. This can happen because the light follows the curve of the Earth.

One very special type is called a Fata Morgana. This name comes from an Italian translation of a fairy name. A Fata Morgana is a complex superior mirage. It is a fast-changing image. It can show many stacked images all at once. These images can look stretched or squished. They can also look right-side up or upside-down.

You can see them from many heights. People can see them from mountaintops or even from airplanes. They are most common over ice, oceans, or lakes. They need a very strong temperature inversion to form.

History shows us how amazing these light tricks can be. In 1596, a ship was stuck in the ice at Novaya Zemlya. This place is above the Arctic Circle. The sailors saw the sun rise two weeks early. The real sun was actually still below the horizon. The light rays bent to follow the curve of the Earth. This is known as a Novaya Zemlya mirage. Mirages can even happen at night. They can affect the way we see the moon or bright stars.

A mirage is a naturally occurring optical phenomenon. It happens when light rays bend through a process called refraction. Refraction is the bending of light as it moves through different layers of air. This bending produces a displaced image of distant objects or the sky. Unlike a hallucination, a mirage is a real physical event. You can actually capture a mirage on a camera. The word comes from the Latin word *mirari*, which means "to look at" or "to wonder at."

To understand how a mirage works, you must look at air temperature. Air density changes based on how much heat it holds. Cooler air is denser than warmer air. When light travels through layers of air with different densities, it bends. In an inferior mirage, the image appears below the real object. This usually happens on hot days when the ground is very warm. The hot air stays near the surface, while cooler air sits above it.

This setup creates a gradient in the refractive index of the air. Light rays from the sky hit the warm air at a shallow angle. These rays bend upward toward the observer's eyes. This makes the blue sky look like a reflection on a puddle. People often mistake these for water or oil on a road. This is frequently called a "highway mirage" on asphalt. It is also known as a "desert mirage" in sandy areas. These images are often upside-down and may appear to vibrate. This vibration happens because the hot air layers mix through convection.

A superior mirage works in the opposite way. The image appears above the actual object. This occurs during a temperature inversion. A temperature inversion is when the air below the line of sight is colder than the air above it. This is common in polar regions over large sheets of ice. During the day, the atmosphere usually has warm air above cold air. In an inversion, the light rays bend downward toward the observer.

Superior mirages can make distant shorelines look much taller. They can also make objects appear closer than they really are. These mirages can even show objects that are below the geometric horizon. This happens because the downward bending of light follows the curvature of the Earth. In 1596, a ship at Novaya Zemlya experienced a special version of this. The crew saw the Sun rise two weeks earlier than expected. The real Sun was still below the horizon. Its light rays followed the Earth's curve to reach the sailors. This is called a Novaya Zemlya mirage.

A Fata Morgana is a very complex type of superior mirage. Its name comes from the Italian translation of Morgan le Fay, a fairy from Arthurian legend. This mirage is famous for being fast-changing and elaborate. It consists of a series of vertically stacked images. These images can be compressed, stretched, or even inverted. A Fata Morgana requires a very strong temperature inversion. The curvature of the light rays must be stronger than the curvature of the Earth.

Observers can see a Fata Morgana from many altitudes. You might see one from a mountaintop or even an airplane. They are most common over ice, oceans, or lakes. One famous account involves the German battleship *Bismarck* in 1941. As the ship passed into a sea mist, it allegedly reappeared suddenly. Observers saw the ship steaming at high speed before it faded away. Radar showed the ship had not actually changed its course. This shows how powerful these optical illusions can be.

Mirages are not limited to the daytime. They can also occur at night. Under certain conditions, astronomical objects can produce mirages. This includes the Sun, the Moon, planets, and bright stars. Sunset and sunrise mirages are the most common examples. These phenomena show how light and temperature work together to change our view of the world. They remind us that what we see is not always exactly where it appears to be.