Where does mirage happen? See what "Mirage" is in other dictionaries. East coast of China

Mirages as an atmospheric phenomenon in nature

Mirages (from the French “mirage”) are an optical phenomenon in the atmosphere, due to which images of objects appear in the visibility zone that are under normal conditions hidden from observation. This kind of miracles happen because in an optically inhomogeneous atmosphere, rays of light are bent, as if looking beyond the horizon. Most often, inhomogeneities arise due to uneven heating of air at different altitudes. IN Ancient Egypt They believed that a mirage is a ghost of a country that no longer exists. Legend says that every place on our planet has its own soul.

More often, mirages can be observed in the desert. This can be explained by the fact that hot air acts like a mirror. For example, in the Sahara, about 160,000 mirages are observed every year; they can be stable and wandering, vertical and horizontal.

Caravans in the Erg-er-Ravi desert in North Africa are especially often victims of mirages. People see oases “with their own eyes” at a distance of 2–3 km, which are actually no less than 700 km away. A mirage can mislead even experienced people.

Thus, 360 km from the Bir-Ula oasis, a caravan led by an experienced guide from local tribes fell victim to a mirage. 60 people and 90 camels died as they followed the deceptive mirage, which carried them 60 km away from the well.

In ancient times, nomads lit a fire to make sure whether they were seeing a mirage or real objects. If there was even a slight movement of air in the desert, then the smoke spreading along the ground quickly dispersed the mirage. Maps have been compiled for many caravan routes, which indicate the places of frequently encountered mirages. These maps even indicate where wells, oases, palm groves, mountain ranges, etc. are visible.

Atmospheric mirages are divided into three classes, and the reasons that cause them are quite diverse.

Mirages of the first class are the so-called lake, or lower, mirages. They are the most common and simple. For example, water seen on desert sand or hot asphalt is a mirage of the sky above the hot sand or asphalt. Airplane landings in films or car races on television are often filmed quite close to the surface of hot asphalt. Then below the car or plane you can see their mirror image (inferior mirage), as well as the mirage of the sky.

The higher you are on land or in the sea, the less dense the air. Under normal conditions, air density decreases with increasing altitude. When light passes over the surface of the earth, the air below the light beam is denser than above. A typical property of light is that it refracts toward a denser medium, and thus a ray that travels across the surface of the earth is actually always slightly refracted downward and travels along the slightly curved surface of the earth instead of heading straight toward the sky.

The denser air seems to slow down the lower end of the beam and pull it towards itself. On the other hand, a person imagines that an object is in the direction from which the light reaches his eyes. Thus, when you look at the distant horizon, you see objects that are actually partially below the horizon. The light from these objects is refracted along the curved surface of the earth or sea and therefore it only seems that the light reaches the observer's eye from the horizon.

Many are familiar with the phrase that states that when we look at the sun as it sets, it is actually already below the horizon. In astronomy, this phenomenon is known as refraction: the refraction of light in the atmosphere raises celestial bodies on the horizon at approximately half a degree of angle.

Very often, air density does not change uniformly with altitude, and cold, denser air and warm air form layers of different temperatures at different altitudes. The movement of light in such air can be quite erratic, thus creating a distorted image of the landscape.

The inferior mirage is identical in structure: there is always only one inverted, more or less flattened mirage below the object. If the landscape itself is beautiful, then its mirage is also beautiful, and together they can spread across the horizon in a string of buildings and treetops.

If this happens in a desert, the surface of which and the adjacent layers of air are heated by the sun, the air pressure at the top can be high, the rays will begin to bend in the other direction. And then interesting phenomena will begin to occur with those rays that should have been reflected from the object and immediately hit the ground. But no, they will turn upward and, having passed perigee somewhere near the surface itself, will go into it.

Let us now imagine that such a beam, already bent, hits the pupil of a traveler walking through the desert. But to subjective perception, the object (say, a palm tree) will be located in the place where the tangent to the ray path points. Accordingly, the image of the palm tree will be reversed, as if reflected in the water. And a lot of water will spill around. Such an insidious joke will be played on the thirsty traveler by the sky moving to the sands.

French scientist Gaspard Monge, who took part in Napoleon’s Egyptian campaign, described his impressions of the lake mirage as follows: “When earth's surface strongly heated by the Sun and just beginning to cool down before the onset of twilight, the familiar terrain no longer extends to the horizon as during the day, but turns, as it seems, at about one league into a continuous flood.

The villages further away look like islands in a lost lake. Under each village there is an overturned image of her, only it is not sharp, small details are not visible, like a reflection in water, swayed by the wind. If you begin to approach a village that seems to be surrounded by a flood, the shore of the imaginary water moves away, the water arm that separated us from the village gradually narrows until it disappears completely, and the lake now begins behind this village, reflecting the villages located further away.

The lower mirage can be observed by anyone. If you stand on a railway track or a hill above it on a hot summer day, when the sun is slightly to the side or to the side and slightly in front of the railway track, you can see how the rails 2-3 km ahead seem to be plunging into a sparkling lake - as if the tracks were flooded. If we try to get closer to the “lake”, it will move away, and no matter how much we walk towards it, it will invariably be at the same deceptive distance.

Mirages of the second class - the rays of which bend beyond the horizon line, are called upper, or distant vision mirages. They appear right in the sky. If warm air, heated somewhere above the desert, invades the upper layers of the atmosphere, and below there is cold dense air of an anticyclone, then the rays that have undergone refraction can look very deeply beyond the horizon. Light reflected from a distant object (for example, an island) finds two paths to the observer's eyes: the first passes almost straight from the island to the observer, and the second rises slightly upward to the warm air layer, where the beam is refracted downward at a slight angle to the colder air and reaches the eye of the observer from above.

Two images of the same island are created - one normal, and the second an inverted image above the island, i.e. a superior mirage. In turn, the specific type of atmospheric phenomenon that creates such a mirage is called a thermal inversion. Then on the surface of the cold air mass lies a clearly defined, lighter and less dense layer of warm air. Severe thermal inversion also causes random interference on radios, television reception, and cell phones.

2006, May 8 - thousands of tourists and local residents observed a mirage that lasted for 4 hours in the city of Penglai off the east coast of China on Sunday. The fogs created an image of a city with modern high-rise buildings, wide city streets and noisy cars. It rained in Penglai for 2 days before this rare weather event occurred. Residents Cote d'Azur France on a clear morning has been seen more than once on the horizon Mediterranean Sea, where the water merges with the sky, a chain of Corsican mountains rises from the sea, about 200 km from the Cote d'Azur.

The superior mirage is described in one of the works of N.V. Gogol:

“A great miracle appeared behind Kyiv! Suddenly it became visible far to all corners of the world. In the distance the Liman turned blue, and beyond the Liman the Black Sea overflowed. Experienced people recognized both the Crimea, which rose like a mountain from the sea, and the marshy Sivash. On the right hand the land of Galicia was visible.

What is it? - the assembled people interrogated, pointing to the gray and white tops that seemed far away in the sky and looked more like clouds.

That Carpathian mountains! - the old people said.”

Lateral mirages can occur in cases where layers of air of the same density are located in the atmosphere not horizontally, as usual, but obliquely or even vertically. Similar conditions are created in the summer, in the morning shortly after sunrise on the rocky shores of the sea or lake, when the shore is already illuminated by the sun, and the surface of the water and the air above it are still cold. Lateral mirages have been repeatedly observed on Lake Geneva. For example, people saw a boat that was approaching the shore, and next to it exactly the same boat was moving away from the shore. A side mirage can appear near a stone wall of a house heated by the sun, and even on the side of a heated stove.

Thanks to a side mirage, silent, foggy ghosts appear, blocking the traveler’s path in the mountains. Usually, a frightened person sees himself. Strongly heated rocks cause such air rarefaction around them that the rays reflected from the observer and directed towards the rocks are bent near them to such an extent that, like a boomerang, they return back.

Images in side mirages are almost always equal in size to reflected objects, but they can double, triple, etc. There is a hypothesis that the famous ghosts that have taken a fancy to some castles are nothing more than a side mirage. In winter, as you know, dank, damp walls need to be intensively heated. The stones that make up the ovens are much hotter than boulders in the midday sun, and the high vaulted ceilings allow the beam to loop around and return to the observer.

Third class mirages are amazing mirages called ultra-long-range vision mirages. For them, distances of thousands of kilometers are not a hindrance. This is the case described in the book “Optical Phenomena in Nature”:

“On the night of March 27, 1898, among Pacific Ocean The crew of the Bremen ship "Matador" was frightened by the vision. Around midnight, the crew spotted a ship about two miles away that was battling a strong storm. This was all the more surprising because there was calm all around. The ship crossed the course of the Matador, and there were moments when it seemed that a collision between the ships could not be avoided...

The crew of the Matador saw how, during one strong wave impact on an unknown ship, the light in the captain’s cabin, which was visible all the time in two portholes, went out. After some time, the ship disappeared, taking with it the wind and waves. The matter was clarified later. It turned out that all this happened with another ship, which at the time of the “vision” was located at a distance of 1,700 km from the Matador.”

Third class mirages have no reliable scientific explanations. In order to somehow justify their appearance, assumptions are made that giant air lenses are formed in the atmosphere or that secondary, tertiary - multiple mirages arise, relaying the same image along a complex chain. Some are even trying to prove that there is a special “mirror” in the ionosphere, from which a solar ray, like a radio signal, is reflected and, simultaneously self-focusing, is carried away to another part of the world.

An interesting version is expressed by Victor Loisha: “Why not admit that under some very successful coincidences of many physical circumstances, natural superconducting light guides, linearly oriented channels of anomalous ionization, through which beams of light are transmitted over very long distances, can be formed in the air - so, that the sunrise over Japan suddenly becomes visible, say, on the Azores Islands...”

Fata Morgana is a complex optical phenomenon in the atmosphere that consists of several forms of mirages, in which distant objects are visible repeatedly and with various distortions. Fata Morgana occurs when several alternating layers of air of different densities are formed in the lower layers of the atmosphere, capable of producing mirror reflections.

As a result of reflection, as well as refraction of rays, real-life objects produce several distorted images on the horizon or above it, partially overlapping each other and quickly changing in time, which creates a bizarre picture of this complex mirage. This phenomenon was named in honor of the heroine of legends - Fata Morgana. They say that she was a half-sister, but after the knight Lancelot rejected her love, out of grief she settled at the bottom of the sea, in a crystal palace, and from that time on she has been deceiving sailors with ghostly visions.

So, in the 1920s, a large ocean liner I was on my next flight from Europe to the USA. And suddenly, not far from the Azores Islands, everyone who was on deck clearly saw "". The thought of a scary ghost ship flashed through the minds of many passengers and sailors. And the unprecedented ship threatened to crash into the steamer. At the very last moment, the captain, in a loud, broken voice, ordered the ship to change course. Heeling to starboard, the sailboat rushed past. And at that time, the frightened, amazed passengers saw something even more amazing: people in ancient costumes were rushing around the deck of the sailing ship.

They raised their hands up and silently shouted something, as if they were trying to warn about something. It is clear that the passengers spent the rest of the voyage in fear of imminent death. After all, according to maritime legend, meeting a ghost ship does not bode well. When the ship arrived at the port, the story of the Flying Dutchman received wide publicity. But later it turned out that the ocean liner encountered a mirage of a sailing ship, intended for filming a historical film and located in a completely different place.

Anyone who spends a lot of time in polar waters will certainly see mirages. For example, experienced Finnish sailors and fairway experts are well aware that there are conditions in which it is unusually difficult to find a familiar route among the confusing mirages on a rocky coastline. In Finland, conditions for mirages are especially favorable in the spring, when the sea ice melts. A water temperature of 0 °C with a spring wave of warm air at a temperature of 15 °C can create incredible mirages in the sky.

Another example of an amazing atmospheric phenomenon took place in the Algerian desert, which was crossed by a French colonial detachment. Ahead, about six kilometers from him, a flock of flamingos walked in single file. But when the birds crossed the border of the mirage, their legs stretched out and doubled, instead of two, each had 4. For better or worse - an Arab horseman in a white robe. The detachment commander, alarmed, sent a scout to check what kind of people were in the desert. But when the soldier entered the zone of curvature of the sun's rays, he himself turned into a ghost mirage, and his horse's legs became so long that it seemed as if he was sitting on a mythical monster.

One person in 1852 saw the Strasbourg Bell Tower in the sky, and the image was gigantic, as if the bell tower appeared before him enlarged 20 times. In 1902, Robert Wood, an American scientist who not without reason earned the nickname “the wizard of the physics laboratory,” photographed two boys peacefully wandering through the waters of the Chesapeake Bay between yachts. Moreover, the height of the boys in the picture was more than 3 meters.

This kind of mirage deception can also be explained by the deviation of light from a rectilinear progression, in which the object is seen in the wrong direction or is distorted. Ghost mirages are usually visible on the horizon. The angle of mirages is very low, but their shapes can be very different. Bushes and stones on small island can be perceived as towers in the sky; the low rocky shores are stretched vertically, and they resemble abysses; the ship and its deck superstructures can warp into unidentifiable square shapes, and the islands themselves appear to spin in the air.

E. Gurnakova

The article talks about what a mirage is, what causes such a phenomenon, how it can be dangerous and what types there are.

Many physical, chemical and other processes occur around us every second. True, most of them have a form that people are accustomed to and no longer pay any attention to. For example, water boiling on the stove, which turns into steam. But even if we think about more global scales, for example, about the burning of the Sun, this fact will still surprise few people. But in fact, in its depths there are amazing reactions that are so far beyond human reproduction. But such reasoning can probably only interest a person who is sincerely interested in science.

However, sometimes there are situations when the simplest and most harmless physical processes can greatly surprise, confuse, and very rarely even kill a person. Or rather, just push him to some unreasonable destructive actions. And one of these is a mirage.

Mirage... All people have probably heard this word, and it is associated primarily with hot deserts, where unfortunate travelers, seeing illusory oases, rushed to them. However, not everyone knows what causes such visions and what types there are. This is what we will talk about.

Origin of the word

It has French roots and in the original sounds like mirage, which literally means “visibility”. A mirage is one of the most common optical illusions that occurs as a result of the refraction of light rays at the boundary between layers of air that differ sharply in temperature. And sometimes, as a result of a mirage, the observer, in addition to a really existing distant object, also sees its reflection in the sky. So a mirage is a rather curious optical atmospheric phenomenon. However, for a very long time people could not understand its nature and endowed it with mystical meaning or mistook it for the machinations of evil spirits. Many legends and beliefs are associated with mirages, especially in the east.

Now let's look at the types of mirages.

Lower

This type of mirage is the most common and has been seen by many. You don't have to be in the hot desert to see it. It is characterized by the fact that as a result of a strong drop in temperature with height, above a flat surface, for example, asphalt, concrete or sand, a person observes puddles of water. And this illusion is very convincing. And for many people in ancient times, who found themselves without water in the desert, to see such a mirage was to receive an imaginary hope of salvation.

Upper

This type of mirage is usually observed in cold conditions, when the air temperature rises with increasing altitude, for example, in the polar regions on large, flat ice floes. This is quite rare in nature, and not even all eminent travelers who have visited the northern parts of our planet have seen this type of mirage. The meaning of this phenomenon is that if the bend of the sun's rays is exactly the same as the curve of the Earth's surface, then this makes it possible to see objects that are located beyond the horizon at a very large distance. There is a legend that the Vikings discovered Iceland thanks to him. So a mirage is sometimes a rather useful phenomenon. And perhaps this is the explanation for the myths about flying ships - such a mirage at sea makes them visible from the horizon and visually greatly increases both the size and speed of the ship.

Side

With side mirages everything is somewhat less exciting than with other types. They arise as a result of strong heating of vertical surfaces by the sun. For example, there is a documented fact when in the Middle Ages the wall of a fortress shone like a mirror, and outwardly it seemed that it had become partially invisible and ghostly. So now we know the meaning of the word mirage and have figured out what it is.

Volume mirage

This type is also quite rare and mainly in the mountains. During this illusion, you can see yourself or other objects relatively nearby in a distorted perspective. This phenomenon is explained by the presence of water particles in the “stagnant” mountain air.

Culture

Mirage as a phenomenon is strongly reflected in culture - films, books, legends and fairy tales. Since ancient times, many travelers or explorers have been deceived by mirages by showing water where there is none. And by the way, if you walk on a hot day on a flat surface, for example, a road, then the lower mirage will move further and further as you approach it. One can only imagine the moral torment experienced by people who were stuck in the desert without a drop of water and saw such a deceptive phenomenon.

A mirage is an illusion of water; it is this form of it that is most common both in life and in culture of various kinds. But as we see, its varieties do not end there.