Each of us has encountered mirages when, on a hot summer day, we saw the mirror-like surface of water above the heated asphalt. But mirages often paint much more impressive pictures. This is a mysterious and often dangerous natural phenomenon.
Or maybe it was all a dream?
Mirages have been known for a long time. This phenomenon caused sacred awe among the ancient Egyptians, who believed that mirages reflected something that no longer existed in the world - this was the ghost of a long-vanished country. The crusaders, marching through the Palestinian desert to liberate the Holy Sepulcher, described amazing visions, however, at that time no one believed them.
Systematic observations of mirages have arisen since the beginning of keeping ship logs. In the summer of 1820, the captain of one of the whaling ships left notes and drawings in which he allegedly reflected a city with castles and temples seen near Greenland, but a later check of that very place did not confirm anything.
A scientific explanation of the mirage phenomenon, close to modern views - as an optical illusion - was first given by the French mathematician Gaspard Monge, who in 1799 participated with Napoleon in his Egyptian campaign. During the long march to the Nile, the expedition members noticed a strange phenomenon: how the desert began to be flooded with water, and villages began to turn into islands. Monge explained this phenomenon as best he could in order to calm the agitated Napoleonic soldiers.
Just something complicated
Mirage (from the French “visibility”) is a phenomenon that has not been thoroughly studied and is quite difficult to formulate in the language of optical physics. But let’s try to give a simple explanation to “refractive errors.” It is known that light propagates rectilinearly in a homogeneous medium, but under conditions of different densities its rays begin to refract, and the greater the difference in the density of neighboring media, the greater the distortion.
A clear example is a spoon placed in a transparent glass of water: refraction occurs at the junction of media of different densities - air and liquid, which creates the effect of a “broken” spoon.
With mirages, we are dealing exclusively with an atmospheric phenomenon, which makes it possible for not just a distorted, but a reflected image to appear. Heat spreads unevenly in the air, which enhances the contrast of the initially different air density. Layering also forms the absence of vertical movement of air masses. But to achieve the mirage effect, the difference in density must be so high that the boundary between the layers can act as a mirror. Rays of light that distort their movement at this boundary make it possible for the cold layer to be reflected in the warm one.
Mirages inferior, superior and lateral
In the desert or on an asphalt road, hot air, seemingly contrary to the laws of physics, concentrates near the ground. But in fact, it moves upward, driven by even hotter air from the hot surface - thus, a higher temperature is constantly maintained below.
This is an ideal condition for the formation of so-called inferior or lake mirages, when the surface of the earth appears to be flooded with water - but in reality it is reflected by the sky. But mirages can show not only the sky, but also other objects located above the surface of the “mirror” - trees, cars, houses, mountains. This phenomenon can be observed from a distance of several hundred meters. But as soon as you want to get closer to a mysterious place, the angle of view changes, and the picture disappears into thin air.
Side mirages are very similar to bottom ones, only reflection occurs near vertical surfaces - heated walls or rocks. A similar mirage was described by the French officer Lazare Pogue, who visited Tunisia. “Approaching the wall of the fort, made of sandstone, I suddenly noticed that it shone like a mirror and dusty palm trees and camels dragging our guns on their humps were reflected in it.”
But an upper mirage is also possible, a necessary condition for which is the movement of warmer layers of air upward. Its nature is more complex than that of the lower mirage. Without going into details, we note that the upper mirage is perceived by the eye from a distance of several kilometers or more. If the distorted rays of light coincide with the curvature of the Earth, then it becomes possible to observe objects located far beyond the horizon. Residents of the French Riviera in the morning often see the chain of Corsican mountains, the distance to which is at least 200 kilometers!
Fata Morgana
According to legend, Lancelot's rejected lover, the fairy Morgana, settled on the seabed in a crystal palace and has been deceiving sailors with ghostly visions ever since. The optical Fata Morgana manages to deceive sailors just as well. Sometimes sailors rush to the aid of a sinking ship, but when they arrive they find nothing, and this is not surprising, because the ship was in distress many kilometers from a visible place.
The condition for the occurrence of Fata Morgana is the formation of several layers of air of different densities. Objects transformed into a mirage do not just receive a mirror image, but create the semblance of a mosaic picture or a surreal landscape, with ships, buildings or entire cities “disintegrating” into fragments.
Residents of the Chinese town of Penglai, located on the eastern coast of China, were able to see such a rare phenomenon. On May 8, 2006, thousands of citizens were surprised to discover a city emerging from the fog with modern high-rise buildings, wide streets and cars moving along them. A person who came to Penglai for the first time would never have guessed that where the city rose, the sea usually splashes.
But if the Chinese mirage can be explained by the presence of large cities in the vicinity, then what was seen in the mountains of Bashkiria is more difficult to squeeze into scientific concepts. One of the local residents stopped his car to look at the blue-green sky, in which a plane with double-decker wings first appeared, and then houses and streets began to appear. Others noted that the roofs of houses and window openings were clearly visible, however, scientists say that Orenburg, located 200 kilometers to the southwest, appeared in this way.
Victims of illusion
Mirages can not only confuse a desperate traveler, but also destroy him. One of the most famous tragedies involves the death of a caravan in the Sahara, despite the fact that it was led by an experienced guide. Not reaching 350 kilometers from the Bir-Ula oasis, the travelers were caught in the net of a mirage, following which they deviated 60 kilometers from the saving well.
An interesting case described in The New Yorker magazine concerns not a person, but an animal. The pelican, apparently flying for many hours over the sun-dried steppe of the Midwest, mistook the road for a flowing river and, hoping to plunge into a cool spring, dived at full speed onto the hot asphalt. The bird escaped with loss of consciousness.
But it turns out that a scientist can also become a victim of illusion. British meteorologist Caroline Botley was picking flowers one August day when suddenly she saw a rather massive figure next to her - out of fright, the woman let go of the flowers from her hands, but what was her surprise when the “ghost” also threw away the flowers. Carolina saw her own reflection in all the details and colors - like in a mirror. Such a phenomenon is rare and is possible only on a hot morning, when vapors are still rising above the ground - they, together with heated air, create favorable conditions for such a mirage.
The ancient Egyptians believed that a mirage was the ghost of a country that no longer exists. Legend says that every place on Earth has its own soul. Mirages observed in deserts are explained by the fact that hot air acts like a mirror. This phenomenon is quite common - for example, about 160 thousand mirages are observed annually in the Sahara: they can be stable and wandering, vertical and horizontal.
On May 8, 2006, thousands of tourists and local residents observed a mirage that lasted for four hours in Penglai off the east coast of China on Sunday. The fogs created an image of the city, with modern high-rise buildings, wide city streets and noisy cars.
It rained for two days in the city of Penglai before this rare weather event occurred.
It is almost impossible to study mirages, since they do not appear on order and are always original and unpredictable. According to scientists, the atmosphere is like a layered, airy cake, which consists of layers with different temperatures. And the greater the temperature difference, the more the path of the light beam is bent. In this case, it is as if a giant airy lens is formed, which moves all the time. In addition, the observed object and the person himself are inside this air lens. Therefore, the observer sees the image distorted. The more complex the shape of the atmospheric lenses, the more bizarre the mirage.
Atmospheric mirages divided into three classes: lower or lake; upper(they appear directly in the sky) or distant vision mirages; lateral mirages.
A more complex type of mirage is called " Fata Morgana". No explanation has yet been found for it. The aurora borealis, werewolf mirages, and the “Flying Dutchmen” are usually classified as types of mirages.
Lower (lake) mirage
Inferior mirages are quite common. 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 movies or car races on television are often filmed very 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. By the same principle, if you look at an object, for example, along a wall heated by the sun, then you can almost always see a mirage of the object next to the wall.
If on a hot summer day you stand on the railway track or a hill above it, when the sun is slightly to the side or to the side and slightly in front of the railway track, then you can see how the rails two or three kilometers away from us seem to be plunging into a sparkling lake, as if the tracks were flooded flood. Let's try to get closer to the "lake" - it will move away, and no matter how much we walk towards it, it will invariably be 2-3 kilometers away from us.
Such “lake” mirages drove desert travelers, languishing from heat and thirst, to despair. They also saw the coveted water 2-3 kilometers away, they wandered towards it with all their strength, but the water receded and then seemed to dissolve in the air.
In the photo, the sailboat almost disappears into the lower mirage. Only the sail is visible.
Lighthouse Isokari
The lower mirage and the ship's mirage.
Superior mirages (distance vision mirages)
This type of mirages is no more complex in origin than “lake” ones, but more diverse. They are usually called "distant vision mirages".
On a clear morning, residents of the Côte d'Azur of France have seen more than once how, on the horizon of the Mediterranean Sea, where the water merges with the sky, the chain of Corsican mountains rises from the sea, about two hundred kilometers from the Côte d'Azur.
In the same case, if this happens in the desert itself, the surface of which and the adjacent layers of air are heated by the sun, the air pressure at the top may turn out to be high, the rays will begin to bend in the other direction. And then curious phenomena will occur with those rays that, having reflected from the object, should have immediately buried themselves in the ground. But no, they will turn upward and, having passed perigee somewhere near the surface itself, will go into it.
A typical example is given in Aristotle's Meteorology: residents of Syracuse sometimes saw the coast of continental Italy for several hours, although it was 150 km away. Such phenomena are also caused by the redistribution of warm and cold layers of air. in the direction of the last segment of the path of the light beam.
Boat against a background with a typical superior mirage
On April 20, 1999, an ordinary charterer was practicing in the waters of the southwestern archipelago of Finland.
The vessel took many different forms; sometimes it seemed there were 2 ships, one of which was upside down.
Superior mirage and sailboat.
House on the archipelago with the upper mirage
Side mirages
This type of mirage 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. Such 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. We saw a boat 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.
Fata Morgana
Fata Morgana is a complex optical phenomenon in the atmosphere, consisting 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 varying densities are formed in the lower layers of the atmosphere, capable of producing specular 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 Fata Morgana.
The mirage received its name in honor of the fairy-tale heroine Fata Morgana or, translated from Italian, the fairy Morgana. They say that she is the half-sister of King Arthur, the rejected lover of Lancelot, who settled out of grief at the bottom of the sea, in a crystal palace, and since then has been deceiving sailors with ghostly visions.
On April 3, 1900, the defenders of the fortress of Bloemfontein, in England, saw the battle formations of the British army in the sky, and so clearly that they could distinguish the buttons on the red uniforms of the officers. This was taken as a bad omen. Two days later the fortress surrendered.
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 photograph exceeded 3 meters.
One man in 1852, from a distance of 4 km, saw the Strasbourg Bell Tower at a distance, as it seemed to him, of two kilometers. The image was gigantic, as if the bell tower appeared before him enlarged 20 times.
TO Fata Morgana can be attributed to numerous " flying dutchmen ", which are still seen by sailors.
At 11 a.m. on December 10, 1941, the crew of the British transport Vendor, located in the Maldives, noticed a burning ship on the horizon. "Vendor" went to the rescue of those in distress, but an hour later the burning ship fell on its side and sank. "Vendor" approached the supposed place of the ship's death, but, despite a thorough search, did not find not only any debris, but even stains of fuel oil. At the port of destination, in India, the commander of the Vendor learned that at the very moment when his team observed the tragedy, a cruiser was sinking, attacked by Japanese torpedo bombers near Ceylon. The distance between the ships at that time was 900 km.
Mirage ghosts
A French colonial detachment was crossing the Algerian desert. 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 separated, instead of two, each had four. Neither give nor take - an Arab horseman in a white robe.
The detachment commander, alarmed, sent a scout to check what kind of people were in the desert. When the soldier himself entered the zone of curvature of the sun's rays, he, of course, figured out who he was dealing with. But he also struck fear into his comrades - the legs of his horse became so long that it seemed that he was sitting on a fantastic monster.
Other visions still baffle us today. The Swedish polar explorer Nordenskiöld has repeatedly observed in the Arctic werewolf mirages:
"One day, a bear, whose approach was expected and which everyone clearly saw, instead of approaching with his usual soft gait, zigzags and sniffing the air, wondering whether foreigners were suitable for him as food, just at the moment of the sniper's sight... spread gigantic wings and flew away in the form of a small green seagull. Another time, during the same sleigh ride, the hunters, being in a tent pitched for rest, heard the cry of a cook fiddling around it: “A bear, a big bear! No - a deer, a very small deer.” At the same moment a shot was heard from the tent , and the killed “bear-deer” turned out to be a small arctic fox, who paid with his life for the honor of pretending to be a large animal for a few moments".
It is also reliably known about mirages-ghosts. This is how British meteorologist Caroline Botley describes this effect.
Mirages lead to victims, but the physical explanation of the phenomenon of mirages does not in the least alleviate the fate of travelers misled by the ephemeral oasis. In order to protect people brought into the desert from the risk of getting lost and dying of thirst, special maps are drawn up marking the places where mirages are usually observed. These guides indicate where wells can be seen, and where palm groves and even mountain ranges can be seen.
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 kilometers, which are actually at least 700 kilometers.
Mirage(French mirage - lit. visibility) - optical phenomenon in the atmosphere: refraction of light streams at the boundary between layers of air that are sharply different in density and temperature. For an observer, this phenomenon consists in the fact that along with a really visible distant object (or part of the sky), its reflection in the atmosphere is also visible.
Mirages are divided into lower ones, visible under the object, upper ones, above the object, and side ones.
Inferior Mirage
It is observed with a very large vertical temperature gradient (it decreases with height) over an overheated flat surface, often a desert or an asphalt road. The virtual image of the sky creates the illusion of water on the surface. So, the road stretching into the distance on a hot summer day seems wet.
Black Mirage
As rare as the side mirage. Can be seen in the mountains, forests, and uplands. A black mirage due to the sun has very different colors, but remains black.
Superior Mirage
Observed over the cold earth's surface with an inverted temperature distribution (air temperature rises with increasing altitude).
Superior mirages are generally less common than inferior mirages, but are often more stable because cold air does not tend to move upward and warm air downward.
Superficial mirages are most common in polar regions, especially on large, flat ice floes with stable low temperatures. They are also observed at more temperate latitudes, although in these cases they are weaker, less distinct and less stable. The superior mirage can be upright or inverted, depending on the distance to the true object and the temperature gradient. Often the image looks like a fragmented mosaic of straight and inverted parts.
Superior mirages can have a striking effect due to the curvature of the Earth. If the curvature of the rays is approximately the same as the curvature of the Earth, the light rays can travel great distances, causing the observer to see objects far beyond the horizon. This was observed and documented for the first time in 1596, when a ship under the command of Willem Barentsz, searching for the Northeast Passage, became stuck in the ice on Novaya Zemlya. The crew was forced to wait out the polar night. Moreover, the sunrise after the polar night was observed two weeks earlier than expected. In the 20th century, this phenomenon was explained and called the New Earth Effect.
In the same way, ships that are actually so far away that they should not be visible above the horizon can appear on the horizon, and even above the horizon, as superior mirages. This may explain some stories of ships or coastal cities flying in the sky, as described by some polar explorers.
Side mirage
The existence of a side mirage is usually not even suspected. This is a reflection from a heated vertical wall.
Such a case is described by one French author. Approaching the fort of the fortress, he noticed that the smooth concrete wall of the fort suddenly shone like a mirror, reflecting the surrounding landscape, soil, and sky. Taking a few more steps, he noticed the same change with the other wall of the fort. It seemed as if the gray, uneven surface was suddenly replaced by a polished one. It was a hot day, and the walls must have become very hot, which was the key to their mirroriness. It turned out that a mirage is observed whenever the wall is sufficiently heated by the sun's rays. We even managed to photograph this phenomenon.
On hot summer days, one should pay attention to the heated walls of large buildings and look for signs of mirage. Without a doubt, with some attention, the number of observed cases of lateral mirage should become more frequent.
Fata Morgana
Complex mirage phenomena with a sharp distortion of the appearance of objects are called Fata Morgana. Fata Morgana (Italian fata Morgana - fairy Morgana, according to legend, lives on the seabed and deceives travelers with ghostly visions) - a rare complex optical phenomenon in the atmosphere, consisting 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 (usually due to temperature differences), capable of giving 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 Fata Morgana.
Volume mirage
In the mountains, it is very rare, under certain conditions, to see the “distorted self” at a fairly close distance. This phenomenon is explained by the presence of “standing” water vapor in the air.
The biggest mirage
The largest known mirage was seen by Crason Prats and Lekman Donrs in 1879. This happened on the seashore. They spent a lot of time near the water in very hot weather. They immediately noticed when the water rose a meter above the sea and began to move towards them. They immediately took off running. After running for several miles, they fell and watched in horror as the water covered them. As a result, Lekman lost consciousness, and the stunned Crason stood up and came to his senses. In 1886, Narukid Milus saw something similar to what Crason and Lekman saw.
Since childhood, I have been interested in mysterious natural phenomena. One of them is mirages. After all, it’s just magic to see something that doesn’t exist or is hundreds of kilometers away from the observer. Fabulous, isn't it? As a child, everything seems so simple. A mirage is a small miracle. By the way, it’s not only children who think this way. After reading a large number of different articles, I made a small discovery for myself. It turns out that people have seen mirages since ancient times. And they explained them by the ordinary intervention of gods or spirits. This information is still kept in various legends.
The crusaders, who went with their good purpose to Palestine, described the mirages especially colorfully and vividly. But, unfortunately, no one believed them. Well, in those days they really loved to tell tales about the wonders of the East.
Even before the Crusaders, mirages were observed, and quite often, by the inhabitants of Ancient Egypt. They believed that mirages were nothing more than the ghost of a country that had disappeared many hundreds of years ago. According to this legend, every place on earth has its own soul. And so the soul of the lost country wandered across the vast Egyptian deserts, trying to find peace.
Yes, the ancients believed in miracles. It turns out that everything is much simpler and the intervention of otherworldly forces is not necessary for the occurrence of mirages. In a purely scientific definition, a mirage (French mirage - literally visibility) is nothing more than an optical phenomenon in the atmosphere, due to which images of objects appear in the visual zone that under normal conditions are hidden from observation.
That is, a mirage is nothing more than a play of light rays. The fact is that in the desert the earth warms up very much. But at the same time, the air temperature above the ground at different distances from it varies greatly. For example, the temperature of the air layer ten centimeters above ground level is 30-50 degrees less than the surface temperature.
All laws of physics say: light propagates in a homogeneous medium in a straight line. However, under such extreme conditions, the law does not apply. What's going on? The rays simply begin to refract at such temperature differences, and generally begin to be reflected near the ground, creating illusions that we are accustomed to calling mirages. That is, the air near the surface becomes a mirror.
Although mirages are usually associated with deserts, they can often be observed above the water surface, in the mountains, and sometimes even in large cities. In other words, wherever sudden changes in temperature occur, you can observe these fabulous pictures.
This phenomenon is quite common. For example, in the largest desert on our planet, about 160 thousand mirages are observed annually.
How did the scientific observation of mirages develop?
The first and honorable place can be given to Monsieur Gaspard Monge. This man, in 1799, was the first to give a written explanation of this phenomenon, which is quite similar to the modern one. He took part in the Egyptian campaign of the famous commander Napoleon Bonaparte. The participants of this expedition walked in the direction of the Nile. The monotonous and rather dull appearance of the plains was broken only occasionally by small hills, on which villages were sometimes visible.
And then one day the soldiers noticed that periodically the plains seemed to be flooded with water, and the villages seemed to them like small islands. Moreover, what especially amazed the people from the expedition was that under each of these islands there was a mirror image of it, and the sky was also reflected.
Naturally, as we got closer, the mirage dissipated. Naturally, the soldiers interpreted this as the machinations of enemies and foreign gods. And Monsieur Monge explained everything from a scientific point of view, which incomparably helped Bonaparte restore order in the ranks.
The commander of the Baffin ship undoubtedly deserved second place. A significant event occurred back in 1820. In the ship's log, he described a wonderful city, in which there are a huge number of ancient castles and temples. Moreover, this phenomenon was not only recorded, but also sketched in great detail by the same captain. Naturally, his evidence was not confirmed.
Third place can be given to the residents of a small island in the north of England. In 1840, they saw magnificent white buildings in the skies. They had never seen anything like this and decided that this was the famous crystal city inhabited by the Finn people. By the way, it is interesting that this vision was repeated 17 years later for three hours.
It is very interesting that although mirages are considered children of deserts, Alaska has long been recognized as the undisputed leader in their occurrence. The colder it is, the clearer and more beautiful the observed mirage.
No matter how common this phenomenon is, it is very difficult to study. Why? Yes, everything is very simple. No one knows where and when he will appear, what he will be like and how long he will live.
After many different records about mirages appeared, naturally, they had to be classified. It turned out that, despite all their diversity, it was possible to identify only six types of mirages: lower (lake), upper (appearing in the sky), side, “Fata Morgana”, ghost mirages and werewolf mirages.
A more complex type of mirage is called " Fata Morgana". No explanation has yet been found for it. Aurora borealis or werewolf mirages are usually classified as a type of mirages.
Lower (lake) mirage.
These are the most common mirages. They got their name because of the places where they originated. As you probably already guessed, Bonaparte’s expedition saw exactly them. They are observed on the surface of the earth and water (it’s not for nothing that their second name is “lake”).
This type of mirage is as simple in origin as the previous type. However, such mirages are much more diverse and beautiful.
They appear in the air. The most fascinating of them are the famous ghost towns. It is very interesting that they usually represent images of objects - cities, mountains, islands - that are located many thousands of kilometers away.
Side mirages
They appear near vertical surfaces that are strongly heated by the sun. These can be rocky shores of the sea or lake, when the shore is already illuminated by the Sun, but the surface of the water and the air above it are still cold. This type of mirage is a very common occurrence in Lake Geneva.
Fata Morgana
Fata Morgana is the most complex type of mirages. It is a combination of several forms of mirages. At the same time, the objects that the mirage depicts are magnified many times over and are quite distorted.
Interestingly, this type of mirage got its name from Morgana, the sister of the famous Arthur. She allegedly took offense at Lancelot for rejecting her. To spite him, she settled in the underwater world and began to take revenge on all men, deceiving them with ghostly visions.
TO Fata Morgana can be attributed to numerous “ flying dutchmen “, which are still seen by sailors.
They usually show ships that are hundreds or even thousands of kilometers away from observers.
Mirages-ghosts or mirages-werewolves.
They produce a special psychological effect on their victims. Some visions baffle modern scientists too. For example, a French colonial detachment crossed the Algerian desert. Not far away they saw a flock of flamingos. But as soon as they crossed the border of the mirage, instead of two legs, each had four. A real Arabian horseman in white.
The detachment commander, naturally, was frightened and sent a scout to check what kind of people were in the desert. When the soldier got into the mirage zone, he figured it all out. But the metamorphoses that happened to him, observed by his comrades, plunged them into shock. His horse's legs became so long that he seemed to be sitting on a fantastic monster.
Perhaps there is nothing more to say about the types of mirages.
I would like to add that although this is an extremely beautiful and mysterious sight, it is also very dangerous. I kill mirages and drive my victims crazy. This is especially true for desert mirages. And the explanation of this phenomenon does not make the fate of travelers easier.
However, people are trying to fight this. They create special guides that indicate the places where mirages most often appear, and sometimes their forms.
Well, that seems to be it. By the way, mirages are obtained in laboratory conditions. Another mystery, I hope, solved. Thank you for your attention.
Mirage (French mirage - literally visibility) is an optical phenomenon in the atmosphere: the reflection of light by the boundary between layers of air that are sharply different in density. For an observer, such a reflection means that together with a distant object (or part of the sky), its virtual image is visible, shifted relative to the object.
Mirage is an atmospheric phenomenon due to which, under certain circumstances, objects become visible in a certain area, the actual location of which is far from the place where they are observed by the viewer. It is explained by the complete reflection of rays at the boundary of two layers of air having different temperatures, if the light ray falls with a very strong inclination onto the boundary plane. If the viewer and the distant object are at only slightly elevated points and between them lies sandy soil strongly heated by the sun, imparting its heat to the nearest layers of air and thereby heating them more strongly than the layers located above, the viewer sees the object in its actual position through the rays, directly from object going towards it, and secondly, in an inverted position, through rays, first coming from the object downwards, then, when meeting warmer and therefore rarer layers of air, being reflected and going to the eye of the observer, seeing the object as if reflected in the water.
Gaspard Monge
This explanation was given by the French mathematician and geometer Gaspard Monge in the "Mémoires de l" Institut d "Egypte". If a very heated warm layer is not below, but above the observer and the observed object, located in a denser cold layer, the Mirage phenomenon can also occur, but only in the upward direction. Thus, those observed in an overturned form above the horizon, for example, ships, towers, castles, etc., are images of real objects. In some areas, in Naples, Reggio, on the shores of the Strait of Sicily, on large sandy plains (in the morning, when the lower layers of air are still colder than the upper layers, already warmed by the sun), in Persia, Turkestan, Egypt, this phenomenon called Fata Morgana is observed often. In the second case, such refraction may occur, but the object appears only raised, but not inverted, and thus complete reflection does not occur in the upper layers themselves. In this form, this phenomenon is observed in the western parts of the Baltic Sea (Kimmung). In the accompanying fig. 1 curved line L means the path of rays in the first case, when the lower layers of air are less dense than the upper ones; SS is a layer that gives total reflection.
The observer at A receives from the object G, in addition to the direct image, a reflected image G1, which is observed in the direction of the tangent (to the line L) drawn from point A. Figure 2 represents the case when colder and denser layers lie below.
Through rays L traveling without reflection, observer A receives a raised, standing image G1 of object G, but if the rays are curved along line L2 and are completely reflected by the layer SS, then an inverted image G2 is obtained.
Encyclopedic Dictionary of F. A. Brockhaus and I. A. Efron. - St. Petersburg: Brockhaus-Efron. 1890-1907.
The ancient Egyptians believed that a mirage was the ghost of a country that no longer exists. Legend says that every place on Earth has its own soul. Mirages observed in deserts are explained by the fact that hot air acts like a mirror. This phenomenon is quite common - for example, about 160 thousand mirages are observed annually in the Sahara: they can be stable and wandering, vertical and horizontal.
On May 8, 2006, thousands of tourists and local residents observed a mirage that lasted for four hours in Penglai off the east coast of China on Sunday. The fogs created an image of the city, with modern high-rise buildings, wide city streets and noisy cars. It rained for two days in the city of Penglai before this rare weather event occurred.
It is almost impossible to study mirages, since they do not appear on order and are always original and unpredictable. According to scientists, the atmosphere is like a layered, airy cake, which consists of layers with different temperatures. And the greater the temperature difference, the more the path of the light beam is bent. In this case, it is as if a giant airy lens is formed, which moves all the time. In addition, the observed object and the person himself are inside this air lens. Therefore, the observer sees the image distorted. The more complex the shape of the atmospheric lenses, the more bizarre the mirage.
Atmospheric mirages are divided into three classes: lower or lake; upper (they appear directly in the sky) or distant vision mirages; lateral mirages. A more complex type of mirage is called Fata Morgana. No explanation has yet been found for it. The types of mirages include the aurora borealis, werewolf mirages, and the “Flying Dutchmen.”
Lower (lake) mirage
Inferior mirages are quite common. 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 movies or car races on television are often filmed very 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.
Mirage over an asphalt road
This is not a type of aircraft :). It's about the heat and the "reflection" from the asphalt. Planes appear as if out of nowhere.
Inferior mirage. Reflection of an airplane on the asphalt
Mirage (mirror-like surface of water) in the Arabian Desert
If on a hot summer day you stand on the railway track or a hill above it, when the sun is slightly to the side or to the side and slightly in front of the railway track, then you can see how the rails two or three kilometers away from us seem to be plunging into a sparkling lake, as if the tracks were flooded flood. Let's try to get closer to the "lake" - it will move away, and no matter how much we walk towards it, it will invariably be 2-3 kilometers away from us. Such “lake” mirages drove desert travelers, languishing from heat and thirst, to despair. They also saw the coveted water 2-3 kilometers away, they wandered towards it with all their strength, but the water receded and then seemed to dissolve in the air.
The French scientist Gaspard Monge, who took part in Napoleon's Egyptian campaign, describes his impressions of the lake mirage as follows: “When the surface of the earth is strongly heated by the Sun and is just beginning to cool 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 located 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.”
Superior mirage or distant vision mirage
Observed over the cold earth's surface with an inverted temperature distribution (air temperature increases with increasing altitude). Superior mirages are generally less common than inferior mirages, but are often more stable because cold air does not tend to move upward and warm air downward. Superficial mirages are most common in polar regions, especially on large, flat ice floes with stable low temperatures. They are also observed at more temperate latitudes, although in these cases they are weaker, less distinct and less stable. The superior mirage can be upright or inverted, depending on the distance to the true object and the temperature gradient. Often the image looks like a fragmented mosaic of straight and inverted parts.
Superior mirages can have a striking effect due to the curvature of the Earth. If the curvature of the rays is approximately the same as the curvature of the Earth, the light rays can travel great distances, causing the observer to see objects far beyond the horizon. This was observed and documented for the first time in 1596, when a ship under the command of Willem Barents, searching for the Northeast Passage, became stuck in the ice on Novaya Zemlya. The crew was forced to wait out the polar night. Moreover, the sunrise after the polar night was observed two weeks earlier than expected. In the 20th century, this phenomenon was explained and called the New Earth Effect.
In the same way, ships that are actually so far away that they should not be visible above the horizon can appear on the horizon, and even above the horizon, as superior mirages. This may explain some stories of ships or coastal cities flying in the sky, as described by some polar explorers.
A normal-sized ship is moving over the horizon. Given a specific state of the atmosphere, its reflection above the horizon appears gigantic.
On a clear morning, residents of the Côte d'Azur of France have seen more than once how, on the horizon of the Mediterranean Sea, where the water merges with the sky, the chain of Corsican mountains rises from the sea, about two hundred kilometers from the Côte d'Azur. In the same case, if this happens in the desert itself, the surface of which and the adjacent layers of air are heated by the sun, the air pressure at the top may turn out to be high, the rays will begin to bend in the other direction. And then curious phenomena will occur with those rays that, having reflected from the object, should have immediately buried themselves in the ground. But no, they will turn upward and, having passed perigee somewhere near the surface itself, will go into it. A typical example is given in Aristotle's Meteorology: residents of Syracuse sometimes saw the coast of continental Italy for several hours, although it was 150 km away. Such phenomena are also caused by the redistribution of warm and cold layers of air in the direction of the last segment of the path of the light beam.
On April 20, 1999, an ordinary charterer was practicing in the waters of the southwestern archipelago of Finland. The vessel took many different forms; sometimes it seemed there were 2 ships, one of which was upside down.
House on the archipelago with the upper mirage
Side mirage
The existence of a side mirage is usually not even suspected. This is a reflection from a heated vertical wall. Such a case is described by one French author. Approaching the fort of the fortress, he noticed that the smooth concrete wall of the fort suddenly shone like a mirror, reflecting the surrounding landscape, soil, and sky. Taking a few more steps, he noticed the same change with the other wall of the fort. It seemed as if the gray, uneven surface was suddenly replaced by a polished one. It was a hot day, and the walls must have become very hot, which was the key to their specularity. It turned out that a mirage is observed whenever the wall is sufficiently heated by the sun's rays. We even managed to photograph this phenomenon.
This type of mirage 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. Such 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. We saw a boat approaching the shore, and next to it exactly the same boat was moving away from the shore.
The once famous lateral (side) mirage, observed in 1869 by Captain Coldway, who visited the shores of Greenland with an expedition on the ship "Germany"
Mirage of Fata Morgana
Fata Morgana is a complex optical phenomenon in the atmosphere, consisting 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 varying densities are formed in the lower layers of the atmosphere, capable of producing specular 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 Fata Morgana.
On April 3, 1900, the defenders of the fortress of Bloemfontein, in England, saw the battle formations of the British army in the sky, and so clearly that they could distinguish the buttons on the red uniforms of the officers. This was taken as a bad omen. Two days later the fortress surrendered.
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 photograph exceeded 3 meters.
One man in 1852, from a distance of 4 km, saw the Strasbourg Bell Tower at a distance, as it seemed to him, of two kilometers. The image was gigantic, as if the bell tower appeared before him enlarged 20 times.
Fata Morganas also include numerous “flying Dutchmen”, which are still seen by sailors. In March 1898, at night, the crew of the Bremen ship Matador, while crossing the South Pacific Ocean, saw a strange haze. A ship jumped out of it and rushed straight towards the Matador. Then it disappeared somewhere. On the seventh bell of the night, that is, half an hour before midnight, a ship fighting the storm again appeared on the leeward side. It was very strange, because around the Matador the water was completely calm. But the sailboat seen from the Matador was flooded by furious waves, rolling over it. The captain of the "Matador" Gerkins, despite the complete calm, ordered all the sails to be reefed, fearing that the unknown sailing ship would bring the wind with it... Meanwhile, the sailing ship approached. The waves carried him straight towards the Matador. And suddenly the ship flew away in a southerly direction, taking with it a mysterious storm, and on the Matador the bright light in the captain’s cabin suddenly went out, which everyone saw through two windows, until the mysterious ship disappeared. Later they learned that on the same night, during a strong storm, a lamp exploded in the captain's cabin of another ship. When the time and degrees of longitude of the two ships were compared, it turned out that the distance between the Matador and the other Danish ship at the time the mirage appeared was about 1,700 km.
At 11 a.m. on December 10, 1941, the crew of the British transport Vendor, located in the Maldives, noticed a burning ship on the horizon. "Vendor" went to the rescue of those in distress, but an hour later the burning ship fell on its side and sank. "Vendor" approached the supposed place of the ship's death, but, despite a thorough search, did not find not only any debris, but even stains of fuel oil. At the port of destination, in India, the commander of the Vendor learned that at the very moment when his team observed the tragedy, a cruiser was sinking, attacked by Japanese torpedo bombers near Ceylon. The distance between the ships at that time was 900 km.
One of the possible explanations, as well as the origin of the name "Flying Dutchman", is associated with the phenomenon of Fata Morgana, since the mirage is always visible above the surface of the water. It is also possible that the glowing halo is St. Elmo's fire. For sailors, their appearance promised hope for success, and in times of danger, for salvation. Currently, methods have been developed that make it possible to obtain such a discharge artificially.
Fata Morgana
This image shows how the Fata Morgana changes the shape of the two ships. The four photographs in the right column are of the first ship, and the four photographs in the left column are of the second.
A chain of changing mirages.
The mirage got its name in honor of the fairy-tale heroine Fata Morgana or, translated from Italian, the fairy Morgana. They say that she is the half-sister of King Arthur, the rejected lover of Lancelot, who settled out of grief at the bottom of the sea, in a crystal palace, and since then has been deceiving sailors with ghostly visions.
Morgana the Fairy, by E. F. Sandys, 1864, Birmingham Art Gallery
Morgana (Morgana le Fay), who is portrayed as a purely evil force, schemed against Arthur to steal his talisman, the sword Excalibur, in order to somehow overthrow him. At the same time, she served him well: when Arthur was mortally wounded at the Battle of Camlen, she was one of the four queens who convinced Arthur to leave for the Isle of Avalon, where she used her magic to save her brother's life. She is sometimes described as a goddess, but in fact the image of Morgana is a composite and comes from various Celtic myths and deities. In Welsh folklore, she was considered one of the lake fairies who seduce and then abandon people in love with them; in Irish folklore, she lived in a magical mound, from where she flew out in frightening outfits and frightened people. In English and Scottish folklore, Morgana lives either in Avalon or in various castles, including one near Edinburgh that was inhabited by a pack of evil fairies. She is also considered one of the sea maidens of the coast of Brittany, who are called Morgans, Mary Morgan or simply Morgan. These sirens lure sailors. Depending on the story, the sailor either goes to his death or is transported to a blessed underwater paradise. In Italy, mirages over Strato from Messina are still called Fairy Morgana. Morgana is sometimes portrayed as an angry, decrepit old woman, as in the stories of Sir Lancelot, the Lake and Gawain and the Green Knight. However, she is not the "Lady of the Lake" in the Arthurian legend cycles. According to stories, Morgana had an insatiable sexual appetite and constantly lured knights to satisfy her passion. As Marion Bradley, a novelist who writes on occult themes, has pointed out, Morgana the Fairy was a girl under the Lady of the Lake, a Druid priestess who studied dragon magic at the Druid College for Priestesses.
Volume mirage
In the mountains, very rarely, under certain conditions, you can see the “distorted self” at a fairly close distance. This phenomenon is explained by the presence of “standing” water vapor in the air.
Auroras
Faraway, cold Alaska has long been recognized as the champion of mirages. The stronger the cold, the clearer and more beautiful the visions appear in her sky. The appearance of mirages in those parts began to be constantly recorded only in the 19th century. Now a special scientific society has been created in Alaska for the study of natural optical phenomena. And tourists are taken on buses to admire how mountains rise straight out of the abyss on the flat ocean horizon, and then disappear to God knows where.
Mirage ghosts
A French colonial detachment was crossing the Algerian desert. 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 separated, instead of two, each had four. Neither give nor take - an Arab horseman in a white robe.
The detachment commander, alarmed, sent a scout to check what kind of people were in the desert. When the soldier himself entered the zone of curvature of the sun's rays, he, of course, figured out who he was dealing with. But he also struck fear into his comrades - the legs of his horse became so long that it seemed that he was sitting on a fantastic monster.
Other visions still baffle us today. The Swedish polar explorer Nordenskiöld more than once observed werewolf mirages in the Arctic: “One day a bear, whose approach was expected and which everyone could clearly see, instead of approaching with his usual soft gait, zigzags and sniffing the air, wondering whether strangers were suitable for him as food, just at the moment of the sniper’s sight... spread his gigantic wings and flew away in the form of a small green seagull. Another time, during the same sleigh ride, the hunters, being in a tent pitched for rest, heard the cry of the cook fiddling around it: “Bear, big bear! No - a deer, a very small deer." At the same moment, a shot was heard from the tent, and the killed "bear-deer" turned out to be a small arctic fox, who paid with his life for the honor of pretending to be a large animal for a few moments."
It is also reliably known about ghost mirages. Here's how British meteorologist Caroline Botley describes this effect: “Mirages lead to victims, but the physical explanation of the phenomenon of mirages does not in any way alleviate the fate of travelers misled by the ephemeral oasis. In order to protect people brought into the desert from the risk of getting lost and dying of thirst, special maps are drawn up marking the places where mirages are usually observed. These guides indicate where wells can be seen, and where palm groves and even mountain ranges can be seen."
