What are examples of optical phenomena. optical phenomena

A person constantly encounters light phenomena. Everything that is connected with the appearance of light, its propagation and interaction with matter, is called light phenomena. Vivid examples optical phenomena can be: a rainbow after rain, lightning during a thunderstorm, the twinkling of stars in the night sky, the play of light in a stream of water, the variability of the ocean and sky, and many others.

Schoolchildren receive scientific explanation physical phenomena and optical examples in the 7th grade when they start studying physics. For many, optics will be the most fascinating and mysterious section in the school physics curriculum.

What does the person see?

Human eyes are designed in such a way that he can only perceive the colors of the rainbow. Today it is already known that the spectrum of the rainbow is not limited to red on one side and purple on the other. Per goes red infrared, behind violet is ultraviolet. Many animals and insects are able to see these colors, but unfortunately humans cannot. But on the other hand, a person can create devices that receive and emit light waves of the appropriate length.

refraction of rays

Visible light is a rainbow of colors, and light white color, for example, sunny, is a simple combination of these colors. If we place a prism in a beam of bright white light, then it will break up into colors or into waves different lengths, of which it consists. First comes red with the longest wavelength, then orange, yellow, green, blue, and finally violet, which has the shortest wavelength in visible light.

If you take another prism to catch the light of the rainbow and turn it upside down, it will combine all the colors into white. There are many examples of optical phenomena in physics, let's consider some of them.

Why the sky is blue?

Young parents are often perplexed by the most simple, at first glance, questions of their little why. Sometimes they are the hardest to answer. Almost all examples of optical phenomena in nature can be explained by modern science.

The sunlight that illuminates the sky during the day is white, which means that, theoretically, the sky should also be bright white. In order for it to look blue, some processes with light are necessary at the time of its passage through the Earth's atmosphere. Here's what happens: some of the light passes through the free space between gas molecules in the atmosphere, reaching earth's surface and remaining the same white color as at the beginning of the journey. But sunlight hits gas molecules, which, like oxygen, are absorbed and then scattered in all directions.

The atoms in the gas molecules are activated by the absorbed light and again emit photons of light in waves various lengths- from red to purple. Thus, some of the light goes to the earth, the rest goes back to the sun. The brightness of the emitted light depends on the color. Eight photons of blue light are released for every photon of red. Therefore, blue light is eight times brighter than red. Intense blue light is emitted from all directions from billions of gas molecules and reaches our eyes.

colorful arch

Once upon a time, people thought that rainbows were signs sent to them by the gods. Indeed, beautiful multi-colored ribbons always appear in the sky from nowhere, and then just as mysteriously disappear. Today we know that the rainbow is one of the examples of optical phenomena in physics, but we do not cease to admire it every time we see it in the sky. The interesting thing is that each observer sees a different rainbow, created by rays of light coming from behind him and from raindrops in front of him.

What are rainbows made of?

The recipe for these optical phenomena in nature is simple: water droplets in the air, light and an observer. But it is not enough for the sun to appear during the rain. It should be low, and the observer should stand so that the sun is behind him, and look at the place where it is raining or just rained.

A sunbeam coming from distant space overtakes a raindrop. Acting like a prism, the raindrop refracts every color hidden in the white light. Thus, when a white ray passes through a raindrop, it suddenly splits into beautiful multicolored rays. Inside the drop, they hit the inner wall of the drop, which acts like a mirror, and the rays are reflected in the same direction from which they entered the drop.

The end result is a rainbow of colors arching across the sky - light bent and reflected by millions of tiny raindrops. They can act like small prisms, splitting white light into a spectrum of colors. But rain is not always necessary to see a rainbow. Light can also be refracted by fog or fumes from the sea.

What color is the water?

The answer is obvious - water has a blue color. If you pour clean water into a glass, everyone will see its transparency. This is because there is too little water in the glass and its color is too pale to see it.

When filling a large glass container, you can see the natural blue tint of the water. Its color depends on how water molecules absorb or reflect light. White light is made up of a rainbow of colors, and water molecules absorb most spectrum colors from red to green that passes through them. And the blue part is reflected back. So we see blue.

Sunrises and sunsets

These are also examples of optical phenomena that a person observes every day. When the sun rises and sets, it directs its rays at an angle to where the observer is. They have a longer path than when the sun is at its zenith.

The layers of air above the Earth's surface often contain a lot of dust or microscopic moisture particles. The sun's rays pass at an angle to the surface and are filtered. Red rays have the longest wavelength of radiation and therefore make their way to the ground more easily than blue rays, which have short waves that are beaten off by particles of dust and water. Therefore, during the morning and evening dawn, a person observes only a part of the sun's rays that reach the earth, namely red ones.

planet light show

A typical aurora is a multi-colored aurora in the night sky that can be observed every night at the North Pole. Shifting in bizarre shapes, huge streaks of blue-green light flecked with orange and red sometimes reach over 160 km in width and can stretch for 1,600 km in length.

How to explain this optical phenomenon, which is such a breathtaking sight? Auroras appear on Earth, but they are caused by processes occurring on the distant Sun.

How is everything going?

The sun is a huge ball of gas, consisting mainly of hydrogen and helium atoms. All of them have protons with a positive charge and electrons revolving around them with negative charge. A halo of hot gas constantly spreads into space in the form of the solar wind. This countless number of protons and electrons are rushing at a speed of 1000 km per second.

When solar wind particles reach the Earth, they are attracted by a strong magnetic field planets. The Earth is a giant magnet with magnetic lines that converge at the North and South Poles. The attracted particles flow along these invisible lines near the poles and collide with the nitrogen and oxygen atoms that make up the Earth's atmosphere.

Some of the earth's atoms are losing their electrons, others are being charged new energy. After colliding with the protons and electrons of the Sun, they give off photons of light. For example, nitrogen that has lost electrons attracts violet and blue light, while charged nitrogen shines dark red. Charged oxygen gives off green and red light. Thus, the charged particles cause the air to shimmer with many colors. This is the aurora borealis.

Mirages

It should immediately be determined that mirages are not a figment of human imagination, they can even be photographed, they are almost mystical examples of optical physical phenomena.

There is a lot of evidence of the observation of mirages, but science can give a scientific explanation for this miracle. They can be as simple as a patch of water amid hot sands, or they can be stunningly complex, constructing visions of pillared castles or frigates. All these examples of optical phenomena are created by the play of light and air.

Light waves bend as they pass first through warm, then cold air. Hot air is more rarefied than cold air, so its molecules are more active and diverge over greater distances. As the temperature decreases, the movement of molecules also decreases.

Visions seen through the lenses of the earth's atmosphere can be highly altered, compressed, expanded, or inverted. This is because light rays bend as they pass through warm and then cold air, and vice versa. And those images that a light stream carries with it, for example, the sky, can be reflected on hot sand and seem like a piece of water, which always moves away when approached.

Most often, mirages can be observed at great distances: in deserts, seas and oceans, where hot and cold layers of air with different densities can simultaneously be located. It is the passage through different temperature layers that can twist the light wave and end up with a vision that is a reflection of something and presented by fantasy as a real phenomenon.

Halo

For most optical illusions that can be seen with the naked eye, the explanation is the refraction of the sun's rays in the atmosphere. One of the most unusual examples optical phenomena advocates solar halo. Basically, a halo is a rainbow around the sun. However, it differs from an ordinary rainbow in both appearance, as well as its properties.

This phenomenon has many varieties, each of which is beautiful in its own way. But for the occurrence of any kind of this optical illusion, certain conditions are necessary.

A halo occurs in the sky when several factors coincide. Most often it can be seen in frosty weather with high humidity. In the air, there is a large number of ice crystals. Breaking through them, the sunlight is refracted in such a way that it forms an arc around the Sun.

And although the last 3 examples of optical phenomena are easily explained modern science, for an ordinary observer, they often remain mystic and a mystery.

Having considered the main examples of optical phenomena, it can be safely assumed that many of them are explained by modern science, despite their mysticism and mystery. But ahead of scientists there are still a lot of discoveries, clues to the mysterious phenomena that occur on planet Earth and beyond.

Many people like funny pictures that deceive their visual perception. But did you know that nature also knows how to create optical illusions? Moreover, they look an order of magnitude more impressive than those made by man. These include dozens of natural phenomena and formations, both rare and quite common. Northern lights, halo, green beam, lenticular clouds - just a small part of them. To your attention - 25 stunning optical illusions created by nature.

Every year in February, the water flows turn a fiery orange color.

This beautiful and at the same time frightening waterfall is located in the central part of Yosemite National Park. It is called Horsetail Fall (in translation - "horse tail"). Every year, for 4-5 days in February, tourists can see a rare phenomenon - the rays of the setting sun are reflected in the falling streams of water. At these moments, the waterfall is painted in a fiery orange color. It seems that red-hot lava flows from the top of the mountain, but this is just an optical illusion.

The waterfall "Horse's tail" consists of two falling streams, its total height reaches 650 meters.

The real sun and two false

If the Sun is low above the horizon and there are microscopic ice crystals in the atmosphere, observers may notice a few bright iridescent spots to the right and left of the Sun. These bizarre halos faithfully follow our luminary across the sky, no matter in which direction it is directed.

Basically, this atmospheric phenomenon It is considered quite common, but it is difficult to notice the effect.

This is interesting: rare cases When sunlight passes through the cirrus clouds at the right angle, these two patches become as bright as the Sun itself.

The effect is best observed in the early morning or late evening in the polar regions.

Fata Morgana - the rarest optical illusion

Fata Morgana is a complex optical atmospheric phenomenon. It is observed extremely rarely. In fact, the Fata Morgana "consists" of several forms of mirages, due to which distant objects are distorted and "bifurcated" for the observer.

It is known that fata morgana occurs when several alternating layers of air are formed in the lower atmosphere (usually due to temperature differences). different density. Under certain conditions, they give specular reflections.

Due to the reflection and refraction of light rays, in reality existing facilities can create several distorted images on the horizon or even above it at once, which partially overlap each other and change rapidly over time, thereby creating a striking picture of Fata Morgana.

A pillar of light emanating from the sun descending below the horizon

We often become witnesses of light (or solar) pillars. This is the name of a common type of halo. This optical effect looks like a vertical strip of light that stretches from the sun at sunset or sunrise. A column of light can be observed when light in the atmosphere reflects off the surface of tiny ice crystals, which are in the form of ice plates or miniature rods with a hexagonal cross section. Crystals of this shape are most often formed in high cirrostratus clouds. But if the air temperature is low enough, they can also appear in lower layers of the atmosphere. We don't think it's worth explaining why. light poles most often observed in winter.

Under certain conditions, the shadow can look like a ghost

When there is thick fog outside, you can observe an interesting optical phenomenon - the so-called Brocken ghost. To do this, you just need to turn your back to the main light source. The observer will be able to see his own shadow lying on the fog (or cloud if you are in a mountainous area).

This is interesting: If the light source, as well as the object on which the shadow is cast, are static, it will repeat any movement of a person. But the shadow will be displayed in a completely different way on a moving “surface” (for example, on fog). Under such conditions, it can oscillate, giving the illusion that the dark misty silhouette is moving. It seems that this is not a shadow belonging to the observer, but a real ghost.

atlantic road

It looks like this bridge is not completed

There are probably no more scenic highways in the world than the Atlantic Road, located in the Norwegian county of Møre og Romsdal. A unique highway runs through the northern coast Atlantic Ocean and includes as many as 12 bridges connecting the individual islands with a road surface.

The most amazing place on the Atlantic Road is the Storseisundet Bridge. From a certain angle, it may seem that it is not completed, and all passing cars, going up, approach the cliff, and then fall down.

The total length of this bridge, opened in 1989, is 8.3 kilometers.

In 2005, the Atlantic Road was named Norway's Building of the Century. And the journalists of the British edition of The Guardian awarded her the title of the best tourist route in this northern country.

moon illusion

It seems that the moon, located above the horizon, is large

When the full moon is low on the horizon, it is visually much larger than when it is high in the sky. This phenomenon seriously puzzles thousands of inquisitive minds trying to find him some kind of reasonable explanation. But in reality, this is just an illusion.

The most straightforward way to confirm the illusory nature of this effect is to hold in outstretched hand a small rounded object (for example, a coin). Comparing the size of this object with the “huge” Moon at the horizon and the “tiny” Moon in the sky, you will be surprised to understand that its relative size does not undergo any changes. It is also possible to roll a sheet of paper into a tube shape and look through the hole formed exclusively at the Moon, without any surrounding objects. Again, the illusion will disappear.

This is interesting: Most scientists, explaining the Moon illusion, refer to the theory of " relative size". It is known that the visual perception of dimensions visible to man object is determined by the dimensions of other objects observed by him at the same time. When the Moon is low above the horizon, other objects (houses, trees, etc.) fall into the field of view of a person. Against their background, our night luminary seems larger than in reality.

cloud shadows

Cloud shadows look like small islands

On a sunny day with high altitude it is very interesting to observe the shadows cast by clouds on the surface of our planet. They are like small constantly moving islands in the ocean. Unfortunately, ground observers will not be able to appreciate the magnificence of this picture.

Atlas moth practically does not fly

The huge atlas moth is found in tropical forests in South Asia. It is this insect that holds the record for the surface area of the wings (400 square centimeters). In India, this moth is bred to produce silk threads. The giant insect produces brown silk that looks like wool.

because of large sizes Atlas moths fly disgustingly, moving slowly and clumsily through the air. But the unique coloring of their wings helps to disguise themselves in natural environment a habitat. Thanks to her, the atlas literally merges with the trees.

It creates the illusion that dew drops are floating in the air.

In the morning or after rain, you can see tiny droplets of water on the cobwebs, resembling a necklace. If the web is very thin, the observer may have the illusion that the drops are literally floating in the air. And in the cold season, the web can be covered with hoarfrost or frozen dew, such a picture looks no less impressive.

Green beam observed after sunset

brief flash green light, observed a moment before the appearance of the solar disk from behind the horizon (most often, at sea) or at the moment when the sun hides behind it, is called a green ray.

You can become a witness to this amazing phenomenon if you observe three conditions: the horizon should be open (steppe, tundra, sea, highlands), the air should be clean, and the area of sunset or sunrise should be free from clouds.

As a rule, the green beam is visible for no more than 2-3 seconds. To significantly increase the time interval of its observation at the time of sunset, immediately after the appearance of the green beam, you need to start quickly running up the earthen embankment or climbing the stairs. If the sun rises, you need to move in opposite direction, that is, down.

This is interesting: During one of the flights over south pole the famous American pilot Richard Baird saw the green beam for 35 minutes! A unique incident occurred at the end polar night, then the upper edge of the solar disk first appeared over the horizon and slowly moved along it. It is known that at the poles the solar disk moves almost horizontally: the speed of its vertical rise is very small.

Physicists explain the effect of the green beam by the refraction (i.e., refraction) of the sun's rays as it passes through the atmosphere. Interestingly, at the time of sunset or sunrise, we should see blue or violet rays first of all. But the length of their waves is so small that when they pass through the atmosphere, they are almost completely scattered and do not reach the earthly observer.

The circumzenithal arc looks like an inverted rainbow

In fact, the circumzenithal arc looks like a rainbow turned upside down. To some people, it even resembles a huge multi-colored smiley face in the sky. This phenomenon is formed due to the refraction of the sun's rays passing through the ice crystals of a certain shape floating in the clouds. The arc is centered at the zenith parallel to the horizon. The top color of this rainbow is blue and the bottom color is red.

Halo

The glowing ring around the moon in the night sky is a halo

Halo is one of the most famous optical phenomena, observing which a person can see a luminous ring around a powerful light source.

During the day, the halo appears around the Sun, at night - around the Moon or other sources, such as street lamps. Exists great amount varieties of halo (one of them is the false sun illusion mentioned above). Almost all halos are caused by the refraction of light as it passes through ice crystals that are concentrated in cirrus clouds (located in the upper troposphere). The appearance of the halo is determined by the shape and arrangement of these miniature crystals.

Mountains and others tall objects dyed pinkish

Probably every inhabitant of our planet has seen a pink reflection. This interesting phenomenon is observed at the moment when the Sun sets below the horizon. Then mountains or other vertical objects (for example, multi-storey buildings) are painted in a soft pink hue for a short time.

Crepuscular rays are observed in cloudy weather

Scientists call twilight rays a common optical phenomenon that looks like an alternation of many light and dark bands in the sky. In this case, all these bands diverge from the current location of the Sun.

Twilight rays are one of the manifestations of the play of light and shadow. We are sure that the air is completely transparent, and the rays of light that pass through it are invisible. But if there are tiny droplets of water or dust particles in the atmosphere, the sunlight is scattered. A whitish haze forms in the air. It is almost invisible in clear weather. But under cloudy conditions, particles of dust or water that are in the shadow of clouds are less illuminated. Therefore, shaded areas are perceived by observers as dark stripes. Well-lit areas alternating with them, on the contrary, seem to us to be bright stripes of light.

A similar effect is observed when the sun's rays, breaking through the cracks in a dark room, form bright light paths, illuminating dust particles floating in the air.

This is interesting: Twilight rays are called in different countries differently. The Germans use the expression "The sun drinks water", the Dutch - "The sun stands on legs", and the British call the twilight rays "Jacob's ladder" or "angels' ladder".

Anti-crepuscular rays come from a point on the horizon opposite the setting Sun

These rays are observed at the time of sunset on east side firmament. They, like the twilight rays, diverge like a fan, the only difference between them is the location relative to the heavenly body.

It may seem that anti-crepuscular rays converge at some point beyond the horizon, but this is only an illusion. In reality, the rays of the Sun propagate strictly in straight lines, but when these lines are projected onto the spherical atmosphere of the Earth, arcs are formed. That is, the illusion of their fan-shaped divergence is caused by perspective.

Northern lights in the night sky

The sun is very unstable. Sometimes on its surface happen powerful explosions, after which they are directed towards the Earth at great speed tiny particles solar matter ( sunny wind). It takes them about 30 hours to reach Earth.

The magnetic field of our planet deflects these particles to the poles, as a result of which extensive magnetic storms. Protons and electrons penetrating into the ionosphere from outer space interact with it. The rarefied layers of the atmosphere begin to glow. The entire sky is painted with multi-colored dynamically moving patterns: arcs, bizarre lines, crowns and spots.

It's interesting to watch northern lights possible in high latitudes each hemisphere (so it would be more correct to call this phenomenon"polar lights"). The geography of places where people can see this impressive natural phenomenon expands significantly only during periods of high solar activity. Surprisingly, auroras also occur on other planets in our solar system.

The shapes and colors of the colorful glow of the night sky are rapidly changing. Interestingly, the auroras occur exclusively in the altitude ranges from 80 to 100 and from 400 to 1000 kilometers above ground level.

Buckthorn - a butterfly with incredibly realistic natural camouflage

In early April, when the weather is consistently warm and sunny, you can see a beautiful bright spot fluttering from one spring flower to another. This is a butterfly called buckthorn or lemongrass.

The wingspan of the buckthorn is about 6 centimeters, the length of the wings is from 2.7 to 3.3 centimeters. Interestingly, the coloration of males and females is different. Males have bright greenish-lemon wings, while females are lighter, almost white.

Buckthorn has amazingly realistic natural camouflage. It is very difficult to distinguish it from plant leaves.

magnetic hill

It seems that cars under the influence of an unknown force are rolling up the slope.

There is a hill in Canada where extraordinary things happen. If you park your car at the bottom of the car and put it into neutral, you will see that the car starts to roll (without any help) uphill. Many people explain amazing phenomenon the impact of an incredibly powerful magnetic force that makes the car roll up the hill and reach speeds of up to 40 kilometers per hour.

Unfortunately, there is no magnetism or magic here. It's all about the usual optical illusion. Due to the peculiarities of the relief, a slight slope (about 2.5 degrees) is perceived by the observer as an ascent.

The main factor in creating a similar illusion, observed in many other places the globe, – zero or minimum horizon visibility. If a person does not see it, then it becomes quite difficult to judge the inclination of the surface. Even objects that are in most cases perpendicular to the ground (for example, trees) can lean in any direction, misleading the observer even more.

Salt deserts

It seems that all these people are floating in the sky

Salt deserts are found in all corners of the Earth. The people who are in the middle of them, the perception of space is distorted due to the lack of any landmarks.

In the photo you can see a dried-up salt lake located in the southern part of the Altiplano plain (Bolivia) and called the Uyuni salt marsh. This place is located at an altitude of 3.7 kilometers above sea level, and its total area exceeds 10.5 thousand square kilometers. Uyuni is the largest salt marsh on our planet.

The most common minerals found here are halite and gypsum. A layer thickness table salt on the surface of the solonchak in some places it reaches 8 meters. General stocks salts are estimated at 10 billion tons. On the territory of Uyuni there are several hotels built from salt blocks. Furniture and other interior items are also made from it. And there are ads on the walls of the rooms: the administration politely asks guests not to lick anything. By the way, you can spend the night in such hotels for only 20 dollars.

This is interesting: During the rainy season, Uyuni is covered with a thin layer of water, due to which it turns into the largest mirror surface on Earth. In the middle of an endless mirror space, observers get the impression that they are floating in the sky or even on another planet.

Wave

Sand dunes turned to stone

Wave - a naturally formed gallery of sand and rock, located on the border of the US states of Utah and Arizona. Nearby are popular national parks in the United States, so the Wave attracts hundreds of thousands of tourists every year.

Scientists claim that these unique rock formations have been formed for more than one million years: sand dunes under the influence of conditions environment gradually hardened. And the wind and rains, which affected these formations for a long time, polished their shapes and gave them such an unusual look.

Apache indian head

It's hard to believe that this rocky formation formed without human intervention.

This natural rock formation in France vividly illustrates our ability to recognize familiar shapes such as human faces, in surrounding objects. Scientists have recently discovered that we even have a special part of the brain responsible for face recognition. Interestingly, the visual perception of a person is arranged in such a way that any objects similar in shape to faces are noticed by us faster than other visual stimuli.

There are hundreds of natural formations that exploit this human ability. But you must admit: the mountain range in the shape of the head of an Apache Indian is probably the most striking of them. By the way, tourists who had the opportunity to see this unusual rock formation located in the French Alps cannot believe that it was formed without human intervention.‎

An Indian in a traditional headdress and with headphones in his ears - where else can you see this?

The Wasteland Guard (another name is "Indian's Head") is a unique geoformation located near the Canadian city of Madison Hat (southeastern part of Alberta). When looking at it from a great height, it becomes obvious that the terrain forms the outlines of the head of a local aborigine in a traditional Indian headdress, looking intently somewhere to the west. Moreover, this Indian also listens to modern headphones.

In fact, what looks like the wire from the headphones is the path leading to the oil rig, and the liner is the well itself. The height of the "Indian head" is 255 meters, the width is 225 meters. For comparison: the height of the famous bas-relief in Mount Rushmore, on which the faces of four American presidents are carved, is only 18 meters.

The Wasteland Guard was formed naturally by the weathering and erosion of soft soil rich in clay. According to scientists, the age of this geoformation does not exceed 800 years.

Lenticular (lenticular) clouds

Lenticular clouds look like huge UFOs

Unique feature lenticular clouds is that no matter how strong the wind is, they remain motionless. Air currents passing over the earth's surface flow around obstacles, due to which air waves are formed. At their edges, lenticular clouds form. At their bottom is continuous process condensation of water vapor rising from the earth's surface. Therefore, lenticular clouds do not change their position. They just hang in the sky in one place.

Lenticular clouds most often form on the lee side of mountain ranges or over individual peaks at an altitude of 2 to 15 kilometers. In most cases, their appearance signals an approaching atmospheric front.

It's interesting: Because unusual shape and absolute stillness, people often mistake lenticular clouds for UFOs.

Thunderstorm clouds

Such a sight inspires fear, agree!

Terrifying clouds with a thunderstorm are observed on flat territories often. They go very low to the ground. There is a feeling that if you climb to the roof of the building, you can reach them with your hand. And sometimes it may seem that such clouds generally come into contact with the surface of the earth.

A thunderstorm shaft (another name is a squall gate) is visually similar to a tornado. Fortunately, in comparison with this natural phenomenon, it is not so dangerous. The thunder bar is just a low, horizontally oriented area thunder cloud. It is formed in its front part during rapid movement. And the squall gate acquires an even and smooth shape under conditions of active upward movement of air. Such clouds, as a rule, form during the warm period of the year (from mid-spring to mid-autumn). Interestingly, the lifetime of thunderstorms is very short - from 30 minutes to 3 hours.

Agree, many of the phenomena listed above seem truly magical, even though their mechanisms can be easily explained from a scientific point of view. Nature, without the slightest participation of man, creates amazing optical illusions that amaze the imagination of even researchers who have seen a lot in their lifetime. How can one not admire her greatness and power?

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Presentation on the topic: optical phenomena

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Optical phenomena are - Optical phenomena in the atmosphere - phenomena caused by scattering, absorption, refraction and diffraction of light. Light sources can be the Sun, the Moon, the ionized air of the upper atmosphere. Optical phenomena include: rainbow, halo, mirage, twilight, dawns, auroras. Optical phenomena are closely related to the weather and in some cases can be used to predict it.

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Mirage This optical phenomenon is often observed in the desert - along with distant objects, their imaginary, "apparent" images are visible. Sometimes reflections of objects hidden behind the horizon line are visible. The reflection of the sky from the surface layers of air often creates the impression water surface. Mirages are explained by the curvature of light rays in unevenly heated layers of air that have different densities. They occur both when the surface air is strongly heated (in deserts, sometimes over the asphalt of the highway), and when it is supercooled.

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Halo Light rings, pillars or spots around the Sun and Moon, "false Suns". Sometimes these rings are iridescent. A halo appears when light is reflected or refracted by ice crystals, forming light cirrus clouds or fog. Most often this happens in the mountains. Like a rainbow, halos are caused by the refraction of rays in the atmosphere, only halos are caused by ice crystals. Sometimes the reflections of the sun become as bright as the sun itself, a phenomenon called "solar dogs".

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Star Rain In fact, not stars fall from the sky, but meteorites, which, entering earth's atmosphere, heat up and burn out. In this case, a flash of light occurs, which is visible at a fairly large distance from the surface of the Earth. Most often, a meteor shower of high intensity (up to a thousand meteors per hour) is called a stellar or meteor shower. meteor shower consists of meteors that burn up in the atmosphere and do not reach the earth, but meteor Rain- consists of meteorites that fall to the ground.

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Gloria If you kindle a fire in the mountains at night under low clouds, your shadow will appear on the clouds and around your head you will have a luminous halo. This phenomenon is called Gloria. Gloria is an optical phenomenon that is observed on clouds located directly in front of the observer or below him, at a point directly opposite the light source. In China, gloria is called the "light of the Buddha." A colored halo always surrounds the observer's shadow.

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Belt of Venus At dusk, just before sunrise or just after sunset, the sky above the horizon is partly colorless and partly pinkish. This phenomenon is called the belt of Venus. A colorless strip between the already darkened sky and blue sky can be seen everywhere, even away from the Sun. The phenomenon of the belt of Venus is explained by the reflection in the atmosphere of the light of the setting (or rising) Sun, which appears reddened.

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Green beam Green beam is a flash of emerald green sunlight at the moment when the last ray of the Sun disappears behind the horizon. The red component of sunlight disappears first, all the others follow in order, and the emerald green remains last. This phenomenon occurs only when only the very edge of the solar disk remains above the horizon, otherwise there is a mixture of colors. The green beam appears for some moments before the disappearance of the sun behind the horizon, or just before dawn. It is a small flash of green and is caused by the refraction of light in the atmosphere.

Many people like funny pictures that deceive their visual perception. But did you know that nature can also create optical illusions? Moreover, they look an order of magnitude more impressive than those made by man. These include dozens of natural phenomena and formations, both rare and quite common. Aurora borealis, halo, green beam, lenticular clouds - just a small part of them. To your attention - 25 stunning optical illusions created by nature.
Fiery waterfall "Horsetail"

Every year in February, the water flows turn a fiery orange color.

This beautiful and at the same time frightening waterfall is located in the central part of Yosemite National Park. It is called Horsetail Fall (in translation - "horse tail"). Every year, during 4-5 February days, tourists can see a rare phenomenon - the rays of the setting sun are reflected in the falling water streams. At these moments, the waterfall is painted in a fiery orange color. It seems that red-hot lava flows from the top of the mountain, but this is just an optical illusion.

The waterfall "Horse's tail" consists of two falling streams, its total height reaches 650 meters.

false sun

The real sun and two false

In principle, this atmospheric phenomenon is considered quite common, but it is difficult to notice the effect.

It is interesting: On rare occasions, when sunlight passes through cirrus clouds at just the right angle, these two patches become as bright as the Sun itself.

The effect is best observed in the early morning or late evening in the polar regions.
Fata Morgana

Fata Morgana - the rarest optical illusion

It is known that fata morgana occurs when several alternating layers of air with different densities are formed in the lower layer of the atmosphere (usually due to temperature differences). Under certain conditions, they give specular reflections.

Due to the reflection and refraction of light rays, real-life objects can create several distorted images on the horizon or even above it at once, which partially overlap each other and change rapidly over time, thereby creating a striking picture of fata morgana.
light pole

A pillar of light emanating from the sun descending below the horizon

We often become witnesses of light (or solar) pillars. This is the name of a common type of halo. This optical effect looks like a vertical band of light that stretches from the sun at sunset or sunrise. A column of light can be observed when light in the atmosphere reflects off the surface of tiny ice crystals, which are in the form of ice plates or miniature rods with a hexagonal cross section. Crystals of this shape are most often formed in high cirrostratus clouds. But if the air temperature is low enough, they can also appear in lower layers of the atmosphere. We think it is not worth explaining why light pillars are most often observed in winter.
Broken Ghost

Under certain conditions, the shadow can look like a ghost

It is interesting: If the light source, as well as the object on which the shadow is cast, are static, it will repeat any movement of a person. But the shadow will be displayed in a completely different way on a moving “surface” (for example, on fog). Under such conditions, it can oscillate, giving the illusion that the dark misty silhouette is moving. It seems that this is not a shadow belonging to the observer, but a real ghost.

Atlantic Road in Norway

There are probably no more scenic highways in the world than the Atlantic Road, located in the Norwegian county of Møre og Romsdal.

The unique highway runs through the northern coast of the Atlantic Ocean and includes as many as 12 bridges connecting the individual islands with a road surface.

The total length of this bridge, opened in 1989, is 8.3 kilometers.

It seems that the moon, located above the horizon, is large

When the full moon is low on the horizon, it is visually much larger than when it is high in the sky. This phenomenon seriously puzzles thousands of inquisitive minds trying to find some reasonable explanation for it. But in reality, this is just an illusion.

The simplest way to confirm the illusory nature of this effect is to hold a small rounded object (for example, a coin) in an outstretched hand. Comparing the size of this object with the “huge” Moon at the horizon and the “tiny” Moon in the sky, you will be surprised to understand that its relative size does not undergo any changes. It is also possible to roll a sheet of paper into a tube shape and look through the hole formed exclusively at the Moon, without any surrounding objects. Again, the illusion will disappear.

It is interesting: Most scientists, when explaining the Lunar illusion, refer to the theory of "relative size". It is known that the visual perception of the dimensions of an object seen by a person is determined by the dimensions of other objects observed by him at the same time. When the Moon is low above the horizon, other objects (houses, trees, etc.) fall into the field of view of a person. Against their background, our night luminary seems larger than in reality.

cloud shadows

Cloud shadows look like small islands

On a sunny day from a great height, it is very interesting to observe the shadows cast by clouds on the surface of our planet. They are like small constantly moving islands in the ocean. Unfortunately, ground observers will not be able to appreciate the magnificence of this picture.
Moth Atlas

Moth Atlas

Due to their large size, atlas moths fly disgustingly, moving slowly and clumsily through the air. But the unique coloring of their wings helps to disguise themselves in their natural habitat. Thanks to her, the atlas literally merges with the trees.
Dew on the cobweb

Dew on the cobweb

In the morning or after rain, you can see tiny droplets of water on the cobwebs, resembling a necklace. If the web is very thin, the observer may have the illusion that the drops are literally floating in the air. And in the cold season, the web can be covered with hoarfrost or frozen dew, such a picture looks no less impressive.
green beam

green beam

A short flash of green light, observed a moment before the appearance of the solar disk from behind the horizon (most often, at sea) or at the moment when the sun hides behind it, is called a green beam.

You can become a witness of this amazing phenomenon if three conditions are met: the horizon must be open (steppe, tundra, sea, highlands), the air must be clean, and the area of sunset or sunrise must be free from clouds.

As a rule, the green beam is visible for no more than 2-3 seconds. To significantly increase the time interval of its observation at the time of sunset, immediately after the appearance of the green beam, you need to start quickly running up the earthen embankment or climbing the stairs. If the Sun rises, you need to move in the opposite direction, that is, down.

It is interesting: During one of the flights over the South Pole, the famous American pilot Richard Baird saw a green beam for a whole 35 minutes! A unique case occurred at the end of the polar night, when the upper edge of the solar disk first appeared from behind the horizon and slowly moved along it. It is known that at the poles the solar disk moves almost horizontally: the speed of its vertical rise is very small.

circumzenithal arc

In fact, the circumzenithal arc looks like a rainbow turned upside down. To some people, it even resembles a huge multi-colored smiley face in the sky. This phenomenon is formed due to the refraction of the sun's rays passing through the ice crystals of a certain shape floating in the clouds. The arc is centered at the zenith parallel to the horizon. The top color of this rainbow is blue, the bottom is red.
Halo

halo around the moon

Halo is one of the most famous optical phenomena, observing which a person can see a luminous ring around a powerful light source.

During the day, the halo appears around the Sun, at night - around the Moon or other sources, such as street lamps. There are a huge number of varieties of halo (one of them is the false sun illusion mentioned above). Almost all halos are caused by the refraction of light as it passes through ice crystals that are concentrated in cirrus clouds (located in the upper troposphere). The appearance of the halo is determined by the shape and arrangement of these miniature crystals.
Pink reflection of the sun

Pink reflection of the sun

twilight rays

A similar effect is observed when the sun's rays, breaking through the cracks in a dark room, form bright light paths, illuminating dust particles floating in the air.

It is interesting: Twilight rays are called differently in different countries. The Germans use the expression "The sun drinks water", the Dutch - "The sun stands on legs", and the British call the twilight rays "Jacob's ladder" or "angels' ladder".

anti-crepuscular rays

Anti-crepuscular rays come from a point on the horizon opposite the setting Sun

These rays are observed at the time of sunset on the eastern side of the sky. They, like twilight rays, diverge like a fan, the only difference between them is the location relative to the heavenly body.

Northern lights in the night sky

The sun is very unstable. Sometimes powerful explosions occur on its surface, after which the smallest particles of solar matter (solar wind) are sent towards the Earth at great speed. It takes them about 30 hours to reach Earth.

The magnetic field of our planet deflects these particles towards the poles, as a result of which extensive magnetic storms begin there. Protons and electrons penetrating into the ionosphere from outer space interact with it. The rarefied layers of the atmosphere begin to glow. The entire sky is painted with multi-colored dynamically moving patterns: arcs, bizarre lines, crowns and spots.

It is interesting: You can watch the northern lights at high latitudes of each hemisphere (therefore, it would be more correct to call this phenomenon "aurora borealis"). The geography of places where people can see this impressive natural phenomenon expands significantly only during periods of high solar activity. Surprisingly, auroras also occur on other planets in our solar system.

Buckthorn - a butterfly with incredibly realistic natural camouflage

In early April, when the weather is consistently warm and sunny, you can see a beautiful bright spot fluttering from one spring flower to another. This is a butterfly called buckthorn or lemongrass.

Buckthorn has amazingly realistic natural camouflage. It is very difficult to distinguish it from plant leaves.

magnetic hill

It seems that cars under the influence of an unknown force are rolling up the slope.

There is a hill in Canada where extraordinary things happen. If you park your car at the bottom of the car and put it into neutral, you will see that the car starts to roll (without any help) uphill. Many people attribute the amazing phenomenon to an incredibly powerful magnetic force that causes cars to roll up hills and reach speeds of up to 40 kilometers per hour.

The main factor in creating such an illusion, which is also observed in many other places on the globe, is the zero or minimal visibility of the horizon. If a person does not see it, then it becomes quite difficult to judge the inclination of the surface. Even objects that are in most cases perpendicular to the ground (for example, trees) can lean in any direction, misleading the observer even more.
Salt deserts

It seems that all these people are floating in the sky

Salt deserts are found in all corners of the Earth. The people who are in the middle of them, the perception of space is distorted due to the lack of any landmarks.

The most common minerals found here are halite and gypsum. And the thickness of the salt layer on the surface of the salt marsh in some places reaches 8 meters. The total salt reserves are estimated at 10 billion tons. On the territory of Uyuni there are several hotels built from salt blocks. Furniture and other interior items are also made from it. And there are ads on the walls of the rooms: the administration politely asks guests not to lick anything. By the way, you can spend the night in such hotels for only 20 dollars.

It is interesting: During the rainy season, Uyuni is covered with a thin layer of water, which turns into the largest mirror surface on Earth. In the middle of an endless mirror space, observers get the impression that they are floating in the sky or even on another planet.

Wave

Sand dunes turned to stone

A wave is a naturally formed gallery of sand and rock, located on the border of the US states of Utah and Arizona. Nearby are popular national parks in the United States, so the Wave attracts hundreds of thousands of tourists every year.

Scientists claim that these unique rock formations have been formed for more than one million years: sand dunes gradually hardened under the influence of environmental conditions. And the wind and rains, which affected these formations for a long time, polished their shapes and gave them such an unusual look.
Apache indian head

It's hard to believe that this rocky formation formed without human intervention.

This natural rock formation in France vividly illustrates our ability to recognize familiar shapes, such as human faces, in surrounding objects. Scientists have recently discovered that we even have a special part of the brain responsible for face recognition. Interestingly, the visual perception of a person is arranged in such a way that any objects similar in shape to faces are noticed by us faster than other visual stimuli.

There are hundreds of natural formations in the world that exploit this human ability. But you must admit: the mountain range in the shape of the head of an Apache Indian is probably the most striking of them. By the way, tourists who had the opportunity to see this unusual rock formation located in the French Alps cannot believe that it was formed without human intervention.‎
Wasteland Guardian

An Indian in a traditional headdress and with headphones in his ears - where else can you see this?

The Wasteland Guardian (another name is "Indian's Head") is a unique geoformation located near the Canadian city of Madison Hat (southeastern part of Alberta). When looking at it from a great height, it becomes obvious that the terrain forms the outlines of the head of a local aborigine in a traditional Indian headdress, looking intently somewhere to the west. Moreover, this Indian also listens to modern headphones.

In fact, what resembles the wire from the headphones is the path leading to the oil rig, and the liner is the well itself. The height of the "Indian head" is 255 meters, the width is 225 meters. For comparison: the height of the famous bas-relief in Mount Rushmore, on which the faces of four American presidents are carved, is only 18 meters.

The Wasteland Guard was formed naturally by the weathering and erosion of soft soil rich in clay. According to scientists, the age of this geoformation does not exceed 800 years.
Lenticular (lenticular) clouds

Lenticular clouds look like huge UFOs

The unique feature of lenticular clouds is that no matter how strong the wind is, they remain motionless. Air currents passing over the earth's surface flow around obstacles, due to which air waves are formed. At their edges, lenticular clouds form. In their lower part there is a continuous process of condensation of water vapor rising from the surface of the earth. Therefore, lenticular clouds do not change their position. They just hang in the sky in one place.

It is interesting: Due to their unusual shape and absolute immobility, people often mistake lenticular clouds for UFOs.

Thunderstorm clouds

Such a sight inspires fear, agree!

Terrifying clouds with a thunderstorm are observed in the flat areas quite often. They go very low to the ground. There is a feeling that if you climb to the roof of the building, you can reach them with your hand. And sometimes it may seem that such clouds generally come into contact with the surface of the earth.

A thunderstorm shaft (another name is a squall gate) is visually similar to a tornado. Fortunately, in comparison with this natural phenomenon, it is not so dangerous. A thunderstorm is simply a low, horizontally oriented region of a thundercloud. It is formed in its front part during rapid movement. And the squall gate acquires an even and smooth shape under conditions of active upward movement of air. Such clouds, as a rule, form during the warm period of the year (from mid-spring to mid-autumn). Interestingly, the lifetime of thunderstorms is very short - from 30 minutes to 3 hours.

Optical phenomena in nature

Phenomena associated with the refraction of light.

Mirages.

In an inhomogeneous medium, light does not propagate in a straight line. If we imagine a medium in which the refractive index changes from bottom to top, and mentally divide it into thin horizontal layers, then, considering the conditions for refraction of light during the transition from layer to layer, we note that in such a medium the light beam should gradually change its direction.

Such a curvature of the light beam undergoes in the atmosphere, in which, for one reason or another, mainly due to its uneven heating, the refractive index of the air changes with height.

The air is usually heated by the soil, which absorbs the energy of the sun's rays. Therefore, the air temperature decreases with altitude. It is also known that air density decreases with height. It has been established that with increasing altitude, the refractive index decreases, so the rays passing through the atmosphere are bent, bending down to the Earth. This phenomenon is called normal atmospheric refraction. due to refraction heavenly bodies seem to us somewhat "raised" (above their true height) above the horizon.

Mirages are divided into three classes.
The first class includes the most common and simple in origin, the so-called lake (or lower) mirages, which cause so many hopes and disappointments among desert travelers.

The explanation for this phenomenon is simple. The lower layers of air, warmed up by the soil, have not had time to rise up; their refractive index is less than the upper ones. Therefore, the rays of light emanating from objects, bending in the air, enter the eye from below.

To see a mirage, there is no need to go to Africa. It can be observed on a hot, quiet summer day and over the heated surface of an asphalt highway.

Mirages of the second class are called superior or distant vision mirages.

They appear in the event that the upper layers of the atmosphere turn out to be for some reason, for example, when heated air gets there, especially rarefied. Then the rays emanating from earthly objects are more strongly bent and reach the earth's surface, going under high angle to the horizon. The observer's eye projects them in the direction in which they enter it.

Apparently, the Sahara Desert is to blame for the fact that a large number of long-range mirages are observed on the Mediterranean coast. Hot air masses rise above it, then are carried away to the north and create favorable conditions for the appearance of mirages.

Superior mirages are also observed in northern countries when the warm south winds blow. The upper layers of the atmosphere are heated, and the lower ones are cooled due to the presence of large masses melting ice and snow.

Mirages of the third class - ultra-long vision - are difficult to explain. However, assumptions were made about the formation of giant air lenses in the atmosphere, about the creation of a secondary mirage, that is, a mirage from a mirage. It is possible that the ionosphere plays a role here, reflecting not only radio waves, but also light waves.

Phenomena related to the dispersion of light

Rainbow is beautiful celestial phenomenon has always attracted people's attention. AT old times, when people still knew very little about the world around them, the rainbow was considered a "heavenly sign." So, the ancient Greeks thought that a hundred rainbow is the smile of the goddess Irida. The rainbow is seen to the side opposite to the sun, against the background of rain clouds or rain. A multi-colored arc is usually located at a distance of 1-2 km from the observer Ra, sometimes it can be observed at a distance of 2-3 m against the background of water drops formed by fountains or water sprayers

The rainbow has seven primary colors that smoothly transition from one to another.

The shape of the arc, the brightness of the colors, the width of the stripes depend on the size of the water droplets and their number. Large drops create a narrower rainbow, with sharply prominent colors, small drops create an arc that is blurry, faded and even white. That's why bright narrow rainbow visible in the summer after a thunderstorm, during which large drops fall.

The rainbow theory was first given in 1637 by R. Descartes. He explained the rainbow as a phenomenon associated with the reflection and refraction of light in raindrops.

The formation of colors and their sequence were explained later, after unraveling complex nature white light and its dispersion in the medium. The diffraction theory of the rainbow was developed by Airy and Pertner.

Light Interference Phenomena

The white circles of light around the Sun or Moon, which result from the refraction or reflection of light by ice or snow crystals in the atmosphere, are called halos. There are small water crystals in the atmosphere, and when their faces form a right angle with the plane passing through the Sun, the one who observes the effect, and the crystals, a characteristic white halo surrounding the Sun becomes visible in the sky. So the edges reflect the rays of light with a deviation of 22 °, forming a halo. During the cold season, halos formed by ice and snow crystals on the surface of the earth reflect sunlight and scatter it into different directions, forming an effect called "diamond dust".

Most famous example The big halo is the famous, often repeated "Brocken Vision". For example, a person standing on a hill or mountain, behind whom the sun rises or sets, finds that his shadow, which has fallen on the clouds, becomes unbelievably huge. This is due to the fact that the smallest drops of fog refract and reflect sunlight in a special way. The phenomenon got its name from the Brocken peak in Germany, where, due to frequent fogs, this effect can be regularly observed.

Parhelia.

"Parhelion" in Greek means "false sun". This is one of the halo forms (see point 6): one or more additional images of the Sun are observed in the sky, located at the same height above the horizon as the real Sun. Millions of ice crystals with a vertical surface, reflecting the Sun, form this most beautiful phenomenon.

Parhelia can be observed in calm weather at a low position of the Sun, when a significant number of prisms are located in the air so that their main axes are vertical, and the prisms slowly descend like small parachutes. In this case, the brightest refracted light enters the eye at an angle of 220 from the vertical faces and creates vertical pillars on both sides of the Sun along the horizon. These pillars can be particularly bright in some places, giving the impression of a false Sun.

Polar Lights.

One of the most beautiful optical phenomena of nature is the aurora borealis. It is impossible to convey in words the beauty of the auroras, shimmering, shimmering, flaming against the dark night sky in the polar latitudes.

In most cases, auroras are green or blue-green in color, with occasional patches or borders of pink or red.

Auroras are observed in two main forms - in the form of ribbons and in the form of cloud-like spots. When the radiance is intense, it takes on the form of ribbons. Losing intensity, it turns into spots. However, many ribbons disappear before they break into spots. The ribbons seem to hang in the dark space of the sky, resembling a giant curtain or drapery, usually stretching from east to west for thousands of kilometers. The height of the curtain is several hundred kilometers, the thickness does not exceed several hundred meters, and it is so delicate and transparent that stars can be seen through it. The lower edge of the curtain is quite distinctly and sharply outlined and often tinted in red or pinkish color, reminiscent of the border of the curtain, the upper one is gradually lost in height and this creates a particularly effective impression of the depth of space.

There are four types of auroras:

1. Uniform arc - the luminous strip has the simplest, calmest form. It is brighter from below and gradually disappears upward against the background of the glow of the sky;

2. Radiant arc - the tape becomes somewhat more active and mobile, it forms small folds and streams;

3. Radiant band - with increasing activity, larger folds are superimposed on small ones;

4. With increased activity, folds or loops expand to huge size(up to hundreds of kilometers), the lower edge of the tape shines with pink light. When the activity subsides, the wrinkles disappear and the tape returns to a uniform shape. This suggests that homogeneous structure are the main form aurora borealis, and the folds are associated with an increase in activity.

Often there are aurora of a different kind. They capture the entire polar region and are very intense. They occur during an increase solar activity. These auroras appear as a whitish-green glow from the entire polar cap. Such auroras are called squalls.

Conclusion

Once a mirage" Flying Dutchman"and" Fata Morgana "terrified the sailors. On the night of March 27, 1898, among Pacific Ocean the crew of the Matador was frightened by a vision when, in a calm at midnight, they saw a ship 2 miles (3.2 km) away, which was struggling with a severe storm. All these events actually took place at a distance of 1700 km.

Today, everyone who knows the laws of physics, or rather its section of optics, can explain all these mysterious phenomena.

In my work, I did not describe all the optical phenomena of nature. There are a lot of them. We admire blue color sky, a ruddy dawn, a flaming sunset - these phenomena are explained by the absorption and scattering of sunlight. Working with additional literature, I was convinced that the questions that arise when observing the world around us can always be answered. True, one must know the basics of the natural sciences.

CONCLUSION: Optical phenomena in nature are explained by the refraction or reflection of light, or wave properties light-dispersion, interference, diffraction, polarization, or quantum properties of light. The world is mysterious, but cognizable.

Portal for the student. Self-training

What does the person see?

refraction of rays

Why the sky is blue?

colorful arch

What are rainbows made of?

What color is the water?

Sunrises and sunsets

planet light show

How is everything going?

Mirages

Halo

atlantic road

moon illusion

cloud shadows

Halo

magnetic hill

Salt deserts

Wave

Apache indian head

Lenticular (lenticular) clouds

Thunderstorm clouds

Presentation on the topic: optical phenomena

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