Reflection of a mirror in a mirror. Reflection in a flat mirror. Reflection of the beam from the mirror

Most likely, today there is not a single house where there was no mirror. It has become so firmly embedded in our lives that it is difficult for a person to do without him. What is this subject, how does the image reflect? And if you put two mirrors opposite each other? This amazing subject became central in many fairy tales. About him, there is a sufficient number of signs. And what does science say about a mirror?

A bit of history

Modern mirrors in the majority are a glass with a dusting. As a coating, a thin metallic layer is applied to the underside of the glass. Literally a thousand years ago, the mirrors were carefully polished copper or bronze discs. But not everyone could afford a mirror. It cost a lot of money. Therefore, poor people were forced to consider their reflection in the water. And mirrors that show a person in full growth - this is generally a relatively young invention. He is about 400 years old.

The mirror of people was surprising, especially when they could see the reflection of the mirror in the mirror - it seemed to them something magical. After all, the image - this is not true, but some of its reflection, a kind of illusion. It turns out that we can simultaneously see the truth and the illusion. Not surprisingly, people attributed to this subject a lot of magical properties and even were afraid of it.

The very first mirrors were made of platinum (surprisingly, but once this metal was not appreciated at all), gold or tin. Scientists have discovered mirrors made in the Bronze Age. But the mirror that we can see today, began its history after in Europe they were able to master the technology of blowing glass.

Scientific view

From the point of view of the science of physics, the reflection of a mirror in a mirror is the multiplied effect of the same reflection. The more such mirrors installed opposite each other, the greater the illusion of fullness with the same image arises. This effect is often used in amusement rides. For example, there is a Disney park in the park, the so-called endless hall. There, two mirrors installed opposite each other, and repeated this effect many times.

The resulting reflection of the mirror in the mirror, multiplied by a relatively infinite number of times, has become one of the most popular among the rides. Such attractions have long entered the entertainment industry. As early as the beginning of the 20th century, an attraction called the Palace of Illusions appeared in Paris at an international exhibition. He enjoyed great popularity. The principle of its creation is the reflection of mirrors in mirrors installed in a row, the size of a full human growth, in a huge pavilion. People had the impression that they were in a huge crowd.

The law of reflection

The principle of operation of any mirror is based on the law of propagation and reflection of light rays in space. This law is the main one in optics: the angle of incidence will be the same (equal to) the angle of reflection. It's like a falling ball. If you throw it vertically down towards the floor, it will also bounce vertically upward. If you throw it at an angle - it will bounce at an angle equal to the angle of incidence. The rays of light from the surface are reflected similarly. At the same time, the smoother and smoother this surface, the better this law works. By this law, reflection works in a flat mirror, and the surface is better, the better the reflection.

But if we are dealing with matte surfaces or with rough surfaces, then the rays are scattered chaotically.

Mirrors can reflect light. What we see, all the reflected objects, is thanks to the rays, which are similar to the solar ones. If there is no light, then nothing is visible in the mirror. When light rays fall on an object or any living thing, they reflect and carry with them information about the object. Thus, the reflection of the person in the mirror is the eye formed on the retina and the idea of the object with all its characteristics, color, size, distance, etc., transmitted to the brain.

Types of mirror surfaces

Mirrors are flat and spherical, which, in turn, can be concave and convex. Today there are already smart mirrors: a kind of media carrier designed to demonstrate the target audience. The principle of his work is as follows: when a person approaches, the mirror seems to come to life and starts showing the video. And this video is not chosen by chance. In the mirror is mounted a system that recognizes and processes the resulting image of a person. She quickly determines his gender, age, emotional mood. Thus, the system in the mirror selects a demonstration video, potentially able to interest a person. This works in 85 out of 100 cases! But scientists do not stop at this and want to achieve accuracy in 98%.

Spherical mirror surfaces

What is the basis of the work of a spherical mirror, or, as they are called, a curve, mirrors with convex and concave surfaces? From ordinary, these mirrors differ in that they distort the image. Convex mirror surfaces make it possible to see more objects than flat surfaces. But at the same time all these objects seem smaller in size. Such mirrors are installed in cars. Then the driver has the opportunity to see the image on the left and right.

The concave curved mirror focuses the resulting image. In this case, you can see the reflected object in as much detail as possible. A simple example: these mirrors are often used for shaving and in medicine. The image of an object in such mirrors is collected from images of a variety of different and individual points of this object. To construct an image of an object in a concave mirror, it is sufficient to construct an image of its extreme two points. Images of the remaining points will be located between them.

Translucency

There is another kind of mirror, which has translucent surfaces. They are so arranged that one side is like an ordinary mirror, and the other is half transparent. From this, the transparent side, you can observe the view behind the mirror, and with the ordinary one you can not see anything except the reflection. Such mirrors can often be seen in criminal films, when police conduct investigation and interrogate a suspect, and on the other hand they are watched or lead witnesses for identification, but so that they can not be seen.

The myth of infinity

There is a belief that by creating a mirror corridor, you can achieve the infinity of the light beam in the mirrors. Superstitious people who believe in divination often use this ritual. But science has long proved that this is impossible. It is interesting that the reflection of light from a mirror is never complete, 100%. This requires an ideal, smooth to 100% surface. And it can be about 98-99%. There are always some errors. Therefore, girls who guess in such mirror corridors by candlelight, risk, at most, simply enter into a certain psychological state, which can adversely affect them.

If you place two mirrors opposite each other, and between them light a candle, then you will see a lot of lights arranged in a row. Question: how many lights can be counted? At first glance this is an infinite number. After all, there seems to be no end to this series. But if we carry out certain mathematical calculations, we will see that even with mirrors that have 99% reflections, after about 70 cycles, the light will become twice as weak. After 140 reflections, it will weaken by a factor of two. Each time, the rays of light dim and change color. Thus, the moment will come when the light will completely go out.

So all the same, infinity is possible?

Infinite reflection of the beam from the mirror is possible only with absolutely perfect mirrors, placed strictly in parallel. But is it possible to achieve such absoluteness when nothing in the material world is absolute and ideal? If this is possible, it is only from the point of view of religious consciousness, where absolute perfection is God, the Creator of everything that is omnipresent.

Due to the absence of an ideal surface of the mirrors and the ideal parallelism of each other, a series of reflections will undergo a bend, and the image will disappear, as if around the corner. If we take into account also the fact that the person looking at this reflection, when there are two mirrors, and he between them - also a candle, too, will not stand strictly in parallel, then the visible row of candles will disappear behind the mirror very fast.

Multiple Reflection

At school, students learn to build images of an object using the laws of reflection. According to the law of light reflection in the mirror, the object and its mirror image are symmetrical. Studying the construction of images using a system of two or more mirrors, students receive as a result the effect of multiple reflection.

If a second plane mirror is added to the second plane at right angles to the first, then there will be not two reflections in the mirror, but three (usually S1, S2 and S3). The rule works: an image that appears in one mirror is reflected in the second, then the first is reflected in the other, and again. The new, S2, will be reflected in the first, creating the third image. All reflections will coincide.

Symmetry

The question arises: why are reflections symmetrical in a mirror? The answer is given by geometric science, and in close connection with psychology. What for us is the bottom and the top, for the mirror changes in places. Mirror as it turns inside out what is in front of him. But surprisingly, as a result, the floor, walls, ceiling and everything else in reflection look the same as in reality.

How does a person perceive a reflection in a mirror?

Man sees through the light. Its quanta (photons) have the properties of a wave and a particle. Based on the theory of primary and secondary light sources, photons of a light beam, falling on an opaque object, are absorbed by atoms on its surface. Excited atoms immediately return energy that they absorbed. Secondary photons are emitted uniformly in all directions. Rough and matte surfaces give a diffuse reflection.

If it is a mirror surface (or the like), then the light-emitting particles are ordered, the light exhibits wave characteristics. Secondary waves are compensated in all directions, in addition to being subject to the law, according to which the angle of incidence is equal to the angle of reflection.

Photons as though elastically jump off from a mirror. Their trajectories start from objects, as if located behind it. It is them that the human eye sees, looking in the mirror. The world behind the mirror is different from the real. To read the text there, you need to start from right to left, and the hands of the clock go in the opposite direction. The double in the mirror raises his left hand when the person in front of the mirror is the right one.

Reflections in the mirror will be different for people looking at him at the same time, but at different distances and in different positions.

The best mirrors in antiquity were those made of polished silver carefully. Today a layer of metal is applied from the back of the glass. It is protected from damage by several layers of paint. Instead of silver for saving, a layer of aluminum is often applied (the reflection coefficient is about 90%). The person's eyes do not notice the difference between the silver coating and the aluminum coating.