Most likely, today there is not a single house wherethere would be 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 areglass with spraying. 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 surprised even more when they couldTo see the reflection of a mirror in a mirror - this seemed to them to be 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. It's no wonder that people attributed a lot of magical properties to this object and were even afraid of it.
The very first mirrors were made of platinum(surprisingly, but once this metal is not appreciated), 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.
From the point of view of the science of physics, the reflection of a mirror inmirror is the multiplier 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 mirror reflection in the mirror,multiplied by a relatively infinite number of times, has become one of the most popular among attractions. 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 lawpropagation and reflection of light in space. This law is the main one in optics: the angle of incidence will be the same (equal) 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 such a law, reflection works in a flat mirror, and the more its surface is perfect, the better the reflection.
But if we deal with matte surfaces or with rough surfaces, then the rays scatter randomly.
Mirrors can reflect light. What we see, all the reflected objects, is thanks to the rays that 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 a person in a mirror is the eye formed on the retina and a representation of the object with all its characteristics, color, distance, etc., transmitted to the brain.
Types of mirror surfaces
Mirrors are flat and spherical, which, inturn, 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 the following: when a person approaches, the mirror seems to come to life and begins to show the video. And this video is not chosen randomly. 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 there and want to achieve accuracy in 98%.
Spherical mirror surfaces
On what is the work of a spherical mirror based, or,as they call it, curve, - mirrors with convex and concave surfaces? From the usual, such mirrors differ in that they distort the image. Convex mirror surfaces make it possible to see more objects than flat surfaces. But 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 resultingpicture. 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.
There is another kind of mirror, in whichtranslucent 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, but with the ordinary one you can not see anything other than 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 mirrorcorridor, 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 it 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, just enter into a certain psychological state, which can adversely affect them.
If we put two mirrors opposite each other, andbetween them to light a candle, then there will be a lot of lights arranged in one 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 be twice as weak. After 140 reflections, it will weaken by a factor of two. Each time the rays of light fade 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 possibleOnly 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, then only from the point of view of religious consciousness, where absolute perfection is God, the Creator of everything that is omnipresent.
Because of the lack of an ideal surfacemirrors and perfect parallelism to each other, a series of reflections undergo a bend, and the image disappears, as if around the corner. If we also take into account 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.
At school, students learn how to build imagesobject, 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 we add to the single flat mirrorthe second located at right angles to the first, then there will be not two reflections in the mirror, but three (designated usually by 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.
The question arises: why are reflections symmetrical in the 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 it's amazing that as a result, the floor, walls, ceiling and everything else in reflection look the same as in reality.
How does a person perceive 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 have absorbed. Secondary photons are emitted uniformly in all directions. Rough and matte surfaces give a diffuse reflection.
If it is a mirror surface (or similar),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 seem to spring off from the 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 right.
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 consideredThose that are made of polished carefully silver. 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 to save, 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.