Most likely, today there is not a single house where there is no mirror. It has become such an integral part of our lives that it is difficult for a person to do without it. What is this object, how does it reflect the image? And if you put two mirrors opposite each other? This amazing item has become central to many fairy tales. There are enough signs about him. What does science say about the mirror?
A bit of history
Modern mirrors are mostly coated glass. As a coating, a thin metallic layer is applied to the reverse side of the glass. Literally a thousand years ago, 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 are generally a relatively young invention. Himapproximately 400 years old.
Mirror people were even more surprised when they could see the reflection of the mirror in the mirror - it generally seemed to them something magical. After all, the image is not the truth, but a certain reflection of it, a kind of illusion. It turns out that we can simultaneously see the truth and the illusion. No wonder people attributed many magical properties to this item and were even afraid of it.
The very first mirrors were made of platinum (surprisingly, once this metal was not valued at all), gold or tin. Scientists have discovered mirrors made back in the Bronze Age. But the mirror that we can see today began its history after they were able to master the technology of glass blowing in Europe.
Scientific view
From the point of view of the science of physics, the reflection of a mirror in a mirror is a 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, in the Disney park there is a so-called endless hall. There, two mirrors were set opposite each other, and this effect was repeated many more times.
The resulting reflection of a mirror in a mirror, multiplied by a relatively infinite number of times, has become one of the most popular rides. Such attractions have long entered the entertainment industry. At the beginning of the 20th century, an attraction called the Palace of Illusions appeared at an international exhibition in Paris. Heenjoyed great popularity. The principle of its creation is the reflection of mirrors in mirrors installed in a row, the size of a full human height, in a huge pavilion. People had the impression that they were in a huge crowd.
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 it is thrown vertically downwards towards the floor, it will also bounce vertically upwards. If it is thrown at an angle, it will rebound at an angle equal to the angle of incidence. Rays of light from a surface are reflected in the same way. Moreover, the smoother and smoother this surface, the more ideally this law works. Reflection in a flat mirror works according to this law, and the more ideal its surface, the better the reflection.
But if we are dealing with matte or rough surfaces, then the rays scatter randomly.
Mirrors can reflect light. What we see, all reflected objects, is due to rays that are similar to those of the sun. If there is no light, then nothing can be seen in the mirror. When light rays fall on an object or on any living being, they are reflected and carry information about the object with them. Thus, the reflection of a person in a mirror is an idea of an object formed on the retina of his eye and transmitted to the brain with all its characteristics (color, size,remoteness, etc.).
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 its operation is as follows: when a person approaches, the mirror seems to come to life and starts to show the video. And this video was not chosen by chance. A system is built into the mirror 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 demo that can potentially interest a person. It works 85 times out of 100! But scientists do not stop there and want to achieve an accuracy of 98%.
Spherical mirror surfaces
What is the basis of the work of a spherical mirror, or, as they also call it, a curved one - a mirror with convex and concave surfaces? Such mirrors differ from ordinary mirrors in that they distort the image. Convex mirror surfaces make it possible to see more objects than flat ones. 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 both on the left and on the right.
A concave curved mirror focuses the resulting image. In this case, you can see the reflected object as detailed as possible. A simple example: these mirrors are often used in shaving and in medicine. Image of the subject insuch mirrors is assembled from images of many different and separate points of this object. To build an image of any object in a concave mirror, it will be enough to build an image of its extreme two points. Images of other points will be located between them.
Translucent
There is another kind of mirrors that have translucent surfaces. They are arranged in such a way that one side is like an ordinary mirror, and the other is half transparent. From this, transparent side, you can observe the view behind the mirror, and from the normal side, nothing is visible except the reflection. Such mirrors can often be seen in crime films, when the police are investigating and interrogating the suspect, and on the other hand they are watching him or bringing witnesses for identification, but so that they are not visible.
The myth of infinity
There is a belief that by creating a mirror corridor, you can achieve infinity of the light beam in the mirrors. Superstitious people who believe in divination often use this ritual. But science has long proven that this is impossible. Interestingly, the reflection of light from a mirror is never complete, 100%. This requires a perfect, 100% smooth surface. And it can be about 98-99% so. There are always some errors. Therefore, girls who guess in such mirrored corridors by candlelight risk, at most, simply entering a certain psychological state that may negatively affect them.
If you put two mirrors opposite each other, and light a candle between them, you will see manylights lined up in a row. Q: How many lights can you count? 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% reflection, after about 70 cycles, the light will become half 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 go out altogether.
So is infinity still possible?
Infinite reflection of a beam from a mirror is possible only with absolutely ideal mirrors placed strictly 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 omnipresent.
Due to the lack of an ideal mirror surface and their perfect parallelism to each other, a series of reflections will undergo bending, and the image will disappear, as if around a corner. If we also take into account the fact that a person looking at this reflection, when there are two mirrors, and he is also a candle between them, will also not stand strictly parallel, then the visible row of candles will disappear behind the frame of the mirror rather quickly.
Multiple reflection
At school, students learn to build images of an object using the laws of reflection. According to the law of reflection of light in a mirror, an object and its mirror image are symmetrical. Studying the constructionimages using a system of two or more mirrors, students get the effect of multiple reflections as a result.
If you add a second one at right angles to the first to a single flat mirror, then not two reflections in the mirror will appear, but three (they are usually designated S1, S2 and S3). The rule works: the image that appears in one mirror is reflected in the second, then this first is reflected in another, and again. The new one, S2, will be reflected in the first one, creating a third image. All reflections will match.
Symmetry
The question arises: why are the reflections in the mirror symmetrical? The answer is given by geometric science, and in close connection with psychology. What is up and down for us is reversed for the mirror. The mirror, as it were, turns inside out what is in front of it. But surprisingly, in the end, the floor, walls, ceiling and everything else in the reflection look the same as in reality.
How does a person perceive reflection in a mirror?
Man sees through light. Its quanta (photons) have the properties of waves and particles. Based on the theory of primary and secondary light sources, photons of a beam of light, falling on an opaque object, are absorbed by atoms on its surface. Excited atoms immediately return the energy they have absorbed. Secondary photons are emitted uniformly in all directions. Rough and matte surfaces give a diffuse reflection.
If this is a mirror surface (or similar), thenlight-emitting particles are ordered, light exhibits wave characteristics. Secondary waves compensate in all directions, in addition to being subject to the law that the angle of incidence is equal to the angle of reflection.
Photons seem to rebound elastically from the mirror. Their trajectories start from objects, as if located behind him. It is them that the human eye sees when looking in the mirror. The world behind the mirror is different from the real one. To read the text there, you need to start from right to left, and the clock hands go in the opposite direction. The doppelgänger in the mirror raises his left hand while the person standing in front of the mirror raises his right.
Reflections in the mirror will be different for people looking into it at the same time, but at different distances and in different positions.
The best mirrors in antiquity were those made of carefully polished silver. Today, a layer of metal is applied to the back of the glass. It is protected from damage by several layers of paint. Instead of silver, to save money, a layer of aluminum is often applied (reflection coefficient is approximately 90%). The human eye hardly notices the difference between silver coating and aluminum.
