Light plays an important role. Thanks to the action of light radiation, a person can not only perceive visual images of objects, but also see the world around him in all its variety of colors.

What is light

Light - in physical optics electromagnetic radiation, perceived by human eye. One of the subjective characteristics of light, perceived by a person in the form of a conscious visual sensation, is its color .

In the 5th century BC. e., Empedocles suggested that everything in the world consists of four elements: fire, air, earth and water. He believed that from these four elements, the goddess Aphrodite created the human eye and lit a fire in it, the glow of which made vision possible.

The retina of the human eye has two types of light-sensitive cells: sticks And cones. The rods are highly sensitive to light and function in low light conditions, thereby being responsible for night vision. Cones have a relatively low sensitivity to light and are responsible for the mechanism day vision, only effective at high light levels.

Light art is an art form where light is the main means of expression.

Examples of the interaction of light and art are clearly visible in medieval stained glass windows.

All visual art uses light in some form, but in photography and film, the use of light is especially important. With the invention of electric light, the possibilities became much wider and many artists began to use light as their main form of expression.

Mohoy -Nagy

Dan Flavin, François Morelli, who created sculptures and installations, used various types of light: neon tubes, diffuse lighting or fluorescence.

Light graffiti

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International Year of Light and Light Technologies December 2015 2015 was declared by the UN General Assembly as the International Year of Light and Light Technologies. The goal of the initiative is to increase the world community's awareness of light issues and improve understanding of new technologies that solve energy problems in all spheres of human activity. 2015 was chosen as the year of light also because it marks a number of important round dates related to the science of light.

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Light is one of the forms of energy that the human eye can discern. Light is generated using electromagnetic radiation and travels strictly in a straight line and at a constant speed. The main colors of light are green, blue and red; when mixed in certain proportions, any existing color and shade can be obtained.

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Following Newton, who demonstrated that white light is made up of a spectrum of different colors, we must educate the world about the importance of light in building a more sustainable and peaceful future. Light brings goodness, Light develops sensitivity, response to and interaction with the world around us.

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Light for me is the stream of LOVE of the universe flowing incessantly. The huge, endless Light is mind and consciousness. Light is will and dream. Light is what reaches out when we need help so much. Light is the path to goodness and happiness. Desire for love. And to be loved. Light is hatred of dishonor, of lies, of what can kill us. Each of us knows the path to light. Don't lie, don't hit, don't humiliate. Replace hate with love. And replace timidity with strength. To look into the eyes of the enemy and light a spark of light in them.

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Sunlight plays a big role in human life. However, in addition to sunlight, people also widely use artificial sources to make the environment more suitable for work and leisure. Thousands of different types of lamps and lighting systems provide people with light and create a new, more beautiful living environment. Properly designed and selected lighting provides comfort and mood, increases productivity, and promotes health. Selecting high-quality lighting is not only about achieving sufficient illumination, but also about reliability, safety, and efficiency. The role of light in human life

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The requirements for lighting quality contained in official standards are mainly aimed at ensuring visual performance. The recommendations are based on dozens of studies conducted in different countries and are therefore the most reasonable. Basic lighting standards: Office (depending on size) - 300-500 lux (unit of illumination) Living room - 500 lux Corridor - 50 lux Staircase - 100 lux Study - 300 lux Supermarket - 500 lux Restaurant - 200 lux Museum - 200 lux Gym - 400 lux Classroom - 300 lux Laboratory - 500 lux The role of lighting in human life

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Light source is any object that emits energy in the visible range of electromagnetic wavelengths. By their nature they are divided into artificial and natural.

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Natural light sources are natural material objects and phenomena. Sun Comets Star clusters Aurora Meteorites and fireballs

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Artificial light sources are technical devices of various designs, the main purpose of which is to receive light radiation

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The sun and sunlight in human life The sun is the greatest thing that human eyes can see Robert Davydov Solar radiation stimulates the production of endorphins, “pleasure hormones,” therefore it is believed that sunlight is the best natural antidepressant. Its positive influence also extends to the sphere of interpersonal relationships: while the cold encourages us to “close ourselves,” the sun, on the contrary, “opens” us in relation to the outside world, to others. It is for this reason that in the summer it is easier for us to make new contacts and make new friends.

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Man felt the importance of the Sun for life on Earth already in ancient times. But to primitive people the Sun seemed to be some kind of supernatural creature. It was deified by almost all peoples of antiquity. Our Slavic ancestors worshiped the god of the sun's rays - Yarila, and the ancient Romans had a god of the Sun - Apollo. Kings and princes, in order to exalt their power, tried to instill in people the idea of their origin from the Sun God. The importance of the Sun for life on Earth

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The sun is a source of heat and light, without which the emergence and existence of life on our planet would be impossible. Without the Sun, there would be no green meadows, shady forests and rivers, flowering gardens, grain fields on Earth; neither humans, nor animals, nor plants could exist. The sun contains a huge amount of energy. Only about one-half of a billionth of this energy reaches Earth. But it is thanks to it that the water cycle occurs on Earth, the winds blow, life has developed and is developing. However, there are also disadvantages to this seemingly positive phenomenon. The importance of the Sun for life on Earth

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The very first source of light used by people in their activities was the fire of a fire. Over time, people discovered that more light could be produced by burning resinous woods, natural resins, oils and waxes. From the point of view of chemical properties, such materials contain a higher percentage of carbon and when burned, carbon particles become very hot in the flame and emit light. Candle Ancient time Lucina

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SIGNAL LANTERNS Before the advent of portable electric lanterns, open kerosene lamps with a wick in the spout were used. Such lamps were used when inspecting steam locomotives. A non-spill oil can was used to replenish kerosene lamps. In the past, the conductor used a flag to signal the driver during the day and a kerosene lantern at night.

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Gas lanterns Lamp gas obtained from the fat of marine animals (whales, dolphins) was used as fuel; later they began to use benzene. The idea of using gas to illuminate streets belonged to the future King George IV, and at that time the Prince of Wales. The first gas lamp was lit at his residence, Carlton House. Two years later - in 1807 - gas lamps appeared on Pall Mall, which became the world's first street with gas lighting.

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"Light in our lives"

The opening ceremony of the International Year of Light took place on 19-20 January at UNESCO headquarters in Paris. UN Secretary-General Ban Ki-moon sent a welcoming message to the ceremony, ending with the words “Let there be a year of light.”

In justifying the choice of the year, the UN General Assembly in its resolution notes that 2015 marks the anniversary of a number of important milestones in the history of light science. These include the writing of works on optics by Ibn al-Haytham (Alhazen) in 1015; Augustin Fresnel's introduction of the concept of light wave in 1815; the emergence in 1865 of the electromagnetic theory of light propagation, created by James Maxwell; the emergence in 1905 of the theory of the photoelectric effect proposed by Albert Einstein; the introduction of the concept of light into cosmology in 1915 thanks to the general theory of relativity; the 1965 discovery by Arno Penzias and Robert Wilson of the cosmic microwave background radiation; advances made in 1965 by Charles Kao in the field of fiber optic communications based on light transmission.

Light source is any object that emits energy in the visible range of electromagnetic wavelengths. By their nature they are divided into artificial and natural.

Natural light sources are natural material objects and phenomena. Sun Comets Star clusters Aurora Meteorites and fireballs

Artificial light sources are technical devices of various designs, the main purpose of which is to receive light radiation

History of the development of artificial light sources

In 1872-1873 Lodygin creates his first incandescent lamp. In the autumn of 1873, Lodygin's light bulbs light up on one of the streets of St. Petersburg. A contemporary of the inventor later wrote about this significant event: “The mass of people admired this lighting, this fire from the sky... Lodygin was the first to take the incandescent lamp out of the physics office onto the street.” 1873 is considered the year of the creation of the incandescent electric lamp. Lodygin’s first light bulbs were simply installed. They resemble modern light bulbs. The outer shell was a glass ball into which two copper rods connected to a current source were inserted (through a metal frame). A coal rod or coal triangle was fixed between the rods. Yablochkov candle Consists of 2 carbon rods, between which an arc discharge occurs. Lodygin's lamp

Yablochkov's candles appeared on sale and began to sell in huge quantities, each candle cost about 20 kopecks and burned for 1½ hours; After this time, a new candle had to be inserted into the lantern. Subsequently, lanterns with automatic replacement of candles were invented. In February 1877, the fashionable shops of the Louvre were illuminated with electric light. Then Yablochkov’s candles flared up in the square in front of the opera house. Finally, in May 1877, they illuminated for the first time one of the capital’s most beautiful thoroughfares - Avenue de l’Opera. Residents of the French capital, accustomed to dim gas lighting of streets and squares, flocked in crowds at the beginning of twilight to admire the garlands of white matte balls mounted on high metal poles. And when all the lanterns flashed at once with a bright and pleasant light, the audience was delighted. No less admirable was the lighting of the huge Parisian indoor hippodrome. His running track was illuminated by 20 arc lamps with reflectors, and the spectator areas were illuminated by 120 Yablochkov electric candles, arranged in two rows.

Halogen incandescent lamps

Energy saving fluorescent lamps

And remember the teaching is light.

> Regulatory Fundamentals of the theory of light. A person receives the main part of information through the organs of vision, and the carrier of this information is radiation called light. Thanks to the action of light radiation, a person can not only perceive visual images of objects, but also see the world around him in all its variety of colors. The meaning of light in human life The effective use of light with the help of the achievements of modern lighting technology is the most important reserve for increasing labor productivity and product quality, reducing injuries and preserving people's health. Modern society is unthinkable without the widespread use of artificial light. Lighting installations create the necessary lighting conditions that provide visual perception (vision), which provides about 90% of the information a person receives from the outside world. Without modern lighting, not a single enterprise can operate; light plays a particularly important role for workers in mines, mines, enterprises in windowless buildings, the subway, and many explosion- and fire-hazardous industries. Not a single modern city can do without artificial light; construction is impossible, as well as the operation of transport in the dark. The main task of modern lighting technology is to create a comfortable light environment for human work and rest, as well as the effective use of optical radiation in technological processes with the rational use of electrical energy. The formation and development of lighting technology is inextricably linked with progress in the field of physiology of vision, optics, and the study of electricity. The works of I. Newton, I. Lambert, M. V. Lomonosov, T. Jung and many others were of great importance for the formation of lighting technology. A new era in the history of the development of lighting technology opened with the transition to the use of electric light sources. The works of A.N. Lodygin, T. Edison, P.N. Yablochkov, which led to the creation of electric lamps, served as the basis for the progress of lighting technology. Important milestones along this path were the development and introduction of fluorescent lamps, which opened up new prospects for high-quality lighting and efficient use of electricity. In the middle of the 19th century, the English physicist Maxwell laid the foundations of the electromagnetic theory of light, according to which visible light is a type of electromagnetic oscillation with a wavelength from 380 to 760 nm (nm = 10 m). Physical foundations of the theory of light Light affects various bodies due to the fact that it transfers energy. Naturally, the effect of light depends on the amount of energy it transfers. The energy measurement system of light takes into account the energy of radiation over the entire range of wavelengths and expresses it in units of energy power - watts (W). Light falling on objects provides sufficient information about the shape and size of the observed objects. It is necessary to choose such lighting in order to obtain comprehensive information about them. Light waves of different lengths cause different color sensations in humans. The pupil of the human eye focuses rays on the sensitive receptors of the retina. The visual centers of the brain synthesize an image from many images received by both eyes viewing an object in a certain sequence. Exposure of the eye to visible radiation causes sensations of different colors from violet to red, and the eye's sensitivity to the colors of the visible spectrum varies. With the same power of light radiation, the eye is most sensitive to yellowish-green color. Towards red and violet colors, the sensitivity of the eye decreases and reaches zero at the boundaries of the visible part of the spectrum. The illumination of objects depends on many reasons: the latitude of the area, time of year and day, meteorological and other factors. All these components are largely interrelated with each other and affect the nature of the propagation of light, which is subject to the following laws. As you will soon see, this task is quite complex. Absorption of light. If rays of light meet any body on their path, then the following phenomena can occur: the rays are absorbed by the body, reflected from its surface and pass through it. Light refraction. Each beam moves uniformly and in a straight line as long as it is in the same environment and does not encounter any obstacles. When passing from one transparent medium to another, the speed of light changes, and at the boundary of adjacent media the direction of its rays changes. Thus, according to the nature of illumination, light is divided into directional and diffuse. Scattering of light. When passing through a transparent body, light rays do not remain unchanged, but are scattered. The scattering of light is greater, the less transparent and homogeneous the medium is and the longer the path light travels in it.

In this section you can find information about the importance of light and lighting in human life. Light ensures vital activity, determines a person’s vitality and biorhythms. Every day we are exposed to natural sunlight, moonlight and light from artificial sources. It would seem that lighting is needed mainly in order to see the objects around us. But in addition to vision, many other very important biological processes take place in our body under the influence of light; most people even know about them.

For most of human history, from the origin of man until the 18th century, only two light sources were available for illumination. The main one is daylight - the basis that allows us to see, having properties to which our eyes have adapted over millions of years. After some time, starting from the Stone Age, with its development of agriculture and tools, the flame of fire was added to daylight as a second, artificial light source. And from that time on, and for a considerable time, the lighting conditions did not change and remained the same. The paintings in the Altamira Cave were created to be seen by humans in the same light in which Renaissance and Baroque paintings were created.

Portal for schoolchildren. Self-preparation

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