Amazing facts about light. The development of the doctrine of light until the creation of the quantum theory of light

The first scientific hypotheses about the nature of light were made in the 17th century. By this time, two remarkable properties of light had been discovered - the straightness of propagation in a homogeneous medium and the independence of the propagation of light beams, i.e. the absence of influence of one beam of light on the propagation of another light beam.

I. Newton in 1672 suggested the corpuscular nature of light. The corpuscular theory of light was opposed by Newton's contemporaries - R. Hooke and H. Huygens, who developed the wave theory of light.

The speed of light. The first great advance in the study of the nature of light was the measurement of the speed of light.

The simplest way to measure the speed of light is to measure the time it takes a light signal to travel a known distance.

However, attempts to carry out experiments of this kind ended in failure; no delay of light was found even at a distance of several kilometers from the mirror.

For the first time, the speed of light was experimentally determined by the astronomical method. Danish scientist Olaf Roemer (1644-1710) in 1676. he discovered that when the distance between the Earth and the planet Jupiter changes due to their circulation around the Sun, there is a change in the periodicity of the appearance of Jupiter's satellite Io of its shadow. In the case when the Earth is on the other side of the Sun with respect to Jupiter, the satellite Io appears from behind Jupiter 22 minutes later than it should happen according to calculations. But the satellites revolve around the planets uniformly, hence this delay is apparent. Roemer guessed that the reason for the delay in the appearance of the satellite of Jupiter with increasing distance between the Earth and Jupiter is the finiteness of the speed of light. Thus, he was able to determine the speed of light.

Definition of light

Light is electromagnetic radiation invisible to the eye. Light becomes visible when it hits a surface. Colors are formed from waves of different lengths. All colors together form white light. When a light beam is refracted in a prism or a drop of water, the entire spectrum of colors becomes visible, for example, a rainbow. The eye perceives the visible light range, 380 - 780 nm, beyond which are ultraviolet (UV) and infrared (IR) light.

The emergence of the theory of light

In the 17th century, two theories of light arose: wave and corpuscular. The corpuscular theory was proposed by Newton, and the wave theory by Huygens. According to Huygens, light is a wave propagating in a special medium, ether, which fills all space. The two theories have existed side by side for a long time. If according to one of the theories it was impossible to explain any phenomenon, then according to another this phenomenon could be explained. That is why these two theories have existed side by side for so long.

For example: the rectilinear propagation of light, leading to the formation of sharp shadows, could not be explained on the basis of wave theory. However, at the beginning of the 19th century, such phenomena as diffraction and interference were discovered, which gave rise to thoughts that the wave theory finally defeated the corpuscular one. In the second half of the 19th century, Maxwell showed that light special case electromagnetic waves. These works served as the foundation for the electromagnetic theory of light. However, at the beginning of the 20th century, it was discovered that when emitted and absorbed, light behaves like a stream of particles.

Corpuscular theory

Emission (corpuscular): light consists of small particles (corpuscles) emitted by a luminous body. This opinion was supported by the straightness of light propagation, on which geometric optics is based, but diffraction and interference did not fit well into this theory. This is where the wave theory comes from.

wave theory

Wave: light is a wave in the invisible world ether. Newton's opponents (Hooke, Huygens) are often called supporters of the wave theory, but it must be borne in mind that they understood the wave not as a periodic oscillation, as in modern theory, but as a single impulse; for this reason, their explanations of light phenomena were not very plausible and could not compete with Newton's (Huygens even tried to refute diffraction). Developed wave optics appeared only at the beginning of the 19th century.

Newton is often considered a supporter of the corpuscular theory of light; in fact, he, as usual, "did not invent hypotheses" and willingly admitted that light could also be associated with waves in the ether. In a treatise presented to the Royal Society in 1675, he writes that light cannot simply be vibrations of the ether, since then, for example, it could propagate along a curved tube, as sound does. But, on the other hand, he suggests that the propagation of light excites vibrations in the ether, which gives rise to diffraction and other wave effects. In essence, Newton, clearly aware of the advantages and disadvantages of both approaches, puts forward a compromise, corpuscular-wave theory of light. In his works, Newton described in detail the mathematical model of light phenomena, leaving aside the question of the physical carrier of light: “My teaching about the refraction of light and colors consists solely in establishing certain properties of light without any hypotheses about its origin.” Wave optics, when it appeared, did not reject Newton's models, but absorbed them and expanded them on a new basis.

Despite his dislike of hypotheses, Newton placed at the end of Optics a list of unsolved problems and possible answers to them. However, during these years he could already afford this - Newton's authority after the "Principles" became indisputable, and few people dared to bother him with objections. A number of hypotheses turned out to be prophetic. Specifically, Newton predicted:

deflection of light in a gravitational field;

the phenomenon of light polarization;

interconversion of light and matter.

Light is an amazing phenomenon, it is direct and figuratively illuminates our lives in many ways. The United Nations declared 2015 the International Year of Light to demonstrate "to the inhabitants of the Earth the importance of light and optical technologies in life, for the future and for the development of society." Here are a few interesting facts about light that you may not have known about.

1. The sun is actually white as seen from space, as its light is not scattered by our atmosphere. You won't see the Sun at all from Venus, as the atmosphere is too thick there.

2. Humans are bioluminescent due to metabolic reactions, but our glow is 1000 times weaker than what can be seen with the naked eye.

3. Sunlight can penetrate to about 80 meters deep in the ocean. If you go down 2000 meters deeper, then you can find a bioluminescent monkfish, which lures its victims with luminous flesh.

4. Plants are green because they reflect green light and absorb other colors for photosynthesis. If you put a plant under a green light, it will most likely die.

5. North and South Polar Lights occurs when the "wind" from solar flares interacts with particles earth's atmosphere. According to Eskimo legends, the aurora borealis are the souls of the dead playing football with the head of a walrus.

6. For 1 second, the Sun radiates enough energy to provide it to the whole world for a million years.

7. The longest-burning lamp in the world is a century-old lamp in the California fire department. It has been burning continuously since 1901.

8. The luminous sneeze reflex, which causes uncontrollable bouts of sneezing in the presence of bright light, occurs in 18-35 percent of people, although no one can explain why it occurs. One way to deal with it is to wear sunglasses.

9. When double rainbow, the light is reflected twice inside each water drop, and the colors in the outer rainbow are reversed.

10. Some animals see light that we cannot see. Bees see ultraviolet light while rattlesnakes see infrared light.

11. Niagara Falls was first electrically illuminated in 1879, and the lighting was equivalent to lighting 32,000 candles. Today, lighting up Niagara Falls is equivalent to lighting up 250 million candles.

12. When light passes through different substances, it slows down and refracts. Thus, the lens focuses the rays at one point and can set fire to the paper.

Laws of Light

13. Light has momentum. Scientists are developing ways to use this energy for deep space travel.

14. Frog eyes are so sensitive to light that researchers in Singapore are using them to develop incredibly accurate photonic detectors.

15. visible light is only part of the electromagnetic spectrum that our eyes see. That is why LED lamps are so economical. Unlike incandescent lamps, LED lamps emit only visible light.

16. Fireflies emit a cool glow through chemical reaction with 100 percent efficiency. Scientists are working on mimicking fireflies to create more energy-efficient LEDs.

17. To study how our eyes perceive light, Isaac Newton inserted needles into the eye socket. He tried to understand whether light is the result of something that comes from outside or from within. (Answer: both assumptions are correct, since the rods in the eyes respond to certain frequencies).

18. If the Sun suddenly came to an end, no one on Earth would notice this for another 8 minutes 17 seconds. This is the time it takes sunlight to reach the earth. But don't worry, the Sun has 5 billion more years of fuel left.

19. Despite the name, black holes are actually the brightest objects in the universe. Despite the fact that we cannot see beyond the event horizon, they can generate more energy than the galaxies in which they are located.

20. A rainbow occurs when light meets water droplets in the air, refracts and reflects inside the drop, and refracts again, leaving it.

Plan: The first information about light in the ancient period.
Creation of the foundations of geometric optics (Euclid,
Archimedes, Ptolemy, Lucretius Carus).
The development of the doctrine of light in the Middle Ages
(Roger Bacon) and in the Renaissance (Leonardo
da Vinci, Porta).
The development of the doctrine of light in the 17th century (Kepler, Hooke,
Huygens, Galileo, Fermi). Creation of beginnings
wave optics and the first optical instruments
(Lippershey, Galileo, Leeuwenhoek).
The development of optics in the 19th century. Creation
theoretical and experimental foundations
wave optics (Jung, Fresnel, Stefan,
Boltzmann, Wien, Maxwell, Michelson).

1. The first information about light in the ancient period. Creation of the foundations of geometric optics (Euclid, Archimedes, Ptolemy, Lucretius Car).

2. Development of the doctrine of light in the Middle Ages (Roger Bacon) and in the Renaissance (Leonardo da Vinci, Porta).

3. Development of the doctrine of light in the 17th century (Kepler, Hooke, Huygens, Galileo, Fermi). Creation of the principles of wave optics and the first optical instruments (Lippe

4. Development of optics in the 19th century. Creation of theoretical and experimental foundations of wave optics (Jung, Fresnel, Stefan, Boltzmann, Wien, Maxwell,

Questions:

Libmonster ID: RU-8780

The first information about the New World without using, however, the term "America" ​​was preserved in Russian in the manuscript "Monk Maximus the Greek, the legend of some partly perplexed sayings in the Word of Gregory the Theologian," dating back to about 1530 1 .

Commenting on one of the sermons of this Patriarch of Constantinople (329-389), dedicated to the superiority of Christianity over paganism in various parts of the then known world, Maxim the Greek, without any connection with the text of the sermon or any transition whatsoever, recalls the following "bewildered saying" by Gregory the Theologian: "Even through Gadir without fail" 2 . "The Hellenic sages believed that it was impossible to sail further than Gadir, since there is the southwestern end of the earth, the sea is very narrow, its course faster than the river, and from both sides the highest coastal mountains, called the "Pillars of Hercules", approached him, since the strongest and most glorious Greek hero Hercules reached this place, everywhere he cleansed the universe of all kinds of wild animals, robbers and villains. The ancient peoples did not know how to swim further than Gadir, and most importantly, they did not dare to do so; the current Portuguese and Spaniards, having taken all precautions, recently, about 40 or 50 years ago (after the seventh thousand years from the creation of the world), began to swim across big ships and they discovered many islands, of which some are inhabited by people, and others are uninhabited; and the land of Cuba, so great in size that even its inhabitants do not know where it is ends. They also discovered, rounding the entire south side and heading northeast, on the way to India, seven islands called Molluk. Cinnamon, cloves, and other fragrant and fragrant plants grow on these islands, which until then were unknown to any person, but now they are known to everyone, thanks to the kings of Spain and Portugal. The sovereigns of these people there, who until then did not know the true God and worshiped most of the creature, and not the Creator, now we will convert to our faith, that is, to the Latin, sending to them "bishops, teachers and priests, and also various artisans and all kinds of local seeds, and now opened there new world and a new congregation of men" 3 .

Gadir - Agadir, or Gaddir Carthaginian - was known to the Greeks as Gadeira, and to the Romans as Hades. This is the seaport of Cadiz (or more correctly - "Cadiz"), the base of the Spanish fleets that delivered the wealth of the New World. Maximus the Greek in this case mixed Cadiz with the Strait of Gibraltar - the "Pillars of Hercules" of the ancients.

"Southern suffering" ( southern country) Maxim the Greek - modern Africa. From the context it is obvious that Maxim the Greek was known in in general terms voyages of Vasco de Gama (1497 - 1499) and other Portuguese around the Cape of Good Hope to the western coast of India, the Malay Peninsula (1509 - 1511), the Molluk Islands (1512).

"However, the mention of the" villagers "of the Molluk Islands does not yet prove that at least vague information reached Maxim the Greek

1 Maxim Grek, secular name who was Macarius, was born in Arta (Epirus) about 1470. He was educated in Paris, Florence and Venice. In Venice, Macarius met the famous humanist and publisher Aldus Manutius. Upon his return to Greece in 1507, Maximus took monastic vows. In 1518 he was sent to Moscow by the Vatopedi monastery on Mount Athos for translation scripture from Greek into Russian, according to the proposal Basil III. Maxim the Greek died in 1556 in the Trinity-Sergius Monastery.

2 This expression is found in Gregory the Theologian in the "Sepulcher of Basil, Archbishop of Caesarea Cappadocia" (Part IV, word 43). However, Maxim Grek comments on it in the words of Gregory "To the holy lights of the manifestations of the Lord" (Creations. Edition of the Moscow Theological Academy. Part III, word 39, pp. 253 - 256. 1844).

3 Works of St. Maximus the Greek in Russian translation. Part II. Trinity-Sergius Lavra. 2911. "An explanation of some of the somewhat incomprehensible sayings in the Word of Gregory the Theologian". Quoted passage on pp. 28 - 29. Russian translation, in our opinion, is not always accurate: for example, instead of "southern side" should be translated "southern country"; instead of "artisans" - "tools" (in the original "any craft").

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about the voyage of Magellan and Del Cano (1519 - 1522). How inadequate were the ideas of Maxim the Greek about sailing to modern India, shows his message that the Molluk Islands lie on the way to India, if you go northeast from Africa 1 .

In the presentation of Maximus the Greek there is no distinct differentiation between the geographical discoveries of the Spaniards in the West Indies and the discoveries of the Portuguese in the East Indies. But Maxim the Greek knows other important cultural and geographical facts, such as the transfer by Europeans to New World"crafts", that is, their means of production, and "every local seed", as well as obtaining spices from the Molluk Islands.

It is not without interest, finally, that Maxim the Greek calls "the land of the greatest verb Cuba." This is the first geographical term in Russian referring to the New World. "Land of Cuba" represents, according to Maxim the Greek, a part of the mainland, "there is no end to the living there." As you know, Columbus, who discovered the island of Cuba on October 28, 1492, also considered it to be part of Eastern Azot.

From the passage quoted from "The Rendering of the Monk Maximus the Greek" it is obvious that he did not know the name of the new continent - America - although he already used the term "New World".

There is no need to wonder how this news about the discovery of the New World, as well as the route around Africa to India and obtaining spices from the Molluk Islands, reached Maximus the Greek. At the end of the XV - the first decade of the XVI century. Maxim Grek studied in France and Italy and was a contemporary of great events. Moscow Rus early XVI in. was not at all completely isolated from ties with the West: it is enough to recall the two-time embassy of S. Herberstein - and in 1517 and 1526. - to Moscow and Gerasimov's embassy to Rome in 1525. The Hellenized transcription of the Molluk Islands also indicates the Greek channels through which the Russians received the first information about the great geographical discoveries Spaniards and Portuguese. It is more important to establish that in the conditions of Muscovite Russia, Maxim Grek managed to get generally correct ideas about the great geographical discoveries of the Spaniards and Portuguese of the late 15th - early 16th centuries and used the term "New World".

With regard to the date of the "Tale" by Maxim the Greek, there are direct indications from him. Maxim Grek refers the voyages of the Spaniards and the Portuguese "beyond Hades" to the moment that came forty or fifty years after the end of the seventh millennium from the "creation of the world", that is, precisely to 1492, according to modern chronology. This gives grounds to attribute the date of writing the "Tale" of the monk Maxim the Greek, - apparently the earliest surviving document relating to the first Russian information about the New World - to about 1530, i.e. forty years after Columbus sailed to west and thirty years after the third expedition of Amerigo Vespucci (1501 - 1502).

The wide distribution of the writings of Maxim the Greek in Muscovite Russia provided penetration into various layers of Russian society in the 16th century. information about the great geographical discoveries of the Spaniards and the Portuguese, in particular about the discovery of the New World 2.

After the Englishman Chancellor visited Moscow in 1554, Jenkinson's travels through Muscovy to Persia in Central Asia(1557 and 1562) and a number of Dutch expeditions, of which the Barents expedition of 1596-1597 was the most remarkable, created new opportunities for trade and cultural relations between Russians and Europeans.

Both the British and the Dutch during this period were looking for a northeastern passage to the markets of Japan, China, and India. This goal, as you know, they did not achieve. Instead of China and India, the northern route to Muscovy was opened. The expedition of Willoughby and Chancellor 1553 - 1554, equipped with "The Company and Fellowship of merchant Adventurers for the discovery of unknown lands, etc.", became known as " Moscow, or Russian, company". One of Chancellor's former companions - Barrow - in 1556 reached Fr. Vaigach and entered the Kara Sea. The British competitors - the Dutch -, in turn, by 1577 established strong trade ties with Muscovy through the White Sea. In 1584 a Dutchman (from Enkhuisen) Olaver Brunel, who was a prisoner of the Stroganovs and traveled beyond the Urals to the Ob and other areas in the north on their behalf, reported detailed information about the "land of the Samoyeds" 3 . To the task of the expedition

1 Maximus the Greek follows in this case the medieval notion of "Upper India", which was supposed to lie north of China. These ideas were also held at the beginning of the new time (see the map of the world of Munster in 1540, reproduced in L. Bagrov's book "History geographical map", p. 22. Petrograd. 1917). In this regard, it is obvious that the expression of Maxim the Greek "to the rising of the winter sun to India" is deciphered as to the northeast in the direction of Upper India (India Superior).

2 Belokurov S. "On the library of Moscow sovereigns in the 16th century", pp. CCXX-CCCCXIV. M. 1899. The prevalence of the writings of Maxim the Greek is evidenced, for example, by those preserved to late XIX in. about 250 manuscript copies in 50 different libraries and private collections.

3 Gomel I. "The British in Russia", pp. 211 - 213, 219. St. Petersburg. 1869.

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Linehoten and Barents (1594) directly included "sail to northern seas to open the kingdoms of Cathay and China to the north of Norway, Muscovy and around Tartaria" 1 .

However, geographical representations in Moscow Rus developed not only as a result of increased contact with foreigners, but also due to the strengthening of the state in the center and the growth of colonization of the outskirts, especially in the north and east, "Amazed Europe, at the beginning of the reign of Ivan III, hardly even suspected the existence of Muscovy , squeezed between Lithuania and the Tatars, was stunned by the appearance of a huge empire on its eastern outskirts" 2 .

And yet, with regard to the great discoveries in the New World and in other parts of the world, the introduction of Russians in the 16th century. continued to be fragmentary. Only half a century after the "Tales of Monk Maxim the Greek", mentioning the New World, was the translation of the Polish "Chronicle of the World" by M. Velsky completed in Moscow. In this "Chronicle" the new continent is called America for the first time in Russian.

The Polish original of the "Chronicle" by Velsky came out in the first edition in 1560. Russian translations were made from the second edition of this Chronicle, 1554, and the third edition, 1564. The first surviving translation of Velsky's "Chronicle" into Russian is dated 1584 and was made not from Polish, but from Western Russian. There are a number of other translations of Velsky's "Chronicle" into Russian.

A handwritten copy of the Russian translation of Velsky's "Chronicle" kept in the Leningrad Public Library is a folio consisting of 1347 numbered sheets measuring 29x38 centimeters. The start of making a copy is dated 1671. The illustrations that were in the Polish original are not in this copy. The empty spaces left for their labels indicate that the illustrations were taken from the printed texts of the Chronicle. The Russian copy is written in cursive.

The study of America is devoted to six chapters, occupying sheets 1213 - 1245. On sheet 1304, a description of the New World is given. The section on America is entitled "On the islands of the sea New" which are nicknamed Novo "Light to the east of the Sun and to the West of the Sun and at noon and midnight, which islands and wise philosophies could not know."

The Russian translation, as a rule, closely follows the original, although there are abbreviations, inaccuracies, typos ("flounders" instead of "cannibals"), unacceptable simplifications (for example, "ounces" instead of "pounds", instead of miles - versts).

In the spirit of that time great place devoted to the story of cannibals. There is a lot in the "Chronicle" of Velsky and in the Russian translation of her fabulous information about the New World. For example, it is said that the brother of Christopher Columbus, Bartholomew, discovered gold deposits in Hispaniola (Haiti), which were developed by King Solomon.

In the section on America in Velsky's Chronicle, brief information about those who first discovered and explored it, about the geography and natives of the newly discovered lands. However, the Chronicle does not yet make a sufficiently clear distinction between discoveries in the West and East Indies.

The section on the New World begins with a description of the first voyage of Christopher Columbus. Apparently, this is the earliest mention of Columbus from the surviving monuments of Russian literature 3 . The Chronicle reports a number of general information about Columbus: that he is an Italian, originally from "Enova" (Genoa); that, having received ships from the Spanish king, Columbus sailed on September 1, 1498, from Spain and after thirty-two days of sailing discovered two islands: about. John, allegedly named after the Queen of Spain (in reality - in honor of the heir Juan), and Fr. Ispaina, or Ishpanna, is a modern Fr. Hispaniola" or Haiti 4. Later, Cuba is mentioned as having nothing to do with John (Juan) Island. John Island, that is, modern Cuba, is characterized as having no population; on the contrary, the population of Ispanna Island (about . Haiti) provides quite solid information.

Chronological information about the first expedition of Columbus in the "Chronicle" of Velsky is far from accurate. As you know, the ships of this expedition left the port of Paloe de la Frontera in Spain on August 3, 1491, on September 2 they joined at about. Ho-

1 Baker G. A history of geographical discovery and exploration, p. 122 - 123. 4930. Tartaria, ill Tataria, in the XVI-XVIII centuries was called Siberia, or the northern and northeastern parts of Asia.

2 K. Marx. "Secret Diplomacy of the 18th Century".

3 Yarmolinsky A. Studies in Russian Americana: I. "The Translation of Bielski Chronicle (1584). - Bulletin of the New York Public Library. Vol. 43. 1939, N 12 p. 899.

4 As you know, Columbus sailed from the port of Paloe de la Frontera in Islam "on August 2, 1492. After 33 part-time navigation, counting from the moment the calm at canary islands, on the ships of the expedition of Columbus, the lights of the new earth were first noticed. October 12, 1492 Columbus landed on about. Guanahani, in the Bermuda group. Guanajana Island, named by Columbus Fr. San Salvador - apparently, the modern about. Watling.

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measure, in the group of the Canary Islands, and on September 6, 1492 sailed from here to the west. On the night of October 12, 1492, the first lights were seen on the ships of the Columbus expedition, and on October 12, Columbus first set foot on a small island, which he called San Salvador (Savior). This islet in the Bahamas group is apparently a modern island. Watling - had nothing to do with either Fr. John (Kuba), nor with Fr. Hispanna (Hispaniola, or Haiti), which the first expedition of Columbus discovered later.

The Russian translation of Velsky's "Chronicle" also provides information about the second and third expeditions of Columbus. When describing the second journey, the islands of Dominica, Santa Cruz and others are mentioned, as well as Fort Tomaso on Hispaniola.

In contrast to the confused and far from accurate chronology of events associated with the previous travels of Columbus, the date of his third travel is indicated correctly; on the other hand, geographical information relating to the third voyage of Columbus sometimes takes on a fantastic shade: for example, instead of the Gulf of Paria between about. Trinidad and the South American continent appeared "Isle of Paria". Wherein, following the Polish original, in the Russian translation the Spanish names of Columbus's satellites are latinized or heavily distorted: instead of "Roland" is "Orlandus", instead of "Pedro Alonso Nino" - "Petrus Alontzus", instead of "Pinson" - "Pintsonus".

The rest of the section on America is devoted to Vespucci's voyages. It begins with a report on the third journey, which in 1501 was made by Albericus vespusius ispan. Then comes an account of the discoveries of the Portuguese in the East Indies, including the voyage of Magellan. This is followed by four chapters describing the relevant actual and doubtful voyages of Vespucci. These chapters are preceded by a general introduction-heading (sheet 1238) "About the campaign of Americus Vesputya; Americus is nicknamed the name of the great island of America, this island can be called for the fourth part of the world: but Americus Vesputya found that island" 1 .

The sources of Velsky's "Chronicle" about America show new channel obtaining geographical information in Muscovite Russia of the 16th century. These are no longer religious sources, but books printed in Basel and compiled by humanists. Through Poland and Lithuania, having passed the stage of preliminary translation into Western Russian or by direct translation of the Polish "Chronicle" of Velsky into Russian. Moscow Russia received more detailed and additional information about the great geographical discoveries, including the voyages of Amerigo Vespucci and Magellan del Cano (1519 - 1522).

A new upsurge in the Russian colonization of Siberia in the 17th century, the strengthening of the Muscovite state after the crisis of 1598-1613, and the expansion of economic and cultural ties with the West aroused great interest among Russians in foreign geographical and cartographic publications. "What was translated in Moscow in the 17th century? People were most interested in geography. All the best works on this science general who appeared in Western Europe at the end of the 16th and in the 17th century, were translated with us. These are the works of Botero, Ortelius, Mercator de Lind, the huge Amsterdam atlas Bleu, several other works, the originals (and together with the authors) of which are unknown to us "2. At the end of the 17th century, other Dutch atlases were translated and widely used in Muscovite Russia: (eg - P. Goos u Da Wit.) Thus, educated Russians in the 17th century already knew everything about the New World that Europeans knew about it at that time. https://site/Sechin

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Light is an amazing phenomenon, it literally and figuratively illuminates our lives in many ways. The United Nations declared 2015 the International Year of Light to demonstrate "to the inhabitants of the Earth the importance of light and optical technologies in life, for the future and for the development of society."Here are some interesting facts about light that you may not have known.

sunlight

1. The sun is actually white, as viewed from space, as its light is not scattered by our atmosphere. You won't see the Sun at all from Venus, as the atmosphere is too thick there.

2. Humans are bioluminescent thanks to metabolic reactions, but our glow is 1000 times weaker than what can be seen with the naked eye.

3. Sunlight can penetrate deep ocean for about80 meters. If you go down to 2000 meters deeper, then you can find a bioluminescent monkfish there, which lures its victims with luminous flesh.

4. Plants are green because they are reflect green light and absorb other colors for photosynthesis. If you put a plant under a green light, it will most likely die.

5. Northern and southern aurora occurs when the "wind" from solar flares interacts with particles of the earth's atmosphere. According to Eskimo legends, the aurora borealis are the souls of the dead playing football with the head of a walrus.

6. In 1 second, the Sun emits enough energy to provide it to the whole world for a million years.

7. The longest-burning lamp in the world is a century-old lamp. at the California Fire Department. It has been burning continuously since 1901.

8. light sneeze reflex, which causes uncontrollable sneezing attacks in the presence of bright light, occurs in 18-35 percent of people, although no one can explain why it occurs. One way to deal with it is to wear sunglasses.

9. When double rainbow, the light is reflected twice inside each water drop, and the colors in the outer rainbow are reversed.

10. Some animals see light that we cannot see. Bees see ultraviolet light, while rattlesnakes see infrared light.

11. Niagara Falls was first electrically illuminated in 1879, and the lighting was equivalent to lighting 32,000 candles. Today, lighting up Niagara Falls is equivalent to lighting up 250 million candles.

12. When light passes through different substances, it slows down and refracts. Thus, the lens focuses the rays at one point and can set fire to the paper.

Laws of Light

13. Light has momentum. Scientists are developing ways to use this energy for deep space travel.

14. Frog eyes are so sensitive to light that researchers in Singapore are using them to develop incredibly accurate photonic detectors.

15. Visible light is only part of the electromagnetic spectrum that our eyes see. That is why LED lamps are so economical. Unlike incandescent lamps, LED lamps emit only visible light.

16. Fireflies emit a cold glow through a chemical reaction with 100 percent efficiency. Scientists are working on mimicking fireflies to create more energy-efficient LEDs.

17. To study how our eyes perceive light, Isaac Newton inserted needles into his eye socket. He tried to understand whether light is the result of something that comes from outside or from within. (Answer: both assumptions are correct, since the rods in the eyes respond to certain frequencies).

18. If only The sun suddenly came to an end, no one on Earth would have noticed this for another 8 minutes 17 seconds. This is the time it takes for sunlight to reach the Earth. But don't worry, the Sun has 5 billion more years of fuel left.

19. Despite the name, black holes are actually the brightest objects in the Universe. Despite the fact that we cannot see beyond the event horizon, they can generate more energy than the galaxies in which they are located.

20. A rainbow occurs when light meets water droplets in the air, refracts and reflects inside the drop, and refracts again, leaving it.