Incredible Facts

People began to measure time relatively recently in relation to our entire long history. The desire to synchronize our actions came about 5000-6000 years ago, when our nomadic ancestors began to populate the land and build civilizations. Before that, we divided time only into day and night, namely: bright days for hunting and work, and dark nights for sleep. But since people began to feel the need to coordinate their actions for holding public meetings and similar events, they saw fit to introduce a time measurement system.

To be sure, scientists will tell you that we are deceiving ourselves when we think we are actually keeping track of time. "The difference between past, present and future is just a persistent illusion," said Albert Einstein. His daily walks near the clock tower in Bern, Switzerland, led the scientist to some world-changing ideas about the nature of time.

However, whether time is real or not, its dimension has nonetheless become vital to us. Over the centuries, people have come up with various creative methods of timekeeping, from the simplest sundials to atomic clocks. Below are various ways measurements of time, some of them newest and some as old as time itself.

Sun

Ancient people turned to nature to create the first timekeeping. People began to track the movement of the Sun across the sky, and then began to use objects to measure changes. The Egyptians are supposed to have been the first to create timekeeping science. In 3500 B.C. they erected obelisks and placed them in strategic places where, at certain times, "instruments" would cast shadows. At first glance, these obelisks could only mark the arrival of noon, but then they began to make deeper subdivisions.

Two thousand years later, the Egyptians developed the first sundial, the "dial" of which was divided into 10 parts. The sundial worked by tracking the movement of the sun. When the clock showed noon, it was necessary to move the clock hand 180 degrees in order to measure the afternoon time. Of course, the ancient sundial could not determine exact time on a cloudy day or at night. In addition, the time shown by the sundial was inaccurate, since at different times of the year the hours were shorter or longer depending on the season. However, a sundial was better than nothing, and by 30 B.C. over 30 various kinds watches were used in Greece, Italy and Asia Minor. Even today, the sun is at the heart of our timing system. We have created planetary time zones in order to simulate the rotation of the Earth around the Sun.

Stars

The ancient Egyptians are believed to have developed the first way of telling time at night, inventing the first astronomical instrument, the merkhet, around 600 BC. The tool is a taut string with a weight that works the same way a carpenter uses a plumb bob today.

Egyptian astronomers used two merkhets oriented to the North Star in order to identify the celestial meridian in the night sky. Time was counted according to the principle of crossing this meridian by the stars.

Stars were used not only to mark the passage of hours, but also the passage of days. This measurement of the Earth's rotation is called sidereal time.

When a certain imaginary point among the stars crosses the celestial meridian, then this moment is designated as sidereal noon. The time that has passed from one sidereal noon to another is called a sidereal day.

Hourglass

The origin of the hourglass goes far back in time. They consist of two glass flasks, one on top of the other with a narrow opening between them. Sand gradually gets from the top to the bottom when the watch is turned over. When all the sand has passed from the top to the bottom, this means that the time is up, however, this does not always mean that an hour has passed.

An hourglass can be made to measure almost any short period of time by simply adjusting the amount of sand it contains, or the opening between the flasks.

water clock

The water clock, known as the "clepsydra", was one of the first devices that did not use the sun or stars to measure time, that is, they could be used at any time of the day.

Water clocks work by measuring the amount of water that drips from one container into another. They were invented in Egypt, but spread throughout the ancient world, and in some countries people used water clocks even in the 20th century.

The ancient Greeks and Romans built large water clocks in the form of towers, and in China such clocks were called "Lu" and were often made of bronze. However, although water clocks were very common, they were not entirely accurate.

Mechanical watches

In Europe, in the 1300s, inventors began making mechanical clocks that worked with a system of weights and springs. These first watches did not have a front and hands, and the passage of the hour was indicated by a bell. In fact, the word clock comes from the French "bell". These huge first clocks, as a rule, were installed in churches and monasteries in order to announce the time of the arrival of the need to pray.

Soon there were watches with two hands, minute and hour. Later, table and mantel clocks began to appear. Although the clock was improved, it was still inaccurate. In 1714, the British Parliament offered a handsome reward to anyone who could develop an accurate clock that would aid the work of maritime navigation. As a result, such clocks were invented, their error was only five seconds. With the advent of the industrial revolution, the mass production of watches began, thanks to which this device got into the house of every person.

Fancy watch

When we think of watches, we tend to think of the familiar dial with two or perhaps three hands. For many centuries, people have created all kinds of designs in order to determine the time. The Chinese invented the incense clock between 960 and 1279, and then it spread throughout East Asia. In one type of incense clock, metal balls were attached to incense with wire. When the incense burned down, the metal ball fell and a gong sounded, indicating the passage of an hour.

Other watches used color in their work, and some used different scents to represent different periods of time. There were also watches made from a marked candle, when the candle burned down to a certain mark, then a specified period of time passed.

Wrist watch

The discovery in the 1400s that spiral springs could be reduced in size led to the creation of wrist watch. At that time and for many centuries after that, pocket watches were the priority of men, while women wore wristwatches. All these fashion rules changed during the Second World War, and as a result, since then, men began to wear wristwatches. The gift of a watch symbolized the transition to maturity.

However, as the 21st century develops, the ubiquitous wristwatch may gradually fade into oblivion, since now we most often check the time by looking at a computer monitor, mobile phone or the display of an MP3 player. However, still an informal survey of several thousand people showed that most of them are not going to give up their watches.

Quartz watch

Mineral quartz, usually with the help of a battery, is the main driving force behind quartz watches.

Quartz is a piezoelectric material, which means that when a quartz crystal is compressed, it generates a small amount of electrical current that causes the crystal to vibrate. All quartz crystals vibrate at the same frequency.

Quartz watches use a battery to create a crystal vibration and to count vibrations. Thus, the system operates in such a way that one pulse per second is generated. Quartz watches still dominate the market due to their precision and low manufacturing cost.

atomic clock

Although the name sounds quite intimidating, in fact, atomic clocks do not pose any danger. They measure time by tracking how long it takes one atom to go from positive to negative energy state and back again.

The official time standard for the United States is set by NIST F-1, the atomic clock of the National Institute of Science and Technology in Boulder, Colorado. The NIST F-1 is a fountain clock named after the atomic movement. Scientists inject cesium gas into the watch's vacuum center and then add direct infrared laser beams at a 90-degree angle. The power of the laser collects all the atoms in one place, which is affected by the microwave-filled area with great force. Scientists measure the number of atoms that are in an altered state, and also control microwaves by setting them at different frequencies until most of the atoms change their state. As a result, the last frequency at which atoms change is the frequency of vibrations of cesium atoms, which is equal to a second. It sounds quite complicated, however, this technology is the world standard for measuring time.

Atomic clocks keep track of the smallest changes in time.

Calendars

As we have seen, the actual counting of minutes and seconds requires quite complex procedures, but the counting of days and months is based on the position of the sun and moon. Different cultures, however, use different methods.

The Christian or Gregorian calendar, one of the most popular today, is based on the sun. The Islamic calendar uses the phases of the moon, the Hebrew and Chinese calendars rely on a combination of both.

In the Gregorian calendar, a day is the time elapsed from one sunrise to the next, or one full revolution of the Earth on its axis. A month, in the Gregorian calendar, is approximately 29.5 days, which is one complete cycle of the phases of the moon, and a year is 364.24 days, or the time it takes for the Earth to make full circle along the orbit of the sun.

When solving some problems of increased difficulty, when solving Olympiad problems, when reading additional literature for the lessons of mathematics, history, etc., there is a need to translate ancient measures of weight, volume, length, time into modern ones and vice versa.

When solving problems with economic content, especially historical problems in the lessons of mathematics and economics, it is necessary to transfer prices from one measurement system to another, to be able to make calculations.

MEASUREMENT

A person in his life cannot do without measurements. Without measurements, he would not be able to sew his own clothes, build a house, design a spaceship. Man has learned to measure many quantities, such as time, area, volume, mass, temperature, length.

On each student's notebook, even if it has not been started, there is already an entry. On the last page of the cover, in clear letters, is printed:

"1 kilometer (km) = 1000 meters (m)"; or "1 cu. meter (cubic meters) \u003d 1000 cubic decimeters \u003d 1,000,000 cubic meters centimeters (cc)”, etc. These are units of measure. Once they were very different.

Since ancient times, different nations have had very different measures of length: the elbow, the foot, the thickness of a camel's hair, the width of the grain, the step of an adult man, etc. Even in one country there were no common measures, so disputes often arose due to measuring and weighing. One of the achievements of the Great French bourgeois revolution was the decision to introduce a single metric system of measures on the territory of the republic. Particular merit in the preparation of the law on new measures belongs to the French mathematician J. Pagrange (1736-1823) and politician Prieur Duvernoy (1763-1827). It was decided to take as a unit of length 1/10,000,000 part of a quarter of the Paris geographic meridian. The measurement of a part of this meridian between the cities of Dunkirk and Barcelona was carried out for almost 6 years by two French scientists: P. Mechain and J. Delambert. In Russia, N.I. was the first to accept the meter as a unit of length. Lobachevsky (1792-1874).

The initiator of the introduction of the metric system of measures as an international one was Russian scientists headed by B.S. Jacobi (1801-1874). This system of measures became obligatory in our country only after the Great October Socialist Revolution.

The Bible counts by cubits. The calculation of the ancient Greeks was based on dactylos - a finger (from dactylos - poetic size dactyl, similar to a finger with one long joint and two short ones), then came the palm - 4 fingers, 16 fingers made up the foot, one and a half feet - the elbow. Pletra - 100 feet, stages - 6 pletras. The same with the ancient Romans: digitus, or thumb, dog - foot, passis, or double step. A thousand double steps, or, in Latin, a mille (thousand) passum, was equal to our 1478.7 meters. The word mile has survived to this day in many languages.

But counting body parts gave more than just a mile. In ancient times, we measured in elbows, spans (the word "span" is also included in today's language), that is, the distance between the spread little finger and the thumb. In the charter of Vsevolod about church courts and about people and measures of trade, until 1136, the “elbow of Evan” was mentioned. During the excavations of A.V. Artsikhovsky in Novgorod in 1948, a wooden sample of the “Evan” elbow with an inscription was also found. The Egyptians used their elbows to measure the rise of the Nile. The old count for arshins of the same origin: arash, in Persian - cubit, passed into the Tatar measure of arshins, and we borrowed it from the Tatars.

The English measure foot also means foot in English. Since the feet of people are not the same size, misunderstandings occurred. Therefore, in the VIII century, King Charlemagne announced that the foot from now on is the length of his foot (why in English language the name "royal foot" has been preserved).

The inch also comes from the name of the body part (thumb). “Inch” is the Dutch name for the thumb, this measure was used to measure small objects (for example, in the fairy tale “Thumbelina” by G.Kh. Andersen, the main character is a girl of very small stature, an inch high; she was called Thumbelina). The concepts of space and time sometimes replaced each other in the language. We often say: "half an hour's journey" and "did not have time to go five miles." Measures of distances figuratively began to mean. That a stage has been passed or completed. Thus, the Greek measure - stage - in our language has become a stage of development. The old Russian measure - the field (about one and a half kilometers) began to mean in the old book language not only the path (on the path of glory, in the field of glory), but also the area of ​​\u200b\u200bactivity (in the field of science). Mathematics, unlike other subjects, has an abstract, abstract character. We have to operate with such concepts as number, measure, spatial forms. Information from the history of length measures, including native Russian ones, convincingly reveals the connection between mathematics and life, shows that people did not invent units of measurement, but first took parts of their bodies as measures, which gradually turned into generally accepted samples.

It should be noted that the ratio between the ancient measures of length and mass was not decimal, as it is now, so it took a lot of time to master the ability to perform operations with quantities. It was even more difficult in those cases when it was required to transfer the measures of one country to the measures of another, since each state had its own system of measures. This complicated trade and relations between people.

FROM THE HISTORY OF MEASURES OF LENGTH

It is impossible to imagine the life of a person who does not make measurements. Even primitive man resorted to measurements during the construction of his dwelling.

The first measuring instruments were body parts: fingers, palm, foot, step. So, among the ancient Egyptians, the cubit (the distance from the end of the fingers to the bent elbow) served as the main measure of length. It was divided into seven palms, and the palm - into four fingers.

With this measure, most often the length of tapes or matter was measured.

A full turn of cloth around the elbow was sometimes called a double elbow. To make measurements more accurate and not depend on the height of people, in ancient Egypt they came up with exemplary measures: elbow, palm, finger. Now it doesn’t matter how long a person’s arm is, he measured it not with his own, but with a common elbow, i.e. conventional stick, one cubit long. They were used in the construction of structures and other works. The sample of the "sacred" elbow was kept by the priests in the temple.

In England, there were also units of length associated with parts of the human body: inch, foot, yard. An inch (translated from Dutch means thumb), equal to the length of three barley grains, pulled out from the middle part of the ear and attached to each other ends. foot (from English word leg).

In 1101, the main measure of the length of a yard was legalized there - the distance from the nose of King Henry I to the end of the middle finger of his outstretched hand.

Many peoples measured length with steps, double steps or canes. Sometimes a double cane was used, equal to four steps. Even before our era, in the Roman state, and later in Italy, in the countries of Asia and Africa, a thousand canes were used to measure long distances, from which a new measure came - a mile (from the Latin word for a thousand). Long distances were also measured by crossings, halts, days. For example, they said that the distance from one city to another is three days' journey.

In Japan, there was a measure called a horse shoe. It was equal to the path during which the straw sole tied to the horse's legs wore out. The nomadic Mongols determined the distances in camel or horse crossings, always adding: "with a good (bad) ride."

For many peoples, the distance was determined by the range of an arrow or a cannon ball. To this day, the expression has been preserved to prevent a cannon shot.

What are the measures of length used in Rus' in the old days?

The most ancient of them were the cubit and fathom. The concept of elbow is already familiar to us. The oldest mention of a sazhen (from syagat - to get to something, to achieve) is found in the "Word about the beginning of the Kiev-Pechersky Monastery" and refers to the 11th century. There is reason to believe that the sazhen was then smaller: not three arshins, but three cubits. But even after the three-arshin sazhen was established, other sazhens existed in everyday life - flywheel and oblique. So,

Fathoms were distinguished oblique and flywheel. Flywheel - the distance between arms outstretched in both directions at the ends of outstretched middle fingers; oblique - from the heel of the right foot to the fingertips of the outstretched left hand. Sometimes they say about a person: "In the shoulders - an oblique fathom." To measure long distances, a verst equal to 500 sazhens was used.

In the 17th century as a result of the development of trade with the eastern peoples, the measure arshin came into use (from the Persian arsh - cubit). It is equal to 71 cm 12 mm. He came to Rus' together with merchants from distant countries.

Merchants brought unprecedented fabrics: the finest Chinese silks, heavy Indian brocade made of real gold and silver threads, velvet, etc. They brought priceless works of art created by folk craftsmen in their bales. Now these fabrics and clothes sewn from them are kept in museums, and they amaze with their splendor no less than 500 years ago. But 500 years ago, merchants traded them and they had to be measured. How was it done? Our stores use wooden meters. Eastern merchants did without any meters: they pulled the fabric over own hand, up to the shoulder. This was called measuring with arshins.

Although the measure was very convenient - hands are always with you - but it had a significant drawback: unfortunately, everyone's hands are different. Some were long, others were short. The cunning merchants quickly realized that they needed to look for clerks with shorter hands: the same piece, but more arshins.

But one day it came to an end. It was strictly forbidden by the authorities to sell “at your own yard”. It was allowed to use only state arshin. The state arshin - a ruler the length of someone's arm - was made in Moscow, then copies were made from it and sent to all parts of Russia. So that the wooden arshin could not be shortened, its ends were bound with iron and marked with a seal. Tens of years are no longer measured in arshins, but this word has not been forgotten. Until now, they say about a shrewd person: “he sees three arshins under the ground”, and about a person who judges everything only by himself, he “measures to his own arshin”.

Question. What did people take as the basis for counting different periods of time? How did they learn to count days, months, years?

Answer. People took the Moon and the Sun as the basis for calculating time intervals, the main thing in this orientation was the Sun. To be more precise, rotation around its axis and rotation around the Sun. A day is the time it takes for the Earth to completely rotate on its axis. A month is the time it takes for the moon to revolve around the earth. A year is the time it takes for the Earth to revolve around the Sun.

Question. How long is the day?

Answer. The day lasts 24 hours.

Question. Why are there 7 days in a week?

Answer. The full moon is not seen every day. First, a narrow crescent appears in the sky, then the Moon becomes wider, grows fatter day by day, and after a while becomes completely round. And then, after a few days, it starts getting smaller and smaller, becoming a narrow sickle again. Such changes of the moon occur every four weeks or 29 and a half days. This is called the lunar month. It served as the basis for the creation of the calendar. Therefore, the crescent of the moon began to be called the "month".

Historical sources date the first mention of the seven-day week to the period of Ancient Babylon (about 2 thousand years BC), from there this tradition passed to the Jews, Greeks, Romans and, of course, to the Arabs. It is believed that India also adopted the 7-day period from Babylon.

For Jews and Christians, the Old Testament gives answers to these questions, from where it becomes clear that the seven-day time structure is established by God. Let me remind you: on the first day of creation, light was created, on the second - water and firmament, on the third - land, seas and flora, on the fourth - luminaries and stars, on the fifth - animal world, on the sixth - man was created and commanded to multiply, the seventh day is consecrated for rest.

The seven-day week turned out to be very viable, even the transition from the Julian calendar to the Gregorian did not change the sequence of days, the rhythm was not disturbed. There is also an astronomical explanation for the 7-day period. 7 days is approximately a quarter of a lunar month, while observing the phases of the moon was for the ancients the most accessible and convenient way to measure time. A more subtle explanation can be found in the correspondence of the seven visible planets to the days of the week, and it is this logical move that sheds light on the origin of the modern calendar names of the days of the week.

Question. Why is there 365 days in a normal year and 366 in a leap year?

Answer. The true year is 365 days 5 hours 46 minutes 48 seconds. Thus, in 4 years, one more day accumulates. It is in this year that February has 29 days and is called a leap year.

What is a day

Question. What was the first measure of time? How did the ancient peoples celebrate it?

Answer. The most ancient “clock”, which, moreover, never stopped or broke, turned out to be the Sun. Morning afternoon Evening Night. Not very accurate measurements, but at first this was enough for primitive man. People made notches on posts, notches on mammoth tusks. Others extruded circles on clay pots, or tied knots on leather straps. So the first records of the lived days appeared. The ancient Egyptians divided the night, and then the day into 12 parts - according to the number of constellations they read, which could be observed during the night.

Then people learned to determine the time more accurately: during the day - according to the Sun, and at night - according to the stars. People have noticed that the stars in the sky are moving slowly. All of them seem to be tied with invisible threads to a bright star, which is always in the same place. Perhaps that is why some nations call it the Nail of Heaven. We call this star the Polaris; it shows the direction to the north, to the North Pole. Not far from the North Star in the sky, you can always find seven stars arranged in the form of a ladle or saucepan with a long handle. This is the constellation Ursa Major. During the day, the Big Dipper goes around the Polar Star in a full circle, in the night half a circle. So it turns out that there is a real night clock with a star arrow in the sky.

Question. Try to explain why we do not notice the rotation of the Earth.

No wonder for a long time people believed that the Earth is flat, like a table or like a pancake, rests on three whales (or three elephants). With the development of science, people's ideas about the Earth have changed. Now we know that the Earth is involved in several movements at the same time.

Without noticing the rotation of the Earth, we observe and feel its consequences - the change of day and night. If the Earth did not rotate, then on the side that faces the light, there would always be day, and the opposite side would always be in darkness. We also do not notice the movement of the Earth around the Sun, but, nevertheless, we see and feel the change of seasons. The Earth revolves around the Sun in 365.25 days. This period of time is called a year.

Our planet is involved in several other types of motion: relative to the Milky Way. The Milky Way moves relative to other galaxies. There is nothing immovable, unchanging, once and for all given in the Universe.

Question. Think about whether it is possible to organize the life of a family, a city, a state without knowing time. What happens if all the clocks suddenly disappear?

Answer. It is impossible to organize the life of a family, a city, a state without knowing the time. Time organizes people's lives; modes of work, study, and the armed forces are subordinate to it. The work of computers is tied to time. Time determines the work of transport and much, much more.

Exercise. Think about whether you can increase or decrease the length of the day. How is it defined?

Answer. It is not possible to increase or decrease the length of the day. It is equal to 24 hours and this is the time of a complete rotation of the Earth around its axis. Now a person is not able to slow down and speed up this rotation.

Exercise. Discuss why in different places on the Earth the length of the day is the same, but the length of daylight hours is different? What does it depend on?

Answer. The rotation of the Earth around its axis is a day and they are equal in all points of the globe. But the length of daylight hours depends on the height of the Sun above the horizon. And it is different in different parts of the world. That is why somewhere the daylight hours are longer, and somewhere shorter.

Exercise. Consider the drawing on p. 12. Think about where on Earth it is noon, midnight, morning, evening.

Answer. On Earth, noon in Africa, midnight in America, evening in Australia, morning in Western Europe.

How the years count

Question. What movement of the Earth is taken as the basis for counting years?

Answer. The calculation of years is based on the movement of the Sun around the Earth. One full rotation is equal to one year.

Question. Explain why we do not notice the movement of the Earth around the Sun.

Answer. Because it is impossible to notice the rotation of the Earth, being on its surface. Man is too small compared to the globe. In addition, we rotate with the Earth. Rotation can only be seen from the side.

Exercise. Think about whether the duration of winter is the same everywhere on Earth.

Answer. The duration of winter on Earth is not the same in different parts. This is due to the tilt of the Earth's axis and the distance from the equator. Due to this, the height of the Sun above the horizon is not the same. The farther from the equator, the lower the Sun above the horizon, so the winter in these places will be longer.

How months are counted

Question. Observing which cosmic bodies can one count days, weeks, months, years?

Answer. Watching the Moon, the Sun, you can count days, weeks, months, years.

Question. Why does the appearance of the moon in the sky change and repeat?

Answer. The Moon is a natural satellite of the Earth. During its movement, it occupies a different position relative to the Sun and the Earth. During its movement, it occupies a different position relative to the Sun and the Earth. Therefore, its appearance in the sky changes. The time of one revolution of the Moon around the Earth is another measure of time - a month.

Question. Why are there 12 months in a year?

Answer. 12 months in a year is equal to the number of revolutions of the Moon around the Earth during the year.

Exercise. Review the drawings. At the beginning or end of the month, does the student observe the moon?

Answer. the schoolboy has to observe the moon at the beginning of the month or at the new moon.

Exercise. Discuss what the images of the moon might have been on ancient objects that marked the weeks of the month.

Answer. In places of ancient settlements, objects with images of views of the moon with notches depicting months are often found. Different nations gave them their names. The ancients noted four types of the moon, which change during the month every seven days. Images could be as follows: a light circle - a full moon. Half of the circle - the direction depending on the moon's waxing or waning, dark circle - the moon is not in the sky.

What clock did man invent

Question. What is the hand in a sundial?

Answer. On a sundial, the arrow is the shadow of the sun. Ancient people measured time during the day with the help of a gnomon - a high vertical pole. During the day, the shadow from him slowly turns and its length changes. Over time, a dial was placed under the gnomon, on which the shadow from it indicated the time. Thus, the sundial was born.

Question. What time does the clock show at noon?

Answer. To determine the onset of noon, you need to take a twig 1 meter high and notice when it casts the shortest shadow. This will take place between 11 am and 1 pm. Perhaps the time of noon will not coincide with 12 o'clock on the dial.

Question. How to check the accuracy of your watch?

Answer. Radio time signals are given by special quartz clocks. They can get ahead or behind by only 7 seconds in 274 years. Even more accurate clocks, by which you can correct the course of all other clocks, are atomic clocks. They are kept at a constant temperature, and sometimes even placed underground, in special deep mines. Despite all possible precautions, even atomic clocks can be slightly faster or slower. Therefore, they are adjusted according to the most important natural clock - according to the star.

Exercise. Look at the drawings of the clock. Explain how they are set up. Which of them are convenient to use? What clock is shown in the center?

Answer. On the image:

Fire clock, time is determined as the candle burns out

Hourglass - as the sand pours out

Clock with a weight - the weight moves the hands on the dial

Water clock - the mechanism of the clock is powered by falling water

Mechanical watch - clock mechanism consists of gears

Electronic clock - based on semiconductors

Star clock - determines the time by the position of the stars

It is most convenient to use an electronic clock - they are the most accurate and reliable. The Kremlin chimes are depicted in the center.

Who is who in the world of discoveries and inventions Sitnikov Vitaly Pavlovich

How was time measured in ancient times?

When we talk about watches, we mean a device for measuring time. But man had known ways of counting time long before he invented such devices.

Sunrise and sunset were the first indicators of time. The increase and decrease in shadows from sticks, stones and trees also served to tell time. The movement of the stars also served man as something like a giant clock. He noticed that as the night wore on, various stars became visible.

The ancient Egyptians divided the night into twelve time periods corresponding to the rising of 12 stars. They divided the day in the same way, and our 24-hour day is based on the Egyptian division of day and night. The Egyptians also made shadow clocks - wooden blocks with signs. Ultimately, these shadow or sundials, having 12 periods for dividing the day, were the first hours.

The next types of clocks were water and fire. The sliced ​​candle counted time as it burned from slice to slice. And in the water clock, a plate with a small hole at the bottom was placed on the water. After a certain time, the floating saucer filled with water and sank.

About 2000 years ago, man invented another type of clock - hourglass. They consisted of two hollow glass vessels connected in such a way that sand could be poured from one to the other. The upper vessel was filled with sand in such quantity that it spilled out into the hole within an hour.

Around 140 BC, the Greeks and Romans used the cogwheel to improve water clocks. The float, placed in the vessel, rose when the water flowed in a thin stream into the vessel. It was connected to a gear wheel. The wheel turned the hand, which gradually moved from one hour mark to another. And after 1400 years, the first mechanical clock was invented. The load was tied to a string, she turned the coil, which in turn moved the axis gear wheels and gears. The wheels turned the arrow on the dial.

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Antiquities of Sant'Omobono In the 1930s, the space southwest of the Capitol along the Tiber embankment was actively rebuilt (part of which was the "liberation" of the Theater of Marcellus from later accretions). Mussolini laid another avenue parallel to the river -

From the book Encyclopedia of the most mysterious places on the planet author Vostokova Evgeniya

ANCIENT UFOs Have UFOs visited Earth before, many millennia ago? Swiss Erich von Däniken has been saying this for decades. His first book on this subject is Memories of the Future. Unresolved mysteries of the past ”- came out in 1968 and immediately glorified

From the book I know the world. wonders of the world author Solomko Natalia Zorevna

Antiquities of Damascus In the year Rome was founded, the first written records of Damascus were over a thousand years old. It is believed that Cain killed his brother Abel near the places where the modern city stands. Forefather Abraham, whose kinship is claimed as

From the book I know the world. Aviation and aeronautics author Zigunenko Stanislav Nikolaevich

Ancient glider pilots Guzman's apparatus is far from the only possible repetition of ancient designs. Let us recall at least the “Paracas candelabra” - one of the images discovered in the vicinity of Nazca. According to experts, the drawing resembles a silhouette ...

From the book Encyclopedia of dowsing author Krasavin Oleg Alekseevich

From the book The Newest Philosophical Dictionary author Gritsanov Alexander Alekseevich

SOCIAL TIME (the time of human existence) is a collective perceptual time, a universal of culture, the content of which underlies the conceptual time, which is constituted in the phenomenon of history as a conscious procedurality of social life. Most

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5.09.2012 World around. EMC "Harmony" 4th grade Makarova M.V.

Homework check What is archeology? What is subsoil? Archaeologists learn the history of mankind by .... What do archaeologists do? Where can we excavate? What can be found? science about the past rocks material sources excavations Makarova M.V. Retelling and Fri No. 4, 5

What is a day? A day is a complete revolution of the Earth around its axis. Solar day = 24 hours Makarova M.V.

Counting the days First, they counted the days, taking as a basis the change of day and night. They made notches or knots. Why does the day give way to night? Why exactly 24 hours in a day? Find the answer on page 12 of your textbook. Makarova M.V. Day Night

Fixing What was the first measure of time? Who divided day and night into 12 equal parts? And why exactly 12? What happens if all the clocks suddenly disappear? Why in different parts of the Earth the length of the day is the same, but the length of daylight hours is different? From the drawing on page 12, determine where noon, midnight, morning and evening are. Makarova M.V.

Counting Years How many seasons are there on Earth? Why are they changing? Observations of the change of seasons prompted the largest unit of time measurement. The ancient Slavs counted the years from summer to summer (centenary, chronicle, how many years?...) Makarova M.V.

The northern peoples determined that the length of day and night changes throughout the year. They determined the beginning of the new year by the shortest day. In England, there were special structures made of huge stones to determine the exact day of the new year. Makarova M.V.

We fix What movement of the Earth is taken as the basis for counting years? The Earth makes a revolution around the Sun in .... 1 year = ... months = ... days What does leap year mean? How is a leap year different from a regular year? Is winter the same everywhere? Makarova M.V.

Why are there 12 months in a year? Why are there 4 weeks in a month? Find the information on pages 16 - 17 of the textbook Time of revolution of the Moon around the Earth ... Fri No. 6 Makarova M.V.

Homework Pages 11 - 17 of the textbook retelling of Fri No. 7 - 10 Makarova M.V.