Astronomy lesson “Starry sky”. UMK Charugin V. M. Lesson 2 lesson plan in astronomy (grades 10, 11) on the topic

Lesson on the topic: Subject of astronomy.

There are three groups of constellations based on the origin of their names:

1. Related to ancient Greek mythology

2. Associated with objects that resemble the figures formed by the bright stars of the constellations (Arrow, Triangle, Libra, Leo, Cancer, Scorpio, Ursa Major, etc.)

Giant star systems consisting of hundreds of billions of stars form a galaxy.

The solar system and its surrounding stars make up an insignificant part of our Galaxy - the Milky Way.

History of Astronomy:

Pythagoras of Samos

: first declared the sphericity of the Earth.

Aristotle:

recognized the sphericity of the Earth, Moon and celestial bodies; created his own geocentric system of the world.

Archimedes:

made the first star globe, which showed the daily rotation of the starry sky, the movement of the planets, the phases of the Moon, solar and lunar eclipses; determined the angular diameter of the Sun; first tried to determine the size of the Universe.

Aristarch:

concluded that the Earth rotates around the Sun; calculated that the Sun is the closest star.

Eratosthenes:

calculated the size of the Earth;

Hipparchus:

entered the geographic coordinates of the area (latitude and longitude); compiled a star catalog that included 850 stars (48 constellations); divided stars by brightness into 6 magnitudes; discovered precession; estimated the distance to the Moon and the Sun; compiled observation tables for the Moon and planets; developed one of the geocentric systems of the world.

Claudius Ptolemy:

tried to create a theory of the apparent motion of the Sun, Moon and planets; developed a geocentric system of the world.

Nicolaus Copernicus:

developed the heliocentric system of the world; received an explanation for the change of seasons.

Giordano Bruno:

created his own natural-philosophical picture of an infinite Universe with many inhabited planetary worlds.

Tycho Brahe:

He considered improving the accuracy of astronomical observations to be the main task of his life; built two observatories in which he carried out observations of Mars and other objects using the metal goniometer instruments he created; compiled a catalog of 777 stars.

Johannes Kepler:

used data from Tycho Brahe's long-term observations of the movement of Mars; formulated three laws of planetary motion.

Galileo Galilei:

invented the telescope; conducted research on comets, noted the periodicity in the movement of comets; discovered mountains, seas and craters on the Moon, the 4 largest satellites of Jupiter; observed spots on the Sun, phases of Venus, rings of Saturn.

Isaac Newton:

based on an analysis of the movement of the planet Earth and its satellite the Moon, forming a single cosmic system, he formulated the law of universal gravitation; put forward a hypothesis about the formation of stars in gas and dust nebulae under the influence of gravity; explained the causes of ebbs and flows.

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Methodological development of an astronomy lesson “Subject of astronomy. Observations are the basis of astronomy.

MOSCOW DEPARTMENT OF EDUCATION

State budgetary professional educational

establishment of the city of Moscow

"Moscow Publishing and Printing College

named after Ivan Fedorov"

(GBPOU MIPC named after I. Fedorov)

Methodological development of an astronomy lesson

«Subject of astronomy. Observations are the basis of astronomy .»

For all first year specialties

Developer:

Popova I.V., teacher of physics and computer science, GBPOU SPO MIPC im. I. Fedorova

2018

Lesson topic:
Subject of astronomy.
Observations are the basis of astronomy. Lesson type: lesson on discovering new knowledge.

The purpose of the lesson:

introducing students to the features of studying a new subject - astronomy.

Lesson objectives:

educational:

• form an idea of ​​the subject of astronomy, the history of astronomy, the structure and scale of the Universe;
• introduce students to the tasks and methods of astronomical research;
• use acquired knowledge and skills to solve practical problems of everyday life.

developing:

• create conditions for the development of thinking (learn to analyze, highlight the main thing, understand texts, explain and define concepts, generalize and systematize, give examples);
• create conditions for the development of cognitive interest and elements of creative activity;
• create conditions for the development of communication abilities and the ability to logically express one’s thoughts.

educational:

• cultivate positive motivation for studying astronomy; culture of mental work;
• to cultivate confidence in the knowability of the surrounding world, awareness of the fundamental role of astronomy in the knowledge of the fundamental laws of nature and the formation of a modern natural science picture of the world;
• cultivate an attentive, friendly attitude towards the answers of classmates, a respectful attitude towards the opinion of another person.

Planned results:

Personal results:

• formation of a responsible attitude towards learning;
• the formation of a holistic worldview that corresponds to the modern level of development of science and social practice;
• formation of a conscious, respectful and friendly attitude towards another person and his opinion; willingness and ability to conduct dialogue with other people and achieve mutual understanding in it;
• formation of communicative competence in communication and cooperation with peers and adults in the process of educational activities.

Meta-subject results:

• the ability to independently set and formulate new tasks for oneself in study and cognitive activity, to develop the motives and interests of one’s cognitive activity;
• the ability to evaluate the correctness of completing a learning task and one’s own capabilities to solve it;
• the ability to define concepts, establish analogies, build logical reasoning and draw conclusions;
• semantic reading;
• the ability to organize educational cooperation and joint activities with the teacher and peers; formulate, argue and defend your opinion;
• the ability to consciously use verbal means in accordance with the task of communication to express one’s feelings, thoughts and needs; planning and regulation of its activities.

Subject results:

• knowledge of objects, tasks and methods of astronomical research;
• knowledge of the main stages in the development of astronomy as a science;
• knowledge of the connection between astronomy and other sciences;
• knowledge about the structure and scale of the Universe;
• the ability to use acquired knowledge and skills to solve practical problems of everyday life.

Teaching methods:

explanatory and illustrative, heuristic.

Technical teaching aids: computer with Internet access; multimedia projector; screen (or interactive whiteboard). Presentation for the lesson.

Presentation of new material.

Slides 3-5. Cosmology. Non-system units of measurement. Age and size of the Universe.

“The Universe is a concept in astronomy and philosophy that does not have a strict definition. It is divided into two fundamentally different entities: speculative (philosophical) and material, accessible to observation at the present time or in the foreseeable future. Following tradition, the first is called the Universe, and the second is the astronomical Universe, or Metagalaxy.” [2] Today we will get acquainted with the structure of the astronomical Universe. And we will determine the place of our planet Earth in the Universe. “The universe is the subject of cosmology.” [2]

The distances and masses of objects in the Universe are very large. Cosmology uses non-systemic units of measurement. 1 light year (1 light year) - the distance that light travels in 1 year in a vacuum - 9.5 * 1015 m; 1 astronomical unit (1 AU) – the average distance from the Earth to the Sun (the average radius of the Earth’s orbit) – 1.5 * 1011 m; 1 parsec (1 pc) - the distance from which the average radius of the earth's orbit (equal to 1 AU), perpendicular to the line of sight, is visible at an angle of one arc second (1′) - 3 * 1016 m; 1 mass of the Sun (1 Mo) – 2 * 1030 kg.

Scientists have determined the age and size of the Universe. The age of the Universe is t=1.3 * 1010 years. Radius of the Universe R=1.3 * 1010 light years.

Slides 6-19. Galaxies. Types of galaxies. Clusters of galaxies.

At the beginning of the twentieth century, it became obvious that almost all visible matter in the Universe is concentrated in giant star-gas islands with a characteristic size of several kpc. These “islands” became known as galaxies.

Galaxies are large star systems in which stars are bound together by gravitational forces. There are galaxies containing trillions of stars. “This group of galaxies is called Stefan's Quintet. However, only four galaxies from this group, located three hundred million light years away, participate in the cosmic dance, moving closer and further away from each other. It's quite easy to find extra ones. The four interacting galaxies have yellowish colors and curved loops and tails, shaped by destructive tidal gravitational forces. The bluish galaxy, located in the picture at the top left, is much closer than the others, only 40 million light years away.” [3]

There are different types of galaxies: elliptical, spiral and irregular.

Elliptical galaxies make up approximately 25% of the total number of high-luminosity galaxies.

Elliptical galaxies have the appearance of circles or ellipses, the brightness smoothly decreases from the center to the periphery, they do not rotate, they have little gas and dust, M 1013 Mo. Before you is the elliptical galaxy M87 in the constellation Virgo.

Spiral galaxies resemble two plates or a lenticular lens placed together in appearance. They contain both a halo and a massive stellar disk. The central part of the disk, which is visible as a bulge, is called a bulge. The dark stripe running along the disk is an opaque layer of the interstellar medium, interstellar dust. The flat disc-shaped shape is explained by rotation. There is a hypothesis that during the formation of a galaxy, centrifugal forces prevent the compression of the protogalactic cloud in the direction perpendicular to the rotation axis. The gas is concentrated in a certain plane - this is how the disks of galaxies were formed.

Spiral galaxies consist of a core and several spiral arms or branches, the branches extending directly from the core. Spiral galaxies rotate, they have a lot of gas and dust, M 1012 M?

“The American aerospace agency NASA has opened its own account on Instagram, where they post photographs of views of the Earth and other parts of the Universe. Stunning photographs from the Hubble Telescope, NASA's most famous Great Observatory, reveal things never before seen by the human eye. Never-before-seen distant galaxies and nebulae, dying and born stars amaze the imagination with their diversity, pushing one to dream of distant travels. Fabulous landscapes of star dust and gas clouds reveal mysterious phenomena of stunning beauty.”[3] Here is one of the most beautiful spiral galaxies in the constellation Coma Berenices.

In the 20s In the 20th century, it became clear: spiral nebulae are huge star systems similar to our Galaxy and millions of light years away from it. In 1924, Hubble and Ritchie resolved the spiral arms of the Andromeda and Triangulum nebulae into stars. It was found that these “extragalactic nebulae” are several times farther from us than the diameter of the Milky Way system. These systems began to be called galaxies by analogy with ours. “The medium-sized galaxy M33 is also called the Triangulum galaxy after the constellation in which it is located. It is approximately 4 times smaller in radius than our Milky Way galaxy and the Andromeda galaxy. M33 is located close to the Milky Way and is clearly visible with good binoculars.”[3]

“The Andromeda Galaxy is the closest giant galaxy to our Milky Way. Most likely, our galaxy looks about the same as this one. The hundreds of billions of stars that make up the Andromeda Galaxy together produce a visible, diffuse glow. The individual stars in the image are actually stars in our Galaxy, located much closer to the distant object.”[3]

“When observing the starry sky far from large cities, on a moonless night a wide luminous stripe is clearly visible - the Milky Way. The Milky Way stretches like a silver stripe across both hemispheres, closing into a ring of stars. Observations have established that all the stars form a huge star system (galaxy).” [1] The galaxy contains two main subsystems, nested one within the other: the halo (its stars are concentrated towards the center of the galaxy) and the stellar disk (“two plates folded at the edges”). “The solar system is part of the Milky Way galaxy. We are inside a galaxy, so it is difficult for us to imagine its appearance, but there are many other similar galaxies in the Universe and from them we can judge our Milky Way.”[1] The Milky Way Galaxy consists of a core located at the center of the galaxy and three spiral arms.

“Studies of the distribution of stars, gas and dust have shown that our Milky Way galaxy is a flat system with a spiral structure.” [1] The size of our galaxy is enormous. The diameter of the galaxy's disk is about 30 pc (100,000 light years); thickness - about 1,000 sv. l.

There are about 100 billion stars in our galaxy. The average distance between stars in the galaxy is about 5 light years. years. The center of the galaxy is located in the constellation Sagittarius. “Astronomers are currently carefully studying the center of our galaxy. Observations of the movement of individual stars near the center of the galaxy showed that there, in a small area with dimensions comparable to the size of the Solar system, invisible matter is concentrated, the mass of which exceeds the mass of the Sun by 2 million times. This indicates the existence of a massive black hole at the center of the galaxy.” [1] The Milky Way Galaxy orbits around the center of the galaxy. The Sun makes one revolution around the center of the galaxy in 200 million years.

Examples of irregular galaxies are the Large Magellanic Cloud and the Small Magellanic Cloud - the closest galaxies to us, visible to the naked eye in the southern hemisphere of the sky, near the Milky Way. These two galaxies are satellites of our galaxy.

Irregular galaxies have no clearly defined core, no rotational symmetry, and about half of the matter in them is interstellar gas. When studying the sky using telescopes, many galaxies of irregular, ragged shape, similar to the Magellanic Clouds, were discovered.

“Violent processes occur in the cores of some galaxies; such galaxies are called active galaxies. In the M87 galaxy in the constellation Virgo, an ejection of matter is observed at a speed of 3000 km/s, the mass of this ejection is This galaxy turned out to be a powerful source of radio emission. Quasars are an even more powerful source of radio emission. Quasars are also powerful sources of infrared, x-ray and gamma rays. But the sizes of quasars turned out to be small, about 1 AU. Quasars are not stars; These are bright and highly active galactic nuclei located billions of light years away from Earth.” [1] “At the center of the quasar there is a supermassive black hole that sucks in matter - stars, gas and dust. Falling onto a black hole, matter forms a huge disk, in which it heats up to gigantic temperatures due to friction and tidal forces.” [2] “Perhaps one of the most detailed photographs of a quasar to date was published on the Hubble website. This is one of the most famous quasars, 3C 273, which is located in the constellation Virgo.” [3] It was the first object of its kind to be discovered; it was discovered by astronomer Alan Sandage in the early 1960s. “Quasar 3C 273 is the brightest and one of the closest quasars: its distance is approximately 2 billion light years, and its brightness allows it to be seen in an amateur telescope.” [3]

Galaxies are rarely solitary. 90% of galaxies are concentrated in clusters, which contain from tens to several thousand members. The average diameter of a galaxy cluster is 5 Mpc, the average number of galaxies in a cluster is 130. “The Local Group of galaxies, whose size is 1.5 Mpc, includes our Galaxy, the Andromeda Galaxy M31, the Triangulum Galaxy M33, the Large Magellanic Cloud (LMC), the Small Magellanic Cloud (MMO) - a total of 35 galaxies connected by mutual gravity. The galaxies of the Local Group are connected by common gravity and move around a common center of mass in the constellation Virgo.” [1]

Slides 21-23. Star clusters.

Every third star in the galaxy is double, and there are systems of three or more stars. More complex objects are also known - star clusters.

Open star clusters occur near the galactic plane. In front of you is the Pleiades star cluster. The blue haze accompanying the Pleiades is scattered dust reflecting the light of the stars.

Globular clusters are the oldest formations in our Galaxy, their age is from 10 to 15 billion years and is comparable to the age of the Universe. The poor chemical composition and elongated orbits in which they move in the Galaxy indicate that globular clusters formed during the formation of the Galaxy itself. Globular clusters stand out against the stellar background due to their significant number of stars and clear spherical shape. The diameter of globular clusters ranges from 20 to 100 pc. M= 104 106 M?

Slides 24-29. Interstellar matter. Nebulae.

In addition to stars, cosmic rays (protons, electrons, and atomic nuclei of chemical elements), which move at speeds close to the speed of light, galaxies contain gas and dust. Gas and dust in the galaxy are distributed very unevenly. In addition to sparse dust clouds, dense dark clouds of dust are observed. When these dense clouds are illuminated by bright stars, they reflect their light, and then we see nebulae.

“The Hubble team releases a stunning photo every year to celebrate the anniversary of the space telescope's launch on April 24, 1990. In 2013, they presented to the world a photograph of the famous Horsehead Nebula, which is located in the constellation Orion, 1,500 light years from Earth.” [3]

“The bright Lagoon Nebula contains many different astronomical objects. Particularly interesting objects include a bright open star cluster and several active star forming regions.”[3]

“The colorful Trifid Nebula allows us to explore cosmic contrasts. Also known as M20, it lies about 5,000 light-years away in the nebula-rich constellation Sagittarius. The size of the nebula is about 40 light years. l." [3]

“It is not yet known what lights up this nebula. Particularly puzzling is the bright, inverted V-shaped arc that outlines the top edge of the mountain-like clouds of interstellar dust near the center of the image. This ghost-like nebula includes a small star-forming region filled with dark dust. It was first spotted in infrared images taken by the IRAS satellite in 1983. Shown here is a remarkable image taken by the Hubble Space Telescope. Although it shows many new details, the cause of the bright, clear arc could not be determined.” [3]

The total mass of dust is only 0.03% of the total mass of the galaxy. Its total luminosity is 30% of the luminosity of stars and completely determines the emission of the galaxy in the infrared range. Dust temperature 15-25 K.

Slides 30-33. Application of spectral analysis. Redshift. Doppler effect. Hubble's law.

The light of galaxies represents the combined light of billions of stars and gas. To study the physical properties of galaxies, astronomers use spectral analysis methods. Spectral analysis is a physical method for qualitative and quantitative determination of the atomic and molecular composition of a substance, based on the study of its spectrum. Astronomers use spectral analysis to determine the chemical composition of objects and their speed of movement.

In 1912, Slipher, an American astronomer, discovered a shift of lines towards the red end in the spectra of distant galaxies. “This phenomenon was called redshift. In this case, the ratio of the shift of the spectral line to the wavelength turned out to be the same for all lines in the spectrum of a given galaxy. The ratio , where is the wavelength of the spectral line observed in the laboratory, characterizes the red shift.”[1]

“The currently generally accepted interpretation of this phenomenon is related to the Doppler effect. The shift of spectral lines to the red end of the spectrum is caused by the movement (removal) of the emitting object (galaxy) with a speed v

in the direction from the observer. At low redshifts (z), the speed of the galaxy can be found using the Doppler formula: , where c is the speed of light in vacuum.”[1]

In 1929, Hubble determined that the entire system of galaxies was expanding. “From the spectra of galaxies it has been established that they “scatter” from us with a speed v

, proportional to the distance to the galaxy:

v

= H·r, where H = 2.4 * 10-18 s-1 is the Hubble constant, r is the distance to the galaxy (m).” [1]

Slides 34-38. The Big Bang Theory. Critical density of matter.

The theory of the expanding Universe has emerged, according to which our Universe arose from a super-dense state during a grandiose explosion and its expansion continues in our time. About 13 billion years ago, all the matter of the Metagalaxy was concentrated in a small volume. The density of the substance was very high. This state of matter was called “singular”. Expansion as a result of the “explosion” (“pop”) led to a decrease in the density of the substance. Galaxies and stars began to form.

There is a critical value for the density of a substance, on which the nature of its movement depends. The critical value of the substance density kr is calculated by the formula:

where H = 2.4 * 10-18 s-1 is the Hubble constant, G = 6.67 * 10-11 (N * m2)/kg2 is the gravitational constant. Substituting the numerical values, we get kr = 10-26 kg/m3. At kp - expansion of the Universe. When kr- compression of the Universe. Average density of matter in the Universe = 3 * 10-28 kg/m3.

Man always strives to understand the world around him. The study of the Universe has just begun. Much remains to be learned. Humanity is only at the very beginning of the journey of studying the Universe and its mysteries. “By presenting the Universe as the entire surrounding world, we immediately make it unique and unique. And at the same time, we deprive ourselves of the opportunity to describe it in terms of classical mechanics: because of its uniqueness, the Universe cannot interact with anything, it is a system of systems, and therefore in its relation such concepts as mass, shape, size lose their meaning. Instead, we have to resort to the language of thermodynamics, using concepts such as density, pressure, temperature, chemical composition.” [2]

V. Primary consolidation of knowledge.

Frontal survey

• What is the name of the science that studies the structure and evolution of the Universe? (Cosmology)
• What extra-system units of measurement are used in cosmology? (light year, astronomical unit, parsec, solar mass)
• What distance is called a light year? (Distance that light travels in one year)

VI. Independent work.

Students are asked to independently solve the problem: Average density of matter in the Universe = 3 * 10-28 kg/m3. Calculate the critical value of matter density and compare it with the average matter density in the Universe. Analyze the result obtained and draw a conclusion about whether the Universe is expanding or contracting.

Lecture course on astronomy lesson plan

Lesson #5. Movement and phases of the Moon. Eclipses of the Sun and Moon. Time and calendar.

The equatorial coordinate system is a system of celestial coordinates in which the main plane is the plane of the celestial equator. The angular height of the celestial pole above the horizon is equal to the geographic latitude of the observation site:

The daily paths of the luminaries on the celestial sphere are circles whose planes are parallel to the celestial equator. A pole is a place on the globe where the axis of the world coincides with a plumb line, and the celestial equator coincides with the horizon. At the North Pole, all stars whose declination is positive will be visible above the horizon, and their altitude will not change during the day. At mid-latitudes, an observer will be able to observe rising and setting stars. By sunrise we mean the phenomenon of the luminary crossing the eastern part of the true horizon, and by sunset - the western part of this horizon. Being on the equator, the observer will be able to see all the stars that rise and set during the day.

Star visibility conditions:

1. If 0 – ϕ, then the star is rising and setting;
2. If 900 – ϕ, then the star in the northern hemisphere is non-setting;
3. If - (900 - ϕ), then the star in the Northern Hemisphere is non-rising.

The phenomenon of a luminary passing through the celestial meridian is called culmination. At the upper culmination, the luminary during its daily movement is at the highest point above the horizon, closest to the zenith. The lower climax occurs half a day after the upper climax.

The height of the star at the upper culmination to the left of the zenith:

The height of the star at the upper culmination to the right of the zenith:

Height of the star at the upper culmination:

“+” - if the star culminates south of the zenith;

“—“—the luminary culminates north of the zenith.

Height of the star at the lower culmination:

By measuring the declination of the star and its altitude at the moments of its culmination, it is easy to determine the geographic latitude at which the observer is located:

The ecliptic is a large circle of the celestial sphere along which the visible annual movement of the Sun occurs.

δN = +23о 26ʹ - summer solstice day.

δS = −23о 26ʹ - winter solstice day.

Ecliptic constellations are constellations along which the ecliptic passes. There are 13 of them: Pisces, Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Ophiuchus, Sagittarius, Capricorn, Aquarius. The 12 constellations with the exception of Ophiuchus are called zodiacal. The beginning of the countdown of zodiac signs was established from the point of the vernal equinox. The vernal equinox point moves by one zodiac sign approximately every 2150 years. This is explained by precession. Precession (precession of the equinoxes) is the phenomenon of a gradual displacement of the points of the spring and autumn equinoxes towards the apparent annual movement of the Sun, arising due to the slow swinging of the axis of rotation of the globe.

The day of the vernal equinox, March 21, is taken as the beginning of the Sun's movement along the ecliptic. Solstice is the moment when the center of the Sun passes through the points of the ecliptic that are most distant from the equator of the celestial sphere. The summer solstice is June 21 (the longest day of the year and the shortest night), the winter solstice is December 22 (the longest night of the year and the shortest day).

At the North Pole, the Sun does not set below the horizon for six months, which is called the polar day, and for six months it does not rise above the horizon, which is called the polar night. At the equator, day is always equal to night.

Movement and phases of the Moon. Eclipses of the Sun and Moon.

The Moon moves around the Earth in an elliptical orbit in the same direction as the Earth rotates around its axis. The apparent movement of the Moon among the stars occurs towards the rotation of the sky - from west to east. Sidereal (sidereal) month is the period of time between two successive returns of the Moon, during its apparent monthly movement, to the same place in the celestial sphere; it is equal to 27 days 7 hours 43.1 minutes. The different shapes of the visible illuminated part of the Moon are called its phase. The light dividing line separating the illuminated part of the Moon from the unlit part is called the terminator. There are 4 phases of the moon: new moon, first quarter, full moon, last quarter. The time interval between two successive identical phases of the Moon is called a synodic month. On average it is 29 days 12 hours 44 minutes 03 seconds.

A lunar year is equal to 12 lunar months, or 354 Earth days.

Mnemonic rule: if the crescent moon in the sky looks like the letter “C”, then this is the Moon “aging”; if, by mentally placing a stick on the lunar crescent, you can get the letter “P”, then this is the “growing” Moon.

An eclipse is an astronomical phenomenon in which one celestial body covers another.

The occultation of the Sun by the Moon is called a solar eclipse. The path of the lunar shadow along the earth's surface is called the streak of a total solar eclipse. Every year from 2 to 5 solar eclipses can be observed on Earth. The average duration of solar eclipses is 7 minutes 31 seconds.

A lunar eclipse is a phenomenon that occurs when the Moon enters the cone of the shadow cast by the Earth. One or two lunar eclipses occur annually.

Saros (draconic period) is a time interval consisting of 223 synodic months (18 years 11 days 8 hours), after which eclipses of the Moon and the Sun approximately repeat in the same order. During Saros, an average of 70-71 eclipses occur: approximately 42-43 solar, 28 lunar.

Time and calendar

The moment of the highest culmination of the center of the Sun is called true noon.

The moment of the lower culmination of the center of the Sun is called true midnight.

A true solar day is the period of time between two successive culminations of the same name at the center of the Sun. The uneven movement of the Earth in its orbit causes uneven apparent movement of the Sun across the celestial sphere. The average solar day is the time interval between two successive culminations of the same name of the average equatorial Sun (an imaginary point that moves uniformly along the celestial equator).

The time measured on a given meridian is called its local time, and it is the same for all points located on it. The further east the earth's meridian is, the earlier the day begins on it.

The local time at two points will differ exactly as much as their geographic longitude differs:

The local mean solar time of the Greenwich meridian is called Universal Time (UT).

Standard time is the local mean solar time at the median meridian of a geographic time zone. Standard time, which is accepted in a particular place, differs from universal time by a number of hours equal to the number of its time zone.

The date line is a conventional line on the surface of the globe, running from pole to pole, on opposite sides of which the local time differs by a day.

International atomic time is time based on electromagnetic vibrations emitted by atoms or molecules during the transition from one energy state to another.

A calendar is a system for counting long periods of time, in which a certain length of months is established, their order in the year and the starting point for counting years. Any calendar is based on periodic astronomical phenomena: the rotation of the Earth around its axis, changes in lunar phases, and the rotation of the Earth around the Sun.

The lunar calendar is based on the synodic month - the period of time between two successive identical phases of the Moon. It is equal to 29 days. 12 hours 44 minutes The year is divided into 12 lunar months, which alternately contain 30 or 29 days. The lunar calendar is shorter than the solar year by about 10 days. Common in the modern Islamic world.

The lunisolar calendar is a calendar based on the periodicity of the visible movements of the Moon and the Sun. 19 solar years = 235 lunar months. This system was preserved in the Jewish calendar.

The solar calendar is a type of calendar based on the tropical year, i.e., the period of changing seasons. A tropical year is the period of time between two successive passages of the center of the Sun through the vernal equinox. It is equal to 365 d 05 h 48 min 45.19 s.

The predecessor of the modern calendar was the Julian calendar. A leap year in the Julian calendar is every fourth year and is 366 days long. The length of the year in the Julian calendar differed from the tropical year by 11 minutes 14 seconds.

The Gregorian calendar is a time calculation system in which the length of the year is taken to be 365.2425 days.

Until 1918, Russia lived according to the Julian calendar. The transition to the Gregorian calendar in Russia took place on January 26, 1918. The new calendar style began counting in Russia on February 1, 1918. By decree of the Council of People's Commissars (abbreviation of the Council of People's Commissars) dated January 24, 1918, it was prescribed that February 1, 1918 be considered February 14th.

The numbering of years in both the new and old styles starts from the year of the Nativity of Christ, the onset of a new era. In Russia, a new era was introduced by a decree of Peter I, according to which after December 31, 7208, “from the creation of the world” came January 1, 1700 from the Nativity of Christ.

Homework:

1. Compose a crossword puzzle based on the questions studied so far.

2. Message about any calendar:

3. Message on the topic (to choose from):

— Twilight and its types;

- White Nights.

additional information

Table of relationships between Julian and Gregorian dates

How to correctly convert historical dates from the old style to the new? We must use the rule that was in force in this era. For example, if an event occurred in the 16th–17th centuries, add 10 days, if in the 18th century - 11, in the 19th century - 12, finally, in the 20th and 21st centuries - 13 days.

It should be remembered that the transition to the Gregorian calendar occurred in different countries at different times: while Catholic countries almost immediately introduced the “papal” calendar, Great Britain adopted it only in 1752, Sweden in 1753.

However, the situation changes when it comes to events in Russian history. It should be taken into account that in Orthodox countries, when dating a particular event, attention was paid not only to the actual number of the month, but also to the designation of this day in the church calendar (holiday, memory of a saint). Meanwhile, the church calendar has not undergone any changes, and Christmas, for example, was celebrated on December 25 300 or 200 years ago, and is celebrated on the same day now. Another thing is that in the civil “new style” this day is designated as “January 7”.

Please note that when converting the dates of holidays and memorial days to the new style, the Church is guided by the current conversion rule (+13). For example: the transfer of the relics of St. Philip, Metropolitan of Moscow, is celebrated on July 3, Art. Art. - or July 16 AD Art. - although in 1652, when this event occurred, theoretically the Julian July 3 corresponded to the Gregorian July 13. But just theoretically: at that time, this difference could have been noticed and recorded only by ambassadors of foreign states that had already switched to the “papal” calendar. Later, ties with Europe became closer, and in the 19th – early 20th centuries, a double date was given in calendars and periodicals: according to the old and new styles. But even here, in historical dating, priority should be given to the Julian date, since it was precisely this that contemporaries were guided by. And since the Julian calendar was and remains the calendar of the Russian Church, there is no reason to translate dates differently than is customary in modern church publications - that is, with a difference of 13 days, regardless of the date of a particular event.

Russian naval commander Fedor Fedorovich Ushakov died on October 2, 1817. In Europe, this day was designated as (2+12 =) October 14th. However, the Russian Church celebrates the memory of the righteous warrior Theodore on October 2, which in the modern civil calendar corresponds to (2+13 =) October 15.

The Battle of Borodino took place on August 26, 1812. On this day, the Church celebrates the Presentation of the Vladimir Icon of the Mother of God in memory of the miraculous deliverance from the hordes of Tamerlane. Therefore, although in the 19th century the 12th Julian August corresponded to September 7 (and it was this day that was entrenched in the Soviet tradition as the date of the Battle of Borodino), for Orthodox people the glorious feat of the Russian army was accomplished on the day of the Presentation - that is, September 8 according to the present day.

Thus, the dates of events in Russian history before 1918 should be given according to the Julian calendar, indicating in brackets the corresponding date of the modern civil calendar - as is done for all church holidays. For example: December 25, 1XXX (January 7, new style).