Standard Time a time counting system based on dividing the Earth's surface into 24 time zones: at all points within one zone at every moment of the Second World War. the same, in neighboring zones it differs by exactly one hour. In the standard time system, 24 meridians, spaced 15° apart in longitude, are taken as the average meridians of time zones. The boundaries of the belts in the seas and oceans, as well as in sparsely populated areas, are drawn along meridians located 7.5° east and west from the average. In other regions of the Earth, for greater convenience, boundaries are drawn along state and administrative boundaries, railways, rivers, mountain ranges, etc., close to these meridians. (cm. time zone map
). By international agreement, the meridian with longitude 0° (Greenwich) was taken as the initial one. The corresponding time zone is considered to be zero; The time of this zone is called universal time. The remaining belts in the direction from zero to the east are assigned numbers from 1 to 23. The difference between the P. of. in any time zone and universal time is equal to the zone number. The times of some time zones have special names. So, for example, the time of the zero zone is called Western European time, the time of the 1st zone is Central European time, the time of the 2nd zone in foreign countries is called Eastern European time. Time zones from 2 to 12 inclusive pass through the territory of the USSR. To make the most efficient use of natural light and save energy, in many countries in summer time clocks are moved forward one hour or more (so-called summer time). In the USSR, maternity time was introduced in 1930; The clock hands were moved forward an hour. As a result, all points within a given zone began to use the time of the neighboring zone located east of it. Maternity time of the 2nd time zone in which Moscow is located is called Moscow time. In a number of states, despite the convenience of zone time, they do not use the time of the corresponding time zone, but use either the local time of the capital or a time close to the capital throughout the entire territory. The astronomical yearbook “Nautical almanac” (Great Britain) for 1941 and subsequent years contains descriptions of the boundaries of time zones and the accepted account of time for those places where P.E. is not used, as well as all subsequent changes. Before the introduction of P. century. In most countries, civil time was common, different in any two points whose longitudes were different. The inconveniences associated with such an accounting system became especially acute with the development of the railway. messages and telegraphic communications. In the 19th century in a number of countries they began to introduce a single time for a given country, most often the civil time of the capital. However, this measure was unsuitable for states with a large length of territory in longitude, because the accepted account of time on the distant outskirts would differ significantly from the civil one. In some countries, uniform time was introduced only for use on railways and telegraphs. In Russia, the civil time of the Pulkovo Observatory, called St. Petersburg time, served for this purpose. P.v. was proposed by the Canadian engineer S. Fleming in 1878. It was first introduced in the United States in 1883. In 1884, at a conference of 26 states in Washington, an international agreement on timekeeping was adopted, but the transition to this timekeeping system dragged on for many years. On the territory of the USSR P. v. introduced after the Great October Socialist Revolution, on July 1, 1919.
Great Soviet Encyclopedia. - M.: Soviet Encyclopedia. 1969-1978 .
See what "World Time" is in other dictionaries:
ZAP time, mean solar time, determined for 24 main geographical meridians, separated by 15 latitude in longitude. The Earth's surface is divided into 24 time zones (numbered 0 to 23), within each of which standard time... ... Modern encyclopedia
Standard Time- PLANT TIME, mean solar time, determined for 24 main geographical meridians, separated by 15° in longitude. The Earth's surface is divided into 24 time zones (numbered 0 to 23), within each of which standard time... ... Illustrated Encyclopedic Dictionary
Mean solar time, determined for the 24 main geographic meridians, separated by 15. by longitude. The Earth's surface is divided into 24 time zones (numbered 0 to 23), within each of which standard time coincides with... ... Big Encyclopedic Dictionary
standard time- The time determined for a given place on Earth depends on the geographical longitude of the place and is the same for all points located on the same meridian. Syn.: local time standard time A system for calculating time across time zones extending... ... Dictionary of Geography
standard time- A single time within a time zone, calculated in the national coordinated time scale and differing from it by an integer number of hours equal to the time zone number. Note Standard time as modified by government regulations... ... Technical Translator's Guide
Time determined in accordance with the international system of its calculation according to conventional zones. The entire globe is divided by meridians into 24 stripes of equal width, and in populated areas the boundaries of the belts are drawn not strictly along the meridians, but with... ... Technical railway dictionary
A system of time keeping now adopted in almost all countries because of the number of practical conveniences which it affords. It consists in the fact that the entire Earth is divided by meridians into 24 belts or zones of 15° width and within each zone one is considered... ... Marine Dictionary
Mean solar time, determined for the 24 main geographic meridians, separated by 15° in longitude. The Earth's surface is divided into 24 time zones (numbered 0 to 23), within each of which standard time coincides with... ... encyclopedic Dictionary
standard time- juostinis laikas statusas T sritis Standartizacija ir metrologija apibrėžtis Laikas, skaičiuojamas pagal Žemės paviršiaus padalijimą į 24 valandines juostas; tai yra kiekvienos juostos viduriu einančio dienovidinio (0°, 15°, 30°, …) vienetinis… … Penkiakalbis aiškinamasis metrologijos terminų žodynas
Time Zones Time zones are regions of the Earth that use the same local time. Sometimes the concept of a time zone also includes the coincidence of the date; in this case, the UTC+14 zones will be considered different, although they have the same time... ... Wikipedia
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Slide captions:
TIME AND CALENDAR
The sun always illuminates only half of the globe. As the Earth rotates around its axis, noon occurs in those places that lie to the west. The position of the Sun (or stars) in the sky determines local time for any point on the globe.
In different places on the globe, located in different meridians, at the same moment the local time is different. When it is 12 noon in Moscow, in Saransk it should be 12.30, in Omsk - 14.23, in Irkutsk - 16.37, in Vladivostok - 18.17, in Sakhalin - 20.00, in St. Petersburg - 11.31, in Warsaw - 10.54, in London - 9.27. 12.00 11.31 10.54 18.17 12.30 14.23 16.37 Local time at two points (T 1, T 2) differs exactly as much as their geographic longitude (λ 1, λ 2) differs in hourly terms: T 1 - T 2 = λ 1 - λ 2 The longitude of Moscow is 37°37´, St. Petersburg - 30°19´, Saransk - 45°10´. The earth rotates 15° in 1 hour, i.e. by 1° in 4 min. T 1 -T 2 = (37°37´-30°19´)*4 = 7°18´*4 = 29 min. T 1 -T 2 = (45°10´-37°37´)*4 = 7°33´*4 = 30 min. Noon in St. Petersburg occurs 29 minutes later than in Moscow, and in Saransk - 30 minutes earlier. 20.00
The local time of the prime (zero) meridian passing through the Greenwich Observatory is called universal time - Universal Time (UT). The local time of any point is equal to universal time at that moment plus the longitude of that point from the prime meridian, expressed in hourly units. T 1 = UT + λ 1 . Greenwich. London
The error of strontium atomic clocks is less than a second in 300 million years. Using the Earth's rotation period as a standard does not provide a sufficiently accurate calculation of time, since the rotation speed of our planet changes throughout the year (the length of the day does not remain constant) and its rotation slows down very slowly. Currently, atomic clocks are used to determine the exact time.
Using local time is inconvenient, since when moving west or east you need to continuously move the clock hands. Currently, almost the entire population of the globe uses standard time.
The zone counting system was proposed in 1884. The entire globe is divided into 24 time zones. The local time of the main meridian of a given zone is called standard time. It is used to keep track of time throughout the entire territory belonging to this time zone. The standard time adopted in a particular location differs from the universal time by a number of hours equal to the number of its time zone. T = UT + n
The boundaries of time zones recede approximately 7.5° from the main meridians. These boundaries do not always run exactly along the meridians, but are drawn along the administrative boundaries of regions or other regions so that the same time applies throughout their entire territory.
In our country, standard time was introduced on July 1, 1919. Since then, the boundaries of time zones have been repeatedly reviewed and changed.
Time is a continuous series of phenomena replacing each other. At the end of the twentieth century. In Russia, maternity time was introduced and then abolished several times, which is 1 hour ahead of standard time. Since April 2011, Russia has not switched to daylight saving time. Since October 2014, maternity time has been returned in Russia, and the difference between Moscow and Universal Time has become equal to 3 hours.
In ancient times, people determined time by the Sun. Moscow popular print calendar, 17th century. A calendar is a system for counting long periods of time, according to which a certain length of months, their order in the year and the starting point for counting years are established. Throughout human history, there have been more than 200 different calendars. Egyptian calendar based on the floods of the Nile Mayan calendar The word calendar comes from the Latin “calendarium”, which translated from Latin means “record of loans”, “debt book”. In Ancient Rome, debtors paid debts or interest on the first days of the month, i.e. on the days of the calendars (from the Latin "calendae").
At the first stage of the development of civilization, some peoples used lunar calendars, since the change of phases of the Moon is one of the most easily observed celestial phenomena. The Romans used a lunar calendar and the beginning of each month was determined by the appearance of the crescent moon after the new moon. The length of the lunar year is 354.4 days. However, the solar year has a length of 365.25 days. To eliminate discrepancies of more than 10 days, in every second year between the 23rd and 24th days of Februarius, an additional month of Mercedonia was inserted, containing alternately 22 and 23 days. The oldest surviving Roman calendar, Fasti Antiates. 84-55 BC Reproduction.
Over time, the lunar calendar ceased to meet the needs of the population, since agricultural work is tied to the change of seasons, that is, the movement of the Sun. Therefore, lunar calendars were replaced by lunisolar or solar calendars. Lunar-solar calendars
The solar calendar is based on the duration of the tropical year - the period of time between two successive passages of the center of the Sun through the vernal equinox. The tropical year is 365 days 5 hours 48 minutes 46.1 seconds.
In Ancient Egypt in the 5th millennium BC. a calendar was introduced that consisted of 12 months of 30 days each and an additional 5 days at the end of the year. Such a calendar gave an annual lag of 0.25 days, or 1 year in 1460 years.
The Julian calendar, the immediate predecessor of the modern one, was developed in Ancient Rome on behalf of Julius Caesar in 45 BC. In the Julian calendar, every four consecutive years consist of three 365-day years and one leap year of 366 days. The Julian year is 11 minutes 14 seconds longer than the tropical year, which gives an error of 1 day in 128 years, or 3 days in approximately 400 years.
The Julian calendar was adopted as Christian in 325 AD, and by the second half of the 16th century. The discrepancy has already reached 10 days. To correct the discrepancy, Pope Gregory XIII in 1582 introduced a new style, the Gregorian calendar, named after him.
It was decided to remove 3 days from the count every 400 years by reducing leap years. Only years of centuries in which the number of centuries is divisible by 4 without a remainder were considered leap years: 16 00 and 20 00 are leap years, and 17 00, 18 00 and 19 00 are simple years.
In Russia, the new style was introduced on February 1, 1918. By this time, a difference of 13 days had accumulated between the new and old styles. This difference will continue until 2100.
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.
Questions 1. What explains the introduction of the belt time system? 2. Why is the atomic second used as a unit of time? 3. What are the difficulties in creating an accurate calendar? 4. What is the difference between counting leap years according to the old and new styles?
Homework 1) § 9. 2) Exercise 8 (p. 47): 1. How much does the time on your clock differ from universal time? 2. Determine the geographic longitude of your school on the map. Calculate the local time for this longitude. How does it differ from the time in which you live? 3. The date of birth of Isaac Newton according to the new style is January 4, 1643. What is the date of his birth according to the old style? .
On February 8, 1919, the RSFSR published a decree of the Council of People's Commissars (SNK) “On the introduction of time accounting according to the international system of time zones” “in order to establish a uniform accounting of time throughout the world throughout the day, causing the same readings throughout the globe hours in minutes and seconds and greatly simplifies the recording of relationships between peoples, social events and most natural phenomena in time."
The idea of streamlining time by introducing time zones was first proposed by Canadian communications engineer Sandford Fleming in the early 1880s. The prologue was the idea of one of the authors of the US Declaration of Independence, Benjamin Franklin, about saving energy resources. In 1883, Fleming's idea was accepted by the US government. In 1884, at an international conference in Washington, 26 countries signed an agreement on time zones and standard time.
The standard time system is based on the theoretical division of the surface of the globe into 24 time zones (15 degrees each) with a time difference of one hour between adjacent zones. The time of the prime meridian is taken to be the time of all points in a given time zone. The zero, “Greenwich” meridian is taken as the starting point. In practice, the boundaries of time zones do not run strictly along meridians, but are consistent with state or administrative boundaries.
The width of the time zone in different countries of the world and even within the territory of one country can differ significantly from the conventionally accepted distribution of “zone time” on Earth. For example, in the USA and Canada there are time zones that are 1.5-2 times wider than the conventionally accepted ones, and in China, which is within five conventional time zones, the time of one of the time zones applies.
By the decree of February 8, 1919 “On the introduction of time accounting according to the international system,” “zone time” was introduced throughout the RSFSR, and the country was divided into 11 time zones (from the second to the twelfth).
Due to technical difficulties in April 1919, the implementation of the decree was delayed until July 1, 1919.
After the formation of the Soviet Union in 1924, by the resolution of the Council of People's Commissars of the USSR dated March 15, 1924, time calculation according to the international system of time zones was introduced throughout the entire territory of the USSR.
Until 1930, summer time was in effect in the USSR, introduced in 1917 by the Provisional Government. In 1930, the clock hands were moved one hour ahead relative to standard time, but they were not returned back in 1931. This time began to be called “maternity leave”, since it was introduced by the Decree of the Council of People's Commissars on June 16, 1930. This order existed until 1981. Starting from April 1981, by a Decree of the USSR Council of Ministers, in addition to “maternity time” for the summer period, the hands were moved forward one hour. Thus, summer time was already two hours ahead of standard time. For ten years, during the winter period, the clock hands were moved back an hour compared to summer time, and in the summer they returned to their place again.
In 1991, the Cabinet of Ministers of the USSR, at the proposal of the authorities of Lithuania, Latvia, Estonia and Ukraine, abolished the effect of “maternity time”. However, on October 23, 1991, “maternity time” was restored, and in 1992 the transition to “summer time” was again implemented.
I am happy to live exemplary and simple:
Like the sun - like a pendulum - like a calendar
M. Tsvetaeva
Lesson 6/6
Subject Basics of time measurement.
Target Consider the time counting system and its connection with geographic longitude. Give an idea of chronology and the calendar, determining the geographic coordinates (longitude) of an area based on astrometric observations.
Tasks
:
1. Educational: practical astrometry about: 1) astronomical methods, instruments and units of measurement, counting and storing time, calendars and chronology; 2) determining the geographic coordinates (longitude) of the area based on astrometric observations. Services of the Sun and exact time. Application of astronomy in cartography. About cosmic phenomena: the revolution of the Earth around the Sun, the revolution of the Moon around the Earth and the rotation of the Earth around its axis and about their consequences - celestial phenomena: sunrise, sunset, daily and annual visible movement and culminations of the luminaries (Sun, Moon and stars), changing phases of the Moon .
2. Educating: the formation of a scientific worldview and atheistic education in the course of acquaintance with the history of human knowledge, with the main types of calendars and chronology systems; debunking superstitions associated with the concepts of “leap year” and the translation of dates of the Julian and Gregorian calendars; polytechnic and labor education in presenting material about instruments for measuring and storing time (clocks), calendars and chronology systems, and practical methods of applying astrometric knowledge.
3. Developmental: formation of skills: solve problems on calculating time and dates and transferring time from one storage and counting system to another; perform exercises to apply the basic formulas of practical astrometry; use a moving star map, reference books and the Astronomical calendar to determine the position and conditions of visibility of celestial bodies and the occurrence of celestial phenomena; determine the geographic coordinates (longitude) of the area based on astronomical observations.
Know:
1st level (standard)- time counting systems and units of measurement; the concept of noon, midnight, day, the connection of time with geographic longitude; prime meridian and universal time; zone, local, summer and winter time; translation methods; our chronology, the emergence of our calendar.
2nd level- time counting systems and units of measurement; the concept of midday, midnight, day; connections between time and geographic longitude; prime meridian and universal time; zone, local, summer and winter time; translation methods; assignment of precise time service; the concept of chronology and examples; the concept of a calendar and the main types of calendars: lunar, lunisolar, solar (Julian and Gregorian) and the basics of chronology; the problem of creating a permanent calendar. Basic concepts of practical astrometry: principles of determining time and geographic coordinates of an area based on astronomical observation data. The causes of everyday observed celestial phenomena generated by the revolution of the Moon around the Earth (changes in the phases of the Moon, the apparent movement of the Moon across the celestial sphere).
Be able to:
1st level (standard)- find universal, average, zone, local, summer, winter time;
2nd level- find universal, average, zone, local, summer, winter time; convert dates from old to new style and back. Solve problems to determine the geographic coordinates of the place and time of observation.
Equipment: poster “Calendar”, PKZN, pendulum and sundials, metronome, stopwatch, quartz clock Earth Globe, tables: some practical applications of astronomy. CD- "Red Shift 5.1" (Time - show, Tales of the Universe = Time and Seasons). Model of the celestial sphere; wall map of the starry sky, map of time zones. Maps and photographs of the earth's surface. Table "Earth in outer space". Fragments of filmstrips"The apparent movement of the heavenly bodies"; "Development of ideas about the Universe"; "How astronomy disproved religious ideas about the Universe"
Intersubject connection: Geographic coordinates, timekeeping and methods of orientation, cartographic projection (geography, 6-8 grades)
During the classes
1. Repetition of what has been learned(10 min).
A) 3 people on individual cards.
1.
1. At what altitude in Novosibirsk (φ= 55º) does the Sun culminate on September 21? [for the second week of October according to PCZN δ=-7º, then h=90 o -φ+δ=90 o -55º-7º=28º ]
2. Where on earth are no stars of the southern hemisphere visible? [at the North Pole]
3. How to navigate the terrain using the Sun? [March, September - sunrise in the east, sunset in the west, noon in the south]
2.
1. The midday altitude of the Sun is 30º, and its declination is 19º. Determine the geographic latitude of the observation site.
2. How are the daily paths of the stars located relative to the celestial equator? [parallel]
3. How to navigate the area using the North Star? [direction north]
3.
1. What is the declination of the star if it culminates in Moscow (φ = 56 º
) at an altitude of 69º?
2. How is the axis of the world located relative to the earth’s axis, relative to the horizon plane? [parallel, at the angle of geographic latitude of the observation location]
3. How to determine the geographic latitude of an area from astronomical observations? [measure the angular height of the North Star]
b) 3 people at the board.
1. Derive the formula for the height of the luminary.
2. Daily paths of luminaries (stars) at different latitudes.
3. Prove that the height of the celestial pole is equal to the geographic latitude.
V) The rest on their own
.
1. What is the greatest height reached by Vega (δ=38 o 47") in the Cradle (φ=54 o 04")? [highest height at the upper culmination, h=90 o -φ+δ=90 o -54 o 04 "+38 o 47"=74 o 43"]
2. Select any bright star using PCZN and write down its coordinates.
3. In what constellation is the Sun today and what are its coordinates? [for the second week of October according to PKZN in convocation. Virgo, δ=-7º, α=13 h 06 m ]
d) in "Red Shift 5.1"
Find the Sun:
- what information can you get about the Sun?
- what are its coordinates today and in what constellation is it located?
- How does the declination change? [decreases]
- which of the stars that have their own name is closest in angular distance to the Sun and what are its coordinates?
- prove that the Earth is currently moving in orbit closer to the Sun (from the visibility table - the angular diameter of the Sun is increasing)
2.
New material
(20 minutes)
Need to pay students' attention:
1. The length of the day and year depends on the reference system in which the Earth’s movement is considered (whether it is connected with the fixed stars, the Sun, etc.). The choice of reference system is reflected in the name of the time unit.
2. The duration of time units is related to the visibility conditions (culminations) of celestial bodies.
3. The introduction of the atomic time standard in science was due to the uneven rotation of the Earth, discovered when the accuracy of clocks increased.
4. The introduction of standard time is due to the need to coordinate economic activities in the territory defined by the boundaries of time zones.
Time counting systems. Relationship with geographic longitude.
Thousands of years ago, people noticed that many things in nature repeat themselves: the Sun rises in the east and sets in the west, summer gives way to winter and vice versa. It was then that the first units of time arose - day month Year
. Using simple astronomical instruments, it was established that there are about 360 days in a year, and in approximately 30 days the silhouette of the Moon goes through a cycle from one full moon to the next. Therefore, the Chaldean sages adopted the sexagesimal number system as a basis: the day was divided into 12 night and 12 day hours
, circle - 360 degrees. Every hour and every degree was divided by 60 minutes
, and every minute - by 60 seconds
.
However, subsequent more accurate measurements hopelessly spoiled this perfection. It turned out that the Earth makes a full revolution around the Sun in 365 days, 5 hours, 48 minutes and 46 seconds. The Moon takes from 29.25 to 29.85 days to go around the Earth.
Periodic phenomena accompanied by the daily rotation of the celestial sphere and the apparent annual movement of the Sun along the ecliptic
form the basis of various time counting systems. Time- the main physical quantity characterizing the successive change of phenomena and states of matter, the duration of their existence.
Short- day, hour, minute, second
Long- year, quarter, month, week.
1.
"Zvezdnoe"time associated with the movement of stars on the celestial sphere. Measured by the hour angle of the vernal equinox: S = t ^ ; t = S - a
2.
"Sunny"time associated: with the visible movement of the center of the Sun's disk along the ecliptic (true solar time) or the movement of the "average Sun" - an imaginary point moving uniformly along the celestial equator in the same period of time as the true Sun (average solar time).
With the introduction of the atomic time standard and the International SI System in 1967, the atomic second has been used in physics.
Second- a physical quantity numerically equal to 9192631770 periods of radiation corresponding to the transition between hyperfine levels of the ground state of the cesium-133 atom.
All the above “times” are consistent with each other through special calculations. Average solar time is used in everyday life
. The basic unit of sidereal, true and mean solar time is the day. We obtain sidereal, mean solar and other seconds by dividing the corresponding day by 86400 (24 h, 60 m, 60 s). The day became the first unit of time measurement over 50,000 years ago. Day- the period of time during which the Earth makes one complete revolution around its axis relative to some landmark.
Sidereal day- the period of rotation of the Earth around its axis relative to the fixed stars, defined as the time interval between two successive upper culminations of the vernal equinox.
True solar days- the period of rotation of the Earth around its axis relative to the center of the solar disk, defined as the time interval between two successive culminations of the same name at the center of the solar disk.
Due to the fact that the ecliptic is inclined to the celestial equator at an angle of 23 about 26", and the Earth rotates around the Sun in an elliptical (slightly elongated) orbit, the speed of the apparent movement of the Sun across the celestial sphere and, therefore, the duration of the true solar day will constantly change throughout the year : fastest near the equinox points (March, September), slowest near the solstices (June, January).To simplify time calculations, the concept of the average solar day was introduced in astronomy - the period of rotation of the Earth around its axis relative to the “average Sun”.
Average solar day are defined as the period of time between two successive culminations of the “average Sun” of the same name. They are 3 m 55.009 s shorter than the sidereal day.
24 h 00 m 00 s sidereal time is equal to 23 h 56 m 4.09 s mean solar time. For the certainty of theoretical calculations, it was accepted ephemeris (tabular) a second equal to the average solar second on January 0, 1900 at 12 o'clock of equicurrent time not associated with the rotation of the Earth.
About 35,000 years ago, people noticed the periodic change in the appearance of the Moon - the change of lunar phases. Phase F celestial body (Moon, planet, etc.) is determined by the ratio of the greatest width of the illuminated part of the disk d to its diameter D: Ф=d/D. Line terminator separates the dark and light parts of the luminary's disk. The Moon moves around the Earth in the same direction in which the Earth rotates around its axis: from west to east. This movement is reflected in the visible movement of the Moon against the background of stars towards the rotation of the sky. Every day, the Moon moves east by 13.5 o relative to the stars and completes a full circle in 27.3 days. This is how the second measure of time after the day was established - month.
Sidereal (sidereal) lunar month- the period of time during which the Moon makes one complete revolution around the Earth relative to the fixed stars. Equal to 27 d 07 h 43 m 11.47 s.
Synodic (calendar) lunar month- the period of time between two successive phases of the same name (usually new moons) of the Moon. Equal to 29 d 12 h 44 m 2.78 s. .jpg)
The combination of the phenomena of the visible movement of the Moon against the background of stars and the changing phases of the Moon allows one to navigate by the Moon on the ground (Fig.). The moon appears as a narrow crescent in the west and disappears in the rays of dawn as an equally narrow crescent in the east. Let's mentally draw a straight line to the left of the lunar crescent. We can read in the sky either the letter “R” - “growing”, the “horns” of the month are turned to the left - the month is visible in the west; or the letter “C” - “aging”, the “horns” of the month are turned to the right - the month is visible in the east. During a full moon, the moon is visible in the south at midnight.
As a result of observations of changes in the position of the Sun above the horizon over many months, a third measure of time arose - year.
Year- the period of time during which the Earth makes one full revolution around the Sun relative to some landmark (point).
Sidereal year- sidereal (stellar) period of the Earth’s revolution around the Sun, equal to 365.256320... average solar day.
Anomalistic year- the time interval between two successive passages of the average Sun through a point in its orbit (usually perihelion) is equal to 365.259641... average solar day.
Tropical year- the time interval between two consecutive passages of the average Sun through the vernal equinox, equal to 365.2422... average solar day or 365 d 05 h 48 m 46.1 s.
World Time is defined as local mean solar time at the prime (Greenwich) meridian ( That, UT- Universal Time). Since in everyday life you cannot use local time (since in Kolybelka it is one, and in Novosibirsk it is different (different λ
)), which is why it was approved by the Conference at the suggestion of a Canadian railway engineer Sanford Fleming(February 8 1879
when speaking at the Canadian Institute in Toronto) standard time, dividing the globe into 24 time zones (360:24 = 15 o, 7.5 o from the central meridian). The zero time zone is located symmetrically relative to the prime (Greenwich) meridian. The belts are numbered from 0 to 23 from west to east. The real boundaries of the belts are combined with the administrative boundaries of districts, regions or states. The central meridians of time zones are separated from each other by exactly 15 o (1 hour), therefore, when moving from one time zone to another, the time changes by an integer number of hours, but the number of minutes and seconds does not change. New calendar days (and New Year) begin on date lines(demarcation line), passing mainly along the meridian of 180°E longitude near the northeastern border of the Russian Federation. West of the date line, the date of the month is always one more than east of it. When crossing this line from west to east, the calendar number decreases by one, and when crossing the line from east to west, the calendar number increases by one, which eliminates the error in counting time when traveling around the world and moving people from the Eastern to the Western hemispheres of the Earth.
Therefore, the International Meridian Conference (1884, Washington, USA) in connection with the development of telegraph and railway transport introduced:
- the day begins at midnight, and not at noon, as it was.
- the prime (zero) meridian from Greenwich (Greenwich Observatory near London, founded by J. Flamsteed in 1675, through the axis of the observatory telescope).
- counting system standard time
Standard time is determined by the formula: T n = T 0 + n
, Where T 0
- universal time; n- time zone number.
Maternity time- standard time, changed to an integer number of hours by government decree. For Russia it is equal to zone time, plus 1 hour.
Moscow time- maternity time of the second time zone (plus 1 hour): Tm = T 0 + 3
(hours).
Summer time- maternity standard time, changed additionally by plus 1 hour by government order for the period of summer time in order to save energy resources. Following the example of England, which introduced daylight saving time for the first time in 1908, now 120 countries around the world, including the Russian Federation, implement daylight saving time annually.
Time zones of the world and Russia
Next, students should be briefly introduced to astronomical methods for determining the geographic coordinates (longitude) of an area. Due to the rotation of the Earth, the difference between the moments of the onset of noon or climaxes ( climax. What kind of phenomenon is this?) stars with known equatorial coordinates at 2 points is equal to the difference in the geographical longitudes of the points, which makes it possible to determine the longitude of a given point from astronomical observations of the Sun and other luminaries and, conversely, the local time at any point with a known longitude.
For example: one of you is in Novosibirsk, the second is in Omsk (Moscow). Which of you will observe the upper culmination of the center of the Sun first? And why? (note, this means that your watch runs according to Novosibirsk time). Conclusion- depending on the location on Earth (meridian - geographic longitude), the culmination of any luminary is observed at different times, that is time is related to geographic longitude
or Т=UT+λ, and the time difference for two points located on different meridians will be T 1 - T 2 = λ 1 - λ 2.Geographic longitude (λ
) of the area is measured east of the “zero” (Greenwich) meridian and is numerically equal to the time interval between the same climaxes of the same star on the Greenwich meridian ( UT) and at the observation point ( T). Expressed in degrees or hours, minutes and seconds. To determine
geographic longitude of the area, it is necessary to determine the moment of culmination of a luminary (usually the Sun) with known equatorial coordinates. By converting the observation time from mean solar to sidereal using special tables or a calculator and knowing from the reference book the time of the culmination of this star on the Greenwich meridian, we can easily determine the longitude of the area. The only difficulty in calculations is the exact conversion of time units from one system to another. There is no need to “watch” the moment of culmination: it is enough to determine the height (zenith distance) of the luminary at any precisely recorded moment in time, but the calculations will then be quite complicated.
Clocks are used to measure time. From the simplest, used in ancient times, are gnomon
- a vertical pole in the center of a horizontal platform with divisions, then sand, water (clepsydra) and fire, to mechanical, electronic and atomic. An even more accurate atomic (optical) time standard was created in the USSR in 1978. An error of 1 second occurs once every 10,000,000 years!
Time keeping system in our country
1) From July 1, 1919 it was introduced standard time(decree of the Council of People's Commissars of the RSFSR dated February 8, 1919)
2) Established in 1930 Moscow (maternity leave)
time of the 2nd time zone in which Moscow is located, translated one hour ahead compared to standard time (+3 to World Time or +2 to Central European Time) in order to ensure a lighter part of the day during the day (decree of the Council of People's Commissars of the USSR dated June 16, 1930 ). The distribution of regions and regions across time zones is changing significantly. Canceled in February 1991 and reinstated again in January 1992.
3) The same Decree of 1930 abolished the transition to summer time in force since 1917 (April 20 and return on September 20).
4) In 1981, the country resumed daylight saving time. Resolution of the Council of Ministers of the USSR of October 24, 1980 “On the procedure for calculating time on the territory of the USSR” summer time is introduced
By moving the clock forward to 0 o'clock on April 1, and moving the clock forward an hour on October 1, since 1981. (In 1981, daylight saving time was introduced in the vast majority of developed countries - 70, except Japan). Later in the USSR, translations began to be made on the Sunday closest to these dates. The resolution introduced a number of significant changes and approved a newly compiled list of administrative territories assigned to the corresponding time zones.
5) In 1992, by Decree of the President, maternity time (Moscow) time was restored from January 19, 1992, with the preservation of summer time on the last Sunday in March at 2 a.m. an hour ahead, and for winter time on the last Sunday in September at 3 o'clock in the morning an hour ago.
6) In 1996, by Decree of the Government of the Russian Federation No. 511 of April 23, 1996, summer time was extended by one month and now ends on the last Sunday of October. In Western Siberia, regions that were previously in the MSK+4 zone switched to MSK+3 time, joining Omsk time: Novosibirsk region on May 23, 1993 at 00:00, Altai Territory and the Altai Republic on May 28, 1995 at 4:00, Tomsk region May 1, 2002 at 3:00, Kemerovo region March 28, 2010 at 02:00. ( the difference with world time GMT remains 6 hours).
7) From March 28, 2010, when switching to daylight saving time, the territory of Russia began to be located in 9 time zones (from the 2nd to the 11th inclusive, with the exception of the 4th - the Samara region and Udmurtia on March 28, 2010 at 2 am switched Moscow time) with the same time within each time zone. The boundaries of time zones run along the borders of the constituent entities of the Russian Federation, each subject is included in one zone, with the exception of Yakutia, which is included in 3 zones (MSK+6, MSK+7, MSK+8), and the Sakhalin region, which is included in 2 zones ( MSK+7 on Sakhalin and MSK+8 on the Kuril Islands).
So for our country in winter T= UT+n+1 h , A in summer time T= UT+n+2 h
You can offer to do laboratory (practical) work at home: Laboratory work"Determination of terrain coordinates from solar observations"
Equipment: gnomon; chalk (pegs); "Astronomical calendar", notebook, pencil.
Work order:
1. Determination of the noon line (meridian direction).
As the Sun moves daily across the sky, the shadow from the gnomon gradually changes its direction and length. At true noon, it has the shortest length and shows the direction of the noon line - the projection of the celestial meridian onto the plane of the mathematical horizon. To determine the midday line, it is necessary in the morning to mark the point at which the shadow of the gnomon falls and draw a circle through it, taking the gnomon as its center. Then you should wait until the shadow from the gnomon touches the circle line a second time. The resulting arc is divided into two parts. The line passing through the gnomon and the middle of the noon arc will be the noon line.
2. Determination of the latitude and longitude of the area from observations of the Sun.
Observations begin shortly before the moment of true noon, the onset of which is recorded at the moment of exact coincidence of the shadow from the gnomon and the noon line according to a well-calibrated clock running according to maternity time. At the same time, measure the length of the shadow from the gnomon. By shadow length l at true noon by the time it occurs T d according to maternity time, using simple calculations, the coordinates of the area are determined. Previously from the ratio tg h ¤ =Н/l, Where N- height of the gnomon, find the height of the gnomon at true noon h ¤.
The latitude of the area is calculated using the formula φ=90-h ¤ +d ¤, where d ¤ is the declination of the Sun. To determine the longitude of an area, use the formula λ=12 h +n+Δ-D, Where n- time zone number, h - equation of time for a given day (determined according to the Astronomical Calendar). For winter time D = n+ 1; for summer time D = n + 2.
| "Planetarium" 410.05 mb | The resource allows you to install the full version of the innovative educational and methodological complex "Planetarium" on a teacher's or student's computer. "Planetarium" - a selection of thematic articles - are intended for use by teachers and students in physics, astronomy or natural science lessons in grades 10-11. When installing the complex, it is recommended to use only English letters in folder names. | ||
| Demo materials 13.08 MB | The resource represents demonstration materials of the innovative educational and methodological complex "Planetarium". | ||
| Planetarium 2.67 mb Clock 154.3 kb Standard time 374.3 kb Standard time map 175.3 kb |
Repeated generalization lesson on astronomy in 10th grade
on the topic “PRACTICAL FUNDAMENTALS OF ASTRONOMY”
Compiled by a physics teacher
GBOU "school No. 763" in Moscow
Knyazeva Elena Nikolaevna
Lesson objectives:
Repeat and summarize students’ knowledge of the material on the topic “Practical Fundamentals of Astronomy.”
To strengthen students’ problem solving skills: computational, qualitative, experimental.
Prepare students for the test in this section.
Strengthen practical skills in working with a star map and a model of the celestial sphere.
Developing interest in the study of physics and astronomy.
Development of logical thinking.
1.Lesson type: Generalization, systematization and repetition of material.
2.Structure of measures o acceptance.
Continueactivity,
min.
Organizing time.
Teacher's opening speech.
oand oral and written tasks of a generalizing, systematizing nature, developing generalized skills, forming generalized conceptual knowledge based on a generalization of facts and phenomena.
Test
Summarizing
3.General methods:
oral control and self-control, written control, independent cognitive activity of students, partially search, visual, stimulation and motivation to learn.
Equipment:
Movable star map, model of the celestial sphere, calculator, computer, projector.
During the classes
Organizing time.
Prepare students for work in class.
Teacher's opening speech.
The teacher communicates the goals and objectives of the lesson, as well as why it is being conducted.
this lesson, where you can apply the knowledge and skills acquired
at the lesson.
Students’ performance of various tasks individually and collectively o and oral and written tasks of a generalizing, systematizing nature, developing generalized skills, forming generalized conceptual knowledge based on a generalization of facts and phenomena.
Questions for frontal survey.
1.What is a constellation called?
2. List the constellations you know.
3.Vega's magnitude is 0.03 and Deneb's magnitude is 1.25. Which of these stars is brighter?
4. How many timesIs a first magnitude star brighter than a second magnitude star?
5.What horizontal coordinates of the star do you know?
6. What is azimuth? How to define it? What units of measurement does azimuth have?
7. What is height? How to determine it? What units of measurement does height have?
8. What coordinates of the luminary are called equatorial?
9. Using the coordinates given in the list of bright stars (Appendix 5 in the textbook), find some of them on the star map.
10. Find its main circles, lines and points on the model of the celestial sphere.
11. Which circle of the celestial sphere do the stars cross twice?
12. How can you determine the height of the luminary at the upper and lower culmination?
13. What is the ecliptic?
14. What zodiac constellations do you know?
15.Why does the midday altitude of the Sun change throughout the year?
16. Determine the position of the Sun on the ecliptic and its equatorial coordinates today.
17. What is a sidereal and synodic month? What are these months for the Moon?
18. Why is only one side of the Moon visible from Earth?
19. Why don’t eclipses of the Moon and Sun occur every month?
20. What explains the introduction of the belt time system?
Test on the topic
"PRACTICAL FUNDAMENTALS OF ASTRONOMY".
Option 1.
Calculate how many times brighter a second magnitude star is than a sixth magnitude star.
a) Express 120° in hourly units.
b) Express the right ascension equal to 5 hours 30 minutes in angular measure.
a) How is the axis of the world located relative to the earth's axis?
b) At what points does the celestial equator intersect with the horizon?
The geographic latitude of St. Petersburg is 60°. At what altitude in this city does the upper culmination of a star whose declination is -16° occur?
The height of the star at the upper culmination was 15°, the declination of this star was -9°. What is the geographic latitude of the observation site?
Capricorn, Dragon, Pisces, Leo, Libra, Cancer, Scorpio.
a) What is the period of revolution of the Moon around the Earth in the reference frame associated with the stars?
b) How many solar eclipses can be observed on average per year?
Universal time 10h 45 min. What time will the clocks in Moscow show?
What date according to the old style corresponds to January 1, 2018 according to the new style?
Option 2.
Calculate how many times a star of the first magnitude is brighter than a star of the fifth magnitude.
a) Express 150° in hourly units.
b) Express the right ascension equal to 18 hours 30 minutes in angular measure.
a) How is the noon line located relative to the plumb line?
b) At what points does the celestial meridian intersect with the horizon line?
The geographic latitude of Moscow is 56°. At what altitude in this city does the upper culmination of a star whose declination is -20° occur?
Determine the declination of the star, the upper culmination of which was observed in Moscow (geographic latitude 56°) at an altitude of 37°.
Aries, Swan, Virgo, Taurus, Gemini, Aquarius, Sagittarius.
Find the odd one out on this list. Justify your answer.
a) What is the full cycle of changing lunar phases?
b) How many lunar eclipses can be observed on average per year?
Moscow time 10h 45 min. What is universal time?
What date according to the new style corresponds to January 1, 2018 according to the old style?
Answers
a)8hb)82°30‘
a) in parallel
b) at points of the east and west
14°
66°
23.5°
0°
9°
The Dragon is not a zodiac constellation
a)27.3 days
b)2-3
13:45
min
2v
a)10h
b)277°30‘
a) perpendicular
b) at points north and south
14°
3°
23.5°
0°
7°
Swan is not a zodiac constellation
a)29.5 days
b)1-2
7:45
min
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