Daily rotation of the Earth around the polar axis.
2.
Evidence of the Earth's rotation.
3.
Geographical consequences of the Earth's rotation.
1Earth
around its axis
rotates from west to
east (when viewed from
sides of the North Pole)
counterclock-wise.
Full
turnover
relatively
stars
those around
solar
the Earth completes the system in
23 hours 56 minutes 4.0905
seconds
For
facilities
accepted
count
time
full rotation 24 hours.
Corner
speed
rotation of all points of the Earth
at
this
is the same:
360°/24 = 15°.
2The linear speed of rotation of the points depends on
the distance they must travel in a period
daily rotation of the Earth. Remain motionless for
surfaces only the exit points of the imaginary axis -
points of geographic poles.
The points on the
equator line – 464 m/s. Therefore the speed
rotation will decrease from the equator to the poles.
Linear speed for any latitude is rounded
formula:
V1 = V cos φ,
where V is the speed at the equator, φ is the latitude of the area:
V1 = 464*cos 52° = 464*0.6032 = 279.88 m/s
We don't notice the rotation of the Earth because everything
objects and atmosphere rotate uniformly with
surface of the Earth. On the contrary, it seems to us that
celestial bodies move from east to west, i.e.
towards the actual movement of the Earth.
3
Foucault pendulum
It is known from physics that the planethe swing of the pendulum does not change if
pendulum does not act any other
forces other than gravity.
In 1851, the French physicist L. Foucault
based on this law I made an experiment,
proving the rotation of the Earth around its axis.
In the tallest building in Paris -
Pantheon - on a thin steel wire
a heavy metal ball was suspended
with a point. Under this huge pendulum
a platform was made on which
sand. When the pendulum started slow
swing, then we noticed that the tip
leaves a mark on the sand, and in
result
everyone
new
rocking
pendulum line passing through the center
swinging, deflected by its ends
right,
If
look
above
from
previous one.
IN
reality
It is not the pendulum that deviates - it maintains
its swing plane, but changes
position in space of the entire earth
along with the room in which it swings
pendulum.
4Swing plane positions
pendulum during daily rotation
Earth
The amount of pendulum deflection
depends on the latitude of the observation site.
On
equator
this
Effect
not expressed at all, but as
As it moves away from the equator it increases
and at the poles it is most noticeable
way. Here the deviation of the lines
swing of the pendulum during each
an hour is 15°, and a day is 360°.
The magnitude of the apparent rotation
swing plane of the pendulum in one
hour can be calculated for any
latitude according to the formula:
α = 15°*sin φ
where a is the desired value, φ is
latitude of the area, and 15° is the angular
the amount of rotation of the Earth in 1 hour.
The swing line of the pendulum deviates in
northern hemisphere to the right, and in
southern - to the left. It means that
rotation
Earth
around
axes
occurs from west to east.
56
Deflection of falling bodies
If you throw any body from a hightower, then it does not fall vertically, but several
deviates in an easterly direction.
This is explained by the fact that the top of the tower
is farther from the center of the Earth than its
basis, and therefore describes more
long circle as the Earth rotates.
The falling body at the top of the tower had
greater horizontal speed than its
base, and therefore reached the surface
Land at a point slightly to the east
plumb line (Fig.).
In a mine 158.5 m deep, a body falls
deviates by 27.5 mm. Deviation effect
falling
body
V
opposite
previous experience is best expressed
at the equator and is completely absent at
poles.
7
Oblateness of the Earth
The oblateness of the Earth indicatesrotating it around its axis. It is known
that rotation generates centrifugal
force, which in the conditions of the Earth, which has
spherical
shape,
unequally
appears in different places.
Linear speed at different
latitudes are not the same. Each at the equator
the point runs 464 m/sec, at latitude
Moscow - only 260 m/sec, and at the pole this
the value is practically zero.
Centrifugal force is proportional
the square of the speed and most of all by
the equator, absent at the poles. That power
gave
Earth
form
ellipsoid
rotation, the surface of which is closer
just to the center of the Earth at the poles and beyond
just near the equator, like the surface
rings compressed during rotation (Fig.)
Thus, centrifugal force and
distance from the center of the earth do
unequal gravity in different
places.
At the equator, every body weighs less,
8
than at the pole, by 1/200th.
GEOGRAPHICAL SIGNIFICANCE OF THE DAILY ROTATION OF THE EARTH
Together with the spherical figure of the Earth's rotation in the fieldsolar radiation determines the zoning of nature.
1.
2. Axial rotation causes the change of day and night. IN
As a result of the change of day and night, a daily regime of processes arises in
GO. If there were no daily rotation of the Earth, then one side of it
would continuously heat up and the other would cool, and this would be reflected
would be on all natural processes of the earth's surface.
2.
9
3. When the Earth rotates around its axis, two points remain motionless - the poles - this makes it possible to construct a coordinate grid on the ball
3. When the Earth rotates around its axis, motionlesstwo points remain - poles - this makes it possible
construct a coordinate grid on the ball, i.e. meridians,
parallels, equator.
Meridian (Latin – “midday”) –
it is the line connecting the poles.
For
definitions
primary
meridian of objective criteria
no, that’s why he was chosen conditionally -
meridian,
passing
through
Greenwich
observatory,
He
called
initial
or
Greenwich. From him the account is kept
longitude
Longitude is the distance in
degrees from the prime meridian to
meridian passing through an object.
For convenience, longitudes are counted in both
sides from Greenwich, from 0° to 180° on
east – eastern longitudes, on
west - western.
10The equator is the line formed
intersection of the earth's surface with a plane,
perpendicular to the axis of rotation of the Earth and
located at equal distances from the poles. This
line of the largest circle on earth
surfaces. It divides the Earth into two hemispheres:
northern and southern.
If you mentally cross the Earth with planes,
parallel to the equatorial plane, then on
surfaces
will appear
lines,
having
west-east direction, which is called -
parallels. Remoteness of parallels, and,
therefore, any point from the equator in
degrees of the meridian is called latitude. Latitude
measured in the range from 0° to 90° and can be
northern and southern.
The length of the parallels decreases from the equator to
stripes, the linear
rotation speed of all parallels. Linear
rotation speed of all points on one parallel
is the same.
11
Geographical coordinates
Geographic latitude is the angle betweennormal to the surface of the ellipsoid (or between
sheer
line
–
perpendicular
To
surface of the geoid) and the plane of the equator.
The values of latitudes, which are measured from
equator to the north pole is taken into account
sign “plus”, “north”, and to the south - with a sign
"minus", "southern". The latitude of the equator is 0°,
The latitude of the north pole is + 90°, the south – –
90 .
Geographic longitude represents
is the dihedral angle between the plane
geographic meridian point and plane
prime geographic meridian. Longitude
counted from the Greenwich meridian to
east from 0 to 360°, or east from 0 to 180°, and
to the west from 0 to 180° indicating “east
longitude", "west longitude". Longitude and latitude
can also be defined accordingly
the length of the arc of the meridian and parallel on
ellipsoid surface.
12
4. The rotation of the Earth causes the deflection force of the Earth's rotation
Gustave Gaspard Coriolis(Gaspard-Gustave de Coriolis)
(21.05.1792 - 19.09.1843)
Deflecting
force
rotation
Earth,
or
force
Coriolis,
manifests itself
V
volume,
What
All
moving on the earth's surface,
or bodies parallel to it, deviate
from its direction in the north
hemisphere to the right, in the southern hemisphere to the left.
When moving, all bodies tend
save
rectilinear
direction. But their movement
occurs in a rotating sphere.
That's why
Seems,
What
They
are rejected
from
original
directions.
On
himself
in fact,
bodies do not deviate, but move
the surface itself on or above
which these bodies move.
13Launched from point A towards the North Pole
rocket. At the moment of launch, its direction coincided with
direction of the meridian. Over time
Point A, as a result of the Earth's rotation, moves to
point B. The direction of the meridian deviated to the left.
According to the law of inertia, a moving body tends
maintain your direction and speed in the world
space. Rocket and saves initially
given direction, but it seems to the observer that
the rocket veered to the right. It's easy to see that
this deflecting force is fictitious, which is not deflected
moving body, but changes its spatial
position of the Earth's surface. The deviation will be
greatest at the poles, and at the equator it is 0°, because
the meridians there are parallel to each other and their
the direction in space does not change.
A deviation in the northern hemisphere occurs
to the right, in the south - to the left. The Coriolis force affects
all moving objects, regardless of
driving directions. Deflection value
the action of the rotation of the Earth on a body weighing 1 kg,
expressed by the formula:
F = 2ω*ν*sin φ
where ω is the angular velocity of the Earth, ν is the speed
body movements, α – latitude.
14
5. The rotation of the Earth around its axis gives the basic unit of time - the day
Solar day is the period of time between two consecutivepassages of the center of the Sun through the meridian of the observation point.
True solar time is the time interval between two consecutive
the upper culminations of the center of the Sun through the meridian of the observation point.
The length of the true solar day varies throughout the year primarily
due to the uneven movement of the Earth in an elliptical orbit. Therefore they
also inconvenient for measuring time.
Mean solar time is the time interval between two consecutive
the upper culminations of the center of the average Sun through the meridian of the observation point -
a fictitious point moving uniformly along the celestial equator with an average speed
the movement of the true Sun along the ecliptic. The average solar day is 24 hours.
For practical purposes, they use the average solar day.
They are longer than stellar ones, because the Earth rotates around its axis in the same direction, in
which moves in orbit around the Sun at an angular velocity of about 1° per day. Because of
This means that the Sun is moving against the background of the stars, and the Earth still needs to rotate about 1°,
so that the Sun “comes” to the same meridian. Thus, per sunny day
15
The Earth rotates approximately 361°. Sidereal day is the period of time between two consecutive
the upper culminations of the star through the meridian of the observation point (time
complete rotation of the Earth around its axis). Time between two transits of a star
through the meridian of a given place, a sidereal day is equal to 23 hours 56 minutes 4
seconds. This is the actual time of the Earth's daily rotation. (since Earth
moves around the Sun and around the axis in one direction, then the solar day
longer than the actual time of a full revolution). The sidereal day concludes
contains 86400 s = 24 hours.
A bit of a starry day
shorter than a sunny day.
When
star
day
ends
Earth
must
more
A little
will turn around
to
"catch up" with the Sun.
Sidereal day. Starting position.
16In everyday life, using mean solar time is also inconvenient,
since each meridian has its own - local time.
The presence at different points lying on different meridians of their own local
time led to many inconveniences. Therefore, at the International Astronomical
Congress in 1884 adopted zone time.
To do this, the entire surface of the globe was divided into 24 time zones of 15° each.
every. Standard time is taken to be the local time of the middle meridian of each zone.
The zero (aka 24th) belt is the one through the middle of which the zero (Greenwich) passes.
meridian. Its time is accepted as universal time. Belts are counted from the west
to the East.
In two neighboring zones, the standard time differs by exactly 1 hour. Time zone boundaries
belts on land for convenience are drawn not strictly along meridians, but according to natural
borders (rivers, mountains) or state and administrative boundaries. To
convert local time to universal time and back, you need to know the angular distance of the place from
prime meridian, i.e. longitude of the place. Universal time is used in astronomy, in
in practical life it is actually not used. To convert local time to
waist and vice versa, the formula is:
Тп = Тм + n – λ,
where Тп – standard time, Тм – local time, n – zone number, λ – longitude.
1718After the October Revolution, February 8, 1918, the zone division was
introduced by decree of the Council of People's Commissars.
By government decree of June 16, 1930, the hands of all clocks in the territory
The Soviet Union were moved forward an hour. Maternity time has formed,
the introduction of which made it possible to save energy. Duration of maternity leave
time was set “until repealed” (existed until 1981).
By resolution of the Council of Ministers on April 1, 1981, the clock hands were moved
another hour ahead. Thus, summer time was already two hours ahead
waist For ten years, the clock hands were set back an hour during the winter season.
back compared to summer time, and in the summer they returned to their place again.
In March 1991, maternity time was abolished. Two hours ahead
forward was abolished. We have switched to the summer-winter time reference system.
In winter, standard time was used, and in summer, clocks were moved forward 1 hour.
In Belarus, by Resolution of the Council of Ministers No. 1229 of September 15, 2011
time calculation was approved in accordance with the international clock system
zones according to standard time plus one hour without changing hands to seasonal time.
19
6. Date line
Magellan's voyage around the worldand the loss of one day.
Meridian
180°
accepted
behind
international date line.
This is a conditional line on the surface
the globe, on both sides of which
hours and minutes coincide, and calendar
the dates differ by one day. For example,
on New Year's Day at 0:00 a.m. west of this
line on January 1 of the new year, and to the east -
December 31st of the old year. When crossing
date boundaries from west to east in counting
calendar days return to one
a day ago, and from east to west - alone
days are skipped in the date count.
For
facilities
calculus
international
agreement
was
It is customary to consider the beginning of a new day on the 12th
time zone, i.e. meridian 180°. This
date line.
20
7. The formation of its geophysical fields is closely related to the structure of the globe and its rotation
218. The change of day and night creates a daily rhythm in living and inanimate nature
229. Ebbs and flows
The result of the Earth's rotation is the ebb and flow of the tides. Moon likeThe celestial body closest to Earth has a strong gravitational force.
This force causes deformation of the Earth's surface, especially its water
shells.
At the point closest to the Moon, as well as at the opposite point
point on Earth, a tidal ledge always forms. The tide is on the side
The Earth facing the Moon is explained by the fact that here is the largest
force of gravity. The tide is on the opposite side of the Earth
explained by the fact that the centrifugal force resulting from
rotation of the Earth and Moon around their common center of gravity, located
inside the Earth, exceeds the gravitational force of the Moon.
High tides are observed on the Earth-Moon line, and low tides are observed on
perpendicular line.
TOPIC: AXIAL ROTATION OF THE EARTH
OBJECTIVE: 1. To introduce students to the concepts of geographic poles on Earth. 2. Time units. 3.Geographical consequences of the Earth’s axial rotation.
REMEMBER: 1. Is the rotation of the Earth noticeable to humans? 2. How many hours are there in a day?
LEARNING NEW MATERIAL
TWO MAIN TYPES OF MOTION OF THE EARTH: 1. Rotation around its axis 2. Orbit around the Sun.
ROTATION OF THE EARTH AROUND ITS AXIS The axis is inclined to the orbital plane - 66.5 Constantly directed towards the North Star The points of intersection of the imaginary earth's axis with the surface of the Earth are called geographical poles
THERE ARE TWO GEOGRAPHICAL POLES - In the central part of the Arctic Ocean In Antarctica
AXIAL ROTATION The Earth rotates around its axis counterclockwise, i.e. from west to east. The Earth completes a full rotation around its axis in 24 hours.
A DAY IS A NATURAL, NATURE-GIVEN BASIC UNIT OF TIME. A day is divided into 24 hours, an hour into 60 minutes, a minute into 60 seconds. The faster the planet rotates around its own axis, the shorter the day; the slower, the longer. Uranus rotates on its axis for 12 hours. On Venus, a day lasts 243 Earth days, or 5832 Earth hours.
THE EARTH'S AXIAL ROTATION HAS GEOGRAPHICAL CONSEQUENCES. 1. Rotation around an axis affects the shape of the planet. The earth is slightly flattened at the poles. 2. Due to the rotation of the Earth, all bodies moving on its surface are deflected to the right in the Northern Hemisphere, and to the left in the Southern Hemisphere. In rivers, due to the deflecting force, the water is pressed against one of the banks, so in the rivers of the Northern Hemisphere the right bank is steep, and in the Southern Hemisphere the left bank is steep. The deviation affects the direction of winds and ocean currents.
3. Thanks to the rotation of the Earth, the change of day and night occurs. This causes either heating or cooling of the surface. With daily changes, many natural processes change. Living organisms are adapted to the circadian rhythm.
IF THE EARTH WOULD STOP ROTATING AROUND ITS AXIS AND AROUND THE SUN, THEN The temperature on the sunny side would reach +100 degrees and all the water would evaporate. The kingdom of eternal cold, where the earth's moisture would accumulate in the form of an ice cap.
REPRESENTATION OF LEARNED MATERIAL 1. Name the two main types of Earth motion. 2. In which direction does the Earth rotate around its axis? 3. What are the consequences of the Earth's rotation around its axis? 4. Why is the Earth not a perfect sphere? 5. How does the change of day and night affect living organisms?
D/Z paragraph 9.
Literature used: 1. Textbook by V. Dronov, L.E. Savelyeva GEOGRAPHY. Geography M. Bustard. 2016 Geography teacher at the Mendyukinsky Secondary School. Strokina I.S.
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Text content of presentation slides: SHOW THE LINES ON THE MAP……. Western Hemisphere Eastern Hemisphere You and I have already borrowed that... 1. That the shape of the Earth is geoid. 2. The Earth rotates around the Sun and the seasons change. 3. The Earth rotates around its axis and the day changes. Why does this happen? 4. Why in winter cold, but warm in summer? 5. Which sides of the horizon do you know? 6. How do you know where north is? Orientation by the polar star. Page 25 The position of the Earth in the circumsolar orbit and the constancy of the tilt of the Earth's axis lead to the fact that the height of the Sun above the horizon changes. The height of the Sun above the horizon on the day of the summer solstice: a) - Cape Chelyuskin; b) - Krasnodar Our planet is in a constant flow of almost parallel solar rays. The angle of their incidence on the Earth's surface at the same moment in time is different and depends on the position of a particular place in relation to the geographic poles. Depending on the illumination, illumination zones are distinguished, limited by the tropics and polar circles (Fig. 11, p. 25). Between the tropics there is a hot equatorial (tropical) zone. Here the Sun is at its zenith twice a year (in the tropics - once), the differences in the length of day and night are small (at the equator there are none), the seasons are either absent (near the equator), or there are only two seasons (dry and wet ). Temperate zones are located between the tropics and the polar circles. Here the Sun is never at its zenith, the length of day and night varies significantly, four seasons are distinguished, and in summer white (polar) nights are observed near the polar circles. Between the poles and the polar circles there are two cold (polar) zones. They are characterized by the coincidence of two seasons of the year with a polar day and a polar night. Dependence of surface heating on the angle of incidence of sunlight. 66.5 The rotation of the Earth around its axis. If we look at our planet from the North Pole, we will see that the Earth rotates around its axis from west to east, that is, counterclockwise (Fig. 7, p. 19). Our planet makes a full revolution in one day. Astronomers divide a day into 24 hours, an hour into 60 minutes, and a minute into 60 seconds. But it is precisely the day - the period of one revolution of the Earth around its axis - that is taken as the basic unit of time. Dependence of surface heating on the angle of incidence of sunlight. The Earth's axial rotation has several geographic consequences. Firstly, the change of day and night as a result of daily rotation causes either heating or cooling of the Earth's surface. 66.5 The rotation of the Earth around its axis. Secondly, due to the daily rotation, the Earth is flattened along the earth's axis and takes on a shape different from a perfect sphere. The interval between sunrise and sunset is called the length of the day. To determine the length of the day, many people use calendars that indicate the moments of sunrise and sunset. Dependence of surface heating on the angle of incidence of sunlight. Notebook. Lesson 7. Daily rotation of the Earth. 1. Light belts. Rear. According to Fig. 13) Fill in the missing words. Summer comes in the ___ hemisphere, winter in ____________. The sun is at its zenith above the ____ line and does not set below the horizon above the ______________ line. In the northern hemisphere, the length of the day is ______ than the length of the night. Date: ____ _____Day ________solstice. Notebook. Lesson 7. Daily rotation of the Earth. 1. Light belts. Rear. According to Fig. 13) Fill in the missing words. Summer comes in the southern hemisphere, winter in the northern. The sun is at its zenith above the line of the southern tropics and does not set below the horizon above the line of the southern polar circle. In the northern hemisphere, the length of the day is ______ than the length of the night. Date: December 22 Winter solstice. Notebook. Lesson 7. Daily rotation of the Earth. 1. Light belts. Rear. According to Fig. 23) Fill in the missing words. The Earth makes a full revolution around its axis in ___ hours. If it is daytime in your locality, then in 12 hours it will be ___. In 24 hours the Earth will rotate by ____ degrees, and in 1 hour by ____ degrees. Notebook. Lesson 7. Daily rotation of the Earth. 1. Light belts. Rear. According to Fig. 23) Fill in the missing words. The Earth makes a full revolution around its axis in 24 hours. If it is day in your locality, then in 12 hours it will be night. In 24 hours the Earth will rotate 360 degrees, and in 1 hour - by 15 degrees.
1 Lecture 4. Axial (daily) rotation of the Earth Daily rotation of the Earth around the polar axis. Evidence of the Earth's rotation. Geographical consequences of the Earth's rotation.
Slide 2
2 The Earth rotates around its axis from west to east (as viewed from the North Pole) counterclockwise. The Earth makes a complete revolution relative to the stars surrounding the solar system in 23 hours 56 minutes 4.0905 seconds. For convenience, it is customary to consider the time of a complete revolution to be 24 hours. The angular velocity of rotation of all points of the Earth is the same: 360°/24 = 15°.
Slide 3
3 The linear speed of rotation of the points depends on the distance they must travel during the period of the Earth’s daily rotation. Only the exit points of the imaginary axis—the points of the geographic poles—remain motionless on the surface. Points on the equator line have the highest rotation speed - 464 m/s. Consequently, the rotation speed will decrease from the equator to the poles. Linear speed for any latitude is rounded by the formula: V 1 = V cos φ, where V is the speed at the equator, φ is the latitude of the area: V 1 = 464*cos 52° = 464*0.6032 = 279.88 m/s We do not we notice the rotation of the Earth because all objects and the atmosphere rotate uniformly along with the surface of the Earth. On the contrary, it seems to us that the heavenly bodies are moving from east to west, i.e. towards the actual movement of the Earth.
Slide 4: Foucault pendulum
4 Foucault pendulum It is known from physics that the plane of swing of a pendulum does not change if no forces other than gravity act on the pendulum. In 1851, the French physicist L. Foucault, based on this law, made an experiment proving the rotation of the Earth around its axis. In the tallest building in Paris - the Pantheon - a heavy metal ball with a point was suspended from a thin steel wire. Under this huge pendulum, a platform was made on which sand was poured. When the pendulum began to slowly swing, they noticed that the tip left a mark on the sand, and as a result of each new swing of the pendulum, the line passing through the center of the swing deviated at its ends to the right, when viewed from above from the previous one. In reality, it is not the pendulum that deviates - it retains its swing plane, but the position in space of the entire earth changes along with the room in which the pendulum swings.
Slide 5
5 The amount of deflection of the pendulum depends on the latitude of the observation site. At the equator this effect is not at all pronounced, but as you move away from the equator it increases and is most noticeable at the poles. Here the deviation of the pendulum swing lines during each hour is 15°, and per day – 360°. The magnitude of the apparent rotation of the swing plane of the pendulum in one hour can be calculated for any latitude using the formula: α = 15°* sin φ where a is the desired value, φ is the latitude of the area, and 15° is the angular value of the rotation of the Earth in 1 hour. The line of swing of the pendulum deviates to the right in the northern hemisphere, and to the left in the southern hemisphere. This means that the Earth rotates around its axis from west to east. Positions of the swing plane of the pendulum during the daily rotation of the Earth
Slide 6
Slide 7: Deflection of falling bodies
7 Deflection of falling bodies If you throw a body from a high tower, it does not fall vertically, but is slightly deflected in an easterly direction. This is because the top of the tower is further from the center of the Earth than its base, and therefore traces a longer circle as the Earth rotates. The falling body at the top of the tower had a greater horizontal speed than at its base, and therefore reached the surface of the Earth at a point lying slightly east of the plumb line (Fig.). In a shaft 158.5 m deep, a body when falling is deflected by 27.5 mm. The effect of deflection of a falling body, in contrast to the previous experiment, is best expressed at the equator and is completely absent at the poles.
Slide 8: Oblateness of the Earth
8 Oblateness of the Earth The oblateness of the Earth indicates its rotation around its axis. It is known that rotation generates centrifugal force, which, under the conditions of the Earth, which has a spherical shape, manifests itself differently in different places. The linear speed at different latitudes is not the same. At the equator, each point runs 464 m/sec, at the latitude of Moscow - only 260 m/sec, and at the pole this value is practically zero. Centrifugal force is proportional to the square of the speed and is greatest at the equator, being absent at the poles. This force gave the Earth the shape of an ellipsoid of revolution, the surface of which is closest to the center of the Earth at the poles and farthest at the equator, like the surface of rings compressed during rotation (Fig.) Thus, the centrifugal force and the distance from the center of the Earth make the force of gravity different in different places. At the equator, every body weighs 1/200 less than at the pole.
Slide 9: GEOGRAPHICAL IMPORTANCE OF THE DAILY ROTATION OF THE EARTH
9 GEOGRAPHICAL SIGNIFICANCE OF THE DAILY ROTATION OF THE EARTH Together with the spherical figure of the Earth's rotation in the field of solar radiation, the zoning of nature is determined. 2. Axial rotation causes the change of day and night. As a result of the change of day and night, a daily regime of processes in the civil defense arises. If there were no daily rotation of the Earth, then one side of it would continuously heat up and the other would cool, and this would affect all natural processes of the earth’s surface.
10
Slide 10: 3. When the Earth rotates around its axis, two points remain motionless - the poles - this makes it possible to construct a coordinate grid on the ball, i.e. meridians, parallels, equator
10 3. When the Earth rotates around its axis, two points remain motionless - the poles - this makes it possible to construct a coordinate grid on the ball, i.e. meridians, parallels, equator. Meridian (Latin for “midday”) is a line connecting the poles. There are no objective criteria for determining the prime meridian, so it was chosen conditionally - the meridian passing through the Greenwich Observatory is called the prime or Greenwich. Longitudes are counted from it. Longitude is the distance in degrees from the prime meridian to the meridian passing through an object. For convenience, longitudes are counted in both directions from Greenwich, from 0° to 180° to the east - eastern longitudes, to the west - western longitudes.
11
Slide 11
11 The equator is a line formed by the intersection of the earth's surface with a plane perpendicular to the earth's axis of rotation and spaced at equal distances from the poles. This is the line of the largest circle on the earth's surface. It divides the Earth into two hemispheres: northern and southern. If you mentally cross the Earth with planes parallel to the equatorial plane, then lines will appear on the surface in a west-east direction, which are called parallels. The distance of parallels, and, consequently, of any point from the equator in meridian degrees, is called latitude. Latitude is measured from 0° to 90° and is northern and southern. The length of the parallels decreases from the equator to the stripes, and the linear speed of rotation of all parallels decreases accordingly. The linear speed of rotation of all points on one parallel is the same.
12
Slide 12: Geographic coordinates
12 Geographical coordinates Geographical latitude is the angle between the normal to the surface of the ellipsoid (or between the plumb line - perpendicular to the surface of the geoid) and the equatorial plane. Latitude values that are measured from the equator to the north pole are taken into account with a “plus” sign, “northern”, and to the south - with a “minus” sign, “southern”. The latitude of the equator is 0°, the latitude of the north pole is + 90°, and the south pole is – – 90 . Geographic longitude is the dihedral angle between the plane of the geographic meridian of a point and the plane of the prime geographic meridian. Longitude is measured from the Greenwich meridian to the east from 0 to 360°, or to the east from 0 to 180°, and to the west from 0 to 180°, indicating “eastern longitude”, “western longitude”. Longitude and latitude can also be determined by the length of the meridian and parallel arcs on the surface of the ellipsoid, respectively.
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Slide 13: 4. The rotation of the Earth causes the deflection force of the Earth's rotation
13 4. The rotation of the Earth causes the action of the deflecting force of the Earth's rotation. The deflecting force of the Earth's rotation, or the Coriolis force, is manifested in the fact that all bodies moving on the Earth's surface, or parallel to it, deviate from their direction in the northern hemisphere to the right, in the southern hemisphere - to the left. When moving, all bodies tend to maintain a straight direction. But their movement occurs in a rotating sphere. Therefore, they seem to deviate from the original direction. In fact, it is not the bodies that deviate, but the surface itself on which or above which these bodies move moves. Gustave Gaspard Coriolis (21.05.1792 - 19.09.1843)
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Slide 14
14 A rocket is launched from point A towards the North Pole. At the moment of launch, its direction coincided with the direction of the meridian. After some time, point A, as a result of the rotation of the Earth, moves to point B. The direction of the meridian deviated to the left. According to the law of inertia, a moving body strives to maintain its direction and speed in world space. The rocket maintains the initially given direction, but it seems to the observer that the rocket has deviated to the right. It is easy to see that this deflecting force is fictitious, that it is not a moving body that is deflected, but the surface of the Earth changes its spatial position. The deviation will be greatest at the poles, and at the equator it will be 0°, because The meridians there are parallel to each other and their direction in space does not change. The deviation in the northern hemisphere is to the right, in the southern hemisphere it is to the left. The Coriolis force affects all moving objects, regardless of the direction of movement. The magnitude of the deflecting effect of the Earth's rotation on a body weighing 1 kg is expressed by the formula: F = 2ω*ν* sin φ where ω is the angular velocity of the Earth, ν is the speed of movement of the body, α is latitude.
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Slide 15: 5. The rotation of the Earth around its axis gives the basic unit of time - the day
15 5. The rotation of the Earth around its axis gives the basic unit of time - the day. Solar day - the period of time between two successive passages of the center of the Sun through the meridian of the observation point. True solar time is the time interval between two successive upper culminations of the center of the Sun through the meridian of the observation point. The length of the true solar day varies throughout the year, primarily due to the uneven movement of the Earth along its elliptical orbit. Therefore, they are also inconvenient for measuring time. Mean solar time is the time interval between two successive upper culminations of the center of the mean Sun through the meridian of the observation point - a fictitious point moving uniformly along the celestial equator with the average speed of movement of the true Sun along the ecliptic. The average solar day is equal to 24 hours. For practical purposes, the average solar day is used. They are longer than stellar ones, because the Earth rotates around its axis in the same direction in which it moves in its orbit around the Sun with an angular velocity of about 1° per day. Because of this, the Sun moves against the background of the stars, and the Earth still needs to turn about 1° for the Sun to “come” to the same meridian. Thus, during a solar day, the Earth rotates approximately 361°.
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Slide 16
16 Sidereal day - the period of time between two successive upper culminations of a star through the meridian of the observation point (the time of the Earth’s complete revolution around its axis). The time between two passages of a star through the meridian of a given place, a sidereal day, is 23 hours 56 minutes 4 seconds. This is the actual time of the Earth's daily rotation. (since the Earth moves around the Sun and around its axis in one direction, the solar day is longer than the actual time of a full revolution). A sidereal day contains 86400 s = 24 hours. Sidereal day. Starting position. A sidereal day is slightly shorter than a solar day. When the sidereal day ends, the Earth must rotate a little more to “catch up” with the Sun.
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Slide 17
17 In everyday life, it is also inconvenient to use mean solar time, since each meridian has its own time - local time. The presence of different local times at different points lying on different meridians led to many inconveniences. Therefore, at the International Astronomical Congress in 1884, zone time was adopted. To do this, the entire surface of the globe was divided into 24 time zones of 15° each. Standard time is taken to be the local time of the middle meridian of each zone. The zero (also known as the 24th) belt is the one through the middle of which the zero (Greenwich) meridian passes. Its time is accepted as universal time. The belts are counted from west to east. In two neighboring zones, the standard time differs by exactly 1 hour. For convenience, the boundaries of time zones on land are drawn not strictly along meridians, but along natural boundaries (rivers, mountains) or state and administrative boundaries. To convert local time to universal time and back, you need to know the angular distance of the place from the prime meridian, i.e. longitude of the place. Universal time is used in astronomy; in practical life it is actually not used. To convert local time to standard time and back, use the formula: Тп = Тм + n – λ, where Тп – standard time, Тм – local time, n – zone number, λ – longitude.
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Slide 18
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Slide 19
19 After the October Revolution, on February 8, 1918, the zone division was introduced by decree of the Council of People's Commissars. By government decree of June 16, 1930, the hands of all clocks on the territory of the Soviet Union were moved forward an hour. Maternity time was created, the introduction of which made it possible to save energy. The duration of maternity time was set “until repealed” (lasted until 1981). By resolution of the Council of Ministers on April 1, 1981, the clock hands were moved forward another 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 March 1991, maternity time was abolished. The two-hour advance lead was abolished. We have switched to the summer-winter time reference system. In winter, standard time was used, and in summer, clocks were moved forward 1 hour. In Belarus, Resolution of the Council of Ministers No. 1229 of September 15, 2011 approved the calculation of time in accordance with the international time zone system according to standard time plus one hour without changing the hands to seasonal time.
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Slide 20: 6. Date line
20 6. Date Line Magellan's trip around the world and the loss of one day. The 180° meridian is taken as the international date line. This is a conventional line on the surface of the globe, on both sides of which the hours and minutes coincide, and the calendar dates differ by one day. For example, on New Year's Day at 0:00 a.m. west of this line is January 1 of the new year, and to the east is December 31 of the old year. When crossing the border of dates from west to east, one day is returned in the calendar days count, and from east to west, one day is skipped in the date count. For ease of calculation, it was customary by international agreement to consider the 12th time zone to be the beginning of a new day, i.e. meridian 180°. This is the date line.
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Slide 22: 8. The change of day and night creates a daily rhythm in living and inanimate nature
22 8. The change of day and night creates a daily rhythm in living and inanimate nature
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Slide 23: 9. Ebbs and flows
23 9. Ebbs and flows The consequence of the rotation of the Earth is the ebb and flow of tides. The Moon, as the celestial body closest to the Earth, has a great gravitational force. This force causes deformation of the Earth's surface, especially its water shell. At the point closest to the Moon, as well as at the opposite point on the Earth, a tidal ledge always forms. The tide on the side of the Earth facing the Moon is because gravity is strongest there. The tide on the opposite side of the Earth is explained by the fact that the centrifugal force resulting from the rotation of the Earth and the Moon around their common center of gravity, located inside the Earth, exceeds the gravitational force of the Moon. High tides are observed on the Earth-Moon line, and low tides are observed on a perpendicular line.
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Slide 24
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Last slide of the presentation: Lecture 4. Axial (diurnal) rotation of the Earth
25 Low Water (Brittany, France)
It’s inconvenient, because each meridian has its own time – local time. The presence of different local times at different points lying on different meridians led to many inconveniences. Therefore, at the International Astronomical Congress in 1884, zone time was adopted. To do this, the entire surface of the globe was divided into 24 time zones of 15° each. Standard time is taken to be the local time of the middle meridian of each zone. The zero (also known as the 24th) belt is the one through the middle of which the zero (Greenwich) meridian passes. Its time is accepted as universal time. The belts are counted from west to east. In two neighboring zones, the standard time differs by exactly 1 hour. For convenience, the boundaries of time zones on land are drawn not strictly along meridians, but along natural boundaries (rivers, mountains) or state and administrative boundaries. To convert local time to universal time and back, you need to know the angular distance of the place from the prime meridian, i.e. longitude of the place. Universal time is used in astronomy; in practical life it is actually not used. To convert local time to standard time and back, use the formula: Тп = Тм + n – ?, where Тп – standard time, Тм – local time, n – zone number, ? – longitude.