KVG P1 Longitude Latitude Rotation Revolution
-
Upload
vijay-raju -
Category
Documents
-
view
227 -
download
0
Transcript of KVG P1 Longitude Latitude Rotation Revolution
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 1/72
Latitudes
Longitudes
Int. date line
1
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 2/72
• earlier , only four main directions• North South East West > called CARDINAL
POINTS
•Guidelines for explores & navigators > to reach
their destinations.
• EARTH’S GRID SYSTEM
• a network of longitudes and latitudes to find
location on the globe.
• to determine the location of any point on the
earth
Why latitudes & longitudes ?
2
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 3/72
•
angular distance of a place•
from the equator
•Measured from the centre of the earth.
• a/k/a Parallels ( akshanshvrut )
• imaginary circles on the surface of the earth• 1* interval on both the hemisphere = total 181
•
distance between each latitude = ~111• 44,000km equator / 360* = 111km
• all are concentric circles – with one common centre
Latitude (
akshansh
)
–
3
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 4/72
4
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 5/72
Five main parallels
• Equator
• 0* > two equal halves
• only one GREAT CIRCLE.
•
Sun rays fall vertically almost trough theyear.
• tropic of cancer - 23.5*N
• sun > 21 June > longest day in N hemi.
• marks the northern limit of apparent
movement of sun .
• tropic of Capricorn - 23.58*S
• 22 dec > longest day
• arctic circle – 66.5*N
• Area within the circle recieves oblique
rays of the sun
• Antarctic circle – 66.5*S• north pole - 90*N
• South pole - 90*S
• sun rays do not reach here except when
the sun is overhead the tropics of cancer
and Capricorn. 5
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 6/72
tropical zone (
ushna
-
katibandhh
)
• heat surplus regions
• never any snowfall and frost
• practically, there is NO WINTER
• DOLDRUMS ( nirvat khetra)
a/k/a EQUATORIAL ZONES
Area of low pressure belts > bcz
receives direct sun light
The climatic zones of the earth
6
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 7/72
•temperate zone (samsitoshna)
• area – receives slant rays of the sun• great diff between summer & winter
temperature conditions
•Ideal for living-bcoz temperature
conditions
• frigid zone (sheet-katibandhh)
•Arctic circle to n-pole
•Antanrctic circle to s-pole
•Extremly cold-bcoz of inclination of axis-
receives very slant rays
•Remains frozen for major part of the
year,hense named 7
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 8/72
Longitudes (rekhansh)
8
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 9/72
• Angular distance of a place
•From the prime meridian
•Measures from the centre of the earth
• a/k/a meridians(rekhanshvrut)
•Means mid day-all the places on the
same meridian have their noon at the
same time
Longitudes(rekhansh)
9
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 10/72
•Prime meridian = 0*
•In 1884 royal astronomical
agreement
•
Greenwich london•360 in total
•Distance between two
meridian=111km
•Only at equator-towards pole
–distance decrease•180* longitude=unlabelled > bcoz
can be reached from both side >
a/k/a international date line
•Imaginary semi circles that run from north pole to south pole thus
the prime meridian and 180* longitude lies opposite-together form
one complete circle.
10
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 11/72
11
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 12/72
•History – 1522 – magellan – reached home on 5th sept. but
it was actually 6th
sept on that day. !!!
International date line
12
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 13/72
International date line
13
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 14/72
•IDL – line concerned with the
dates of calender
•180* longitude bcoz passes
through middle of pacific oceanand practically no land mass.
• bent at two places
•75*N towards east to avoid
division of siberia and again
bent over berring strait towards
west.
•To maintain continuity of land
in fiji and new zealand – benttowards east
•Travelling east=Loosing a Day
•
Travelling west=Gaining a Day 14
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 15/72
31st Dec
Morning Russia
30th Dec
Morning Alaska
15
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 16/72
International Date Line
Moving
West
1 DAY
Lost
Moving
East1 DAY
Gain16
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 17/72
Longitude and Time
17
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 18/72
Longitude and Time
•As earth rotes by 360* in 24 hrs-takes 4
mins to move by1* longitude
•15* longitude = 1 hr
•
Earth moves from West to East >East : Gain – add
West : loose - subtract
•Move towards left=time reduce by
4min / 1* longitude
• Move towards Right=time enhance by
4min / 1* longitude
18
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 19/72
If 12 noon at GMT what is the time at 75
°E?
• Difference = 75 °
• 15 ° => 1 hour
• 75 ° => 5 hours
• East (means add) 12 +5 = 5 pm
• Question
If 12 noon at GMT what is the time at 30
°W?
•
Difference = 30 °•15 ° => 1 hour
•30 ° => 2 hours
•East (means minus) 12 - 2 = 10 am
19
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 20/72
Local time –
•When sun is overhead its longitude
Standard time-•For each country-fixed time as per rule
•greenwich mean time ( GMT) – 0* - std time of England –
noon time of old greenwich observatory.
•International time follows GMT worldwide
• adopted worldwide by all the countries. 20
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 21/72
Indian Standard Time
•India 82.5*E – IST
•Passes through allahabad.
•Nepal and Sri lanka also
follows.
•Difference between IST and
GMT is 82.5*
• =5.30 hrs
• means , noon at england =
5:30 pm in india
21
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 22/72
Russian Time Zones
22
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 23/72
Map work
23
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 24/72
Prelims2006
Q. Through which one of thefollowing groups of countries
does equator pass?a) Brazil, Zambia andMalaysia
b) Columbia, Kenya andIndonesia
c) Brazil, Sudan andMalaysia
d) Venezuela, Ethiopia andIndonesia
UPSC
Exercise
24
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 25/72
Prelims
2008
Q. Which of the following
cities is nearest to the
equator ?
a) Colombo
b) Jakarta
c) Manila
d) Singapore
UPSC
Exercise
25
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 26/72
26
E i
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 27/72
Prelims
2008
Q. Which one of the
following straits is nearest
to the International Date
Line?
a) Malacca Straitb) Bering strait
c) Strait of Floridad) Strait of Gibraltar
UPSC
Exercise
27
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 28/72
The equator passes through 13 countries:
Ecuador, Colombia, Brazil, Sao Tome & Principe, Gabon,
Republic of the Congo, Democratic Republic of the
Congo, Uganda, Kenya, Somalia, Maldives, Indonesia and
Kiribati.
28
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 29/72
General map to remember :
29
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 30/72
Tropic of Capricorn passes through which countries ?
in west to east direction :
1- Chile, 2- Argentina, 3- Paraguay, 4- Brazil,5- Namibia, 6- Botswana, 7- South Africa, 8- Mozambique,
9- Madagascar, 10- Australia.
Through which countries does the Tropic of Cancer pass?
The Tropic of Cancer passes through-
(America-)the Bahamas, Mexico,
(Africa-) Mauritania, Mali, Western Sahara, Algeria, Niger, Libya,
Egypt, Saudi Arabia, Abu Dhabi, Oman,India, China,
Bangladesh, Burma and Taiwan.
It also passes through the United States in the Hawaiian region
but it does not pass through any of the islands.30
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 31/72
31
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 32/72
Prime Meridian Passing Through
Countries
1- United Kingdom( Greenwich,London),2- France,3- Spain
4- Algeria,5- Mali,6- Burkena
Faso,7- Togo,8- Ghana
Apart from countries, through
what other places Prime Meridian
Passes?
1- Arctic Ocean,2- NorwegianSea,3- Greenland Sea,4-
Mediterranean Sea
5- Atlantic Ocean,6- Southern
Ocean,7- Antarctica.32
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 33/72
What countries does the
Arctic Circle pass through?
The land on the Arctic Circle
is divided among eight
countries
Norway, Sweden, Finland,
Russia,
the United States (Alaska),
Canada, Denmark
(Greenland), andIceland(where it passes
through the small offshore
island of Grimsey).
33
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 34/72
The Antarctic
Circle as outlined
in yellow on the
map.
The nearest
neighbouring
country isArgentina and the
second nearest is
New Zealand.
Antarctica circle
34
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 35/72
35
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 36/72
1
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 37/72
Rotation = paribraman•Rotes on its axis
•From west to east like a top
•Responsible for the cycle of day and night = a/k/aDaily motion
Revolution = parikraman•An elliptical path•One round in 365 days and 6 hours
•(23hrs 56mins 4.09sec !!!)
•Orbit = elliptical path traced by the earth
•a/k/a annual movement
2
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 38/72
• viewed from the north pole =
the earth rotes and revolves in a
counter clockwise direction.
3
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 39/72
Uranus – lying planet > higher inclination of axis.
Like Venus, Uranus also rotates clockwise ( revoles
the sun from east to west)
Courtesy : Barnwal
4
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 40/72
•Perihelion (upp-surya)•Greek – peri=near, helion= the sun
•Min. distance from the sun
•3rd january = ~ 147 mKm
•Aphelion (app-surya )• greek – app= away from
•Max. distance from the sun
•4th july = ~152mKm
5
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 41/72
Sideral day = determined by stars
• duration btw passage of a perticular star over
a meridian twice…
• about 23 hrs 56mins
Solar day=•When duration of earth’s
revolution around the sun is
calculated in terms of days –
taking sun as stationary.
6
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 42/72
7
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 43/72
A sidereal day is the time it takes for the Earth to rotate about
its axis so that the distant stars appear in the same position in
the sky.
A solar day is the time it takes for the Earth to rotate about its
axis so that theSun appears in the same position in the sky.
The sidereal day is ~4 minutes shorter than the solar day.
Our usual definition of an Earth day is 24 hours, so the sidereal
day is 4 minutes faster. This means that a particular star will rise
4 minutes earlier every night, and is the reason whydifferent constellations are only visible at specific times of
the year.
8
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 44/72
9
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 45/72
•The earth spins on an imaginary lines called axis
•
Passins through north pole and south pole
•Earth rotates on its axis but not at right angle –
•It makes an angle of 66.5* with the plane of
ecliptic. (kranti-vrut)
•which is coplanar with the orbit of theEarth around the Sun (and hence the
apparent orbit of the Sun around the Earth.)
•And makes 23.5*
from a line perpendicular to that palne.
Inclination of axis & its significance
10
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 46/72
11
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 47/72
•Imp points –
•Earth axis keeps a fixed angle with the plane of
ecliptic.
•Axis always points the same place stars during
the period of its revolution.
Effects of the inclination of the axis –
alternation of seasons / seasonal changes.
12
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 48/72
Reference
https://www.youtube.com/watch?v=HmmbOVfHqcg 13
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 49/72
•In astronomy, axial precession = is a gravity-induced, slow and continuous change in the
orientation of an astronomical body's rotational axis.
• = the gradual shift in the orientation of Earth's axis of rotation, which, like a wobbling top
•= in a cycle of approximately 26,000 years (called a Great or Platonic Year in astrology).
•Simply explained, it is the change in an astronomical body's rotational axis due to gravity.
The change is slow and continuous.•Hipparchus = discovered it.
•planetary precession = the ecliptic itself moved slightly,
•lunisolar precession= the dominant component.•Their combination was named general precession.
•Lunisolar precession is caused by the gravitational forces of the Moon and Sun on
Earth's equatorial bulge, causing Earth's axis to move with respect to inertial space.
•Planetary precession (actually an advance) is due to the small angle between the
gravitational force of the other planets on Earth and its orbital plane (the ecliptic),
causing the plane of the ecliptic to shift slightly relative to inertial space.
•Lunisolar precession is about 500 times larger than planetary precession.
14
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 50/72
• Causes
•The precession - is caused by the gravitational forces of the Sun and the Moon, and to
a lesser extent other bodies, on the Earth.•It was first explained by Sir Isaac Newton.
•The Earth is not a perfect sphere but an oblate spheroid > bulges on equator.
• Because of the Earth's axial tilt, during most of the year the half of this bulge that is
closest to the Sun is off-center, either to the north or to the south, and the far half is off-
center on the opposite side. The gravitational pull on the closer half is stronger, sincegravity decreases with distance, so this creates a small torque on the Earth as the Sun
pulls harder on one side of the Earth than the other.
•The axis of this torque is roughly perpendicular to the axis of the Earth's rotation so the
axis of rotation precesses.
•If the Earth were a perfect sphere, there would be no precession.
•Although the above explanation involved the Sun, the same explanation holds true for
any object moving around the Earth, notably, the Moon. The combined action of the
Sun and the Moon is called the lunisolar precession.
•In addition to lunisolar precession, the actions of the other planets of the solar system
cause the whole ecliptic to rotate slowly around an axis = called planetary precession.
15
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 51/72
Effects
•First, the positions of the south and north celestial poles appear to move in circles
against the space-fixed backdrop of stars, completing one circuit in 25,772 Julian years
(2000 rate). Thus, while today the star Polaris lies approximately at the north celestialpole, this will change over time, and other stars will become the "north star".
•Secondly, the position of the Earth in its orbit around the Sun at the solstices,
equinoxes, or other time defined relative to the seasons, slowly changes. For example,
suppose that the Earth's orbital position is marked at the summer solstice, when the
Earth's axial tilt is pointing directly towards the Sun. One full orbit later, when the Sun
has returned to the same apparent position relative to the background stars, the Earth's
axial tilt is not now directly towards the Sun: because of the effects of precession, it is a
little way "beyond" this.
•In other words, the solstice occurred a little earlier in the orbit.
Thus, the tropical year, measuring the cycle of seasons (for example, the time from
solstice to solstice, or equinox to equinox), is about 20 minutes shorter than the sidereal
year, which is measured by the Sun's apparent position relative to the stars. Note that
20 minutes per year is approximately equivalent to one year per 25,772 years, so after
one full cycle of 25,772 years the positions of the seasons relative to the orbit are "back
where they started".
16
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 52/72
• Daily occurrence of Day and night
• variation in temperature during day and night
• Apparent movement of the sun is the evidence of the
earth rotation• Another proof is if one drops a ball from top of a
multistorey building it will fall slightly towards East.
• creates centrifugal force – bulge at equator
• Coriolis force and ferrell’s Law
• Alternate rise and fall in the ocean waves
rotation
• Changing altitude of the mid-day sun at difftimes of the year eg. Equinox and solstice
• Varying length of day and night
• Change in the seasonsrevolution
Effects of the inclination of the axis – alternation of
seasons / seasonal changes.17
In physics the Coriolis effect is the apparent deflection of moving
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 53/72
In physics, the Coriolis effect is the apparent deflection of moving
objects when the motion is described relative to a rotating
reference frame.
Newton's laws of motion describe the motion of anobject in a (non-accelerating) inertial frame of reference.
When Newton's laws are
transformed to a
uniformly rotating frameof reference, the Coriolis
and centrifugal forces
appear. Both forces are
proportional tothe mass of the object.
18
A commonly encountered rotating reference frame is the Earth The
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 54/72
A commonly encountered rotating reference frame is the Earth. The
Coriolis effect is caused by the rotation of the Earth and
the inertia of the mass experiencing the effect. Because the Earth
completes only one rotation per day, the Coriolis force is quite small,
and its effects generally become noticeable only for motions
occurring over large distances and long periods of time, such as
large-scale movement of air in the atmosphere or water in the
ocean.
This force causes movingobjects on the surface of the
Earth to be deflected to the
right (with respect to the
direction of travel) in
the Northern Hemisphere and
to the left in the Southern
Hemisphere.19
Variations in length of
Question
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 55/72
Prelims
2013
Variations in length ofdaytime and night-time fromseason to season are due to
a) Earth’s rotation on its axis
b) Earth’s revolution around
the sun in an ellipticalmanner
c) Latitudinal position of theplace
d) Revolution of earth on atilted axis
UPSC
Question
20
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 56/72
Circle of illumination
•
While rotating, a part of earth facing the sun hasday and the other part night.
•= imaginary line which shows clear demarcation
btw day and night.
21
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 57/72
Solstice & equinox
22
• solstice = latin
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 58/72
Features –
•Duration of day is longer than night
•Daylight last for the entire 24hrs beyond the arctic
circle towards the North pole
• length of day – increases with increasing latitude from
equator to north.
•Arctic circle to north pole = LAND OF MID-NIGHT SUN
• Antarctic – totally dark.
• solstice = latin
= sun standing still
(reaching the zenith point-
highest point)
• june 21/22
• tropic of cancer recieves
direct sun rays.
• summer in northern hemi.
23
l ti l ti
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 59/72
• solstice = latin =
•sun standing still
(reaching the zenith point-
highest point)
• december 22
• tropic of capricorn recieves
direct sun rays.
• winter in northern hemi.
• south pole inclined directly
towards the sun
Features –
• length of the day increases as on goes towardsthe south pole
• day is longer than night in southern hemi.
• btw arctic circle to north pole = total dark = 6
months 24
EQUINOX =
vishuv
-
sampat
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 60/72
20/21 march = vernal/spring equinox
22/23 september = autumnal equinox
All the places on earth have 12 hrs of day and 12 hrs of night >circle of illumination passes through the poles and divides earth
into equal halves.
Hence , day-night are of
equal length = equinox =
Latin = acquus (equal) & nox
(night).
25
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 61/72
March 21 Spring equinox Equator
June 21 Summer solstice Tropic of cancer
Sept 23 Autum equinox equator
Dec 22 Winter solistice Tropic of capricorn26
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 62/72
Eclipse
solar lunar27
• synchronous rotation of the moon –
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 63/72
•only one part of the moon can be seen from the earth bcoz of
equal rotational speed of both.
• illuminated face of the moon is seen on the earth once a
month on full moon.
• on new moon, the moon is not seen at all bcoz on this night
the completely dark part of the moon faces the earth.
28
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 64/72
Moon rotation
29
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 65/72
Full moon = poonam
New moon = amaavasya
30
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 66/72
•When the earth > btwn sun and moon > light of the sun is not
able to reach the moon > shadow of the earth falls on the moon =Lunar eclipse.
•Lunar eclipse occurs on a FULL MOON.
•When the moon > btwn
the sun and the earth >
light of the sun is
interrupted > shadow of
the moon falls on the earth
= Solar eclipse.
•Solar eclipse occurs on a
NEW MOON.
31
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 67/72
When the sun, the earth and the moon are aligned in a straight
line, this position is called SYZYGY-
• where in conjunction (the sun and the moon in one side ofthe earth) occurs in the case of SOLAR ECLIPSE
•While, opposition (the earth btwn the sun and the moon)
occurs in the case of LUNAR ECLIPSE.
32
THERE WOULD BE MAXIMUM SEVEN OCCASIONS FOR THE LUNAR
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 68/72
THERE WOULD BE MAXIMUM SEVEN OCCASIONS FOR THE LUNAR
AND SOLAR ECLIPSE IN ONE YEAR as lunar and solar eclipses do not
take place on every full moon and new moon.
Bcoz- of moon’s inclination of 5* on its own axis.
So when the earth and the moon reach the same point of
revolutionary path, the moon, due to its inclination, moves a littlebit ahead of the earth, as a reasult, eclipse does not occur on every
full and new moon.
33
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 69/72
34
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 70/72
35
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 71/72
Points to remember
•a ring of solar eclipse > poosible > due to diif. In size of the sun ,
the earth and the moon. = DIAMOND RIND AROUND THE SUN
• but ring of lunar eclipse > NOT possible.
36
8/17/2019 KVG P1 Longitude Latitude Rotation Revolution
http://slidepdf.com/reader/full/kvg-p1-longitude-latitude-rotation-revolution 72/72