Rotation and Revolution of the earth

 Rotation and Revolution

let us learn rotation and revolution of the earth and its effects 

Rotation

The spinning of the earth around its own axis which is an imaginary axis is known as rotation of the earth now this axis is tilted tilted at an angle of 23 and 1/2 from the vertical and with this tilted axis the Earth revolves around the Sun and that is known as revolution so these are the two important motions of the earth that is rotation and revolution the axis of the earth is an imaginary line passing through the centre of the earth as it does on the globe the two end points through which the axis passes is known as North Pole and South Pole the axis is tilted at an angle of 23 and a half from the vertical this means that if a line were drawn parallel to the plane of the Earth's orbit the earth would make an angle of sixty six and a half degrees to this line now

 let us understand the characteristics of rotation the first one is direction the earth completes one rotation from west to east on its axis in 23 hours 56 minutes and 4.0 9 seconds which roughly comes to 24 hours then it is inclination of the axis of the earth the earth is always tilted in the same direction that is it is pointing towards pole star that is its North Pole is pointing towards pole star as it is moving around the Sun third is the speed of the Earth's rotation the speed of the Earth's rotation at the equator is 1670 km/h the cause the circumference of the earth is 40,000 70 kilometers so at the equator the earth would be traveling 40 thousand 70 kilometers and it is covered in 24 hours so in 1 are the Earth rotates 1670 km/h so if we sum of the characteristics of rotation of the earth it is the earth completes one rotation from west to east on its axis in 23 hours 56 minutes four point zero nine seconds that is roughly 24 hours the earth is always tilted in the same direction as it is moving around the Sun the speed of the Earth's rotation at the equator is 1670 km/h now

Effects of rotation

 let us learn the effects of rotation the first and the important effect is that day and night are caused by the rotation of the earth on its axis this is because a part of the earth faces the Sun and it has idli and the other part which does not face the Sun has night and this happens with precision and progression and not suddenly so I will say this happens accurately and gradually it does not happen suddenly the time when the Sun begins to cast its light in the morning is known as dawn at noon the Sun is overhead at dusk that is in the evening we see the Twilight. Twilight is the light that we see after the Sun sets so here the Sun is disappearing in the sky at night we all know it is so beautiful and completely dark the duration of the day and night is not equal at all the places on the earth this is because of the inclined axis of the if you look at the important latitudes on the earth it is equator Tropic of Cancer Tropic of Capricorn Arctic Circle and the Antarctic Circle now if you see the lines carefully in the southern hemisphere you will understand that the duration of night is longer and in the northern hemisphere the duration of day is longer than the night the reason is the northern hemisphere is facing the Sun

the southern hemisphere is facing away from the Sun but if you look at the Arctic Circle and Antarctic Circle the Arctic Circle is completely in day so when the earth is rotating the entire region beyond the Arctic Circle will have day there the Sun will not set whereas in the southern hemisphere beyond the Antarctic Circle you will see it is completely dark and here the Sun will not rise the length of the day varies with respect to even seasons as well as latitudes so the length of the day varies with respect to latitude but also seasons and we shall be learning about them gradually then it is the sunrise and the sunset this happens because of rotation of the earth then it is the Coriolis effect now we all know that the earth is spinning at a great speed at the equator it is 1670 km/h second

 we have learned that because of the spherical nature of the earth different part of the earth  receives different amount of sunlight so there is difference in temperature at different places because there is difference in temperature there will be difference in pressure some places will have a high pressure and some other place will have a low pressure and because of that the wind moves the wind always moves from a high pressure area towards low pressure area now when the wind is moving on the surface of the earth the wind banks the wind bends because the earth is rotating at a great speed in the southern hemisphere the wind will bend towards left and in the northern hemisphere the binged bends towards right now when you look at these arrows it is very clear that they are bending towards left but when you are looking at these arrows it will appear as if they are also bending towards left but for the arrows in the South you will be looking from the southern end similarly for the arrows in the northern hemisphere you have to look at it from the northern end then you will see that they are actually bending towards right so the wind in the northern hemisphere always bends towards right and in the southern hemisphere they bang towards left but in the equatorial region that is region between five degree north and five degrees south 

the wind does not Bend these are the regions of doldrum or we say these are the regions of calm and these are the regions of low pressure the next important phenomena that we see is the Sun the moon and the stars seems to move from east to west now you may say that you have seen Sun moving from east to west what about the moon and the stars but actually if you see in time-lapse you will understand that they all are moving from east to west this is because the earth is spinning from west to east now this effect is similar to what one experiences while sitting in a train and looking out of the window what do we see we see the trees and buildings and everything moving in the opposite direction to that of the Train the reason is the Train is moving at a very great speed the same happens with the earth when you look at the sky it appears as if the Sun Moon and the stars are moving but actually the earth spinning on its imaginary axis then the earth also generates centrifugal force

centrifugal force is the force that is generated from the center towards the periphery that is towards the edges this is because the earth is spinning at a very great speed it is the same effect that we see every day in our kitchen when when we are operating a mixer the all the chutney will come and stick on the edges of the glass and this is the reason that along the equator there is a bulge in the earth and the earth is said to be G odd shape then rotation also causes difference in time because when the earth is spinning some part of the earth has de and some other part has night some part of the earth there is sunrise happening and somewhere else the Sun is setting so different part of the earth will have different time then the short rotational period makes the variation of temperature between day as well as night moderate so neither day nor night is extreme it is moderate the rotation revolution also causes seasons and variation in the length of day and night 

The effects of rotation are occurrence of day and night sunrise and sunset Coriolis effect the Sun Moon and stars seem to move from east to west centrifugal force rotation and we have seen rotation causes difference in time and the last one is the sight of the earth now we have seen that the earth is spinning around its own axis and this axis is tilted with this tilted axis when the Earth revolves around the Sun in an elliptical orbit that is the orbit that appears like an L elipse means an elongated circle so when the earth is revolving around the Sun in an elliptical orbit we call it as revolution of the earth and this leads to various phenomena the earth moves at an average speed of twenty nine point eight kilometers per second or it is easy to remember one lakh kilometers per  hour so earth is spinning at a speed of 1670 km/h and the earth is revolving around the Sun in an elliptical orbit at a speed of 1 lakh kilometers per hour.

Revolution

Now if we see the revolution the Sun is not exactly in the center of the ellipse because it is not at the center of the ellipse the earth when it is revolving around the Sun there are times when it is closer to the Sun and there are times when it is far away from the Sun when the earth comes closer to the Sun that time the speed of revolution around the Sun increases and when the earth is away from the Sun the speed of revolution reduces this is mainly because of the gravitational force of the Sun now the earth completes one revolution around the Sun in 365 days 5 hours 48 minutes and 45.5 1 seconds but we roughly take it as 365 days and 6 hours now to add just this 6 hours we have the concept of leap year and leap here comes once and for years so on the 4th year February instead of 28 days we have 29 days and in this way we edges this 6r.

Effects of Revolution

let us learn the effects of revolution of the earth the first effect is the seasonal changes because of the revolution of the earth we have in the first phase in the second phase rains in the third phase it is retreating monsoon and in the fourth phase it is winter now how does this happen suppose we take these four positions of the earth in the first position the date is 21st of March in the second position it is 21st of June in the third position it is 23rd September and the fourth position it is 22nd December when the earth is in the second position if you look carefully the northern hemisphere is facing the Sun 

 then the earth is in the fourth position this southern hemisphere is facing the Sun but when the earth is in the first position or in the third position none of the poles are facing the Sun so the inclination of the Earth's axis does not have any impact on the sun rays that it receives so on 21st of March vertical rays of the Sun falls on the equator and the entire Earth has equal day an equal night but as it is moving from the first position to the second position slowly the northern hemisphere tilts towards the Sun so in the northern hemisphere the day's become longer and nights become shorter and this gives rise to summer conditions and we say in this phase it in somewhere in India on 21st of June the vertical rays of the Sun falls on the Tropic of Cancer this is the maximum inclination of the Earth's axis of the northern hemisphere towards the Sun and this is referred to as summer solstice 

we come to the third position once again the day and night are equal and in this phase India experiences rain when the earth comes to the third position entire Earth has equal day and equal night and as we come to the fourth position the date is 22nd December southern hemisphere is facing the Sun and the vertical rays of the Sun falls on the Tropic of Capricorn and this is the time the northern hemisphere experiences winter solstice so the first and the third positions are referred to as equinoxes because it is equal day and equal night 

the first position is referred to as spring equinox and the third position is referred to as autumn equinox then as the earth is revolving around the Sun there are times when the earth is closest to the Sun and this position is called perihelion and when it is farthest from the Sun it is called as a PE Lian when it is closest that time the distances 1/4 to 7.3 million kilometers and when it is farthest that time the distance is 152 million kilometers the minimum distance of the Earth from the Sun is reached on January 3rd and the maximum distance that is farthest from the Sun the date is 4th July so Eppie Helion happens on 4th July and perihelion on 3rd January next effect of the revolution is the creation of heat zones the entire Earth can be divided into heat zones like the torrid zone which lies between 23 and 1/2 degrees north and 23 and 1/2 degrees south this region is referred to as torrid zone or the tropical zone beyond 23 and 1/2 degrees north as well as south up to 66 and a half  degrees the region is temperate zone beyond 6 to 6 and a half degrees in north and south it is the frigid zone so there are creation of heat zones this again is because of revolution of the earth 

 if we sum up the effects of revolution it is first one the seasonal changes inclination of axis and the seasonal changes Gillian and Eppie Helion positions and creation of hate zones thank you.