THE EARTH IS ROUND ,IT
has been known for more than 2000 years,but we were able
to actually see this much later only when we flew into
space .The Earth is made up of rocks, soils ,and water.It is
surrounded by an air cover called the atmosphere.
INTERNAL STRUCTURE OF THE EARTH.-Like an Onion Earth has several layers.The outer most layer, the Earth's crust,has an average depth of 40 k.m.As compared with the diameter of the Earth ,which is around,12,700 km,the Earth's crust is very small.It is primarily made up of solid rocks.Below the crust is the mantle reaching to a depth of about 2900km.Due to the heat inside the earth ,the mantle consist of solid and molten rocks..Below the mantle is core,made up of Iron and Nickle.The deeper one travels inside the Earth ,the hotter it is .The temperature in the core is between 4000 and 5000 degree centigrade.
INSIDE THE EARTH-ONE CAN look deep inside the Earth in the aftermath of earthquakes or by creating nuclear explosions.The explosions generate sound or seismic waves .They also throw off rock particles .By measuring their intensity and timing ,scientists discover the composition of the earth's interior.
ATMOSPHERE -THE word ' Atmosphere' meas a gaseous cover enveloping a planet..Without atmosphere life would not have been possible on the Earth.One-fifth of the atmosphere is oxygen and four fifth is nitrogen .Like the Earth's interior , the atmosphere too is made up of several layers.All animals and plants live in the lower most layer of the atmosphere called the 'troposphere'.All weather phenomena take place in the troposphere .Even aeroplanes fly in the outer edge of the troposphere .The stratosphere ,the mesosphere, the ionosphere and the exosphere lie above the troposphere.
WHY ONE DO NOT FALL OFF FROM THE EARTH.
Gravity is the force of the Earth that attracts every object towards itself.This force always acts downwards. For a long time people did not believe that the Earth is round because then the people 'underneath' the sphere would have actually fallen down.In 1687 , a physicist ,Issac Newton , proved that the force of gravity always act towards the center of the Earth.On the Earth ,the force of gravitation always acts 'downwards' irrespective of Eskimos in the Arctic region , people in Europe , or inhabitants of Australia.
The first person who proved that Earth was round was Ferdinand Magellan , who was the first to sail around the Earth.,in 1522.
The Earth is not a perfect globe .It is slightly flattened at poles .Like an orange.Its circumference at the Equator is 40,077 km .Where as measured over the poles ,it is 68 km less
SHAPE OF THE EARTH
Structure of the Earth-
INTERNAL STRUCTURE OF THE EARTH.-Like an Onion Earth has several layers.The outer most layer, the Earth's crust,has an average depth of 40 k.m.As compared with the diameter of the Earth ,which is around,12,700 km,the Earth's crust is very small.It is primarily made up of solid rocks.Below the crust is the mantle reaching to a depth of about 2900km.Due to the heat inside the earth ,the mantle consist of solid and molten rocks..Below the mantle is core,made up of Iron and Nickle.The deeper one travels inside the Earth ,the hotter it is .The temperature in the core is between 4000 and 5000 degree centigrade.
INSIDE THE EARTH-ONE CAN look deep inside the Earth in the aftermath of earthquakes or by creating nuclear explosions.The explosions generate sound or seismic waves .They also throw off rock particles .By measuring their intensity and timing ,scientists discover the composition of the earth's interior.
ATMOSPHERE -THE word ' Atmosphere' meas a gaseous cover enveloping a planet..Without atmosphere life would not have been possible on the Earth.One-fifth of the atmosphere is oxygen and four fifth is nitrogen .Like the Earth's interior , the atmosphere too is made up of several layers.All animals and plants live in the lower most layer of the atmosphere called the 'troposphere'.All weather phenomena take place in the troposphere .Even aeroplanes fly in the outer edge of the troposphere .The stratosphere ,the mesosphere, the ionosphere and the exosphere lie above the troposphere.
WHY ONE DO NOT FALL OFF FROM THE EARTH.
Gravity is the force of the Earth that attracts every object towards itself.This force always acts downwards. For a long time people did not believe that the Earth is round because then the people 'underneath' the sphere would have actually fallen down.In 1687 , a physicist ,Issac Newton , proved that the force of gravity always act towards the center of the Earth.On the Earth ,the force of gravitation always acts 'downwards' irrespective of Eskimos in the Arctic region , people in Europe , or inhabitants of Australia.
The first person who proved that Earth was round was Ferdinand Magellan , who was the first to sail around the Earth.,in 1522.
The Earth is not a perfect globe .It is slightly flattened at poles .Like an orange.Its circumference at the Equator is 40,077 km .Where as measured over the poles ,it is 68 km less
SHAPE OF THE EARTH
Structure of the Earth-
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