Our Earth

Will you want this earth along with millions of other animals plants and microorganisms we human beings arrived on the earth about one lakh years ago more than any other animal-human beings have been trying to make their a better place to live in? We have been constantly trying to change ourselves and our surroundings in this process we have entered into conflict with each other. For a long, we have looked at the earth as a store of resources that we can exploit and we use gradually we are releasing the viewpoint our reckless explosion of the earth as the destruction of foresters reverse hills fellow animals, and even fellow humans. 

This has resulted in what many are calling the environmental crisis like global warming and poisoning of our soils water and air today more than at another time we need to build a new understanding of the Earth how it works and what we do on it and what we do with each other we will study about the earth as a large interconnected system. We will see how the rock, soils, minerals, water, air, sunshine, forests, animals, and humans interact with each other and change each other constantly.


                The Evolution of the Earth

Scientists are still debating at home most scientists are of the view that Earth began to form around four and a half billion years ago. The Earth has reached its region from two several places it began as balls, dust, and clouds and passed through a molten stage at the time the Earth was very hot. If you boil a thick soup containing much substance, you may observe the heavier particle tend to go bottom and lighter particles come to the top these lighter particles cool at the top and form a layer of crust similarly while heavier substances formed part of the molten core lighter substance rose to the surfaces are cold so slowly an upper crust of the lighter and collar materials formed covering the molten interior.

                  As the Earth's interior continued to cool it contracted and the outer crust wrinkled farming ridges and basins the atmosphere of the Earth consisted of different kinds of gasses including water vapor most of these gasses were such that life, as we know it today, could not have survived on it it didn't have oxygen which is necessary for us it took a long time for the air we breathe to develop the rain filled the great basins on the earth crust with water thus the oceans were formed for perhaps half of the long span of Earth's history the planet Earth remained barren and lifeless.


                  Internal Structure of Earth

The Earth has three layers:

1. Crust

2. Core

3. Mantle


Crust: We live on the outer part of the earth which is called the crust you saw in the last section how these layers were formed this layer goes up to a depth of 30 to 100 kilometers the crust mostly contains various kinds of rocks.

Core: There are two types:

1. Outer core: The outer core is 2900 to 5100 km and is composed of liquid metallic material like nickel and iron.

2. Inner core:   The earth is made up of iron compounds and heavy substances like gold interestingly matter from deep inside the mantle suits up through volcanoes End fixtures all ocean floods and cooldowns to form the Earth's crust. In many regions of the Earth part of the Earth's crust enter into the mountain and once again become mortal this constant process of formation and destruction of the crust explains the fact that our Earth is still very active the crest on which we live is still being changed by earthquakes, volcanoes, subduction of land and rise of the mountain due to the process having deep down the Earth.

Mantle: It is 100 to 2900 km in thickness in the upper part of the earth. The mantle is not very hot and consists mainly of chemicals called silicates. 


                             Latitudes

 The horizontal Circle that goes around the earth exactly in the middle at an equal distance from the north and south poles is called the equator, because it divides the earth divided into two equal parts this is a circle designed as 0-degree latitude from the equator going towards the poles are a series of the parallel circle each circle. Some latitudes are given special names that are related to the patterns of these unlike the falling of earth and that evaluation around the sun's equator is the largest among all the latitudes all other latitudes on either side gradually become smaller toward polls at the polls than the 90 degrees north and 90 degrees south are not circles at all they are just points off of the earth between the equator and N Pole is called the Northern Hemisphere hemi means half hemisphere means of half a sphere the hope that is between the equator and the South Pole is called the South Hemisphere counting from 1 pole to another there are 180 main latitudes.

                           Longitudes

Latin gives the word "longitudo" meaning length from which we get longitudinal the right of the math longitudes are not full circles these are semicircles connecting pole to pole every longitude cuts across every latitude the longitude that passes through astronomical observant at Greenwich England is called 0 Meridian, Prime meridian,  Greenwich Meridian.

Several countries tried to fix a longitude that passes through their own territory as zero degrees longitude however England decides that the Greenwich Meridian will be the 0-degree longitude. They rule a large part of the world at that time so everyone else ended up following their system there are 360 longitudes we are in the main longitude into two groups 0 degrees to 180 degrees, going east which are the east longitudes and 0 degrees to 180 degrees going west which are west longitudes zero degrees and 180 longitudes don't have directional makers other longitudes have direction makers the longitude directly opposite to zero degrees longitude is caught the anti-Meridian the east longitudes from the eastern hemisphere and the west longitudes on the Western Hemisphere.