EARTH AS THE WORLD.

The Earth is also known as the “LIVING WORLD”, Terra [Gaia]. The earth is the third planet from the sun and it’s the terrestrial planets including “MARS”, others non- terrestrial planets may include; Mercury, Venus, Jupiter, Saturn, Uranus, Neptune, Pluto and the newly discovered dwarf planet (VP113).

          The shape of the Earth approximates an oblate spheroid, a sphere flattened along the axis from pole to pole such that there is a bulge around the equator. This bulge results from the rotation of the Earth, and causes the diameter at the equator to be 43km (kilometer) larger than pole to pole diameter. Thus the furthest point on the surface from the Earth’s center of mass is the Chimborazo volcano in Ecuador. The average diameter of the reference spheroid is about 12,742km, which is approximately 40,000km, as the meter was originally defined as 1/10,000,000 of the distance from the equator to the North Pole through Paris, France. The Earth has tolerance of about one part in about 584 or 0.17%, from the reference spheroid, which is less than the 0.22% tolerance allowed in billiard balls.

     The Earth’s name comes from the Anglo-Saxon word “erad” which means “Ground” or “Soil”. The Earth was formed approximately 4.54 billion years ago. It is a home of about 8.74 million species. Its total mass is about 5,972,190,000,000,000 billion kg. Its Equatorial Diameter is about 12,714km; its Equatorial Circumference is about 40,030km. The Earth has a single moon. The Earth Orbit Distance is about 149,598,262km. Its Orbit period is 365.26 Earth days. The Earth’s surface Temperature is about -88 to 58°C.

     According to evidence from sources such as radiometric dating, Earth was formed around four and a half billion years ago. Within its 1^st billion years, life appeared in its oceans and began to affect its atmosphere and surface, promoting the proliferation of aerobic as well as anaerobic organisms and causing the formation of the atmosphere’s ozone layer. This layer and Earth’s magnetic field block the most life- threatening parts of the sun’s radiation, so life was able to flourish on land as well as water. Since then, Earth’s position in the solar system, its physical properties and its geological history have allowed life to persist.