Earth Spheres

Definition: Biosphere is a closed self-control system combining biological and non-biological elements of planet (Lenkeit). The biosphere is part of the outer shell of the planet including the atmosphere, hydrosphere and lithosphere (Answers.com). Hydrosphere is an open system that contains all the solid, liquid and gaseous water of the earth (Answers.com). As an open system, the hydrosphere interacts with surrounding systems via input and output (Lenkeit). The atmosphere is an open system consisting of a mixture of gases surrounding the earth (Answers.com).

The simplest model of the shape of the entire earth is a sphere. The radius of the earth is about 6,371 kilometers (3,959 miles) from the center of the earth to the surface of the earth. "Radius" is usually a characteristic of a perfect sphere, but the earth is only 3 percent of the sphere and is often close enough to prove the term "earth radius", considering it as a sphere. The concept of spherical earth dates back to the 6th century BC, but it was still a question of philosophical thinking until the 3 rd century BC. The first scientific estimate of the radius of the earth is given by Eratosthenes around 240 BC and the measurement accuracy of Eratosthenes is estimated to be between 2% and 15%.

In the 3 rd century BC before the 20 th century BC, the theory of the earth was confirmed by Greek astronomy. Or we thought about that. For centuries before the 3rd century BC, the idea of ​​the sphere of the earth was always speculation, but most people suggest that this is an absolute fact if it proves that the flat theory of the earth is wrong I think to a round planet. Until recently you can ask the person you know, the person you meet, or the person to contact, and they say confidently that the earth is round. However, the world has been taught to circulate for centuries, but modern theorists once again promote the flat theory of the earth. Through the social media platform, people are open to the public in spite of being ridiculed by the masses of this theory.