Like the Sun and other planets, the Earth was formed from nebula gas and dust approximately 4.6 billion years ago. But the world we see today , the world of that day was not like that. At that time it was impossible to imagine the existence of life on earth. In fact, the world of this modern age is not the same as the world of 4.6 billion years ago. We know that dinosaurs existed 200 million years ago and now humans are ruling the earth. The process of forming the earth is still going on. Its molten material , which is occasionally erupted by volcanic eruptions. Earth's plates , which often collide with each other, cause earthquakes. In this article we will try to find out how the world came to be as it is today. Earth 400 million years ago: At that time the earth was so hot that everything here was in a gaseous state. At that time it was impossible to find any small particle of water in solid and liquid state. There was no oxygen in its atmosphere. There was no ozone layer. So the sun's terrible ultraviolet rays would fall directly on the earth. We know that the center of the earth is still so hot that the matter inside it is in a molten state. Which occasionally reaches the Earth's surface through eruptions , creating mountains and new layers of new earth. Earth 100 billion years ago: By then, the Earth's surface has cooled , and volcanic eruptions have decreased a lot. Water has taken its form and formed the ocean. Green algae grows in the water. These produce oxygen through photosynthesis and release it into the atmosphere. The newly produced oxygen forms the ozone layer in the atmosphere. As a result, the earth is protected from the toxic ultraviolet rays of the sun. The earth's surface continues to shape , and continents continue to form. Earth 400 million years ago: At this time , life on the earth began to grow through trees and herbs. They tend to produce much more oxygen. A changing climate with cool temperatures prevails around the world. This climate, rich in rain , snow , storms , and snow, helps to create the highlands and plains of the earth. The emergence and development of dinosaurs continues. They continue to rule the world. Later flowers and insects begin to emerge. Earth six and a half billion years ago: At this time, life on earth ceased to exist. The idea is that a huge meteor or comet hits the earth's surface. Its atmosphere is filled with suffocating gases and dust particles. The extinction of dinosaurs and other life. Toxic chemicals continue to flow around the earth's surface. As a result, even life-giving solar rays could not penetrate the earth's surface. Gradually this situation changed. The surface of the earth became alive again. The emergence of the human species.