Solar Nebula Theory
How our galaxy began
The Solar Nebular Theory (SNT) is an idea of how the universe was created. It says that the universe was created with clouds of dust and gases. These come together to form stars, planets, and other celestial formations.
A dense cloud begins to form from the dusts and gases, and keeps expanding until pressure forces it to collapse, where it flattens out to a single star surround by a rotating disk. The star in the middle became the sun, and the dust and gas around it collided to create planets.
Several ideas from different people came together to create the theory. Some well-known people are Immanuel Kant and Pierre-Simon Laplace in the 18th century.