The Nebular Theory is one of the famous theories which explains the formation of the universe primarily the stars, planets and other heavenly bodies. The theory was first applied on to the creation of the solar system and was later applied to the universe. It is sometimes called solar nebular model. According to the theory, the universe was created accidentally from a cloud of dust and gas called Nebula.
The cloud collapsed due to its unstable gravitational force and spin faster and faster due to its angular momentum conservation. The gas involved in the nebula was mostly hydrogen. The nebular disk due to the unstable gravitational forces collapse and forms the sun, moon, and the planets. The theory is highly debated due to its inability to explain many of its proponents like angular momentum, the formation of giant planets and stars etc.
Uniformitarianism in relation to the evolution of Earth and solar system Uniformitarianism is the assumption that natural processes which operated in the past can be observed and said to be also operating in the present. In relation to the evolution of the earth and the solar system, this philosophy of science explains that the Earth’s processes like moving of the tectonic plates and the formations of mountains and seas can be seen in the past.
Uniformitarianism explains that what happens today has also happened in the past. This is why the evolution of the earth and solar system can be observed and known to us by observing the present state of the Earth and the solar system through thorough scientific methods of observation. Uniformitarianism is a principle used to explain why scientist observe and evaluate the earth today and is able to formulate hypothesis and theories on how the earth and solar system evolved through time.