What Is Nebular Hypothesis?

The Nebular hypothesis is related to the forming of the stars and planets. It tries to explain how the solar system and other cosmic elements have evolved. The theory was first proposed by Emanuel Swedenborg in 1734 highlighting the probable incidents that led to the forming of the Earth's solar system. The word nebula (plural: nebulae) has the origin from Latin, which means mist. Originally, nebula was a common name for any astronomical objects. Emanuel suggested that our solar system has formed from the solar nebula, which is nothing but a solid body revolving around a gaseous nucleus. Though the hypothesis was initially brought on the backdrop of our solar system, it was brought forward further by Immanuel Kant in 1755 to support the evolution of all other planetary components of the universe.

The present form of the Nebular hypothesis tells that all the respective responsible nebulae initially exist as a large (approx. 10,000 AU in diameter) cloud of very cold interstellar gas in slow rotation, then they collapse due gravity and other pressure waves of the neighbourly elements giving birth to the stars and planets. The composition of those nebulae determines the constituent elements of the resulting heavenly bodies. The hypothesis also highlights that while collapsing, the nebula heats up, increases its spin, and flattens to form disk (protoplanetary disk). Such disks are eventually settled down into the cosmic elements.

A German philosopher in 1955 suggested that origin of the earth could be linked to a spinning cloud which is composed of different types of gases and fine dust .Different kinds of discoveries that were made in the last few centuries again led astronomers back to that old idea which is known as Nebular hypothesis. Now with different latest equipment they now discovered that our outer space beyond our solar system is not as empty as it was in past. Astronomers have noticed different clouds as the once mentioned by German philosopher and they given a name to those clouds as Nebulae. Now the main thing is that they have to identify the material form which these clouds formed. The gases found mostly are Helium and Hydrogen. They are 2 main elements that make up the whole with the small fraction with our sun. The dust sized material found is similar to material found on earth. Now question normally arise in mind that how it is possible that our solar system take form from a Nebulae? Answer is in the force of gravity .there is attraction between different pieces because of their mass. When spinning cloud under the force of gravity contract, in turn it increases the rotation of particles.