Origin of the Universe
Many scientific theories attempted to explain the origin of the universe. But couldn’t provide evidence that could be widely accepted.
However, The Big Bang theory is the widely recognized and acceptable theory that provided evidence to unravel the mystery of origin of the universe.
The Big Bang theory states that the universe began as a hot and infinitely dense point. And that was only a few millimeters wide which was similar to a supercharged Black Hole.
The Big Bang
At the Big Bang 13.7 billion years ago that tiny ball with an unimaginably small volume, infinite temperature and infinite density violently exploded and that explosion resulted in the creation of matter, energy, space and time.
This led to a huge expansion and the expansion continues even to the present day. During that period of time, it passed through the radiation era and the matter era which shaped the universe.
Origin of the Galaxies
Energy and matter were distributed unevenly in the early universe. And these initial density differences gave rise to differences in gravitational forces. It caused the matter to get drawn together. These formed the bases for the development of galaxies. A galaxy started to form by the accumulation of hydrogen gas in the form of a very large cloud called a nebula.
A galaxy is a collection of gases, dust, planets, black holes, moons, nebula, asteroids, comets, dark matter, stars etc. And these bodies are connected to each other due to gravity. There are an infinite number of galaxies present in our universe.
Our solar system is located in the Milky Way Galaxy. There are numerous solar systems present in our milky way galaxy. Our solar system is situated in the outer area of the milky way galaxy.
Earlier, people used to believe that there is only a milky way galaxy present in the entire universe. But in 1924, Edwin Hubble revealed that there are more galaxies present in the universe.
Hubble Ultra Deep Field-by-NASA
Finally, the Hubble deep field was observed in 1995 and this real deep look into the universe proved that there are many galaxies present in the universe. Andromeda Galaxy is the closest galaxy to our milky way galaxy.
Galaxies are found in many shapes and sizes but three main basic types are spiral galaxies, elliptical galaxies and irregular galaxies.
Formation of Star
A galaxy contains a large number of stars. A growing nebula developed localised clumps of gas and these clumps continued to grow into denser gaseous bodies that gave rise to formation of stars. The formation of stars had taken place 5 – 6 billion years ago.
Formation and Evolution of the Solar System
The Nebular Hypothesis explain the formation of the solar system. It suggest that the solar system has formed from the dust and gas orbiting the Sun.
The Nebular Hypothesis was first developed in eighteenth century by Emanuel Swedenburg, Emmanuel Kant and Laplace. The theory was developed by Immanuel Kant and published in his work Universal Natural History and Theory of Heaven ( 1755). Later, it was modified and revised by Pierre Laplace in 1796.
The solar system was formed about 4.6 billion years ago due to the gravitational collapse of a small part of a giant molecular cloud. and this collapsing mass collected in the center resulted in the formation of the Sun while the rest flattened into a protoplanetary disc. The planets, moons, asteroids and other small bodies have been formed out of that disc.