The best-supported theory of our universe’s origin centers on an event known as the big bang. This theory was born after the successful observation of various theories. It’s been observed that the universe is moving away from our own at great speed in all directions as if they had all been propelled by an ancient explosive force.

One of the most significant developments in space science is our understanding of the origins of the universe. Scientists have used telescopes and other instruments to observe the early universe and gather data on its formation.

In the 1920s, a Belgian priest named G Lemaître first suggested the big bang theory, when he theorized that the universe began from a single primordial atom. The idea received major boosts from Edwin Hubble’s observations that galaxies are speeding away from us in all directions, as well as from the 1960s discovery of cosmic microwave radiation—interpreted as echoes of the big bang—by Arno Penzias and Robert Wilson.

It has evolved from a formless soup of elementary particles into the richly structured cosmos of today.

This data has led to the development of the Big Bang Theory, which suggests that the universe began as a single point of infinite density and has been expanding ever since.

The origin of the universe is a topic of great interest and debate among scientists. According to the Big Bang theory, the universe began as a singularity – a point of infinite density and temperature – about 13.78 billion years ago.

Just after the Big Bang, the universe began to expand and cool, and matter began to form. In the first few minutes, hydrogen and helium nuclei were formed, but these nuclei later became the building blocks for stars and galaxies and the whole universe.

As time passed, gravity caused the matter to clump together, forming galaxies and clusters of galaxies. Within these galaxies, stars were born and eventually died, releasing heavy elements into the universe. These elements became the building blocks for the planets and life that we know now.

While the Big Bang theory is the most widely accepted explanation for the origins of the universe, there are other theories that have been proposed, such as the steady-state theory and the cyclic model. However, these theories have not been supported by as much evidence as the Big Bang theory.

Radiation in the early universe was so intense that colliding photons could form pairs of particles made of matter and antimatter, which is like regular matter in every way except with the opposite electrical charge. It’s thought that the early universe contained equal amounts of matter and antimatter. But as the universe cooled, photons no longer packed enough punch to make matter-antimatter pairs. So like an extreme game of musical chairs, many particles of matter and antimatter paired off and annihilated one another.

There wasn’t a single star in the universe until about 180 million years after the big bang. It took that long for gravity to gather clouds of hydrogen and forge them into stars. Many physicists think that vast clouds of dark matter, a still-unknown material that outweighs visible matter by more than five to one, provided a gravitational scaffold for the first galaxies and stars.

[ref-nationalgeographic]