How were the universe created ?

According to modern science, the universe is thought to have been created 13.7 billion years ago.
Until the beginning of the 20th century, the universe was thought to have no beginning or end.

But things changed when American astronomers discovered in 1929 that the universe continued to expand.
Some people wondered, "If the universe is expanding over time, if we go back in time, the universe would be a small point."

There are still many things we don't know about the beginning of the universe.
Many scientists agree with this theory that the universe started from one point.
It is not yet known how that point was made from "nothing".

It is believed that the origin of the universe was like a fireball with an extremely high temperature.
It suddenly began to swell with tremendous momentum, just like a big explosion 13.7 billion years ago.
This is the moment when the universe was born, called the Big Bang.

The momentum swells to the size of one light-year in just one second.
A collection of stars called galaxies began to form about a billion years after the universe was created, and the Sun and the Earth were formed more than eight billion years later.
One light-year is about 9.46 trillion kilometers.
The number 13.7 billion years ago was calculated from the results of observations of space light by American artificial satellites.