Ever wondered how this universe began? Well, there is a theory that is pretty accurate. The big bang theory.
The big bang happened about 14 billion years ago. Then, the universe was held by a tiny red ball called a singularity. Eventually it was too much for the ball to handle, and it exploded. After it exploded the temperature was over 10,000,000 degrees. But the temperature cooled down.
In the 1940s Georges Lemaite made the big bang theory. He didn’t have much evidence to support it, and the theory was criticized by many people.
Later in the 1960s-the 1990s evidence of the big bang was discovered. Using telescopes scientists found remains of the big bang. They also found out that the universe keeps on expanding.
And that is probably how the universe began. Remember its just a theory. Who knows? Maybe when time machines are invented we might really find out how the universe began.