The Mystery of the Origin of the Universe
The "Big Bang Theory of the Universe" proposed by British scientist Stephen Hawking suggests that: The universe originated from a big explosion that took place 15-18 billion years ago. At first, all matter in the universe was densely concentrated at a certain point. After the big bang occurred, the universe expanded infinitely, with temperatures reaching as high as 15 billion degrees. There were only basic particles such as neutrons, electrons, photons, and neutrinos in the universe. When the temperature dropped to 10 billion degrees, chemical elements were formed and the matter was in a plasma state. Afterwards, as the temperature continued to decrease, gases were formed.