the universe began with a Big Bang哪位大哥大姐帮忙用英文写一段关于宇宙大爆炸的作文

Big Bang theory of the main opinion is that our universe had a period from hot to cold evolutionary history. During this period, the universe is not a static system, but are constantly expanding, so that the density of matter from the dense to dilute to evolve. This from hot to cold, from dense to dilute the process as the outbreak of an enormous scale. According to Big Bang cosmology opinion, the big bang the whole process are: early in the universe, the temperature is extremely high at 10 billion degrees. Material density is likely to be considerable, the whole system of the universe balanced. The universe only neutrons, protons and electrons, photons and neutrinos and other elementary particles form the material. However, because the whole system continues to expand, the results of the temperature dropped quickly. When the temperature dropped to around one billion degrees, neutrons begin to lose the freedom of the conditions exist, it either happened decay, or with protons into d