Unit 1 – T

Apuntes

•The Big Bang and the Universe 1.1 Origin of the Universe – The Big Bang The Universe began approximately 13.8 billion years ago from a single point with extremely high temperature and density. This event is known as the Big Bang. Following the explosion, matter and energy expanded and cooled, leading to the formation of the first subatomic particles, then hydrogen and helium atoms. 1.2 Evidence for the Big Bang Evidence includes the Cosmic Microwave Background (CMB), which is leftover radiation from the early Universe; the redshift of galaxies, indicating that most are moving away from us and the Universe is expanding; and the abundance of light elements like hydrogen and helium, which Big Bang theory predicts. 1.3 Formation and Life Cycle of Stars Stars form from collapsing clouds of gas and dust called nebulae, which create protostars. When nuclear fusion begins, a star is born. The life cycle varies: low-mass stars become red giants, then white dwarfs, and finally black dwarfs. High-mass stars evolve into red supergiants, then supernovae, and may become neutron stars or black holes. 1.4 Star Clusters and Galaxies Star clusters are groups of stars formed toget...