What does the big bang theory prove

Evidence for the Big Bang

Following the idea of ​​the Big Bang, our universe began expanding from a single point 13.8 billion years ago. There are three main pieces of evidence to support this theory. First: the expanding universe. In 1929, Edwin Hubble discovered that galaxies were all moving away from each other. To do this, he observed the redshift of the light emitted by stars and galaxies. As light moves through an expanding space, the waves are stretched, making the light appear redder than it originally was. An expanding universe requires a starting point. If we went back in the past, the galaxies would move towards each other, to a point, as the Big Bang theory puts it. Second, radiation measured in space. The apparent darkness of the universe looks astonishingly different with a microwave telescope. It shows a remarkably even distribution of radiation in space. This is consistent with the idea that the radiation that arose immediately after the Big Bang spreads in all directions as the universe expanded. We call this cosmic microwave background radiation. This is the afterglow of the Big Bang and was first discovered in 1965. Third: the abundance of light elements. The theory is that matter started in very simple form and got more complex over time. The simplest elements would have formed first. And they would exist in greater quantities than the heavier elements that were first formed in stars. Those first elements were hydrogen and helium. The fact that there is an abundance of these lighter elements supports the Big Bang theory. All of this evidence makes the Big Bang theory the most compelling explanation of the science of how the universe came about.