Start of the Universe

The big bang was not the first thing that occurred in the creation of the universe. Although it was one of the first things that occurred, there were other things that happened earlier. In the beginning, there was an extremely small point called the singularity. Cosmologists believed that during this time there was an inflaton field. When this field is in a high energy state it creates a repulsive force which causes cosmic inflation. Cosmic inflation is the very first thing that occurred. What was really interesting for me was that this cosmic inflation happened so rapidly that it took only 10^-32 seconds! The universe expanded faster than the speed of light. Immediately after the inflation stopped, the force of energy that caused the inflation to occur converted to light and this is when the big bang occurs. The universe became extremely hot and filled with neutrons, protons, and electrons which collided to form the first elements: helium and hydrogen. Roughly 380,000 years after the big bang, the universe cooled down and atoms started forming. The atoms produced their own light which can still be detected today. The light is known as the cosmic microwave background, and it is the oldest observable light in the universe.

Fast forward in time to 200 million years after the big bang. The first stars start to form and then entire galaxies. The process of how planetary systems form is very interesting and I will go more in depth about that process in a different blog. Some cosmologists believe that the expansion of the universe is slowing down and would eventually stop. The gravity of the universe will then lead to the universe collapsing into a singularity that may expand again, restarting the cycle. Other cosmologists believe that the expansion of the universe is accelerating and will expand forever. I will also be making a blog on the end of the universe, if there is an end. There are so many unanswered questions about the future of our vast universe.

Source:Cosmic History - NASA Science