The Big Bang Theory

What is the Big Bang Theory?

The Big Bang Theory is a topic in astrophysics and the most widely used explanation of how the universe first came to be. In the simplest terms, at some point 13.8 billion years ago universe started as a singularity (zones where finite matter is condensed into infinite densities) that continued to grow and expand into what it is today.

What Happened

When the universe first appeared, it was extremely hot and the first thing that appeared was an expanse of protons, neutrons, electrons, and photons among others. As the universe rapidly cooled and expanded, the neutrons would become protons or electrons or they would combine with protons to make an isotope of hydrogen called deuterium. Before this happened, because electrons would have caused photons (light) to scatter causing the universe to be opaque. Once these electrons were used to form neutral atoms, the electrons couldn't scatter light and the universe became transparent. These photons became what is known as cosmic background glow and can still be seen today.

Timeline

• Singularity Epoch (Planck Epoch)- the earliest period of the universe that we know of. This was the point where all matter was condensed at a single point. This is also where the universe first start to cool down and expand.
• Inflation Epoch- the universe was filled with high-energy density. The high temperatures and pressure caused led to the universe expanding and cooling quickly.
• Cooling Epoch- the density and temperature of the universe decreasing caused particle energy to decrease.
• Structure Epoch- the denser regions of the universe became attracted each other and grew denser leading to the formation of gas clouds, stars, galaxies and others.

Forces Created by the Big Bang

The four forces created by the Big Bang are:

Electromagnetism-

The interaction between electric and magnetic currents/fields.

Strong nuclear force-

The force that holds together the subatomic particles that make up the nucleus. Compared to the other forces, this has to have a short range to be experienced. This is also the basis of the law of attraction.

Weak nuclear force-

The force that causes matter to decay.

Gravity-

The force that pulls down mass towards the center of the Earth or to another physical mass.

Reference List

1. BBC - GCSE Bitesize: The Big Bang theory. (n.d.). Retrieved February 14, 2017, from http://www.bbc.co.uk/schools/gcsebitesize/science/ocr_gateway/energy_resources/big_bangrev1.shtml
2. Big Bang Theory. (n.d.). Retrieved February 14, 2017, from http://www.big-bang-theory.com/
3. H. (2015, December 18). Big Bang Theory: Evolution of Our Universe. Retrieved February 14, 2017, from http://www.universetoday.com/54756/what-is-the-big-bang-theory/
4. Strickland, J. (2008, June 18). How the Big Bang Theory Works. Retrieved February 14, 2017, from http://science.howstuffworks.com/dictionary/astronomy-terms/big-bang-theory1.htm
5. The Big Bang. (n.d.). Retrieved February 14, 2017, from https://science.nasa.gov/astrophysics/focus-areas/what-powered-the-big-bang
6. What Is the Big Bang Theory? (n.d.). Retrieved February 14, 2017, from http://www.space.com/25126-big-bang-theory.html