The Big Bang

What is The Big Bang Theory:

The Big Bang Theory is a fascinating theory that explains the origin and evolution of the universe. The Big Bang Theory suggests that the universe began as a dense boiling point,  called a singularity. This singularity quickly expanded and continues to do so. The theory is supported by lots of observational evidence, such as the cosmic microwave background radiation, primordial nucleosynthesis, and the expansion of the universe. Let’s dive into more detail about this interesting theory.

The Beginnings of the Universe:

The Big Bang Theory suggests that around 13.8 billion years ago, the universe was just a singularity, smaller than the size of an atom. Then gravitational waves caused a rapid expansion known as cosmic inflation. This sudden growth caused the universe to expand faster than the speed of light, which caused the creation of space and time as we know them now. As the universe expanded and cooled down, the first particles and atoms formed about 380,000 years after the event. Protons and electrons combined to create the first hydrogen atoms. Over millions of years, gravity pulled this matter together to form stars and galaxies. The fusion reactions in these stars produce heavier elements, which were then released into space when the stars exploded (supernovas). Then these heavier elements are pulled together by gravity, once again forming more stars and galaxies, which will then later explode.  This cosmic recycling process continues to spread diverse elements all over the universe. 

Primordial Nucleosynthesis:

During the first few minutes after the Big Bang, a process which is known as primordial nucleosynthesis took place. In this process, protons and neutrons combine to form the lightweight elements of deuterium (a heavier isotope of hydrogen), helium, and small amounts of lithium. These first-ever elements that were heavier than hydrogen are the first to join the recycling process mentioned above.  The ratios of these elements observed in the universe today provide lots of information about the conditions and timeline of the universe.

Dark Matter and Dark Energy:

Even though dark matter and dark energy are invisible, these unusual materials have very important roles in the shaping of the universe. Dark matter does not interact with electromagnetic forces, so it does not absorb, reflect, or emit light. This makes it extremely hard to find. This results in researchers having only been able to infer the existence of dark matter due to the gravitational effect it seems to have on normal matter. Dark matter's gravitational power keeps galaxies together. You can think of dark energy as an “anti-gravity” because dark energy pushes objects apart at a very quick rate rather than pulling them together like gravity does. Dark energy is believed to be responsible for the accelerated expansion of the universe.

Evidences of The Big Bang Theory:

One of the main pieces of evidence supporting the Big Bang Theory is the discovery of cosmic microwave background radiation (CMBR) in 1965 by Arno Penzias and Robert Wilson. Spreading  throughout the entire universe, this faint glow of CMBR  serves as a fossilized remainder of the early universe. The Big Bang Theory also explains the redshift of far galaxies. This is because redshift is the red light seen when an object moves farther away from us, and The Big Bang Theory says that the universe is constantly expanding, so when we observe the redshift in our universe, we know it is expanding.    Edwin Hubble's observations in the early 20th century revealed that galaxies are moving away from each other, in an expanding universe. This expansion provides support for the idea that the universe came from a singularity, because the “bang” of the singularity would cause expansion. Modern observatories and space telescopes continue to show more about the history of the universe.

The End of the Universe:

 If the universe continues to grow at about the same rate, in approximately 30 billion years from now, all the galaxies would be pulled away from  each other. Eventually all of the stars would burn out in about 100 trillion years.

 Dark energy could also increase the possibility of a Big Rip in the universe. This event would take place approximately 50 billion years from now. Dark energy would tear everything apart, even atoms. But, if dark energy slowed down, then this would give gravity the upper hand and lead to another event 30 billion years from now known as the Big Crunch. The Big Crunch is an event, in which the expansion of the universe eventually reverses and the universe collapses on itself, because of the force of gravity. However, there is still hope, because with The Big Crunch comes a new Big Bang!

What I Think:

Even though the Big Bang Theory has been successful in explaining a lot of our observations, there are still parts of the early universe that remain mysterious. For example, what happened in the first moments after the Big Bang? What do dark matter and dark energy look like, and why do they together make up about 95% of the universe's total mass-energy content? Scientists continue to explore these questions using advanced telescopes, particle accelerators, and mathematical models. The Big Bang Theory explains many ideas, but pursuing a better understanding of the origin of our universe  continues.