This is the first actual post on this blog, so let’s start off with a bang. The big bang. Everything in reality starts somewhere, the device you are reading this on begun in the head of some engineer, you begun in pretty romantic circumstances, a painting begun as a set of pigments and brushes etc. All things have a cause and effect, it is common sense, but let’s think bigger and ask ourselves, “How did the universe begin?” Answering this question could really ground us in reality and make us understand what lies at the start of this seemingly endless chain of causes and effects.
The Big Bang is the most probable way in which the universe began. Some theists may argue that reality was created by some form of a god, yet all evidence suggests otherwise. The Big Bang theory was first proposed by Georges Lemaitre in 1927, when he said that the expanding universe could be traced back to a single point. That point is what we call a singularity, an infinitely dense and small point, which is a central feature of black holes. The theory states that about 13.8 billion years ago, such a singularity exploded, and created everything that we know.
The birth of the universe is said to have begun as a random fluctuation of time and space. This somehow exploded and got really hot, around 5.5 billion degrees Celsius. Many of the fundamental particles were created, such as the proton and neutron, and as things cooled down, these particles combined to form matter. The early universe expanded outwards, the basic atoms, such as Hydrogen and Helium, combined and formed stars, planets, gas clouds, galaxies, and the reality we live in. This process took a really long time, the first atoms were formed approximately 1 billion years after the Big Bang, which is 1/14th of time as a whole.
What evidence is there for the Big Bang? The simple answer is the cosmic microwave background, which you can read more about in the sources below. It is said to be the “afterglow” of the birth of the universe. Scientists can recreate conditions similar to the Big Bang in laboratories, yet we cannot observe the event itself, as light was trapped in the early soup of electrons, therefore we ought to rely on mathematical models. A nice analogy would be your early memories, you probably don’t recall the first time you spoke or your first breath, however you trust your parents when they tell you that those events really happened. Physicists trust math in a similar fashion.
What came before the Big Bang? We may never know, yet some people argue that it was an infinite stretch of very hot and dense material, and something caused the universe to erupt from it. However, as Stephen Hawking put it, the time before the Big Bang has no observational consequences, so we can just it out of the theory and say that time begun at the Big Bang. Trying to figure out if there was time before the notion of time existed is always going to be interesting and we are always going to be keen to pursue it, same as we ask our parents about their life and what lead to the creation of us.
The significance of the Big Bang is immeasurable. It created you, me, the Earth, the Solar System, religion, economics etc. The fact that there are sentient beings (a.k.a. humans) to be conscious of this event is even more miraculous. It is one of the most important things to be investigated by science, and if you are still not convinced that it is important, then I don’t know how to help you. We have basically traced back the history of the universe to its birth without the need for written materials, bones and accounts of living things. Now “Was the Big Bang the beginning of time?”, “How did the singularity originate?”, “Will there be another Big Bang in the future?”, and many others are questions still unanswered by science, and it is up to our generation to find out.
If you want further reading here are some great sources:
Wikipedia (obviously): https://en.wikipedia.org/wiki/Big_Bang
Alternate theories: https://www.space.com/24781-big-bang-theory-alternatives-infographic.html
Before the Big Bang: https://www.livescience.com/65254-what-happened-before-big-big.html
A more mathematical approach: http://math.ucr.edu/home/baez/einstein/node7.html
Cosmic microwave background: https://en.wikipedia.org/wiki/Cosmic_microwave_background