Origin of the universe

According to a 2018 report by the National Science Board, only 39% of Americans think the universe emerged from a huge explosion (the big bang). While the report acknowledges that the wording of the question can affect the outcome of the poll, the results still leave a residue of anxiety among those interested in the welfare of science while left in the care of America’s democracy. For comparison, the United States was beaten by Canada and South Korea who correctly answered the question with percentages at 68% and 67% respectively.

The question may have been met with such low results due to the complexity of the information at hand. Average people cannot be expected to have an intuitive understanding of the kind of information that could leave one to confidently conclude the origin of the universe. Though, it is also true that the Big Bang Theory can more be thought of as a model of the evolution of the universe, rather than an explanation of the universe's origin. For the sake of awareness, this article makes an attempt to simplify the concepts that have lead so many scientists to adhere to the Big Bang model as the most well-supported theory for the evolution of our universe. It is worth noting that this article will only serve as a very layman approach to understanding these concepts in cosmology so expect many complex ideas to be omitted. It is highly encouraged that the reader explores the topics discussed in this article further.

Firstly, if we are going to answer possibly the biggest question known to mankind, we will first have to break the question down into smaller ones. What is the Universe made out of? All the matter that we tangibly interact with is made out of atoms which are categorized on the periodic table of elements.

The Periodic Table of Elements allows us to categorize all of the known elements.

Each element is comprised of the same three particles: the proton, neutron, and electron. Each element is distinguished by the number of protons it has. Reading the table from left to right and top to bottom (like a book) shows the element getting heavier as it gains another proton and generally an equal amount of accompanying particles. This is a bit of a simplified version as there are also ions and isotopes which can allow an element to have plus or minus a number of neutrons or electrons.

A simplified model of the atom allows us to see its particles.

Duality between matter and energy demonstrated in Einsteins most famous equation.

In any case, we have now simplified the question from ‘where did the universe come from’ to ‘where did these three particles come from?’ The question gets simplified further when one considers that all matter is made out of energy thanks to Einstein's famous and innovative equation.

Before answering that lets first side track to point out another interesting implication of this. You may have noticed that the periodic table of elements contains only a finite amount of elements meaning that there are only so many arrangements that these elements can combine to form. Depending on how big space is (which it may or may not be infinite) there will eventually come a point where every single combination of atoms exhausts itself; at which point every single number of combinations of atoms after that will only be a repeat of prior combinations. If the universe is at least twice this size then that means that there is at least one repeat of every single combination of atoms; including the atoms that make up our planet and all of the individuals on it. If space is infinite then there is an infinite amount of repeating configurations of atoms. This can and has been calculated and it is one of the many ways in which the idea of a multiverse is satisfied as a necessary consequence of number theory. That can be a little mind-boggling so let us cool off with a picture of some geese.

Geese are a natural part of our environment.

Crude edit highlights the Doppler effect in the waves of water.

Speaking of which, also take notice how the ripples in front of the geese are more dense in frequency than the waves behind it. This is a property of all waves emitted by a moving object (including waves of light) and it is known as the Doppler effect. Objects in motion that reflect light will have the wavelengths of light shorter in the direction it is traveling and longer in the opposite direction. This will cause the shorter wavelengths of light to appear bluer while the longer wavelengths appear redder. The latter of which called red-shifting. This is important because it allows us to measure where everything in the universe is traveling.

The electromagnetic spectrum of radiation shows radiation like microwaves and visible light as tiny snippets out of the whole spectrum of radiation.

There are essentially two directions in which anything in three-dimensional space can move: inward and outward. In order to see where everything in the universe is traveling one must measure all the inward and outward motions of all the objects in the universe. Whichever number is bigger will tell which direction everything in the universe is traveling. Thanks to the Doppler effect we can observe that everything in the universe is moving outward because everything is redder than it would be otherwise. As light travels through the cosmos it shifts further and further down the red spectrum until it shifts out of our band of visible light entirely. Objects that are particularly far away will fade further and further down the spectrum until it cannot be detected at all; causing a three dimensional, cosmic bubble horizon around what is called The Observable Universe beyond which nothing can be detected.

Everything in the universe is traveling outward, against the force of gravity, due to a mysterious force called dark energy. This will cause the heat death of the universe where everything in the universe slowly spreads apart before all matter and energy decay to nothing. If one reverses time you will notice that everything in the universe would instead come crashing together. When the universe was concentrated in a smaller area it existed as a soup of plasma where pools of energy would create, and interact with, all the matter in the universe. The evidence for the remnants of such a cosmic plasma can be found in two measurements.

First, the cosmic microwave background which was first observed completely by accident by Arno Penzias and Robert Wilson in 1965 using the Bell Labs horn antenna. Microwaves are scattered all throughout empty space like dust particles spread around in an empty room. The hot plasma at the beginning of the universe emitted a lot of radiation roughly 300,000 years after the big bang due to the expansion of space separating a large amount of matter and energy; an event known as decoupling. This radiation has since been red-shifted into microwaves which we now detect as the cosmic microwave background.

Second, the cosmic plasma created a disproportionate amount of lighter elements such as hydrogen and helium. Ordinarily, the particles that comprise the nuclei of elements repel each other so it takes a lot of energy to push these particles together so that they bind into heavier elements. This process is done with the energy produced by stars. However, there are not enough stars to account for the amount of hydrogen and helium.

The big bang model is more than “just a theory.” It is an empirical model of the evolution of the universe supported by evidence using experiments and measurements devised by some of the brightest people to have touched mankind. There are still many unanswered questions that are rigorously debated by scientists; such as ‘what produced the big bang?’. Though with more experimentation, and time, more pieces of the puzzle ill come together in ways we may not expect and a greater understanding of the universe will be realized.