“In the beginning God created the heavens and the earth.” This is how the Bible kicks off, and for almost two millennia was the accepted theory for how the Universe and the Earth came into being. A tricky subject and something that takes a great deal of thought to even contemplate, the origin of time is not an easy thing to study. Up until modern technological advances and the advent of space telescopes it would in fact seem logical to credit a divine being with the creation of the Universe, simply for lack of a better explanation. However what this simple sentence does not explain is how the Universe was created, it merely says that it was done.
In the late 19th century and early 20th century scientific thinking began to overtake religious ideas as men such as Darwin and Einstein began to publish their theories. Many of the new scientific ideas would look to explain the laws that govern the way things are and the way that they came to be. While Darwin would upset a great number of religious people with his ideas on the origin of life on Earth, Einstein and his contemporaries’ ideas would cause relatively less stir in those circles due to the vagueness in the description of the start of time in the Bible.
While Einstein would lay the foundations for modern scientific thinking with his theories of special and general relativity his work would be expanded on later by numerous scientists, physicists and astronomers. Through the 1910s and 1920s it was discovered that the Universe was expanding, the term ‘big bang’ was actually coined as a derogatory term for the theory by Fred Hoyle while speaking on BBC radio. The genesis of the modern big bang theory started in the 1960s and has come on massively in the last ten years with additional data from the Hubble Space Telescope and NASA’s Wilkinson Microwave Anisotropy Probe (WMAP).
Big Bang theory states that the Universe was created in a single event 13.7 billion years ago. The initial condition of the Universe is still not fully known, but it is widely thought that it began as a singularity of infinite density and temperature. The first stage of the Big Bang is known as the Planck Epoch, lasting just a couple of trillionths of a second. At this tiny interval in time gravity was thought to have been as strong as the other fundamental forces, suggesting that everything was united as one single force. Understanding of this phase of the Big Bang is still limited, but experiments are planned in the future to gain a better knowledge of what happened. The Large Hadron Collider at CERN will enable further research to be done into the earliest phases of matter but will not allow research to be done directly into the Planck Epoch.
Still during the initial fractions of a second the Universe would undergo several major changes in its infant state. The main things being a cooling and then exponential growth through cosmic expansion. At this stage the Universe consisted of a quark-gluon plasma, which is essentially the building blocks of matter as we know it. As particles such as photons continued to form over the crucial first few seconds of the Universe the matter that was coming into being started to become more recognisable. After three minutes the temperature had dropped to the level where protons and neutrons can begin to combine into atomic nuclei. After 17 more minutes the temperature and density fell to a point where nuclear fusion was no longer possible.
For the next 70,000 years matter continues to form. Following this hydrogen and helium atoms start forming as the density of the fledgling Universe starts to fall and photons are free to travel, resulting in the cosmic microwave background that we can see present. This radiation gives us a picture of what the Universe was like at this point in time.
Over time the Universe starts to become transparent and structures begin to form due to gravitational forces. The Universe loses its homogenous nature as matter starts to clump together. After approximately 100 million years the first stars begin to form, eventually generating the heavy elements that will start to give life to planets. Even larger groups of matter will collapse and form galaxies. After billions of years the Universe begins to resemble that which we see today. Around 8 to 9 billion years after the Big Bang our own solar system is formed, with life evolving just one billion years after the formation of the Earth.
So while we have a fairly decent idea of how the Universe came to be it is quite apparent that there are a large amount of unanswered questions. Undoubtedly these will be solved in time. The Universe does however give us a lot more to work with in regards to how our solar system was made, and what the Universe was like to begin with than you might think. If you take into account the speed of light when we look out at the systems outside the Milky Way it is effectively like looking back in time as it has taken light millions, if not billions of years to reach Earth. The further out we look, the further back in time we’re looking.
As scientific theory advances and experiments are more detailed it’ll be interesting to see if there are any significant advances in the Big Bang theory and if any questions on the origin of our Universe are answered. When the Large Hadron Collider is switched on at CERN we may have some of these answers, and it’ll be interesting to see what conclusions are drawn.
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