When it comes to the world’s cosmic origins, there have been a number of theories that have advanced throughout the course of history. Most cultures and regions of the world have had their own mythological tradition, which naturally included a creation story, whether it was based on religion or science, or even a combination of both. With the birth of the Space Age, scientists began to understand the Universe in terms of its fundamental physical laws that could be tested and proven, to an extent.
The Steady-State model states that the density of matter in the expanding universe remains unchanged over time since matter is being continuously created. In other words, the observable Universe essentially remains the same regardless of time or place. This places it in sharp contrast to the theory that the majority of matter was created in a single event (the Big Bang) and has been expanding ever since.
Newton’s Mathematical Principles of Natural Philosophy (Philosophiæ Naturalis Principia Mathematica) published in 1687. He theorised that the Universe beyond the Solar System was an empty space that extended uniformly in all directions to immeasurable distances. He further explained through mathematical proofs and observations that all motion and dynamics in this system were explained through the single principle of universal gravitation.
Einstein formed the theory of special relativity to incorporate with gravity. As John Wheeler summarised it, “space-time tells matter how to move; matter tells space-time how to curve.”
By 1917, theoretical calculations based on Einstein’s field equations showed that the Universe had to be in either a state of expansion or contraction. By 1929, George Lemaitre (who proposed the Big Bang Theory) and Edwin Hubble (using the 100-inch Hooker telescope at the Mount Wilson Observatory) demonstrated that the latter was the case.
Based on these revelations, a debate began by the 1930s about the possible origins and true nature of the Universe. Some argued that the Universe was something that will end, and evolved over time through cooling, expansion and the formation of structures due to gravitational collapse. This theory was satirically named the “Big Bang” by Fred Hoyle, and the name stuck.
- Meanwhile, most astro-physicists at the time stuck to the theory that while the observable Universe is expanding, it nevertheless does not change in terms of the density of matter.They had argued that the Universe has no beginning, no end, and that matter is continuously being created over time – at a rate of one hydrogen atom per cubic meter per 100 billion years.
This theory also extended Einstein’s Cosmological Principle, proposed in 1931, the Cosmological Constant (CC). According to Einstein, this force was responsible for somewhat “holding back gravity” and ensuring that the Universe remained steady, homogenous, and isotropic in terms of its large-scale structure.
The Steady State theory became widely-known by 1948 with the publication of two papers:“The Steady-State Theory and the Expanding Universe” by the British-Austrian astrophysicist and cosmologist team, Hermann Bondi and Thomas Gold, and “A New Model for an Expanding Universe” by English astronomer Fred Hoyle.
Throughout history, many different theories have been proposed to explain the universe, some far more bizarre than others. The steady state model was just one of the many theories that have been proposed in the last century to explain where the universe came from and where it is heading. Looking back with the information we know now, it can sometimes be hard to believe that theoretical models such as these could have ever been thought of. After all, there are so many more gaps to fill in the fields of astrophysics. But this is science- for the past centuries, people have been coming up with new trendy theories but these get disproved with further evidence as we advance in technology. An obvious example is the history of the atom – there were so many proposed theories which were all changed and modified through further evidence. Who knows- there could be more theories to explain how the universe formed as we head further into the future.