Did the Big Bang really happen?
The Big Bang is a concept familiar to many. It seems Brian Cox is contractually obliged to mention it whenever he talks publicly, while the phrase has even made its way into the English language to mean a sudden beginning. A new idea suggests the Big Bang may never have happened though, and that the universe could have existed – perhaps for an infinitely long time – with no beginning.
The current scientific belief is that before the Big Bang, there was nothing. In an instant, time, space, matter and all of existence were created from an infinitely dense point, known as a singularity. Alexander Friedmann developed the Freidmann Equations in 1924 from Einstein’s highly accurate theory of General Relativity. These equations show the universe to be expanding and, because expanding objects usually have a starting point, it was inferred that the universe started from a singularity.
The laws of physics, however, break down in the moments before and during the Big Bang, which makes it impossible for accurate mathematical models to be created. Many scientists have been troubled by the notion that there was absolutely nothing before the Big Bang; how could it occur if there was nothing to trigger it?
A famous problem in physics is the issue of “Quantum Gravity”, the attempt to merge Einstein’s General Relativity with Quantum Theory. Saurya Das of the University of Lethbridge, Canada and Ahmed Farag Ali of Benha University, Egypt have published a paper in Physics Letters B that tweaks the Friedmann equations to include quantum effects.
Their study implies the universe cannot have started from a single point, and consequentially must have existed forever. In the past, the end of the universe has been proposed to be a “Big Crunch”. This is essentially a reversed version of the Big Bang, where it expands, pauses and then starts to shrink into an infinitely dense singularity. This scenario would also never occur according to this new research, and so the universe may exist without beginning and also without end. According to the paper, the equations suggest a static universe, with a finite size but an infinite age.
The paper also suggests a “cosmological constant”, an idea Einstein touched on that removes the need for dark matter and dark energy to be included in new theories of astrophysics. The tweaks Ali and Das made to the Friedmann equations do appear to be supported by several measures of the current cosmological constant and density of the universe.
Does this mean the Big Bang never happened and all of the textbooks need to be rewritten? No, not quite. The authors say that they did not set out with the intention of removing the Big Bang – it happened purely as a result of the equations. Since publication, this paper has attracted a lot of attention, but critics point out that a universe without beginning is not a new idea. In fact, even the phrase “Big Bang” was coined by Fred Hoyle to poke fun at the thought of the universe beginning from a single point.
The Big Bang won’t be discarded any time soon. It is a very robust theory and has survived for over 100 years thanks to the weight of evidence behind it. Two of the strongest arguments are the cosmic microwave background and the red shifting of distant light, which have both been verified time and time again.
Scientific knowledge is constantly evolving to incorporate new evidence. These ideas, whether or not they turn out to be correct, provide a fresh angle for viewing the universe and could even be a tentative first step on the road to a theory of Quantum Gravity.
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