What if the Big Bang theory is wrong? – An Introduction To Quantum Gravity
Two scientists Dr Ahmed Farag Ali and Professor Saurya Das have shaken up the world of quantum physics with http://www.sciencedirect.com/science/article/pii/S0370269314009381” target=”_blank”>a paper that was published in January 2015. They attempted to combine two fundamental theories which underpin the way that our Universe works. These are Quantum Theory and Einstein’s Theory Of General Relativity.
Quantum theory – This explains the microscopic constituents of nature and the way that they interact.
General Relativity – This deals with gravity, and specifically the curvature of space-time and the way this effects large objects.
Both theories work extremely well in their own domain – the problem is (and it is a huge problem) that they are mutually incompatible. They simply do not work when combined. The rules of quantum mechanics cannot be applied to gravity. Consider for example Stephen Hawkin’s discovery that black holes (which are extremely dense pockets of gravity, so intense that light cannot even escape them) radiate photons. Let me repeat that. Black holes emit particles.
“The Big Bang singularity is the most serious problem of general relativity because the laws of physics appear to break down there,” says Ali.
The scientists did not set out to disprove the Big Bang theory at all. They were looking at building a framework of rules that would incorporate both of these theories. They used work published by Bohm to make quantum ‘corrections’ in equations put together by Raychaudhuri (which describes the motion of nearby particles of matter). We will briefly quote the two bodies of work that they used here.
In this paper we systematically develop an ontology that is consistent with the quantum theory. We start with the causal interpretation of the quantum theory, which assumes that the electron is a particle always accompanied by a wave satisfying Schrodinger’s equation. This wave determines a quantum potential, which has several qualitatively new features, that account for the difference between classical theory and quantum theory.
Raychaudhuri equations play important roles to describe the gravitational focusing and space-time singularities. Amal Kumar Raychaudhuri established it in 1955 to describe gravitational focusing properties in cosmology. When the star is heavier than a few solar masses, it could undergo an endless gravitational collapse without achieving any equilibrium state. The final outcome of gravitational collapse of a massive star must necessarily be a black hole which covers the resulting space-time singularity and causal message from the singularity cannot reach the external observer at infinity. In this article Raychaudhuri equations are derived with the help of general relativity and topological properties. An attempt has been taken here to describe gravitational focusing and space-time singularities in some detail with easier mathematical calculations.
When Ali and Das used Bohm’s theories to correct Raychaudhuri’s equations for quantum use, they came up with a Universe that is potentially smaller than we have thought, noting that it that was not infinitely dense.
It suggests that the Universe has actually existed forever, rather than forming at a single infinitely dense point as the Big Bang theory suggests. They are clear that this is not a complete theory of quantum physics but say that it can work with future paradigms.
Limitations of the Big Bang Theory
As well as the issue mentioned earlier regarding General Relativity not fitting in with this theory, scientists are also completely unable to say what happened before the Big Bang or what caused it.
Dark Matter and Dark Energy
Ali and Das’ research helps to shed light on some fascinating quantum mysteries, including dark matter and dark energy. These terms were coined by scientists to name the majority of matter in the Universe that we can not explain. Matter as we know it makes up a tiny percentage of the universal content, leaving 95% that we have very little understanding about.
Ali and Das believe that a mind blowing substance is present in the universe, known as the Bose-Einstein Condensate. Put simply it is a dilute gas of bosons cooled to an extremely low temperature. This is thought to be the coldest thing in the Universe, close to absolute zero (0 K or −273.15 °C). Under these extreme conditions, the particles behave in a way consistent with macroscopic phenomena.
The wave patterns within this condensate could provide an explanation for the dark energy content. They suggest that massive gravitons could be the matter that make up this condensate.
So this a quantum fluid that they believe fills the ‘space’ in the universe may be composed of theoretical particles known as gravitons. These particles are thought to emit gravity in the same way that protons transmit electromagnetic energy.
Gravity has infinite range and can bind galaxies together, so the gravitons would therefore have zero mass. Gravity also works in space where there is no electrical charge, meaning that gravitons would be neutral in order to operate. They would also only attract particles rather than repel. Here on Earth, the gravitational pull is relatively weak, especially when compared to electromagnetism. For example the electromagnetic pull between two particles exerts more pressure on them than the gravitational pull.
If gravitons exist it would mean that the Earth emits gravitons, which emit a downward force on objects. It is possible to disrupt the force exerted by the gravitons with other forces.
The following is quoted from Ali and Das’ research.
We show that Dark Matter consisting of bosons of mass of about 1eV or less has critical temperature exceeding the temperature of the universe at all times, and hence would have formed a Bose-Einstein condensate at very early epochs. We also show that the wavefunction of this condensate, via the quantum potential it produces, gives rise to a cosmological constant which may account for the correct dark energy content of our universe. We argue that massive gravitons or axions are viable candidates for these constituents. In the far future this condensate is all that remains of our universe.
In summary the research by Ali and Das opens up the study of Quantum Gravity to further investigation. They have put a spot light on theories that had come to be accepted as fact and reminded us to look further into the great mysteries of the Universe. What do you think? Are you a supporter of the Big Bang?
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