FINELY TUNED UNIVERSE: Is it by the creation or accident?

We humans have been asking one of the common questions, “Are we alone in the Universe?”. Various researchers and cosmologists have concluded that we may not be the only ones. Then, If we are not alone, why we have not discovered other life so far? Almost all of us believe that “Aliens,” are the ones. Actually, we should keep note that we refer them as we might not know what they are actually. We believe that they are far more advanced than us or they might see us as primitive. But nobody has ever thought of Aliens being intellectually similar to us and even lesser than us. To this, I think that my claim is also not that illogical. Till now, it seems that we are the only intelligent being in this universe.

Cosmologists haven’t finished asking what actually was the beginning of the Universe. What actually happened at t=0? Why Universe expands so fast that the Universal Law of Gravitation and Quantum mechanics can’t account for all? What actually happened at the verge of the start of the Universe? How Universe chose the value of constants like the Gravitational constant? Speed of light? Fine Structure constant? Planck constant? What is the Ultimate composition of the Universe? And more noticeably the question: Why the Universe is the way it is? And why is appears to be finely tuned? In this article, I will try to express some of the finely tuned parameters that hold true for our Universe. If not, it would result in a completely different Universe.

1. Dark Energy and Gravity

Newton and Einstein gave quantitative and geometrical descriptions of the one of Universe’s fundamental forces: gravity. Gravity is what stuff in Universe are kept in place the way it is. It is the force which accounts for the apple falling from the tree, planets revolving around the sun, and the moon around the earth, that keeps hair straight down, humans firmly attracted towards the surface. It is the force, which attracts each other. According to Newton’s law of universal gravity, the force is dependent on the masses of bodies for which it is accounted. But, the truth is Universe is found to be expanding exponentially. 

To account for the anomalies in the current expansion rate against known laws of physics, Physicists and cosmologists believe so-called the negative energy “dark matter,” pushes the stuff outward opposing gravity. But the intensity is so low that it becomes significant only on large scale like Universe as a whole. But what would have happened if either gravity or dark energy strength been slightly different than what it is for our Universe? 

If the gravity is a little stronger than what it is, it would have been too strong for the dark energy to counteract, so it might have resulted in the clumping of masses into infinite densities resulting in Blackholes not suitable for intelligent life. On the contrary, if dark energy is a little stronger than gravity, it would have resulted in a high expansion rate taking away masses from each other making it impossible for galaxies, planet systems, clusters, and stars to form. Therefore, there is obviously no chance of intelligent life to exist so isolated from the star.

2. Neutron-Proton ratio

If we carefully see the trend in the periodic table, the lighter elements till Calcium(Z=20) have almost similar numbers of neutron(s) and proton(s) such that the neutron-to-proton ratio (n/p) is exactly equal to or nearly equal to one (n:p = 1:1). After that, the ratio drastically increases up to 1.58 at the highest Z(Atomic Number which is equal to the proton number; p). The n:p ratio is so important as it determines the stability of the nucleus. A nucleus is said to be unstable if n:p ratio is less than 1 or greater than 1.5. In short, the forces which make the nucleus balanced, it is said to be a stable nucleus. If not, a nucleus having too few or too many neutrons is considered to be unstable. In terms of binding energy per nucleon, Iron(Fe) has the highest(which means most stable) and then it decreases. As the stronger nuclear force is governed by gluons and weak by W and Z bosons, the stronger nuclear force holds up neutral neutrons and protons together as well as protons together (overcoming repulsive forces due to positive charge within protons). But, for a nucleus having higher (n:p) than 1.5, weak force simply takes over and therefore undergoes radioactive decay. As, the compositions of the early Universe were Helium and Hydrogen, they are made up of a highly stable nucleus which makes it possible to remain stable and formed stars. If not, Universe might not be possible to form.

Fig: Binding Energy graph

Image source:https://www.researchgate.net/figure/Binding-energy-per-nucleon-B-Z-N-A-as-a-function-of-the-mass-number_fig1_234065870

   

3. Ratio of electromagnetic force to the gravitational force between two protons

We know that the ratio of electromagnetic force to the gravitational force between two protons is in order of 10^{36}. If it is slightly lower, it would have resulted in a small and short-lived universe. 

4. Hoyle Sate: Carbon and Oxygen

The third lowest energy state of carbon 12 (C12) is 7.756MeV above ground level. If it is lower than 7.3 or greater than 7.9MeV, then, carbon would have been unstable and not sufficient to support life. For carbon to remain abundant, its value should be between 7.596 and 7.716 MeV. For continuous production of carbon and oxygen, the strong force should be tuned to the precision of 0.5% and gravitational force to at least 4%. 

Fig: Process and the formation of 12C

Image: https://www.semanticscholar.org/paper/Towards-the-pair-spectroscopy-of-the-Hoyle-state-in-Kib%C3%A9di-Stuchbery/8eb143f3a91e904624f440c96584b434e04165c5/figure/0

5. The value of Cosmological constant

Lambda, commonly known as the Cosmological Constant describes the ratio of the density of dark energy to the critical energy density of the universe, given certain reasonable assumptions such as that dark energy density is a constant. In terms of Planck Units, and as a natural dimensionless value, is on the order of 10^{-122}. This is so small that it has no significant effect on cosmic structures that are smaller than a billion light-years across. A slightly larger value of the cosmological constant would have caused space to expand rapidly enough that stars and other astronomical structures would not be able to form.

Conclusion

Through these examples, we have seen how well our universe is being tuned and how little deviations from the value would rise to a completely different universe unfit for formation or life. Therefore, it is obvious that we should be grateful for the probability that it has been tuned to this way. I am always blown up by how beautifully the universe is being organised. And it will continuously be one of the exciting moments to learn what led to the tuning. Is it by the creation or by accident?