The Laws of physics and constants, the initial conditions of the universe, the expansion rate of the Big bang, atoms and the subatomic particles, the fundamental forces of the universe, stars, galaxies, the Solar System, the earth, the moon, the atmosphere, water, and even biochemistry on a molecular level, and the bonding forces of molecules like Watson-Crick base-pairing are finely tuned in an extremely narrow range to permit life. In 2008, Hugh Ross mentioned 140 features of the cosmos, including the laws of physics, and over 1300 fine-tune parameters of a planetary system and its galaxy that must fall within extremely narrow ranges to allow for the possibility of advanced lifes existence. Since then, that number has doubled.
Roger Penrose estimated that the odds of the initial low entropy state of our universe occurring by chance are 1 in 10123 power. The incredibly low entropy state of the initial conditions had to be finely tuned and was required to avoid excessive black holes. The second law of thermodynamics arises because there was an enormous constraint (of a very particular kind) placed on the universe at the beginning of time, giving us the very low entropy that we need in order to start the universe. Why did it not begin in a high entropy, highly disordered state? Why did it start off in such a special, improbable, low-entropy state?
To put that in perspective: The distance to the edge of the observable universe is about 46 billion light-years in any direction. That means there would be roughly 10^102nd power of atoms if we filled the entire volume of the universe with atoms without leaving any space. An atom is 99,9% of empty space. If we would fill its entire space with protons, there would be 2,5^13 power of protons filling it. The odds to find one red proton in one hundred universes, the size of ours, filled with protons, is about the same as to get a universe with a low entropy state at the beginning, like ours. If we had to find our universe amongst an ensemble of almost infinite parallel universes, it would take 17000 billion years to find one which would be eventually ours.
Price, a philosopher of science at Cambridge, has called the low-entropy condition of the early universe “the most underrated discovery in the history of physics.”
But having a low entropy state is not the only parameter to kickstart the expansion of the universe. In the paper: Do We Live in the Best of All Possible Worlds? The Fine-Tuning of the Constants of Nature, states: The evolution of the Universe is characterized by a delicate balance of its inventory, a balance between attraction and repulsion. It mentions 4 parameters that must be finely tuned.
These physical factors are themselves independent of each other, and each must also be fine-tuned to the extreme. Together, the odds to have the right expansion rate is in the order above 10^400 power. That is picking one red atom amongst 4 entire universes the size of ours filled with atoms. But that will not guarantee us a universe, later filled with life. For that, we need atoms, and the periodic table, with heavy elements.
At the earliest stage of the universe immediately after the big bang no matter existed in the universe. It had only Energy and the Superforce, a Combination of 4 natural forces, that’s is Gravity, the strong nuclear, weak nuclear and electromagnetic force). Fast-forward a nanosecond or two and in the beginning there was a cosmic soup of elementary stuff - electrons and quarks and other particles.
There had to have been a mechanism to produce the various particles that makeup matter and stuff, all the elements, that make up galaxies, stars and planets, and us, instead of just one thing. There could have been a cosmos where the sum total of mass was pure neutrinos and all of the energy was purely kinetic. Right at the beginning of the Big bang, things were very hot, and had to cool down enough for the quarks, the subatomic particles, to bind together and form electrons, Neutrons and Protons.
Fine-tuning is necessary to form atoms. And all of these bits and pieces have to mesh like a clock - or even a watch. One can't just assemble these bits and pieces in just any way and expect things to work out. These processes are governed by the laws, principles and relationships of quantum mechanics, all of which had to come from somewhere or from something.
Protons and neutrons are made up from more fundamental particles, called quarks. Without the right configuration of these quarks, there would be no atoms, and no life. They are hold together by the strong nuclear force. Electrons are hold in their orbit by the electromagnetic force. And gravity is the large scale attractive force, which holds people on planets,stars, and galaxies together. The fundamental forces have to be in the right relationship to permit our universe to be filled with atoms. The strong force is approximately 137 times as strong as electromagnetism, 10 million times as strong as the weak interaction , and 10^38 power times stronger than gravity. Another very impressive fine-tuning occurs at the level of chemistry. All of chemistry is essentially defined by only two parameters, one is the electromagnetic force constant, also called fine-structure constant. Its value forms a deep mystery.
137 is the number that defines how stars burn, how chemistry happens and even if atoms exist at all. It is that electromagnetic force that holds electrons in their orbit. Increase it too much, and protons repel each other so strongly that small atomic nuclei can’t hold together. Go a bit further and nuclear fusion factories within stars grind to a halt and can no longer produce carbon, the element on which life is based. The two fundamental forces of gravity and electromagnetism need to be balanced on razors edge, and the radiation of the sun has to be finely tuned to permit life on earth.
It was this number that made Feynman making following statement: There is a most profound and beautiful question associated with the observed coupling constant. It is a simple number: about 137. It has been a mystery ever since, and all good theoretical physicists put this number up on their wall and worries about it. Immediately you would like to know where this number for a coupling comes from. It’s one of the greatest damn mysteries of physics: a magic number that comes to us with no understanding by man. You might say the “hand of God” wrote that number, and “we don’t know how He pushed his pencil.” We know what kind of a dance to do experimentally to measure this number very accurately, but we don’t know what kind of dance to do on the computer to make this number come out, without putting it in secretly! Good argued that a numerological explanation would only be acceptable if it could be based on a good theory that is not yet known but "exists" in the sense of platonic idealism. So science has no predictive model for our life-permitting universe.