From galaxies and stars down to atoms and subatomic particles, the very structure of our universe is determined by these numbers. These are the fundamental constants and quantities of the universe. If any one of these numbers were altered by even a 
hairsbreadth, no physical, interactive life of any kind could exist anywhere.

1.  Gravitational Constant

The gravitational constant controls the force binding matter together. If it varied by even 1 in 10^60, stars and planets couldn’t form. This is like filling billions of Milky Way galaxies with pennies and then blindly picking the one correct penny.

2.  Electromagnetic Force Constant

The electromagnetic force holds atoms together. If it changed by 1 part in 10^40, atoms couldn’t form. Imagine covering a continent in sand stacked to the moon—and then blindly finding the 1 correct grain.

3.  Ratio of Protons to Electrons

The proton-to-electron ratio keeps atoms stable. If it differed by 1 part in 10^37, matter couldn’t hold together. Imagine dealing yourself seven royal flushes in a row. That’s how improbable this is.

4.  Rate of Universe Expansion

The universe’s expansion rate lets galaxies form. If it varied by 1 part in 10^55, the universe would collapse or spread too thin. That’s like randomly picking the correct grain of sand from all sand on Earth 10 billion times in a row.

5.  Strong Nuclear Force Constant

The strong force binds protons and neutrons in atoms. If it changed by 1 part in 10^40, only hydrogen would exist or no atoms. Imagine covering a billion Earths in dimes stacked to the moon and finding the one correctly marked dime.

6.  Cosmological Constant

The cosmological constant governs expansion. If it varied by 1 part in 10^120, the universe would collapse or expand uncontrollably. This number is so vast that it’s nearly impossible to find an analogy to capture the sheer improbability of it.

7.  Initial Entropy of the Universe

The universe’s initial entropy allowed galaxies to form. If it varied by 1 part in 10^10^123, matter couldn’t organize. This number has more digits than there are particles in the universe—and it’s not even close.

The fact is, our universe permits physical, interactive life only because these and many other numbers have been independently and exquisitely balanced on a razor's edge.

What is the best explanation for this astounding phenomenon? There are three options.

The fine-tuning of the universe is due to either physical necessity, chance, or design. Which of these options is the most plausible? 

1.  Physical necessity

According to this alternative, the universe must be life permitting. The precise values of these constants and quantities could not be otherwise. But is this plausible? Is a life-prohibiting universe impossible? Far from it. It's not only possible; it's far more likely than a life-permitting universe. The constants and quantities are not determined by the laws of nature. There's no reason or evidence to suggest that fine-tuning is necessary. 

2.  Chance

How about chance? Did we just get really, really, really, really lucky? No; the probabilities involved are so ridiculously remote as to put the fine-tuning well beyond the reach of chance, so in an effort to keep this option alive, some have gone beyond empirical science and opted for a more speculative approach known as the multiverse. They imagine a universe generator that cranks out such a vast number of universes that, odds are, life permitting universes will eventually pop out. However, there's no scientific evidence for the existence of this multiverse. It cannot be detected, observed, measured, or proved, and the universe generator itself would require an enormous amount of fine-tuning.

Furthermore, small patches of order are far more probable than big ones, so the most probable observable universe would be a small one, inhabited by a single, simple observer. But what we actually observe is the very thing that we should least expect: a vast, spectacularly complex, highly-ordered universe inhabited by billions of other observers. So even if the multiverse existed, which is a moot point, it wouldn't do anything to explain the fine-tuning. 

3.  Design

Given the implausibility of physical necessity or chance, the best explanation for why the universe is fine-tuned for life may very well be it was designed that way.

"The heavens declare the glory of God; and the firmament sheweth his handywork. Day unto day uttereth speech, and night unto night sheweth knowledge. There is no speech nor language, where their voice is not heard." - Psalms 19:1-3 KJV

The Fine Tuning of the Universe Youtube