According to standard cosmology model, the initial state of the space-time, and thus gravity, of the early universe had very low entropy[1]. The ‘mass-energy’ of the initial universe had to be precise to get galaxies, planets, and for us to exist. The most extreme example of fine-tuning has to do with the distribution of mass-energy at that time.
Just how precise?
The odds of a low-entropy state to exist by chance alone are one out of 1010^123 – the Penrose number. Let us try to get an idea of what type of a number are we talking about? You don’t have enough particles in the universe (that we know of) to write down all the zeroes! This number is so large, that if every zero were 10 point type, it will fill up a large portion of our universe! That is why we will explain it with three illustrations:
First, balancing a billion pencils all simultaneously positioned upright on their sharpened points on a smooth glass surface with no vertical supports does not even come close to describing an accuracy of one part in 1060.
Second, this is much more precision than would be required to toss a dart and hit a penny across the universe!
Third, cover America with coins in a column reaching to the moon (380,000 km or 236,000 miles away), then do the same for a billion other continents of the same size. Paint one coin red and put it somewhere in one billion of the piles. Blindfold a friend and ask her to pick the coin. The odds of her picking it are 1 in 1037.
All these numbers are extremely small when compared to the precise fine-tuning of the Penrose number, the most extreme example of fine-tuning that we know of.
In summary, the fine-tuning of many constants of physics must fall into an exceedingly narrow range of values for life to exist. If they had slightly different values, no complex material systems could exist. This is a widely recognized fact.
