The Mountains as Pegs
Allaah The Almighty Says (what means):
{We made the mountains as pegs.}
(Quran, 78:7)
Scientific Analysis
Mountains were once thought to be massive piles of rock towering over the earth. That was until 1735, when French geophysicist Pierre Bouguer (1698-1758) noted that the gravitational force in the Andes was much less than expected, considering the apparent size of these “piles of rock”. This led him to believe that another part of the rock was buried beneath the earth, thus compensating for the variations in gravity.
In the middle of the nineteenth century, Welsh geographer Sir George Everest (1790-1866) noticed the variation in gravitational measurements between two different spots in the Himalayas. But he was unable to explain this phenomenon, viewing it instead as one of India's mysteries.
Sir George Airy (1801-1892) concluded in 1865 that all mountain chains are masses floating on magma, and that this molten material is denser than the mountains themselves. As a result, the mountains must “plunge” into this high density material to maintain their erect structure.
Geologists discovered that the earth's crust is composed of adjacent continental plates; that massive mountains float along a sea of higher-density molten magma; and that mountains have roots to help them float and to affix them to the plates so the earth will not shake. Geologist Oscar Diedrich Engeln (1880-1965) stated in his book Geomorphology (p. 27) that according to the current understanding, each mountain must have its own root beneath the earth's crust.
The principle of hydrostatic equilibrium, regarding the way in which mountains are affixed to the earth's crust, was mentioned in 1889 by Clarence Dutton (1841-1912). He stated that mountains plunge into the earth in accordance with their height. After the existence of plates was proven in 1969, it became clear that mountains maintain the balance for every plate.
The Miracle
At the time of man's ignorance about the nature of mountains, which lasted until the mid-nineteenth century, the Quran decisively stated the fact that mountains are like pegs in form and function, driven into the earth. This was only recently confirmed by modern science.
A peg has two parts: the first part is on the surface, while the other is underground, stabilizing whatever is attached to it. Similarly, a mountain has one part protruding from the crust of the earth, while the other is buried deep beneath the ground in accordance with its height. Its function is to stabilize the plates of the earth's crust and prevent them from disarray due to the magma beneath.
This is another indication that the Quran is the Speech of Allaah, The Maker of mountains and universes. He Says (what means): {He cast into the earth anchored mountains, lest it shake with you, and rivers and paths that you might be guided.} (Quran, 16:15)