Measurements made with today's technology have revealed that between 3 and 30 percent of the sunlight is reflected at the surface of the sea. Then, almost all of the seven colours of the light spectrum are absorbed, one after another, in the first 200 metres, except for blue light (picture at left). Below a depth of 1,000 metres, there is no light at all (above picture). This scientific fact was pointed out in Sura Nur 40 in the Qur'an 1,400 years ago.
In deep seas and oceans, the darkness is found at a depth of 200 meters and deeper. At this depth, there is almost no light, and below a depth of 1,000 meters there is no light at all.61
Today, we know about the general formation of the sea, the characteristics of the living things in it, its salinity, as well as the amount of water it contains, and its surface area and depth. Submarines and special equipment, developed with modern technology, have enabled scientists to obtain such information.
The picture to the left represents internal waves at interface between two layers of water of different densities. The lower layer is denser than the upper one. This scientific fact, declared in Sura Nur 40 of the Qur'an 14 centuries ago, has been discovered by today's scientists only very recently.
Human beings are not able to dive to a depth of more than 70 meters without the aid of special equipment. They cannot survive unaided in the dark depths of the oceans, such as at a depth of 200 meters. For these reasons, scientists have only recently been able to discover detailed information about the seas. However, that the depth of the sea is dark was revealed in the Qur'an 1,400 years ago. It is certainly one of the miracles of the Qur'an that such information was given at a time where no equipment to enable man to dive into the depths of the oceans was available.
In addition, the statement in Surat an-Nur 40 "…like the darkness of a fathomless sea which is covered by waves above which are waves above which are clouds…" draws our attention to another miracle of the Qur'an.
Scientists have only recently discovered that there are sub-surface waves, which "occur on density interfaces between layers of different densities." These internal waves cover the deep waters of seas and oceans because deep water has a higher density than the water above it. Internal waves act like surface waves. They can break, just like surface waves. Internal waves cannot be discerned by the human eye, but they can be detected by studying temperature or salinity changes at a given location.62
The statements in the Qur'an run parallel precisely the above explanation. Certainly, this fact, which scientists has discovered very recently, shows once again that the Qur'an is the word of Allah.
61. Danny Elder, and John Pernetta, Oceans (London: Mitchell Beazley Publishers: 1991), 27.
62. M. Grant Gross, Oceanography, A View of Earth, 6th ed. (Englewood Cliffs: Prentice-Hall Inc.: 1993), 205.