THE SEAS NOT MINGLING WITH ONE ANOTHER
A satellite photograph of the Strait of Gibraltar.
One of the properties of seas that has only recently been discovered
is related in a verse of the Qur'an as follows:
He has let loose the two seas, converging together,
with a barrier between them they do not break through. (Qur'an,
This property of the seas, that is, that they
meet and yet do not intermix, has only very recently been discovered
by oceanographers. Because of the physical force called "surface
tension," the waters of neighbouring seas do not mix. Caused by
the difference in the density of their waters, surface tension prevents
them from mingling with one another, just as if a thin wall were
It is interesting that, during a period when there was little knowledge
of physics, and of surface tension, or oceanography, this truth
was revealed in the Qur'an.
There are large waves, strong currents, and tides in the
Mediterranean Sea and the Atlantic Ocean. Mediterranean
Sea water enters the Atlantic by Gibraltar. But their temperature,
salinity, and densities do not change, because of the barrier
that separates them.
60. Richard A. Davis, Principles
of Oceanography (Don Mills, Ontario: Addison-Wesley Publishing Company),