As we have already said elsewhere in this book, the Arabic word, ``SAMAA'' has been used with various meanings in Qurän, like; overhead, the whole universe, the solar system; and here it means the atmosphere, or the ocean of air, which surrounds our globe.

      Frank Alen, the professor of physic, has said that the atmosphere consists of gases which protect our life. The air has such a volume and height that can do as a chain mail in protecting the earth against the rush of some twenty millions pieces of deathful meteores everyday. These transient celestial bodies, large and small, enter the atmosphere with a great velocity of 50Km per second. They possibly may hit the earth in a collision and cause calamities by their clashes, but the sky is usually protected from such a danger wisely. When the meteore reach the atmosphere, through the power of friction with the particles of the air, they become enormously hot and then melt and finally turn to ashes and fine particles before coming down to the earth. However, there are occasions when a remainder or residue of them do reach the earth. As an instance of this, in 1908 one such great meteore hit the ground in Siberia in a part of Soviet Russia, the diameter of which covered a length of 40 miles and caused a great casualty:

      ``And We made the sky a protected ceiling, and they turn away from its signs.''