In the Qur'an, Allah Almighty calls our attention to a very important attribute of the sky: "We made the sky a preserved and protected roof, yet still they turn away from Our signs." [21:32]
This attribute of the sky has been proved by scientific research carried out in the 20th century: The atmosphere surrounding the Earth serves crucial functions for the continuity of life. While destroying many meteors - big and small - as they approach the Earth, it prevents them from falling to Earth and harming living things.
In addition, the atmosphere filters the light rays coming from space that are harmful to living things. The most striking feature of this function of the atmosphere is that it lets only harmless and useful rays-visible light, near ultraviolet light and radio waves pass through. All of this radiation is vital for life. Near ultraviolet rays, which are only partially let in by the atmosphere, are very important for the photosynthesis of plants and for the survival of all living things. The majority of the intense ultraviolet rays emitted from the Sun are filtered out by the ozone layer of the atmosphere. Only a limited and essential part of the ultraviolet spectrum reaches the Earth.
The protective function of the atmosphere does not end here. The atmosphere also protects the Earth from the freezing cold of the space, which is approximately -2700C (-4540F).
It is not only the atmosphere that protects the Earth from harmful effects. In addition to the atmosphere, the Van-Allen Belt - the layer caused by the magnetic field of the Earth - also serves as a shield against the harmful radiation that threatens our planet. This radiation, which is constantly emitted by the Sun and other stars, is deadly to living things. If the Van-Allen belt did not exist, the massive outbursts of energy called solar flares that frequently occur in the Sun would destroy all life on Earth.
On the importance of the Van-Allen Belt, Dr. Hugh Ross says:
"In fact, the Earth has the highest density of any of the planets in our Solar System. This large nickel-iron core is responsible for our large magnetic field. This magnetic field produces the Van-Allen radiation shield, which protects the Earth from radiation bombardment. If this shield were not present, life would not be possible on Earth. The only other rocky planet to have any magnetic field is Mercury—but its field strength is 100 times less than the Earth's. Even Venus, our sister planet, has no magnetic field. The Van-Allen radiation shield is a design unique to the Earth. (The Incredible Design of the Earth and our Solar System)
The energy transmitted in just one of these bursts detected in recent years was calculated to be equivalent to 100 billion atomic bombs, each akin to one dropped on Hiroshima at the end of World War II. Fifty-eight hours after the burst, it was observed that the magnetic needles of compasses displayed unusual movement and 250 kilometers (155 miles) above the Earth's atmosphere, the temperature suddenly increased to 25,000C (45,320F).
In short, a perfect system is at work high above the Earth. It surrounds our world and protects it against external threats. Centuries ago, Allah Almighty informed us in the Qur'an of the world’s atmosphere functioning as a protective shield.
The sky made a dome
"[He] who made for you the earth a bed [spread out] and the sky a ceiling and sent down from the sky, rain and brought forth thereby fruits as provision for you. So do not attribute to Allah equals while you know [that there is nothing similar to Him]." [Qur’an 2:22]
Here, the sky is described as "as-Samaa’ binaa’." As well as the meaning of "dome" or "ceiling," this also describes a kind of tent-like covering used by the Bedouin. By describing the sky as a tent-like structure, the Qur’an is emphasizing that it is a form of protection against external elements.
Even if we are generally unaware of it, a large number of meteors fall to the Earth, as they do to the other planets. The reason why these make enormous craters on other planets but do no do harm on Earth is that the atmosphere puts up considerable resistance to a falling meteor. The meteor is unable to withstand this for long and loses much of its mass from combustion due to friction. This danger, which might otherwise cause terrible disasters, is thus prevented by the atmosphere. Besides the verses regarding the protective properties of the atmosphere cited above, attention is also drawn to the special creation in the following verse:
"Do you not see that Allah has subjected to you whatever is on the earth and the ships which run through the sea by His command? And He restrains the sky from falling upon the earth, unless by His permission. Indeed Allah, to the people, is Kind and Merciful." [Qur’an 22:65]
The protective property of the atmosphere protects the Earth from space, in other words, from external elements. With the word "dome," referring to the sky in the above verse, attention is drawn to this aspect of the sky, which could not possibly have been known at the time of our Prophet sallallaahu `alayhi wa sallam ( may Allah exalt his mention ). The fact that this information was imparted 1,400 years ago in the Qur’an, when there were no spacecraft or giant telescopes, shows that the Qur’an is the revelation of our Lord, the Omniscient.
The sky that returns
The verse 11 of at-Tariq (Chapter 86) refers to the "returning" function of the sky: "By the sky which returns.” [Qur’an 86:11]
The word "raj'" interpreted as "return" in Qur’an translations has meanings of "sending back" or "returning." As is known, the atmosphere surrounding the Earth consists of many layers. Each layer serves an important purpose for the benefit of life on Earth. Research has revealed that these layers have the function of turning the materials or rays they are exposed to back into space or back down to the Earth. Now let us examine, employing a few fitting examples, this "returning" function of the layers encircling the Earth.
The troposphere, 13 to 15 kilometers (8 to 9.3 miles) above the Earth, enables water vapor rising from the surface of the Earth to be condensed and turned back as rain. The ozone layer, the lower layer of stratosphere at an altitude of 25 kilometers (15.5 miles), reflects harmful radiation and ultraviolet light coming from space and turns both back into space.
The ionosphere reflects radio waves broadcast from the Earth back down to different parts of the world just like a passive communications satellite. Thus, it makes wireless communication, radio, and television broadcasting possible over long distances. The magnetosphere layer turns the harmful radioactive particles emitted by the Sun and other stars back into space before they reach the Earth.
The fact that this property of the atmosphere's layers, that was only demonstrated in the recent past was announced centuries ago in the Qur’an, once again confirms that the Qur’an is Allah's Word.