Air Pressure
Allaah The Almighty Says (what means):
{Whoever Allaah wants to guide, He opens his breast to Islam. Whoever Allaah wants to leave astray, He makes his breast narrow and confined, as if he is ascending into the sky. As such, Allaah gives torment to those who do not believe.}
(Quran, 6:125)
Scientific Analysis
Knowledge of the atmosphere's composition remained a mystery until the year 1648, when Blaise Pascal (1623-1662) confirmed that air pressure decreases as the distance above sea level increases.
It later became apparent that air was most concentrated in the lowest levels of the atmosphere. About 50% of atmospheric mass accumulates between 0 to 20,000 feet above sea level. That increases to 90% when it is between 0 to 50,000 feet above sea level. In other words, density will generally decrease with an increase in elevation.
Rarefaction of the air reaches its peak in the upper layers, just before dissipating completely into space.
When man is at an elevation less than 10,000 feet above sea level, there is no serious cause for concern. The respiratory system can acclimatize itself to elevations between 10,000 and 25,000 feet.
But as man rises into the sky, air pressure decreases and oxygen levels decline. This results in a feeling of tightness in the chest and severe difficulty in breathing (dyspnea), as well as a rise in the respiratory rate.
High elevation will also cause irregular breathing due to the sharp decline in oxygen levels (resulting in hypoxia). If he is unable to obtain a sufficient supply of oxygen to his body, his respiratory system will fail, and he will die.
The Miracle
It is indisputable that mankind, at the time of the revelation of the Quran, knew nothing of the atmosphere's gaseous composition and its various layers. Consequently, a decrease of air pressure in the upper layers and a decline in oxygen levels, to the point of unsustainability, was equally unknown. People were ignorant of the effects this would have on breathing and life, the results of which are respiratory failure and death.
Rather, the opposite belief was prevalent: that the further man ascends, the more open his chest becomes, and that he will only enjoy a more invigorating breeze the higher he goes.
This noble verse clearly indicates two truths only recently affirmed by modern science:
First, that the chest is tightened and breathing is restricted as man ascends through the atmosphere. It is clear that this is caused by a lack of oxygen and a decline in atmospheric air pressure.
Second, that this confinement (ḥaraj in Arabic), which precedes death by suffocation, was relatively recently determined to be at an elevation of 30,000 feet. This is due to a serious decline in air pressure and a dangerous lack of oxygen needed to sustain life, until oxygen is completely absent from both lungs thus leading to man’s death.
Without oxygen supply and a special pressurized suit, an astronaut would be unable to stay in space.
