Atmospheric pressure and oxygen levels in Quran

[ميس أحمرو]

I have a quiz just for the clever

God says in The Holy Quran:

“125 So whoever Allah wants to guide - He expands his breast to [contain] Islam; and whoever He wants to misguide - He makes his breast tight and constricted as though he were climbing into the sky. Thus does Allah place defilement upon those who do not believe.” Surat Al-An’am

The question is:

If Mohammad PBUH was the writer of the Quran, how did he know that when a person moves up in altitude his/her chest contracts, in which modern science has proven?

Modern science says that, Atmospheric pressure and inspired oxygen pressure fall roughly linearly with altitude to be 50% of the sea level value at 5500m and only 30% of the sea level value at 8900m (the height of the summit of Everest).

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1114067/

Also modern science talks about “Altitude sickness” which is a pathological effect of high altitude on humans, caused by acute exposure to low partial pressure of oxygen at high altitude. It commonly occurs above 2,400 metres (8,000 feet). It presents as a collection of nonspecific symptoms, acquired at high altitude or in low air pressure, resembling a case of "flu, carbon monoxide poisoning, or a hangover" Wikipedia

http://en.wikipedia.org/wiki/Altitude_sickness

How did the Prophet know that when a person goes up in altitude, the atmospheric pressure declines as well as the amount of oxygen that gets entered into his system due to the thinning of air. As the oxygen content declines he has trouble breathing and Hypoxia because his chest contract against his lungs?