What is the mass of air? The ancient scientists did not know the answer to this question. During the infancy of science, many believed that the air had no mass. In the ancient world and even in the early Middle Ages, numerous misconceptions related to a lack of knowledge and a lack of accurate instruments were widespread. Not only such a physical quantity as air mass was included in the list of funny misconceptions.
Medieval scholars (it would be more correct to call them curious monks), not being able to measure non-obvious quantities, quite seriously believed that light spreads in space infinitely quickly. However, this is not surprising. Science then interested very, very few. Much more people at that time gathered theological discussions on the topic "how many angels fit on the tip of a needle."
But as time went on, knowledge about the world was becoming more voluminous. Scientists already knew that everything in the world has weight, but they could not yet figure out what was the mass of air. And finally, in the eighteenth century, it was possible to calculate the density of air, and with it the mass of the entire earth's atmosphere. The total mass of air on our planet was equal to a number with seventeen zeros - 53x10 17 kilograms. True, this figure also includes the mass of water vapor, which is also part of the atmosphere.
Today it is believed that the Earth’s atmosphere is about one hundred and twenty kilometers thick, and the air is unevenly distributed in it. The lower layers are denser, but gradually the number of gas molecules constituting the atmosphere per unit volume decreases and disappears.
The specific gravity of air (density) at the Earth's surface under normal conditions is approximately one thousand three hundred grams per cubic meter. At an altitude of twelve kilometers, air density decreases by more than four times and already has a value of three hundred nineteen grams per cubic meter.
The atmosphere consists of several gases. Ninety-eight to ninety-nine percent are nitrogen and oxygen. In minor amounts, there are others - carbon dioxide, argon, neon, helium, methane, carbon. The first to determine that air is not gas, but a mixture, Scottish scientist Joseph Black in the mid-eighteenth century.
At altitudes of more than two thousand meters, both atmospheric pressure and the percentage of oxygen in it decrease. This circumstance has become the cause of the so-called "altitude sickness." Doctors distinguish several stages of this disease. In the most severe case, it is hemoptysis, pulmonary edema, and death.
The internal pressure of the human body at high altitude becomes much greater than atmospheric, and the circulatory system begins to fail. The capillaries are the first to break.
It has been established that the height limit that people can endure without an oxygen device is eight thousand meters. Yes, and up to eight thousand can only reach a well-trained person. Long-term residence in high altitude conditions negatively affects health. Doctors observed a group of Peruvians living for generations at an altitude of 3, 500-4, 000 meters above sea level. They noted a decrease in mental and physical performance, there are changes in the central nervous system. That is, the highlands are not adapted for human life. And a person cannot adapt to life there. Yes and whether it is necessary?
