Jun 12, 2022
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Interesting facts about atmospheric pressure

Atmosphere pressure

Welcome to our website, dear readers. Atmospheric pressure, also called barometric pressure, is the force with which air presses on the earth’s surface and on everything that is on it. It can be measured with a barometer (hence the name barometric). And today we decided to take a closer look at this natural force. In the article we have collected the most interesting facts about atmospheric pressure.


It can be expressed in several international units of measurement: millimeters of mercury (mm Hg), pascals (Pa), bars (bar), pounds-force per square inch (psi), etc.


Normal pressure – 760 mm Hg. Art. At the surface of the Earth, the pressure decreases with height by about 3.5 millibars for every 30 meters. However, over cold air, its decline can be much more dramatic because its density is greater than that of warmer air. At an altitude of 270 km, it is comparable to the pressure in the best vacuum ever created by man. At an altitude of 1500 to 3000 m. y. m, it is low enough to cause altitude sickness and lead to serious physiological problems.

Number 3

This is not a constant value in the conditions of our planet. This is caused by the movement of air masses and its ability to create so-called baric vortices. For example, if in the Northern Hemisphere the air rotates clockwise, then this is called an anticyclone. An anticyclone is an area of ​​high atmospheric pressure. They bring us clear and cloudy weather, do not bring rain and winds. If it rotates in the opposite direction, then it carries cyclones (an area of ​​​​low atmospheric pressure), with heavy precipitation, thunderstorms, etc.

If we are talking about the Southern Hemisphere, then everything is exactly the opposite. If the wind turns clockwise, then it is a cyclone, and against it, it is an anticyclone.


At an altitude of 10,000 meters, the pressure is very low, about 210-220 mm Hg. Art. At the same time, the planes fly well, and passengers normally tolerate the flight at such a height. But what is the secret? The thing is that in passenger aircraft, the pressure is pumped up by compressors and is approximately 550 mm Hg. Art. Such pressure is equivalent if you were at an altitude of 2500-3000 m. y. m. Not ideal pressure, but for a person a short stay in such conditions is not critical. Inflate it to the level of 760 mm Hg. Art. not profitable due to too much difference in the cabin and outside. Because of this, the risk of depressurization and wear of the fuselage increases, and, accordingly, the durability of the aircraft itself decreases.


It is formed due to the force of attraction. Scientists have conducted many experiments and found that air has mass. It consists of a number of gases, which have their own specific weight. The air is influenced by the force of gravity of our planet, which contributes to the formation of atmospheric pressure.


At a pressure of 760 mmHg, a person feels as comfortable as possible. But it is worth noting that being in such conditions, the air pressure on a person is about 16 tons. The question immediately arises, why do we not feel anything?

This is due to the fact that in the process of evolution the human body (and the body of other living organisms) has adapted to such a load. There is pressure in our body too. All human organs have been formed and developed under the influence of this force and are prepared for such loads.


It has a significant effect on the human body. There is such a term as meteorological dependence. Meteopaths are those people whose body reacts even to minor deviations from the norm (in total, about 30-35% of the population belongs to this category of people on the planet). Meteopaths also include people with chronic diseases.


We cannot live without atmospheric pressure. Our body regularly uses this power. Every time we breathe, we use this power. The diaphragm is the most important muscle for inhalation. It alternately contracts and relaxes, thereby changing the pressure in the lungs and their volume. When the volume of our lungs increases, the pressure in them drops below atmospheric pressure. Accordingly, air begins to penetrate into our body. When the volume of the lungs becomes smaller, the pressure increases and the air leaves the body. This is how our breathing works, providing us with vital oxygen.


Some people, due to their profession, are forced to work underground or under water (miners, divers, etc.). Going deep into the mine, the miners are faced with increased atmospheric pressure. In very deep mines, the barometer may read 850 mmHg. The pressure under water is also much higher than atmospheric pressure. For example, when diving to about 100 meters, the pressure will be 9.7 bar or 7,275 mmHg. Art., which is almost 10 times the normal pressure.


Atmosphere pressure

Ice has the unique ability to melt at temperatures below 0 degrees Celsius. But you say how, because ice turns into water only when the ambient temperature rises above 0 degrees Celsius? Not really. Ice melts at zero temperature at normal atmospheric pressure. If the pressure is changed, the melting point will also change. For example, the pressure of skaters’ skates lowers the melting point of the ice, so a film of water usually forms under the skates. It is this film that reduces friction and allows skaters to glide across the ice so easily.


There is such a thing as the Armstrong Line (Armstrong Limit). This is a height (19 km) beyond which no one can survive. The reason for this is very low atmospheric pressure (6.3 kPa or 47.25 mm Hg). At this temperature, you need to wear an airtight suit, because without it, even ordinary water boils at a temperature of 36.6. Accordingly, a person without a suit at such a height will begin to boil the blood. If a person stays in such conditions for more than a minute, it will lead to death. This concludes our article, dear readers. Thank you for paying attention to our Internet resource.

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