What is the normal pressure of the atmosphere

Everyone knows that our planet is enveloped in an atmosphere, that is, a shell of air consisting of various gases, molecules of which are attracted to the Earth. Thus, the upper layers of the air exert pressure on the lower layers, as well as on the surface of the Earth and objects located on it. Thus, the mass of air causes normal atmospheric pressure.

The history of the discovery of atmospheric pressure originates in the seventeenth century, when scientists Torricelli conducted an experiment using mercury. As a result of this experiment, it was established that the more the height above the Earth increases, the smaller the AD. So the formula was developed, according to which it is possible to calculate the pressure dependence on the lift height above the Earth level.

Thus, the normal pressure of the atmosphere is 760 mm Hg. However, on the Earth's surface, atmospheric pressure can vary, depending on the location and time. This is especially important in determining the weather conditions that are associated with the development of high pressure areas and a rapidly moving air mass with low pressure inside.

Thus, the pressure of the atmosphere is a changeable element, and depends on the height and density of the air column, as well as the force of gravity in a certain place and time interval. But, despite the variability, the average monthly air pressure on the Earth's surface is the same every year. The closer to the equator, the blood pressure is lower, so you can argue that its indicators affect the geographical location of the terrain, the time of the year and the time of day. Thus, the maximum value of atmospheric pressure is observed at ten o'clock in the morning and in the evening, while the minimum value is at three o'clock in the morning and of the day.

It can be said that atmospheric pressure fluctuates depending on the height above the Earth and weather conditions, while the normal pressure of the atmosphere is a constant value.

AD is measured by special instruments called barometers, which in their structure are similar to Torricelli's device, which made discovery in science. The normal pressure (mmHg) can also be measured with this device. The mercury barometer has the most accurate pressure readings, its only drawback is its fragility. At present, metal barometers or aneroids are widely used.

Atmospheric pressure has the ability to influence the human body. So, in the case of reducing air pressure in humans, there is an increase in respiration and heart rate, as well as a decrease in blood pressure. The basis of the negative effect of BP on a person is oxygen starvation, because a decrease in the pressure of the air helps to reduce the concentration of oxygen, so it enters the human body in smaller quantities, resulting in anoxemia. This phenomenon can be observed in the presence of work associated with the rise to a greater height. However, the normal pressure of the atmosphere does not affect the state of the human body in any way.

Oxygen starvation causes dizziness, nausea and vomiting, impaired coordination of movements and rapid fatigue. Moreover, gases that are in the gastrointestinal tract, stretch the internal organs, and the state of the diaphragm changes, which leads to shortness of breath and disruption of the heart and vessels.

High blood pressure can cause headache, pain in the heart area, increased blood pressure, leading to angina or tachycardia. All changes in the human body occur at a high rate of change in the air pressure index.

Thus, the normal air pressure is one bar. The atmospheric pressure itself is not constant, it varies with the time of the year and day, the altitude above sea level, the geographic location of continents and oceans.