Everyone knows that the surface of the Earth is surrounded by a layer of air.It is located on the surface of the planet for tens and hundreds of kilometers up.But the amazing properties of surface air is extremely interesting.The air around us is so weightless, transparent and invisible, that people did not even realize that he has a permanent impact on all living things.
first pay attention to this in 1640.The occasion was broken fountain on the terrace of the palace of the Duke of Tuscany.Water is not able to raise a considerable height.Explanation of the phenomenon suggested Torricelli.They have suggested that there is the air pressure which acts on all located on the earth's surface.To confirm his thoughts, he took a glass tube, one end of which was sealed, and filled it with mercury.The free end of the tube Torricelli put into a flat container with mercury.
Mercury in the container fell, its height above the surface of the bowl was 760 millimeters.Since it was first proved that there is atmospheric pressure, and barometric pressure are measured.It is measured in millimeters of mercury.Sincemercury column was the first device of this type, the measured pressure so called barometric.It explains the result is simple - the air pressure on the surface with a force equal to the weight of the mercury column height of 760 millimeters.
These findings were confirmed by the French scientist Pascal.He suggested that the air pressure depends on the height above the ground.The higher the pressure should be less.His measure he spent with tubes filled with water.They were taken to the mountain, and there was an experiment.The results proved the assumption Pascal - raising the level of water in the tube on top of the mountain was less than at the surface.
If so deeply immersed in the history of the discovery of atmospheric pressure, it is necessary to recall the experience carried out in 1654 in the city of Magdeburg German scientist Otto von Guericke.He took the two hemispheres, joined them together and pumped out of the internal volume of air.Two teams of horses, each of which pulled in different directions, could not separate from one another hemisphere.That's how hard they squeezed the air pressure.
This experience can be regarded as decisive proof of the assumption of the presence of atmospheric pressure.In the future, the scientists involved in the study of the atmosphere and directly influenced by barometric pressure on the body of humans and animals.Do not forget about the study of weather and its relation to atmospheric pressure.Pressure measurements were performed at different heights, in different territories, identify patterns and air pressure due to natural phenomena
now to measure the pressure tube is not used with mercury and aneroid special.His foundation, the air pressure sensor is a metal box with a corrugated surface, which is attached to the arrow pointing to the scale of the instrument air pressure.This arrangement itself is much more compact mercury barometer and can be used in difficult field conditions.
I must say that the discovery and further investigation of the atmospheric pressure has played a huge role in the study and understanding of many processes occurring on Earth.Changes in weather, cyclones and anticyclones, the impact of weather on the human body is largely due to changes in atmospheric pressure.So our current knowledge about the world and health based on the findings of brilliant medieval scholars.
There has been considered the origin and history of the study of such concepts as the air pressure.Describes the experiments were performed to confirm the time for the new theory describes how the measurement is air pressure.
