About Air Pressure

Air pressure is defined by Webster's dictionary as the weight of air calculated by the force exerted per unit area. Although this formula is probably foreign to most people, the uses for air pressure are not. Air pressure is used to blow up tires, pump spray cans and fill gas tanks. It helps sustain the diverse tastes of humanity, and is an essential part of modern life.

Features

Air pressure is made up of tiny particles of air. It is colorless and odorless. Although it is all around us, we rarely feel it unless it's being forced through, up or by something.

History of

Physicists Evangelista Torricelli is the first person to discover the existence of air pressure. He did it in the early 1600s through a series of experiments involving a vacuum. Torricelli was trying to solve a practical problem presented by pump makers trying to lift water using piston pumps higher than 30 feet in one cycle. After filling a vacuum tube with mercury and submerging it in water, he recognized that something was pushing both matters up and that it was pressure from air. This discovery led to the creation of the barometer, which measures air pressure.

The Facts

Since Torricelli's discovery of air pressure in the 1600s, humankind's information about air pressure has expanded greatly. We understand and manipulate it better. Air pressure is read through millibars (MB). For example, the average sea-level pressure is 1013.25 MB. It is a useful tool to determine weather. Falling air pressure means the weather will be stormy. Lines called isobars connect equal air pressure. Basically, air pressure has scientific properties that can be used to explain the world in a variety of ways.

Evolution

Air pressure hasn't really changed through the years. In form, it is the same. The use of air pressure is what has changed. No longer is it just a means to help pump water; air pressure is now used to dust a room or clean out a computer keyboard. With time, humanity has found unique ways to harness air pressure that coincides with other discoveries in science and technology.

Significance

The importance of air pressure is real. Air is an element that is natural, free and seemingly unlimited. Its use is ever-changing and almost always helpful. As a result, it is a key part of everyone's life. Air pressure is just an offshoot of this truth.

Resources

• Pressure Variations Across the Eearth