Tuesday, November 13, 2012

Are you pressed by the air?

by mindylin610, This post first appeared at Science Avengers.

There is a force moving around us all the time, but you can't see it. Creepy, huh? Its name is the atmospheric pressure that also can be called air pressure. The atmospheric pressure is formed by the colliding between huge amounts of air molecules. It is connected directly to the amount of air that is necessary for us to stay alive. The amount of atmospheric pressure can be affected by many factors such as the temperature, altitude, etc.


Do some experiments at home and you will find out the huge magic inside it. Here is one example.


Material: Paper, a full glass of water (it has to be a full glass!!)

Procedure: a. Cover the paper on the glass. b. Flip the cup around.

Here is the MIRACLE!! The paper won't come down!

WHY?? As the paper occupies the whole glass cup, there is no air inside the cup which means no atmospheric pressure toward the paper with a regular amount of atmospheric pressure outside the cup.

Evangelista Torricelli is one of Galileo's students who found the existence of atmospheric pressure. Otto von Guericke, the governor of a German city called Magdeburger, was very interested in science and read Torricelli's experiments, so he designed an experiment to prove the strong force of atmospheric pressure called Magdeburg hemisphere experiment.



You can also feel the difference when you are at the mountain top!

When you start climbing a Himalayan mountain, you might find it easy and made the determination to go up to the top. At this point, the atmospheric pressure around you is equivalent to the amount of oxygen that you need to stay alive. When you are at one third of the mountain, which is approximately 3000 m, you might feel crazy tired but you decide to continue. When you are at two thirds of the mountain, which means you have already passed half of the mountain, you might find it hard to breathe and even hard to move. When you are at the top of a Himalayan mountain, which is about 9000 m, without an oxygen mask, I can bet 1 cent with you that you are close to death. The reason is that the higher the altitude is, the less atmospheric pressure it has. The lack of atmospheric pressure means less oxygen. However, when you feel dizzy and going to die soon, assuming you jump down the mountain without breathing. God bless you and let you stay alive at the foot of the mountain. At this time, there is little amount of air inside you but a bigger amount around you. YOU ARE PRESSED BY THE AIR!

About this Contributor: mindylin610 is a tenth-grade high school student with a special love of random things and a passionate heart toward math and science.

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