The Earth’s Atmosphere is Heavy, But Why Don’t We Feel It?
The atmosphere stretches several kilometers above the Earth. The boundary between the Earth’s atmosphere and outer space, known as the Kármán line, is located about 100 kilometers above the ground. However, approximately 99.9% of the atmosphere’s mass is found below an altitude of 48 kilometers.
The air is lighter than our bodies, but the total layer of air in the atmosphere is indeed very heavy. The total mass of the Earth’s atmosphere is about 5.1 billion kilograms. Just a cylindrical column of air with a diameter of 0.3 meters has a mass of up to 754 kilograms.
The Earth has a thick atmosphere covering it. (Photo: Internet).
So, why aren’t we crushed by the atmosphere?
One reason is pressure distribution. The air flows around our body, and the pressure from the air is distributed evenly across all parts of our body rather than being a direct force pushing down from above.
Nevertheless, the pressure that the atmosphere exerts on our entire body is not small. Each cm2 experiences a weight of 1 kilogram.
We are not crushed by air pressure because our bodies have evolved over time to withstand this pressure. The air inside our bodies essentially exerts an outward pressure that balances the external air pressure.
This balance of forces occurs only if the air is in contact with all sides of the body. If you place the nozzle of a vacuum cleaner against your arm and it sucks out all the air pressing against your skin, the force your arm feels is the weight of the air being drawn into the vacuum tube.
The air at higher altitudes is less dense, which is why the atmospheric pressure decreases as you ascend. This explains why you may experience ear popping when flying during takeoff and landing. It takes time for the air pressure inside your body to equalize with the outside air pressure, and the eardrum is the most sensitive part to this change.
The internal pressure in our bodies is also a reason we cannot travel in space without protective suits. The pressure in space is essentially zero.
Without the external air pressure acting on our bodies, the internal pressure would cause our bodies to swell like a balloon until that pressure is released.
