Science Common Sense

1265 - What causes atmospheric pressure

Atmospheric pressure is caused by the weight of the air surrounding the Earth. Imagine you're under a big stack of heavy blankets. The more blankets there are, the heavier they feel on you.

The same thing happens with the air around us. The Earth's atmosphere is made up of a huge amount of air molecules that weigh down on us. The molecules are stacked on top of each other, and the weight of all those molecules is what we feel as atmospheric pressure.

The pressure is strongest near the ground because there are more molecules stacked on top of us. As you go higher, the number of molecules decreases, so the pressure gets weaker. That's why it's harder to breathe at high altitudes, like on top of a mountain.