Cabin pressurization

Ok, so imagine you're going on a very long trip in an airplane. You're going so high up in the sky that the air outside is very different from the air down on the ground. In fact, the air up there is much thinner than the air down here.

Now, if the airplane just let in that thin air into the cabin where all the people and their things are, it would be very uncomfortable and even dangerous for everyone. So, what the airplane does is it has a special system that brings in air from outside but also adds more air to make it a good pressure for everyone inside.

This process is called cabin pressurization. The airplane pumps in more air and also kind of seals the cabin tight so that the pressure inside is just right for you to breathe and be comfortable.

So, next time you're on a flight and you feel your ears popping or your head feels weird, that's just your body adjusting to the new pressure in the cabin. And thanks to cabin pressurization, you can travel safely and comfortably even at very high altitudes!