Lighter than air

Okay kiddo, have you ever played with a balloon? How it can float in the air and doesn't fall down like a rock? That's because the air inside the balloon is lighter than the air outside of it.

Well, some things are also lighter than the air around them, and that makes them float too! These things are called "lighter than air" objects. They can be made of different materials, but most of the time they're made of super-thin materials, like plastic or paper, that are filled with a gas that's lighter than air.

This gas is often helium or hydrogen, which are both lighter than the air we breathe. When these gases fill up a big enough balloon or blimp, they lift it up into the sky! You might have seen big blimps with words or pictures on them at a football game or parade.

Even airplanes use the principle of being lighter than air to stay up in the sky! The wings on an airplane are designed to lift it up by using the speed of the air around them to create lift, which makes the airplane lighter than the air below it.

So, to sum it up, "lighter than air" just means something that is lighter than the air around it, and because of that, it can float or fly in the sky!