ELI5: Explain Like I'm 5

Pi in the Sky

Okay kiddo, have you ever heard of the number pi? It's a special number that helps us figure out how round things are, like circles. Pi is really long and starts with 3.14159 and goes on and on and on forever without repeating any numbers.

Now, imagine we have a round pizza that we want to share with our friends. We want to cut it into equal slices so everyone gets the same amount of pizza. To do that, we need to know how big the pizza is round. That's where pi comes in!

Pi tells us exactly how big the pizza is around the edges. We can use that information to make sure we cut the pizza into equal slices so everyone is happy.

Now, imagine we have a special kind of pizza that we want to send up to the sky. It's not a real pizza, it's actually a type of parachute called a "parasail". We attach the parasail to a weather balloon and send it up into the sky.

But how do we make sure the parasail will fly correctly and not get tangled up? We need to know how big it is around the edges, just like the pizza! That's where pi comes in again.

We can use pi to calculate the size of the parasail and make sure it will fly properly in the sky. So, pi in the sky is just a special way to use the number pi to help us do cool things like send parasails into the sky. Pretty neat, huh?