ELI5: Explain Like I'm 5

Riemann sphere

Okay kiddo, do you know what a sphere is? It's like a ball, right? Well, the Riemann Sphere is a special kind of sphere that was invented by a smart guy named Bernhard Riemann.

The Riemann Sphere is like a 3D version of a number line. Imagine a number line that goes forever in both directions, from negative infinity to positive infinity. Now imagine taking all those real numbers and putting them onto a sphere. The Riemann Sphere is exactly that - a way of visualizing complex numbers on a sphere.

Complex numbers are like regular numbers, but they have two parts - a real part and an imaginary part. Just like how a point on a number line can be represented by a single number, a point on the Riemann Sphere can be represented by a single complex number.

But why use a sphere? Well, the Riemann Sphere lets mathematicians do some really cool things with complex analysis - a type of math that deals with complex numbers. It lets us see things like infinity and infinite limits in a new way and helps us understand how complex functions behave.

So there you have it, the Riemann Sphere is like a special ball that helps mathematicians understand complex numbers in a new way.