ELI5: Explain Like I'm 5

A-infinity operad

Okay, kiddo, imagine you have a toy car and a toy truck. They both have wheels, but the number of wheels is different. The car has four wheels and the truck has six wheels. Now if you wanted to play a game where you combine the wheels from the car and truck to make a new vehicle, you'd need some rules to follow. Maybe you'd say that you can't have more than six wheels on your new vehicle, because that would be too many.

Now, let's switch to math. It turns out that mathematicians use rules like this when they study things called "operads". Operads are like sets of instructions for combining different mathematical objects in specific ways. You can think of them like recipes for making different kinds of cakes - each recipe has a list of ingredients and steps you need to follow.

An a-infinity operad is a special kind of operad that follows some very specific rules about how to combine things. In our toy car and truck example, you might say that the "set of wheels" is one of the things you can combine using the rules of the a-infinity operad. The rules of the a-infinity operad say that you can combine these wheels in specific ways, but you have to follow certain rules. For example, you can't have more than six wheels on your new vehicle.

So, why do mathematicians care about a-infinity operads? Well, they're really useful for studying all sorts of things - from algebraic topology to string theory. You see, when you follow the rules of an a-infinity operad, you get some really interesting patterns and structures that can tell you a lot about the mathematical objects you're working with. Just like how following a recipe gives you a delicious cake, following the rules of an a-infinity operad can give you some amazing insights into some of the most complex and interesting things in math!
Related topics others have asked about: