ELI5: Explain Like I'm 5

Tautological bundle

Okay kiddo, let's talk about tautological bundles. Imagine you have a big piece of paper and draw some dots on it. Each dot represents a point on the paper. Now, imagine you want to draw lines from each dot to show which points are connected. These lines are like strings that connect the dots. But sometimes, there are special strings that connect a point with itself (like a string tied in a loop). We call these special strings "tautological".

Now, let's think about a way to use these tautological strings to make more complicated shapes. Imagine you take a bunch of different big pieces of paper and draw dots on each of them. Then, you connect the dots on one piece of paper to the dots on another piece of paper using tautological strings. This creates a new shape that is made up of all the original dots, but now they are connected in a different way.

In math, we use this idea of tautological strings to create something called a tautological bundle. A bundle is like a bunch of pieces of paper stacked on top of each other. In this case, we are stacking pieces of paper that have dots (points) on them and connecting the dots using tautological strings. The result is a new shape (the tautological bundle) that has all the original points, but now they are connected in a special way.

Now, what's the point of all this? Well, tautological bundles are used in lots of different areas of math and science to study the structure of shapes and spaces. They help us better understand the connections between different points in a shape and how those connections relate to other properties of the shape. So, even though it may seem like a small thing to connect a point to itself with a string, it can actually help us learn a lot about the world around us!