ELI5: Explain Like I'm 5

Jordan normal form

Jordan Normal Form is a way of writing a square matrix (a grid of numbers) in a special way so that it is easier to solve some problems with matrices. It is like putting the matrix into a neat and organized form so that it is easier to understand what is going on. Let's say we have a big bunch of blocks and we want to put them into a specific shape, like a pyramid. We would start by finding the right size and shape of the blocks we need and then stacking them up in the correct order. The same idea goes for Jordan Normal Form.

When we stack up the blocks to create a pyramid, we make sure that we use the same size and shape of blocks, and then space them out in the right way to create the structure we want. In the same way, we rearrange numbers in a matrix so that they are in a specific order and spaced out in just the right way to make it easier to solve problems. We don't change the underlying "structure" or "shape" of the matrix, only the way it looks on the outside.

The way that we rearrange the numbers in a matrix to get the Jordan Normal Form is by using something called "eigenvectors" and "eigenvalues," which are just special mathematical tools that help us simplify the matrix. We use these tools to find a bunch of new numbers that represent the matrix in a different way, and then we use these new numbers to create the Jordan Normal Form.

When we're done, we end up with a matrix that looks like a bunch of diagonal lines with numbers on them, and some zeros elsewhere. These diagonal lines are called "Jordan blocks," and they represent clusters of related numbers that we can easily work with. The zeros represent parts of the matrix that aren't as important, so we can ignore them for now.

Overall, the Jordan Normal Form is just a way of organizing a matrix so that we can solve problems more easily. It's like building a pyramid out of blocks - we start with something messy and complicated, and then we rearrange it in a special way to make it neat and organized.