Expansion tensor
Okay kiddo, so imagine a rubber band. When you stretch it, it gets longer and thinner, right? And when you let go, it goes back to its original shape.
Now, imagine something in space doing the same thing. It's getting longer and thinner, and then going back to its original shape. Scientists call this stretching an expansion.
The expansion tensor is just a mathematical way for scientists to calculate how much something is being stretched. They use it to study things in space, like galaxies or the universe as a whole. It helps them understand how the things in space are moving and changing over time.
So, think of it this way - the expansion tensor is like a tool that scientists use to understand how things are changing shape in space. Just like how you might use a ruler to measure the length of something, scientists use the expansion tensor to measure how things are stretching or contracting.
Now, imagine something in space doing the same thing. It's getting longer and thinner, and then going back to its original shape. Scientists call this stretching an expansion.
The expansion tensor is just a mathematical way for scientists to calculate how much something is being stretched. They use it to study things in space, like galaxies or the universe as a whole. It helps them understand how the things in space are moving and changing over time.
So, think of it this way - the expansion tensor is like a tool that scientists use to understand how things are changing shape in space. Just like how you might use a ruler to measure the length of something, scientists use the expansion tensor to measure how things are stretching or contracting.