Fundamental plane (elliptical galaxies)

A fundamental plane is like a recipe for making a cake. In this case, the cake is an elliptical galaxy. Scientists have found out that if they measure three different things about the galaxy - how big it is, how fast it's spinning, and how much light it's making - they can figure out a lot of other things about it, like how heavy it is and how old it is. This is kind of like knowing that if you use the right ingredients and the right measurements, you can make a really yummy cake every time. By using the fundamental plane recipe, scientists can learn more about elliptical galaxies and how they formed.