What are moment of inertia tensors?

A moment of inertia tensor is like a special map that tells us how easy or hard it is for an object to spin in different directions.

Imagine you're holding a toy airplane. When you twirl it around, sometimes it spins smoothly, like when you turn it on its own axis, but other times, it wobbles or twists in unexpected ways. That’s because the moment of inertia tensor helps us understand how the airplane's shape and weight affect its spinning.

If your toy airplane is balanced and light, it spins easily, like a smooth spinning top. But if it has heavy wings or a big engine on one side, it might feel more like a wobbly top, making it harder to spin smoothly.

The tensor part means the map can show different values for spinning in different directions, left-right, front-back, and up-down, just like how you need different kinds of maps to navigate a city.

So, the moment of inertia tensor is like a super-smart map that helps us predict how an object will spin based on its shape and weight, turning tricky physics into something fun and familiar!