What's a Tensor? - Summary

Summary

This video by Dan Fleisch explains what tensors are and how they relate to vectors. He starts by defining vectors as quantities with both magnitude and direction, often represented by arrows. He then explains how vectors can represent areas and introduces the concept of basis vectors. He demonstrates how to find vector components and how to represent a vector using components and basis vectors. Fleisch goes on to introduce higher rank tensors, giving examples of rank two and three tensors, and explains why the combination of components and basis vectors makes tensors so powerful - all observers in all reference frames agree on the combination, making tensors "the facts of the universe."

Facts

1. The video is about vectors and tensors.
2. The speaker's goal is to explain what a tensor is.
3. Vectors have both magnitude and direction.
4. Vectors can represent an area.
5. To understand tensors, one must understand vector components and basis vectors.
6. A coordinate system is necessary to find the components of a vector.
7. Higher rank tensors have more components and sets of basis vectors.
8. The combination of components and basis vectors is what makes tensors powerful.
9. All observers in all reference frames agree on the combination of components and basis vectors.