# Why do we not want our stress state to be like this?

In this article they mention that Cauchy stress is defined by studying the forces acting on the deformed body, and these forces are constant in space. But if a body is subjected to pure rotation, the actual values of stress component will change, meaning now there is a full tensor with both normal and shear stress components. Why is this something we dont want - do they mean cauchy stress is inaccurate since forces are fixed in space, when in reality we have all sorts of normal and shear stress due to rotation?