Excellent, thanks for sharing! I found particularly useful the explanation that dF = SdA implies that the tensor S must convert the area vector dA in a force ve

Excellent, thanks for sharing! I found particularly useful the explanation that dF = SdA implies that the tensor S must convert the area vector dA in a force vector dF and that vector can have any direction. But something that I miss is a visual representation of what kind of change of directions tensors do. I can see in my mind how a vector multiplication works, but I haven't the same intuition for tensors. For example, if I have a cube of marble and I put a heavy weight over it, qualitatively how the tensorial space in the cube? What kind of values I would see near the top? Which ones near the bottom? What's the direction of dF if I chose a dA parallel to each side of the cube? which one if I chose an arbitray vector, say one at 45° of one side?