I was reading the Feynman Lectures awhile back and I remember reading something he said about the Uncertainty Principle and it seemed slightly odd to me. I don't remember the exact quote and combing through some of the lectures online I can't quite find it. I've heard it more than once from different sources so I know it's something someone said. It is roughly as follows: A way the Uncertainty Principle manifests itself in the macroscopic world is when you are applying an increasing force on a floor, you are reducing the Δx of the atoms. This causes the Δp to increase or increasing the range that the momenta of the atoms can take. So, due to this compression in x and gradual increase in the range of p, the floor will push back more and more as the force increases. Now, I understand this from a classical point of view with electromagnetic forces and the properties of solids but can this quantum phenomenon be applied as a legitmate explanation for this macroscopic phenomenon?