They have erected a small black fabric fence running along the side of the university campus near us. I naively thought it was a silt fence, used to control sediment flow and erosion from the road construction project beginning there. My son B has corrected me. He informs me that it is actually a “physicist fence” which is used to keep the physicists on campus and prevent them from roaming free in the community and administering random physics lessons to unsuspecting citizens. I am lucky to have an expert around to inform me of these things.