The phenomenon of seeing a friend or acquaintance by sheer chance extremely often and in extremely random places.
Also analogous to the gravitational "lensing effect," observed in astronomy.
Man: "OMG, I see Lindsey everywhere. She's in so many of my classes AND I run into her in the most random places in town. This can only be the result of a strange unseen force."
Woman: "That sounds like a case of lensing effect; when the force of gravity is so strong that it can bend light and causes stars (that should be hidden) to appear in multiple new places."
Man: "What did you say that was called... Lindsey Effect?"