Spherical cow

An incident involving a spherical cow once occurred in the apartment building where Jenny Everywhere lived with Kim in one universe. Whatever its nature, the incident drove the company who owned the apartment to introduce a new, much stricter pet policy, although existing pets were grandfathered-in. Jenny found the ruling unfair, especially as the cow hadn't actually belonged to her at all. (PROSE: Fragment: Fanfic Critique)

Behind the scenes

Jenny says it's not her cow.

“Spherical cows” are a common joke spoofing overly-simplistic models in theoretical physics: asked to improve the efficiency of a dairy farm, a physicist works tirelessly until he comes back to the former to tell him that he “has the solution, but it only works with perfectly spherical cows in a vacuum”. In its original context, the joke is of course based on the fact that there are no such things.