Stu­dent #1, com­ment­ing on hole in graph: Is it a black hole?
Stu­dent #2, sar­cas­ti­cal­ly: No, a red hole.
Teacher, writ­ing on brown black­board: It’s a brown hole.
(class bursts in­to laugh­ter)

–Math Class, Bronx HS of Sci­ence

Over­heard by: Lil­lian