This Lesson Is Bull-Shift

(We have just learned about the blue-shift and red-shift in light, and we just finished our quiz on it recently.)

Teacher: “Uh, [Student], you need to fix this…”

Student: Why?”

Teacher: “Well, because you left out the “f” in “Shift”. I’ve never heard of a blue one before. A brown, one, yes, but not a blue one…”