Overheard: rainbows and unicorns

Astronomy 210L, Fall Semester 2010
Cuesta College, San Luis Obispo, CA

(Overheard during an introductory astronomy laboratory on spectrometers.)

Student: (Looking through a spectrometer at fluorescent light tube, which has a faint continuous spectrum along with bright emission lines.) "I'm not sure if this working!"

Instructor: "What do you see? Do you see the rainbow?"

Student: "Uh-huh."

Instructor: "What else do you see? Do you see the unicorns?"

Student: "The...what?!?"

Instructor: "Do you see a bunch of colored lines?"

(Beat.)

Student: "I see them."

Instructor: "Those colored lines are the horns of unicorns."