Big Bang Theory Quote
Mrs. Latham: What happened to you, Wolowitz? Couldn't stick with it long enough to get your Ph.D.?
Howard: I'm an engineer. Most engineers don't bother with a Ph.D. But you may be interested to know I designed the zero-gravity waste disposal system for NASA.
Mrs. Latham: Got it. You're a space plumber.
Quote from S04E15 - The Benefactor Factor