Leonard: The europium laser is so cool. It has a four-level f-f transition which provides for high power output, and its quantum efficiency is off the charts.
Sheldon: What are you going to use it for?
Leonard: I have no idea.
Sheldon: Leonard, there's a crow on your roof.
Leonard: I see it.
Sheldon: Is that one of Dr. Lee's crows?
Leonard: It has a tag on its leg.
Sheldon: Don't make any sudden moves.
Leonard: Smart. Let's stand perfectly still and-
Sheldon: [running away] He's the one you want!