Raj: What's that?
Howard: Sounds like a cricket.
Sheldon: Hang on. Based on the number of chirps per minute and the ambient temperature in this room, it is a snowy tree cricket.
Howard: Oh, give me a frickin' break. How could you possibly know that?
Sheldon: In 1890, Emile Dolbear determined that there was a fixed relationship between the number of chirps per minute of the snowy tree cricket and the ambient temperature. A precise relationship that is not present with ordinary field crickets.
Raj: How do you know what the exact temperature of the room is?
Sheldon: Under the terms of my roommate agreement with Leonard, I've had unilateral control of the thermostat ever since the sweaty night of '06.