Howard: I've been at this lab for three years, you've never came by to say hello.
Sheldon: Well, up until now I've had better things to do. So, what are we making today?
Howard: A small payload support structure for a European science experimental package that's going up on the next space shuttle.
Sheldon: Really, how does it work?
Howard: When this is done, it will be attached to the payload bay, and the sensor apparatus will rest on it.
Sheldon: Uh, huh. So it's a shelf?
Howard: No, you don't understand, during acceleration it needs to stay perfectly level and provide ... yeah, okay, it's a shelf.

Raj: I don't like bugs, okay. They freak me out.
Sheldon: Interesting. You're afraid of insects and women. Ladybugs must render you catatonic.

Sheldon: Scissors cuts paper, paper covers rock, rock crushes lizard, lizard poisons Spock, Spock smashes scissors, scissors decapitates lizard, lizard eats paper, paper disproves Spock, Spock vaporizes rock, and as it always has, rock crushes scissors.

Sheldon: Why are you crying?
Penny: Because I'm stupid.
Sheldon: That's no reason to cry. One cries because one is sad. For example, I cry because others are stupid, and that makes me sad.

Raj: Can you believe it! He watched me work for 10 minutes and than he tried to build a little piece of software that could replace me.
Leonard: Is that really possible?
Raj: As it turned out, yes.

Sheldon: Engineering. Where the noble semiskilled laborers execute the vision of those who think and dream. Hello, Oompa-Loompas of science.

Leonard: Okay, Sheldon, I understand that youre going through a bit of a career crisis, you're searching for some other area where you can feel valuable and productive but I need to tell you something and I want you to listen carefully.
Sheldon: All right.
Leonard: Go away!