Penny: All right, when do you see her next?
Raj: Uh, we're having dinner tonight.
Penny: Okay, put a rubber band around your wrist, and any time you start planning your wedding or naming your children, I want you to stab yourself in the hand with a fork.
Raj: What's the rubber band for?
Penny: To slow the bleeding.

Sheldon: Woman, you are playing with forces beyond your ken.
Penny: Yeah, well your Ken can kiss my Barbie.

Raj: [to Amy] If you were having Sheldon's baby, would you really want him in the room?
Penny: Yeah, if he's in the room when they're making the baby, I'll give you $10.

Leonard: If I take it off, Sheldon wins.
Penny: Sweetie, every night you don't kill him in his sleep, he wins.

Sheldon: They're very different. Physics answers the question: what is the nature of the universe? Geology answers the question: you know, what'd I just trip over?

Sheldon: I've been modeling different types of dark matter and the traces they would leave on the zircon inside your meteorite.
Bert: What's this one here?
Sheldon: That's actually a dark matter model of my own creation. I call it the Cooper Boson.
Bert: Cool. I got to name a rock once. I named it Moderately Sedimented Shale. Guess I kind of pooped the bed on that one.

Raj: Are you saying that you don't believe two people fall in love?
Ruchi: Of course they do. It's just that what people call "love" is actually a series of biochemical reactions in the brain that fade over time.
Raj: Yes. Like the old song, "When a man has a biochemical reaction for a woman."