Leonard: So, listen, do you remember when I said the similarities of the equations of general relativity and hydrodynamics suggest you could find the equivalent of Unruh radiation in a large body of water?
Penny: I thought I said that to you.

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

Leonard: What am I supposed to do?
Penny: Err, keep your mouth off other women.

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

Leonard: Sheldon's nervous about me leaving. Just keep an eye on him while I'm gone.
Penny: Oh, I don't know. Remember what happened when I took care of your goldfish?
Leonard: Well, flush Sheldon down the toilet and get me a new one.

Raj: Okay, I have a request to make.
Amy: And now he can talk. I want to cut open your brain and see what the heck is going on in there.

Bernadette: You know, one of the things that helped me get through Howard being in space for so long was getting married before he left.
Penny: Bernadette, sweetie, shut up.