Raj: (Inside the closet) Don't forgive them. Stay mad at them.
Howard: What is he doing in there?
Raj: Busting you.
Bernadette: It's okay. They apologized.
Penny: Yeah, it's fine.
Raj: Well this is kind of anti-climactic.
Howard: You know what wasn't anti-climactic? The end of the movie. Get this.
Raj: No spoilers. No spoilers.
Penny: And he's back in the closet.

Leonard: It's the greatest scientific feud of all time. I mean, you can forget about Leibniz and Newton.
Penny: Done.

Penny: So, Tesla's the one that invented the electric car?
Sheldon: (laughs) No, Penny. No, the car is just named after him.
Penny: Okay, you don't have to be so smug about it. You know, you went to see that movie It because you thought it was about scary I.T. guys.

Raj: So Ruchi and I decided to keep things casual.
Penny: (scoffs)
Raj: What? What? I can handle casual.
Penny: (scoffs)
Raj: Oh, why do you keep doing that with your face?
Penny: Because you keep saying stupid things with yours.

Bernadette: Howie, slow down.
Howard: I can't. I'm not allowed to eat for 12 hours before my surgery, and I only got two more minutes.
Leonard: What surgery are you having?
Raj: I'm stress eating. My best friend's getting a vasectomy tomorrow.
Penny: And you're sad you won't be able to bear his child?

Raj: You can't let this stop you. Almost any scientific advancement can be used for destructive purposes.
Amy: It's true. Even Einstein's theory of relativity was later applied to the development of nuclear weapons.
Penny: E equals MC squared. Yeah. E is for energy, M for mass, and C for the speed of light.
Amy: How do you know that?
Penny: Oh, Leonard mumbles it when he wants sex to last longer.

Sheldon: All right, back to learning.
Penny: Okay.
Sheldon: Oh, easy. Bill Nye the Science Guy.
Penny: Or as I know him?
Sheldon: Creepy old dude from Dancing with the Stars.
Penny: Ding, ding, ding, ding, ding.

Bernadette: Can we really help?
Howard: While we finish soldering these boards, it'd be great if you guys could wrap these pipe fittings with Teflon tape.
Leonard: I'll show you how to do one.
Penny: Hey, wouldn't it be funny if after all your years of hard work, I'm the one who makes a scientific breakthrough? (To Bernadette) He doesn't think that's funny.

Sheldon: I am a respected theoretical physicist. I aspire to win a Nobel Prize someday. But nobody's gonna take me seriously if they find out I've been dabbling in geology.
Penny: Well, why not? They're both sciences. And I know because they're classes my high school counselor said "weren't for me."

Penny: So, did you tell him about Princeton yet?
Amy: No, I'm waiting till he's in a good mood.
Penny: Oh, sweetie, you might not live that long.

Sheldon: I know that you worked hard to put this together. I'm sorry I'm ruining it.
Penny: Oh, pl- you're not ruining it. Look, at some point, Raj will try to get everyone to do the Electric Slide. Now, that will ruin it.

Penny: Hey, I thought you were coming right back.
Leonard: I was, but we're both depressed, and decided to drown our sorrows.
Penny: With mouthwash? Man, that is so summer camp.
Sheldon: It's Romulan ale, from Star Trek.
Leonard: It was briefly legalized during the alliance between the Romulan Empire and the Federation at the time of the Dominion War.
Penny: Aw, now I'm depressed.

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.

Amy: Where are you moving?
Penny: And when? But a-also where?

Penny: Auntie Penny's here. Shh. Let's get you changed. Your mommy and daddy say they trust me, but they're full of the same stuff your diaper is.