Penny: So what's all this?
Leonard: Well, Amy and I were talking about old science fair projects, and how fun it would be to recreate them.
Amy: We're making hot ice.
Leonard: It's pretty cool.
Amy: (chuckles) Nice one. (Amy and Leonard high five)

Leonard: I'm sorry, we don't have to do more experiments. Let's do something we can all enjoy.
Amy: Hey, uh, you want to watch that show you like where people want to buy a house and then they do?

Penny: No, no, you guys do your experiments. I'll go pick up dinner.
Leonard: Are you sure?
Penny: Yeah, you're having science fun, and I don't want to interfere, or watch you.

Sheldon: Did I actually do it? I did. I did. [picks up his phone and dials] The answer is one in 18 million.
Mary Cooper: What is?
Sheldon: The odds of you running into Mr. Watkins.

Penny: [3 knocks] Sheldon? [3 knocks] Sheldon? [3 knocks] Sheldon?
Sheldon: It's annoying when you do it.

Sheldon: I have been working pretty hard. I could use a break.
Penny: What's that?
Sheldon: Oh, yeah, that is an experiment to see how many parallelograms I could draw while holding my breath.
Penny: [pointing to the board] Is that where you blacked out?
Sheldon: [pointing behind the couch] No, actually, that's where I blacked out.

Penny: And this?
Sheldon: That is a list of all the different types of natural disasters.
Penny: "Fire-quake"?
Sheldon: I made that one up. Which I shouldn't have, because now I'm scared of it.

Penny: Maybe I'll just eat this in the laundry room.
Sheldon: No, no. Wait. You don't have to go, as long as you sit quietly and don't say anything.

Leonard: So, I think if we want to predict the height of the wave, we need to use elasticity theory and model the lattice as one continuous flexible piece.
Amy: This is fun.
Leonard: Mm-hmm.
Amy: Playing with Popsicle sticks, exploring ways to store kinetic energy. It's like preschool all over again.

Leonard: Except now if I eat paste, it's because I want to, not because Craig Schultz is making me.
Amy: Hey, can I ask you a question?
Leonard: Is it, "Where was the teacher?" She was in the bathroom smoking, that's where.
Amy: It wasn't, but I'm glad to see you've moved on.

Amy: I was gonna ask if being married felt any different.
Leonard: Oh, uh, not really. Sorry. That probably wasn't the answer you were looking for.
Amy: No, actually it is. I mean, Sheldon and I are in a really great place right now, and I just, I don't want anything to mess that up.
Leonard: Mm-hmm. You do remember you're here because he kicked you out of your apartment?
Amy: Yes. His work is important to him. It's one of the things I find the sexiest about him. Well, that and-
Leonard: Aah! [setting off the lattice]
Amy: - his butt.
Leonard: Ugh.

Sheldon: And then I was thinking about inventing a new dark matter particle to evade the omega baryon constraints, but that just seems like something anyone could come up with.
Penny: Mm. Agreed. You know what's blowing my mind? Somebody thought about putting cheese in this crust.

Sheldon: I just wish I could find something that excites me.
Penny: You do understand that crust doesn't normally come with cheese in it?

Penny: What got you excited about dark matter in the first place?
Sheldon: Well, I left string theory, which I'd been working on for a long time, and everyone was talking about how cool dark matter was, and I thought, "€œWell, sure, I'll give that a whirl".
Penny: So it's your rebound science?
Sheldon: What's that?
Penny: Well, not the science you spend the rest of your life with, but the one you use to make yourself feel pretty again.

[Howard playing keyboard in bed with headphones, making a clacking noise]
Bernadette: What is happening?
Howard: I was trying not to wake you.
Bernadette: Did it work?