*Howard answers his front door*
Mark Hamill: Hi.
Howard: I'm gonna need a minute. [closes the door] That's Mark Hamill!

Amy: Sheldon, you're awfully quiet. Are you okay?
Sheldon: Oh. Oh, I'm sorry. I was thinking about string theory. But catch me up.
Mrs. Fowler: What'd I miss? Are you seeing this, Larry? These are the people I'm gonna have to live with after you're dead.

Howard: Welcome, Bert. Don't you look nice.
Bert: Yeah. Like a geode, I clean up good.
Howard: Don't you crack a geode open?
Bert: It's not a perfect metaphor.

Sheldon: Leonard. That's Mark Ha-Ha-Ha. It's-it's Mark Hami-Ha-Ha-
Leonard: Yep. Thank Wolowitz. He set it up.

Stephen Hawking: Are you sitting in a bathroom?
Sheldon: Yes. I needed a place to storm off to and it was all that was available.
Stephen Hawking: Fine. But if I hear a flush, this conversation is over.

Penny: Is it possible that the sleep-talking is a part of your brain that's telling you everything's gonna be okay and you just need to relax a little?
Sheldon: So you're proposing that the self is an illusion, and that we actually have multiple centers of consciousness that are communicating with one another?
Penny: In laymen's terms, yeah.
Sheldon: Huh. Interesting. So you don't believe there's a Cartesian self that underlies the flux of experience?
Penny: Maybe in my twenties, not anymore.

Bert: Alone in my temple in the middle of Peru, A giant stone ball with nothing much to do, But if you steal my idol, I will roll right over you, 'Cause I'm six tons of granite and micaceous schist, Yeah, I'm six tons of granite and,
Both: Micaceous schist, Yeah, I'm six tons of granite and, micaceous schist, Yeah, I'm six tons of granite And, uh, micaceous schist Yeah, I'm six-

Sheldon: There's something I need to tell you. Wow, you look amazing! That's not what I need to tell you. But you do!
Amy: What's wrong?
Sheldon: Something incredible just happened. Remember when you were telling me about my bow tie and how a little asymmetry is good?
Amy: Yeah?
Sheldon: My equations have been trying to describe an imperfect world, and the only way to do that is to introduce imperfection into the underlying theory.
Amy: So, instead of super symmetry, it would be super asymmetry?
Sheldon: (gasps) Super asymmetry. That's it! Give me your lipstick.
Amy: What?
Sheldon: Just give it to me, you beautiful thing! We have work to do!

Leonard: Uh, Surprise!
Penny: Oh, crap. Is it our anniversary?
Leonard: No. Wait. No.

Ira Flatow: So, it has been five years since the discovery of the Higgs boson. What's the next big thing gonna be?
Leonard: Wow, that's hard to say. There's so much going on. We've been collecting tons of data that could revolutionize the way we understand the universe. For instance, there's a particle called a squark, which could prove super-symmetry.
Ira Flatow: That is interesting. Have you found it?
Leonard: What, the squark?
Ira Flatow: Yes.
Leonard: No, no. Wouldn't that be exciting? But we're also looking for the selectron, the gluino and the neutralino.
Ira Flatow: Well, and have you found that?
Leonard: No.

Leonard: Uh, can we just drop this and have lunch like adults?
Howard: Fine.
Sheldon: Very well. Leonard?
Leonard: What?
Sheldon: Pff!

Amy: Is this about what Leonard said on the radio?
Sheldon: Absolutely not. And I do not want to talk about Leonard. Can we please just talk about anything else?
Amy: We could talk about my day.
Sheldon: Walked right into that one, didn't I?

Penny: That is enough. Your lives are not wasted. Your careers are not at a dead end. You just hit a rough patch. Instead of feeling sorry for yourselves, you need to get up and get inspired.
Leonard: How?
Penny: I don't know. You know, when I'm feeling down, I go for a run, which is exactly why I'm not 180 pounds, genius!

Penny: I had no idea Richard Feynman was dead.
Howard: Yep. Most people don't know he's actually buried right here in Altadena.
Sheldon: I'm sure they keep a lid on that to avoid traffic jams.

Sheldon: You know, Feynman used to say he didn't do physics for the glory or the awards, but just for the fun of it.
Leonard: He was right. Physics is only dead when we stop being excited about it.
Raj: Even beyond the grave, he's imparting wisdom.
Sheldon: Um, I'm the one who remembered it.