Amy: Sheldon told me he had a new assistant named Alex. He didn't mention that Alex was a girl.
Penny: Maybe he didn't notice.

Bernadette: How you doing, Howie? You feeling a little better?
Howard: Oh, a lot better, thanks. One sec. Listen close, I don't have a lot of time. I need you to go to my house. In my bedroom, you'll find a model rocket. I want you to take it and bring it back to your place.
Bernadette: Okay.
Howard: Step two, build a version roughly fourteen stories high. Fill it full of rocket fuel and come get me. I'll leave the door unlocked.
Bernadette: Howie, honey, maybe you should talk to someone, let them know you're having a little anxiety.
Howard: No, no, I'm fine. No anxiety. We should probably talk in code. From now on, frog is me, sandwich means you and lemon means rocket. So, come on, sandwich, build me a lemon 'cause froggy wants to come home.

Penny: Well, of course he's desirable. I mean, he's great. He's smart, he's sweet and, ooh, in the bedroom, whew, let me tell you he really tries.

Bernadette: Hey, Howie, how you feeling?
Wolowitz: Better. Much better. The other astronauts held me down, gave me a shot. Oooh. Attention, people of Earth. Tonight, there will be two moons in the sky.
Bernadette: Howie, stop that. NASA's watching this! Put your pants back on!

Wolowitz: If I die, promise me you'll never have sex with another man.

Leonard: If you want help, just hire a grad student.
Penny: Maybe I could do it.
Sheldon: You, really? You can assess the quality of my work? Okay, um, here. I wrote this when I was five years old.
Penny: A proof that algebraic topology can never have a non self-contradictory set of abelion groups. Im just a blond monkey to you, aren't I?
Sheldon: You said it, not me.

Sheldon: Are you familiar with the Higgs boson?
Penny: Of course, it is - it's been in the news. And it's a very famous boson.
Sheldon: Nice try.

Howard: Well, remember the Soyuz capsule they were sending to bring us home?
Bernadette: Uh huh.
Howard: It's delayed. We're gonna be here for at least another week. Maybe ten days. It's the Russians, so you don't know. They left dogs up here in the sixties.

Penny: Fine, it bothers me a little. No. You know what? This is stupid. It doesn't bother me. Okay, it bothers me. But only because she wouldn't stop laughing. Leonard is not that funny.
Amy: And there you have it, prefrontal cortex reasoning versus limbic lust. If this were a boxing match, they might call it the thrilla adjacent to the amygdala. If you were a brain scientist, you would be busting a gut right now.

Leonard: Wait, Alex, do you want to join us?
Sheldon: Alex, a moment. I need a word with Dr. Hofstadter.
Do you think it's appropriate for her to sit with us, given her station?
Leonard: Given her what?
Sheldon: If I've learned anything from British television shows on PBS, it's that servants dine down stairs with their own kind.
Leonard: What?
Sheldon: It's a kindness, Leonard. Otherwise, you're cruelly tempting them with a glimpse of a world that's just beyond their soot-stained fingertips.

Howard: I don't know how much longer I can take this. I can't sleep, and zero gravity is giving me crazy acid reflux. I'm down to my last three Tums.
Bernadette: You're going to be fine. You survived that Weight Watchers cruise with your mom. And they ran out of low-fat ice cream on day two. Just calm down and take a few deep breaths.
Howard: Okay, okay. What am I doing? I'm using up all the oxygen. If I die, promise you'll never have sex with another man.

Amy: Oh, yeah. I'm a man-eater now.
Penny: Okay, for the final touch, this is an eyelash curler. You just place it on your lashes and squeeze it closed.
Amy: Oh, I don't know. Looks like something used by Tinkerbells gynecologist.
Penny: Who I hope for her sake is not Captain Hook.

Sheldon: Oh, good, Leonard, you're here. Science news. This will interest you. And, Penny, feel free to paint your nails.
Leonard: What do you got?
Sheldon: I believe Alex may have unearthed the grade school science project that could be my ticket to the Nobel Prize. Behold.
Leonard: "Magnets: What Do They Stick To?" If the answer is metal, it's not exactly groundbreaking.
Sheldon: The original title was A Rederivation of Maxwell's Equations Regarding Electromagnetism. I dumbed it down because some of the more religious people in town were starting to say I was a witch.

Howard: I really miss gravity. Can you drop something so I can watch it fall?
Bernadette: Really, you're serious? Okay.
Howard: Oh, baby, you're killing me.

Penny: You really think there's some kind of scientific discovery in here?
Sheldon: Well, this box only covers my work through nursery school. There's a good deal more to come. I didn't really hit my academic stride until I cut out that time-suck known as playing outdoors.