Sheldon: Earlier today, I invited Professor Stephen Hawking to join me in the popular online game Words with Friends. Moments ago, he accepted my request. Do you understand what that means?
Howard: That somewhere right now Stephen Hawking is saying, "Damn it, I mean to click no."

Sheldon: It's been three days. Why hasn't Stephen Hawking played a word?
Raj: The guy's a genius. Maybe you weren't challenging enough for him?
Sheldon: Not challenging? I was humiliating the man. I was thinking of writing a book called A Brief History of the Time I Made Stephen Hawking Cry Like a Little Girl.
Howard: There's the problem. You can't beat Hawking like that. He hates to lose. Everyone knows the guy's a big baby. I mean, forget the wheelchair, he should be in a stroller.

Howard: One time when I was working with him, he said that Johnny Depp was in The Matrix. I told him he was wrong, but he kept insisting. So I looked it up online and showed him. Well, the next day, he had a pizza party, and everyone got invited but me. And then he was all, your invitation must have gotten lost in the matrix.

Howard: A week ago, I was an astronaut.
Bernadette: Yeah, well, today you're a Smurf! Keep moving!

Howard: (Mimicking Bernadette in a high voice) Oh Howie, stop talking about space so much. Nobody likes it.
Bernadette: (In a low voice) I don't sound like that.

Stuart: "To Stuart, your comic book store is out of this world. Just like the guy in this picture was."
Sheldon: For the record, he also thinks Walgreens and the dry cleaners are out of this world.
Howard: That's not true. At Walgreens I was over the moon for their store-brand antacids.

Howard: But you know what wasn't a party? That hotel in Kazakhstan they put you up in before the launch. I mean, it's your last night on Earth. You'd think you'd get one porn channel.
Leonard: Have you noticed that Howard can take any topic and use it to remind you that he went to space?
Sheldon: Interesting hypothesis. Let's apply the scientific method, perform an experiment.
Leonard: Okay. Hey, Howard, any thoughts on where we should get dinner?
Howard: Anywhere but the Space Station. On a good day, dinner was a bag full of meat loaf. But, hey, you dont go there for the food, you go there for the view.
Sheldon: It's fascinating. Let me see if I can duplicate the result. Howard, I've always thought the lemon was an underrated fruit. Care to weigh in?
Howard: Not really.
Sheldon: Oh, well.
Howard: You know, people say the Soyuz capsule was a lemon. But, hey, that baby got me to space and back.

Howard: That reminds me, I was thinking about wearing my NASA jumpsuit as a costume. But then I realized everyone would be, like, where's your costume? Why are you wearing your work clothes, you nut?

Leonard: Hello, boys.
Sheldon: What are you smiling at?
Leonard: Nothing.
Howard: You know where's there's a lot of nothing?
Everyone: Space.

Howard: So, here we are, just a couple of young newlyweds. What to do? What to do to you? Astronaut Wolowitz, reporting for booty. Preparing thrusters. We have liftoff. Are we clear to jettison that nightgown?
Bernadette: Okay, we need to talk.

Howard: What?
Bernadette: Howie, I know you went to space. I'm incredibly proud of you. But you might want to try and not bring it up every minute.
Howard: I don't talk about it every minute.
Bernadette: Tonight at dinner you went on bout it for an hour straight.
Howard: What was I supposed to talk about? We were eating at Johnny Rockets.

Crowd at the airport: There he is! Howie! Howie!
Wolowitz: Whoa, thank you. Great to be back on Earth.
Howie Mandel: Uh, I think they're here for me, Ringo.

Bernadette: Come on, let's go home so I can tear off those little pants.
Howard: Great. Just keep in mind astronauts lose a lot of muscle tone in space, so you might have to do most of the heavy lifting.

Howard: Well, that was quick and a little gross. Now I know how she feels.

Howard: (singing) Baruch atah, Adonai, Eloheinu. Melech haolam, hamotzi. Lechem min haaretz
Mike: What's that?
Howard: The Jewish prayer for eating bread. We don't have one for falling out of space!