Sheldon: *singing in the tune of "Eye of the Tiger"* It's the eye of the tiger, it's the ear of the bat. It's the whiskers of a catfish and the walrus--
Howard: Hang on. Not that your song isn't terrible-- it is... but how do you mention bats and leave out sonar?
Sheldon: You didn't let me finish. *singing* And also regarding the bat. It has sonar.

Sheldon: *singing in the tune of "Bingo Was His Name-o"* There was a scientist who had a theory, and James Clerk Maxwell was his name-o. J-A-M-E-S, C-L-E-R-K, space, M-A-X-W-E-L-L, and James Clerk Maxwell was his name-o. There was a scientist who had a theory, and James Clerk Maxwell was his name-o. *claps* A-M-E-S--
Leonard: Okay, okay, we get it.

Howard: First take a picture with me.
Bernadette: Why?
Howard: Well, Raj and I always talked about learning how to make cocktails like this together, so I taught myself and I'm putting this on Instagram so he can see it and feel like a turd. Say cheese!

Raj: Okay, so, what it sounds like is, what we want is a device that can deliver a message through not only sight, but other senses, as well.
Leonard: The most basic sense that any space-faring civilization would have to possess is touch.
Raj: Ooh. Ooh, ooh! We could make a video-playing device that simultaneously translates the information into a tactile medium.
Leonard: All we have to do is rig up a 3-D communication system!
Raj: We-we can totally do that!
Leonard: I know!
Raj: This is great!
Leonard: Yeah, you know what else it is?
Raj: What?
Leonard: Exactly what Sheldon and Howard said.
Raj: Well, thank you for peeing in my slippers.

Sheldon: You can't breathe our air without an inhaler. He's allergic to Earth nuts, but I'm the alien.

Howard: So I have a dominant personality. We all know that.
Bernadette: I'm sorry. What do we know?
Howard: In social groupings, I just naturally wind up in charge.
Bernadette: Don't take this the wrong way, but how many of these little booze balls have you had?

Penny: *using Sheldon's knock* Sheldon? Sheldon? Sheldon? *Sheldon answers with a suspicious and smiling look on his face*
Sheldon: I bet that started off as a joke, but by the third one, you realized there was something strangely enjoyable about it.
Penny: Yeah, I kind of wanna do it again.
Sheldon: I don't recommend it. You'll be doing it the rest of your life.

Penny: You are a wise man.
Sheldon: Well, Penny, who's smarter, the wise man or the person who comes to him for advice?
Penny: Oh, I guess you're right. Maybe it is the person who asks.
Sheldon: No, it's the wise man. That's why they call him the wise man.

Raj: You guys know the new discovery class missions that NASA's been working on?
Howard: Yeah.
Raj: Well, they're looking to include a message from Earth in case one of them is encountered by alien life.
Leonard: When I encountered alien life, I discovered that the key thing was not to sit in its spot.

Sheldon: Now, we can play this one of two ways. You can say, "Trains! Tell me more," or, you can just look at me like that and I'll start.

Bernadette: What's going on in here?
Howard: I am making molecular cocktails. This sphere is actually a cosmopolitan.
Bernadette: Oh. How do you drink it?
Howard: Just put it in your mouth and pop it like a zit.

Howard: You don't think I'm a leader?
Bernadette: I was kidding. Of course you are.
Howard: Right. I couldn't change if I wanted to.
Bernadette: You better not change, because I love who you are. Now, will you need help cleaning all this up when you're done or can you do it all by yourself?
Howard: All by myself.
Bernadette: There's my big boss man.

Leonard: That would be more helpful if E.T. were real.
Raj: Well, my feelings were real when he was about to die.
Leonard: My God, when he's on the table and they use the paddles on him.
Raj: And he's all white.
Leonard: They zip him up in that bag.
Raj: And Gertie can't stop crying.
Leonard: The flower dies.
Raj: Okay, let's talk about something else.

Leonard: So it sounds like we need a way to communicate that's simple.
Raj: And doesn't require outside machinery to be built to access it.
Leonard: It's also a problem because we don't even know if the aliens who find this can see. I mean, they might communicate in a totally different way than us.
Raj: Like when my dog is mad at me, she tells me by peeing in my slippers.

Leonard: That's actually a valid example. Animals do deliver messages through scent.
Raj: Bees talk to each other by dancing. Whales have their songs.
Leonard: Penny has about 20 different ways of rolling her eyes that each mean something different.