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.

Leonard: What would you be if you were attached to another object by an inclined plane, wrapped helically around an axis?
Sheldon: Screwed?
Leonard: There you go.

Leonard: Penny, as a scientist, my job is to figure out why things happen. But I don't think I'll ever understand how someone like me could get to be with someone like you. You know maybe I don't need to understand it, I just need to be grateful. I love you, Penny.

Sheldon: This song is never going to stop. Have you ever dealt with something so relentlessly irritating?
Leonard: That's a trick question, right?

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.

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.