Howard: Why would the military want Sheldon?
Leonard: I don't know. Target practice?

Barry Kripke: Whoa, whoa, whoa. You didn't tell me we were doing this just to stick it to Sheldon.
Leonard: Well-
Barry Kripke: I messing with you. This sundae just got a cherry on top!

Sheldon: And worse than that, Edison filmed the first on-screen kiss, so he's basically a pornographer. Although every time I put that in Wikipedia, someone takes it out.

Leonard: Hey, is Sheldon working on our project again?
Colonel Williams: Did he say that?
Leonard: No, he wouldn't tell us.
Colonel Williams: Huh. So he can keep his mouth shut. How do I get him to do that?

Sheldon: Can you believe they said I was just like Edison? Yeah, and in front of a lady, no less.

Raj: All I'm saying is before you attack Ruchi, maybe you should take a long hard look in the mirror, because you know what you'll see, apart from radiant skin and luxuriously thick hair? Hypocrisy!
Bernadette: It is thick.

Penny: I thought they fired you guys.
Sheldon: They did, but then they hired me back.
Leonard: Well, you better not be working on our project, because we're a team.
Sheldon: Leonard, there is no "I" in team. However, there is an "I" in "I'm working with the military and you're not." There's five of them, in fact.

Leonard: It's the greatest scientific feud of all time. I mean, you can forget about Leibniz and Newton.
Penny: Done.

Penny: So, Tesla's the one that invented the electric car?
Sheldon: (laughs) No, Penny. No, the car is just named after him.
Penny: Okay, you don't have to be so smug about it. You know, you went to see that movie It because you thought it was about scary I.T. guys.

Raj: Can we start the movie? Before Sheldon gets here?
Howard: Last time we did that, he didn't talk to us for a month. So do it!

Leonard: Edison was kind of a publicity hog and a bully.
Raj: Yeah, he electrocuted an elephant named Topsy just to make himself famous. If I had an elephant named Topsy, he would want for nothing. Also, he'd be named Jumbo.

Penny: You know, that documentary last night was actually better than I thought it would be.
Leonard: Really? Should've been about Samuel Morse the way they telegraphed that ending.
Penny: I already pretended to laugh at that joke once. Do I have to do it again?
Leonard: Yeah, I'd appreciate it. (chuckles)
Penny: (forced laugh) Samuel Morse. You kill me.

Sheldon: Leonard, can you drive me to work?
Leonard: Yeah, sure. Oh, hey, the guys and I were talking about going to see the Tesla coil at the observatory later on, if you want to join.
Sheldon: Oh, I'm sorry, I can't. I'm busy.
Leonard: Why? What are you doing?
Penny: Leonard, what are you doing? He said he can't go. Make a sad face, move on.

Bernadette: Hey, what are you two doing here?
Ruchi: We won't stay long. I just wanted to drop something off from me and the girls at work.
Bernadette: None of the girls at work like me enough to get me a gift.
Ruchi: Okay, so you'll know why everyone at the office has the same handwriting.

Sheldon: You know whose fault this is?
Amy: I do. Yours.
Sheldon: No, my mother's. "Go make friends, Sheldon." What happens? 20 years later, they call me names.