Sheldon: It's happening. Leonard, it's happening. Professor Proton is coming to our house.
Leonard: You're kidding.
Howard: You mean the guy who used to host that lame kids show?
Sheldon: And you just got yourself uninvited. See? I told you I'd find a tactful way to do that.

Raj: I don't like bugs, okay. They freak me out.
Sheldon: Interesting. You're afraid of insects and women. Ladybugs must render you catatonic.

Sheldon: Scissors cuts paper, paper covers rock, rock crushes lizard, lizard poisons Spock, Spock smashes scissors, scissors decapitates lizard, lizard eats paper, paper disproves Spock, Spock vaporizes rock, and as it always has, rock crushes scissors.

Sheldon: Why are you crying?
Penny: Because I'm stupid.
Sheldon: That's no reason to cry. One cries because one is sad. For example, I cry because others are stupid, and that makes me sad.

Professor Proton: Okay, as, as I put the egg on top, and, and the flame goes out and, and, and the air pressure decreases in, in the flask, what do you think will happen?
Penny: I think I know.
Sheldon: It's gonna get sucked in. It's going to get sucked in.
Penny: Okay, I didn't know.
Sheldon: Yes!
Penny: See, I'm not a scientist like them.
Professor Proton: I, I figured that out.

Professor Proton: I'm having trouble with my pacemaker.
Leonard: I'll call for help.
Penny: Any chance we could plug it into the potato?
Professor Proton: No.

Howard: How'd you get him to come to your house?
Sheldon: As Professor Proton always says, there is no problem you can't solve if you use your noggin.
Leonard: And he wrote him a check.
Sheldon: Yeah, that too. A big check.