Ira Flatow: Thanks for being with us today, Dr. Cooper.
Sheldon: My pleasure, Ira.
Ira Flatow: Now, let's talk about magnetic monopoles. Can you explain to our audience just what a monopole is?
Sheldon: Of course. First, consider an ordinary magnet, which has, as even the most uneducated (voice becoming high-pitched) in your audience must know, two poles (clears throat) a north and south pole. If you cut that in half, you have 2 smaller magnets each with it's own north and south pole.
Ira Flatow: Dr. Cooper, I think there might be something wrong with our connection.
Sheldon: No, I hear you fine. As I was saying, an ordinary magnet has 2 poles. The primary characteristics of a monopoles is that it has only one pole, hence, "monopole".

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.

Barry Kripke: Hey, Cooper. I hear you're going to be on the radio with Ira Flatow from Science Friday next week.
Sheldon: Thank you, Kripke, for depriving me of the opportunity to share my news with my friends.
Barry Kripke: My pleasure.
Sheldon: My thanks were not sincere.
Barry Kripke: Ah, but my pleasure is.

Sheldon: What are you talking about?
Leonard: The cultural paradigm in which people have sex after 3 dates.
Sheldon: I see. Now, are we talking date the social interaction or date the dried fruit?

Sheldon: Biologically speaking, Howard is perfectly justified in seeking out the optimum mate for the propagation of his genetic line. Howard: Thank you, Sheldon. Sheldon: And whether that propagation is in the interest of humanity is, of course, an entirely different question.