"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: No, we don't. We have to take in nourishment, expel waste, and inhale enough oxygen to keep our cells from dying. Everything else is optional.
Sheldon: No it doesn't. Not unless the two doors are connected by relays, or there are motion sensors involved...
Penny: No, no, I meant--
Sheldon: Or if the first door closing creates a change of air pressure that acts upon the second door...
Sheldon: Well, there's always the possibility the trash can spontaneously formed around the letter. But Ockham's Razor would suggest that someone threw it out.
Sheldon: Then I'll settle for an aneurysm!
Leonard: Stop it!
Sheldon: You hit me! You saw that! He hit me!
Leonard: You were trying to blow up my head.
Sheldon: It was working?!
Leonard: No, it wasn't! It was not! YOU ARE A NUT CASE!
Sheldon: Oh, we'll see about that! Heads up, you people in the front row, this is a splash zone!
Sheldon: [smirking] Level 3 and she thinks she's rich! What a noob!