Sheldon: Now, Introduction to Physics. What is physics? Physics comes from the ancient Greek word physika. It's at this point that you'll want to start taking notes. Physika means the science of natural things. And it is there, in ancient Greece, that our story begins.
Penny: Ancient Greece?
Sheldon: Hush. If you have questions, raise your hand. It's a warm summer evening, circa 600 BC. You've finished your shopping at the local market, or agora, and you look up at the night sky. There you notice some of the stars seem to move, so you name them planetes, or "wanderer". Yes, Penny?
Penny: Um, does this have anything to do with Leonard's work?
Sheldon: This is the beginning of a twenty six hundred year journey we're going to take together from the ancient Greeks through Isaac Newton to Niels Bohr to Erwin Schrodinger to the Dutch researchers that Leonard is currently ripping off.
Penny: Twenty six hundred years?
Sheldon: Yeah, give or take. As I was saying, it's a warm summer evening in ancient Greece…

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.

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.

Howard: Hey, ma, can I have lamb stew for dinner?
Mrs. Wolowitz: Lamb stew? I'd have to go to the supermarket.
Howard: Please? I got a real hankering.
Mrs. Wolowitz: Oh, I can't say no to my little tushie face. I'll be back soon.

Penny: Look, can we just forget about this extra stuff and can you just tell me what Leonard does?
Sheldon: Alright. Leonard is attempting to learn why subatomic particles move the way they do.
Penny: Really? That's it? Well, that doesn't sound so complicated.
Sheldon: It's not. That's why Leonard does it.