This episode establishes that Sheldon has his own "spot" on the couch. Even though he does eventually sit somewhere else in this episode, it is clear he is uncomfortable not sitting in his "spot".
Penny's clothes change after her shower, but she didn't have another set with her and it appears she didn't return to her apartment since Raj and Howard were there.
In this episode we learn that Penny is from a suburb just outside Omaha, Nebraska.
This episode establishes that Leonard is lactose intolerant and cannot process corn.
Howard: Bon douche. (Penny stares at him) That means "good shower" in French—a sentiment I can express in six languages.
Leonard: Save it for your blog, Howard.
Leonard: At least I didn't have to invent 26 dimensions just to make the math come out.
Sheldon: I didn't invent them, they are there!
Leonard: In what universe?
Sheldon: In all of them, that's the point.
Leonard: We need to widen our circle.
Sheldon: I have a very wide circle. I have 212 friends on MySpace.
Leonard: Yes, and you've never met one of them.
Sheldon: That's the beauty of it.
Penny: I'm a Sagittarius, which probably tells you way more than you need to know.
Sheldon: Yes, it tells us that you participate in the mass cultural delusion that the sun's apparent position relative to arbitrarily defined constellations at the time of your birth somehow affects your personality.
Penny: (puzzled) Participate in the what?
Penny: (after seeing Leonard and Sheldon pantsed) I'm so sorry. I really thought if you guys went instead of me, he wouldn't be such an ass.
Leonard: No, it was a valid hypothesis.
Sheldon: That, "was a valid hypo"—what is happening to you?
(at the high-IQ sperm bank, discussing committing genetic fraud)
Sheldon: What if she ends up with a toddler who doesn't know if he should use an integral or a differential to solve for the area under a curve?
Leonard: I'm sure she'll still love him.
Sheldon: I wouldn't.
Leonard: Our babies would be smart and beautiful.
Sheldon: Not to mention imaginary.
Howard: (upon seeing Penny) Enchante, Mademoiselle. Howard Wolowitz, Caltech Department of Applied Physics. You may be familiar with some of my work. It's currently orbiting Jupiter's largest moon, taking high-resolution digital photographs.
Penny: (a little confused) Penny. I work at the Cheesecake Factory.
Sheldon: Are you still mad about the sperm bank?
Sheldon: Do you want to hear an interesting thing about stairs?
Leonard: Not really.
Sheldon: If the height of a single step is off by as little as two millimeters most people will trip.
Leonard: I don't care—two millimeters?! That doesn't seem right.
Sheldon: No, it's true! I did a series of experiments when I was twelve; my father broke his clavicle.
Penny: I'm a vegetarian. Well, except for fish, and the occasional steak. I love steak!
Sheldon: Well, that's interesting. Leonard can't process corn.
(Althea is having trouble with a crossword puzzle; Leonard takes a look at it)
Leonard: One across is Aegean, eight down is Nabokov, twenty-six across is MCM, fourteen down is, move your finger... (Althea moves her finger) phylum, which makes fourteen across Port-au-Prince. (Althea gives him a look) See, Papa Doc's capital idea, that's Port-au-Prince, Haiti.
(as they walk up the stairs after being "pantsed")
Leonard: Sheldon, I am so sorry I dragged you through this.
Sheldon: It's ok. It wasn't my first pantsing, and it won't be my last.
Leonard: But you were right about my motives. I was hoping to establish a relationship with Penny that might have someday led to sex.
Sheldon: Well, you got me out of my pants.
Penny: And on top of everything else, I'm all gross from moving. My stupid shower doesn't even work.
Leonard: Our shower works.
Penny: Really? Would it be totally weird if I used it?
(on their way to pick up the TV from Penny's ex-boyfriend)
Sheldon: And why can't she get her own TV?
Leonard: Come on, you know how it is with break-ups.
Sheldon: No, I don't and neither do you.
Leonard: But I -- I broke up with Joyce Kim.
Sheldon: You did not break-up with Joyce Kim, she defected to North Korea.
Leonard: To mend her broken heart.
Penny: So, what do you guys do for fun around here?
Sheldon: Well, today we tried masturbating for money.
This episode is rated TV-14-DL.
When aired in syndication, the sperm bank scene is not shown, likely because it contrasts with the nearly asexual Sheldon that would be established in later seasons' episodes.
Leonard's and Sheldon's names are an homage to the late Sheldon Leonard, a renowned actor, director, producer and writer who is best remembered for his body of work in the 1960's. Penny is so named because in the original pilot, the guys found her sitting curbside, as though they'd found a lucky penny.
The German episode title is "Penny und die Physiker", meaning "Penny and the Physicists". The French title is "La Nouvelle Voisine des surdoués", meaning "The Gifted Ones' New Neighbor". The Italian title is "Pilota", and the Spanish and Mexican title is "Piloto".
Original International Airdates:
Turkey: September 9, 2008 on CNBC-e
Czech Republic: April 7, 2009 on Prima COOL
Germany: July 11, 2009 on ProSieben
Slovakia: August 17, 2011 on Markiza
All the whiteboard equations are real equations from quantum mechanics and physics. The writers have a physicist to assist them with the physics jargon.
This episode's end titles has Chuck Lorre's Vanity Card #182.
Music: "Smile" by Lily Allen
This is not Chuck Lorre and Bill Prady's first time working together, they worked together on Two and a Half Men.
The show was supposed to air in 2006, but CBS didn't want to air it during the 2006 fall lineup because they had too many shows during the 2006-2007 season.
Kaley Cuoco is the third person tapped to play the female lead (originally named Katie, then Gilda, and finally Penny). The others were Amanda Walsh and Iris Bahr.
This is not Johnny Galecki's first time working with Chuck Lorre, they worked on Roseanne together.
The series is filmed at Warner Bros. Studios, Burbank, CA.
Filming started on Wednesday, February 14, 2007, at 4:30pm.
Sheldon: "Do you think this possibility will be helped or hindered when she discovers your Luke Skywalker No More Tears shampoo?"
Leonard: "It's Darth Vader shampoo. Luke Skywalker's the conditioner."
Luke Skywalker and Darth Vader are characters from George Lucas' film series phenomenon, Star Wars.
The number 42:
In this episode, Koothrappali wears a ballcap with the number "42" stitched upon it. According to Douglas Adams' The Hitch Hiker's Guide to the Galaxy book series, 42 is the answer to the ultimate question of life, the universe, and everything.