The Lunar Excitation

"The Lunar Excitation " is the twenty-third episode and the final episode of the third season of the  sitcom The Big Bang Theory. This episode first aired on Monday, May 24, 2010.

Summary
The gang meets Penny's dim-witted new guy Zack while performing a  on the apartment building roof. Raj and Howard sign up Sheldon for and find him a match: Amy Farrah Fowler.

Extended Plot
The are up on the apartment roof performing a   experiment. While Raj is using the after he's done watching "" on someone's, Leonard thinks Penny would like to be up here to see what they are doing. Sheldon does admit that  left by  on the  that they are using could qualify as a shiny object. Leonard goes to Penny’s apartment and finds her with Zack, her, wonders how you can bounce stuff on the moon if there's no up there. Zack wants to see it anyway. Zack designs the s for the Cheesecake Factory. Leonard tries to explain what's going on Zack is afraid that when the laser hits the moon, the laser will. Sheldon tells everyone that Zack is a man for Penny. They fire the laser and get a return 2.5 s later and the guys are excited. Zack is not impressed. Leonard, “Don't you see what we've done? It's the only definitive proof that a put objects on the moon. A species that only 60 years before had just invented the .” Zack doesn't know what species Leonard is talking about. Now Sheldon thinks that Penny can do better. Penny and Zack depart with Penny having been embarrassed by Zack.

Back in Apartment 4A, Howard suggests getting Leonard an online profile. He’s had eight dates in the last month, twelve if you count the ones that just show up and leave. Sheldon asks for help with a heavy  tank down from the roof and Leonard ends up getting it himself. Raj suggests that they create an online dating profile for Sheldon like when was lonely and they found him a. Howard corrected him; they did not find him a wife, they made him a wife. Raj suggests we keep that in mind for plan B.

Very early in the Leonard answers a banging on their door and it’s a en Penny. She claims that Leonard had ruined her because she would have never have known that Zack was so. He has destroyed her ability to tolerate s. Therefore, the two of them are going to have which Leonard is fine with. Sheldon wakes up and is advised to break out the because they are going to get loud. Sheldon is disturbed that he is going to have to put up with the two of them again.

In the morning, Penny tries to sneak out, but disturbs Sheldon. He comments on her use of the phrase 'yee-haw' used during their which thrills Penny as she leaves. Leonard wonders why Penny left without saying good-bye. Sheldon replies that Penny went back to her to  and.

Leonard and Penny run into each other as she heads off to. Leonard wants to go and a, and Penny tells him last night was a mistake since she was  and drunk. She wants him to forget it, but the whole thing is kind of implanted on his. Leonard accuses her of using him for sex and then learns that Mrs. Gunderson in 3A also heard them last night. (Yee-haw!)

Later, Raj has the proof that s walk among us since the dating site matched Sheldon with a. She is an actual woman with and everything. They reply to her with an.

What Leonard thinks he has learned is that it’s okay for people to return to former and have  with them. He goes to see Leslie Winkle who talks awkwardly with him including asking him whether “Blondie” had dumped him. Since it's OK to have recreational sex with people they've known before, he asks her. She says she'll think about it...and slams the in his.

Now Sheldon's perfect match wants to meet him. Howard and Raj decide to resort to the. They got Sheldon a date with his perfect match for the next. Of course, Sheldon thinks the used to determine the compatibility of potential  are pure, but that is literally the  they gave when the  asked what they thought of. Even Spock had a date once every seven. Sheldon correct them that he was experiencing, burning. Raj also hid the dirty that freaked Sheldon out on the  somewhere in the apartment and refuses to take it out unless Sheldon meets Amy Farrah Fowler. Sheldon curses him, but agrees to do it.

Leonard comes back to the apartment drunk and goes to Penny's. He tells her that he was a perfectly happy, lonely little guy, and you ruined it for me! He wants to have sex and it's not going to mean a thing. Penny tells him that he’s out of your and throws him out. Leonard feels that he experiencing a. At the, Sheldon tells them that their experiment is going to fail. (Neener-neener.) Amy Farrah Fowler shows up because she agreed to date once a year just to keep her mother off her back. She shares Sheldon's aversion to soiled and they connect over agreements they had made with their s. And all forms of physical contact up to and including  are off the table. Sheldon offers to buy her a as they step up to the counter. Amy turns away and has a very satisfied expression on her face. Howard wonders, “Good God, what have we done?”

Critics

 * "As we end season three I thought the writers addressed the Penny-Leonard relationship in a nice way. For both the relationship has changed their perspective on their future partners. The point was made in a somewhat subtle way that they both now have higher standards thanks to the other...It's a familiar refrain but the writers still don't handle Penny and Leonard's situation with the skill they need to...A passable end to a really decent season from The Big Bang Theory . "Really decent" might sound like damning with faint praise but the show has got better this season. The writing went to new places and did on occasion flesh out its characters." - The TV Critic's Review
 * IMDb user reviews

Costume Notes

 * WHAT DOES LEONARD'S ORANGE / PURPLE SWIRL T SHIRT SAY?

Trivia

 * First appearance of Zack.
 * First appearance of the of the guys' and Penny's building. It makes two subsequent appearances in "The Countdown Reflection" (S5E24) and "The Prom Equivalency" (S8E8).
 * So far the only time the final episode of a season does not end with a to be resolved at the start of the next season unless you count not knowing what will happen between Sheldon and Amy.
 * The gang's  ranging experiment utilizes a, as is referenced on the  near Sheldon and Leonard's apartment door.  crystal lasers typically emit light with a wavelength of 1064 nm, in the ; however, the high-intensity pulses may be efficiently  to generate green laser light at 532 nm. Both of these wavelengths are written on the lower half of the whiteboard, along with the chemical formula Y3Al5O12 for the yttrium aluminum garnet crystal structure and the atomic transition 4F3/2 → 4I11/2 in the neodymium ion, after being "pumped" into excitation. The upper half of the whiteboard calculates the round-trip travel time of a light pulse bouncing off lunar retro-reflectors as 2.56 seconds, based on the ratio of the semi-major  of the lunar orbit to.
 * Raj loves "", in which Christine Baranski, who plays Leonard's mother, is enlisted in the main cast.
 * Sheldon refers to Albert Einstein establishing the theoretic foundation for the laser in his paper Zur Quantentheorie der Strahlung (On the Quantum Theory of Radiation) in 1917.
 * Sheldon mentions that he only  in months with an "r" in them. Thus, his quirk doesn't allow him to drink hot chocolate in the consecutive months of, , , and , which spans the  season in the . It makes perfect sense; in California, it would be much too hot in the summer months to drink hot chocolate.
 * Raj states that Sheldon's for the question "How do you feel about " would be "hokum", which was exactly the same word that Sheldon himself used to described on-line dating algorithms in "The Barbarian Sublimation" (S2E3). They know their.
 * Last appearance of a main character (Leslie Winkle) and the first appearance of another main character (Amy).
 * This episode is Amy Farrah Fowler's first appearance in this series; interestingly, her full name is revealed even before her first appearance.
 * Sara Gilbert's final appearance as Leslie Winkle. Interestingly enough, Leonard's final line in her scene- "She's not coming back," refers to both Leslie not taking him back and not returning to the series.
 * Just like Howard and Bernadette when they first meet, Sheldon and Amy find a connection when talking about their.
 * The beverage Amy asks for is ; water that is moderately . Also tepid can mean lacking in al warmth which also describes their at this point in their relationship.
 * This is the second time Penny calls Leonard a "Rat ." The first time was in The Pancake Batter Anomaly which was in episode 11 on Season 1 of The Big Bang Theory.

Quotes

 * (Howard. Sheldon and Raj are at the café waiting to meet Amy Farrah Fowler.)
 * Amy Farrah Fowler: Excuse me, I'm Amy Farrah Fowler, you're Sheldon Cooper.
 * Sheldon: Hello, Amy Farrah Fowler. I'm sorry to inform you that you have been taken in by unsupportable mathematics designed to prey on the gullible and the lonely. Additionally, I am being blackmailed with a hidden dirty sock.
 * Amy: If that was slang, I'm unfamiliar with it. If it was literal, I share your aversion to soiled hosiery. In any case, I am here because my mother and I have agreed that I will date at least once a year.
 * Sheldon: Interesting. My mother and I have the same agreement about church.
 * Amy: I don't object to the concept of a deity, but I am baffled by the notion of one who takes attendance.
 * Sheldon: Well then, you might want to avoid East Texas.
 * Amy: Noted. Now before this goes any further, you should know, that all forms of physical contact, up to, and including coitus, are off the table.
 * Sheldon: May I buy you a beverage?
 * Amy: Tepid water, please.
 * (Both go to the counter, while Raj and Howard just stare.)
 * Howard: Good God, what have we done?

(Sheldon notices Penny taking Leonard to his bedroom)
 * Sheldon: What's going on?
 * Penny: Get your noise-cancelling headphones, 'cause it's gonna get loud.
 * Sheldon: Oh, not this again!


 * Sheldon: That's not afternoon. That's prevening.


 * Penny: Damn you, you rat bastard! In the olden days, I never would have known he was that stupid!


 * Zack: Is that the laser? It's bitchin'.
 * Sheldon: Yes. In 1917, when Albert Einstein established the theoretic foundation for the laser in his paper "Zur Quantentheorie der Strahlung", his fondest hope was that the resultant device be bitchin'.
 * Zack: Well, mission accomplished.


 * Leonard: (Explaining the significance of the experiment to Zack) Think about what this represents. The fact that we can do this is the only way of definitively proving that there are man-made objects on the moon, put there by a member of a species that only 60 years before had just invented the airplane.
 * Zack: (Astonishingly) What species is that?


 * Zack: One question. How can you be sure it won't blow up?
 * Leonard: The laser?
 * Zack: The moon.


 * Leonard: Okay, we’ve got power to the laser.
 * Sheldon: I should’ve brought an umbrella.
 * Leonard: What for? It’s not going to rain.
 * Sheldon: I know that, but with skin as fair as mine, moon burn is a real possibility.
 * Howard: That’s a bazinga, right?
 * Sheldon: One of my best, don’t you think?