The Decoupling Fluctuation

"The Decoupling Fluctuation" is the second episode of the sixth season of the sitcom The Big Bang Theory. This episode first aired on October 4, 2012.

Summary
Penny is starting to have doubts about her relationship with Leonard, while Stuart is added to their group as a replacement for Howard, who is in orbit om the International Space Station.

Extended plot
At Bernadette's apartment, Penny and Amy are helping her sort through her wedding presents. Sheldon's is engraved with instructions to return it should the couple get. Penny thinks Sheldon's comment is inappropriate but wonders why she did not think of buying a gravy boat in the first place. When the subject of marriage comes up, Amy says that she plans on marrying Sheldon in four years, but she tells Bernadette to not tell Sheldon about it because he is still a. When Penny is asked about Leonard, she keeps saying that he is a great guy. Bernadette thinks that Penny does not sound like she is in love and asks her about it Penny admits that the feelings she has for Leonard is not the same as the feelings she had when she was in love before. She concludes that maybe it is a new, better, boring kind of love. She just is not sure that it is the real thing, how Leonard would react if she told him or that she will stay together with him.

Meanwhile, Raj, Leonard, and Sheldon are talking to Howard at the International Space Station and Howard tells them he cannot believe that he is on this incredible adventure. A fellow astronaut then tells him to go clean the space toilet since he is the new guy, and that next time, they will let him use a brush.

The gang, sans Bernadette, goes to a movie and Stuart tags along, claiming that Raj invited him. Sheldon insists that he acts just like Howard would and among them, he has to eat. He also asks Stuart where he went to school to compare him to Howard. Stuart attended an, which Sheldon thinks is equally ridiculous has Howard's education so Stuart passed his test. During the movie, Amy insists that Sheldon holds her hand, which he hesitantly obliges to do. He sees that Leonard is not holding Penny's hand. Amy tells Sheldon that there may be a reason for that and tells him that Penny may be breaking up with him. Sheldon does not believe her because Penny is seen drinking Leonard's diet (and germy). Amy tells him things are complicated but he does not agree with her as a complicated matter would be the. For the sake of argument, Sheldon asks Amy what she means about Penny wanting to break things off with Leonard. Amy tells him that Penny is not sure how she feels about Leonard. Sheldon finds it preposterous for a person to not know how she feels, because he is certain about what he likes and dislikes. (Handholding, no; fish with tools on their noses, yes) Amy tells him that regardless, he has to keep it a secret, something Sheldon openly admits he does not like to do. Just then Stuart offers Sheldon Raisinets, to which he points out that Stuart is disrupting them trying to watch a movie, and he tells Amy that he does not think Stuart can fit in with their group after all.

Later in Sheldon and Leonard's apartment, Sheldon is in a dilemma about whether or not to tell Leonard about the secret. Leonard gets annoyed by Sheldon's restless behavior and does not mind even if Sheldon decides to keep quiet about it. However, Sheldon succumbs and decides to tell Leonard anyway. He uses as an analogy about Leonard's relationship with Penny, by telling him that what he sees outside can mean a different thing inside, just like how their current conversation about Transformers can actually be regarding one of them in the room. Leonard tells Sheldon that he gets it, but misinterprets Sheldon's words as pertaining to him and how he used to be a heartless robot but after meeting Amy he maybe becoming a red-blooded man with sexual desires. Sheldon tells Leonard that that was the stupidest thing he has ever heard.

Sheldon attempts to tell Leonard again during the early morning hours, but instead he goes into Penny's waking her up as she screams hysterically. Sheldon beats around the bush telling Penny about Leonard's great attributes as a, until Penny asks him what Amy had said. Sheldon replies that he had heard that she was thinking of breaking up with Leonard. Penny patiently tells him that it is sweet that he is worried about his friend, but that her relationship is none of his business. He asks her to keep dating Leonard no matter how she feels and to keep everything in "" or unchanging, the way that Sheldon likes his life. He also wants her to change her shampoo from coconut back to green apple. Finally Sheldon leaves and asks her "not to hurt my friend". Penny responds that that is the last thing she wants to do.

Amy gets an early morning phone call from Penny complaining that because of what she had told Sheldon, she was now in a terrible position. At the same time, an incoming call from Sheldon comes and he tells Amy that he is calling just to give her the heads up since he has told Penny about the secret. Amy says that Penny is already on the other line, making Sheldon say that everything is now fine now that everyone is on the same page.

Bernadette is talking to Howard at the ISS who complains about his fellow astronauts being mean to him. She tells him to stand up and tell them that "being mean is lame, but being nice is cool". She asks if she should call NASA, and Howard replies that his mother already did that and it made things worse.

Stuart is playing Mystic Warlords of Ka'a with the rest of the gang and plays a card that Sheldon says Howard would not play. After changing cards, Sheldon goes out and wins. Stuart and Raj are going out to a bar to pick up women. Sheldon suggests that Leonard go along to find a back-up for Penny because of her illogical death-defying actions, though he thinks that they may be breaking up.

Later Penny and Leonard are having dinner at her place. While Leonard is telling her about Sheldon's misadventures at the, Penny seems very distracted. Finally she says that she has to tell him something. Leonard sits back, looks at her with what Penny describes as his big sad eyes and she appears conflicted again. Later, at Bernadette's apartment, she tells the girls about what happened and Amy exclaims, "You slept with him?" Penny says that she was looking into his big sad eyes and could not tell him. Penny demonstrates and Amy replies that it is a good thing that she does not have a dog. Bernadette tells her that she will have plenty of times to break-up with him like on their wedding day, their honeymoon or their 50th anniversary. Penny insists that they aren't getting married and that they'll keep their relationship in a homeostasis condition. Amy thinks that she is cute when she tries to use s. Leonard texts her telling her how amazing she is while Amy and Bernadette look at her with big sad eyes.

Finally Bernadette is again talking to Howard about how her idea worked and that he got a great night's sleep. Unfortunately on his face his fellow astronauts had drawn a mouse's face, whiskers, glasses and his nickname "f. loops". Bernie gives him a "proud" face and does not tell him that she knows.

Critics
"Sheldon is a funny character and even though this was repetitive material the odd line still worked.This was absolutely classic Big Bang Theory... I can’t argue that the writers aren't addressing the Penny and Leonard relationship. But they are spinning their wheels frantically to make sure it looks like something is happening while no momentum is gained...Same old, same old. Come on Chuck Lorre. Will people really stop watching if something interesting happens?" The TV Critic's Review

Trivia

 * Bill Prady tweeted that a post-show backstage party was organized for the Mars Rover Landing Team after the taping of the episode, with pictures of Kevin Sussman (Stuart) and Steven Molaro caught together with the team too.
 * In "The Countdown Reflection", Sheldon mentioned that he bought an $88 gravy boat as the wedding gift for Howard and Bernadette. This appears in this episode.
 * Mayim Bialik's injury is not written into the episode, with writers opting to hide her injury instead, just as they did with Kaley Cuoco's Penny when she broke her leg during the fourth season.
 * While on the International Space Station, Howard is forced by fellow astronauts Mike Massimino and Dimitri Rezinov, who are giving him a hard time as the new guy, to clean the toilet. Mike says, "You want to see the meteor shower? Look at what Dimitri left for you in the toilet." This is probably an ironic reference to Howard's Wolowitz Zero-Gravity Waste Disposal System which went terribly wrong in "The Classified Materials Turbulence".
 * To assess the potential of Stuart as a replacement for Howard, Sheldon inquires about Stuart's education, with Stuart stating that he went to art school. In "The Hofstadter Isotope", Leonard explained to Penny that he's a terrific artist and attended the.
 * Sheldon inquired if Penny knew that "while Leonard is not considered a tall fellow in our country, in today’s North Korea, he’s downright average." Since the average male height in North Korea is currently 5 ft 5 in (1.656 m), Leonard's height is known. Indeed, this measurement is consistent with actor Johnny Galecki's height of 5 ft 5 in (1.65 m).
 * Assuming an exact correspondence between the character's height and that of the portrayer, the rest of the main character heights are as follows: Sheldon (Jim Parsons) stands 6 ft 1 $$\tfrac{1}{4}$$ in (1.86 m), Raj (Kunal Nayyar) stands 5 ft 7 in (1.70 m) , Penny (Kaley Cuoco) stands 5 ft 6 in (1.68 m) , Howard (Simon Helberg) stands 5 ft 4 in (1.63 m) , Amy (Mayim Bialik) stands 5 ft 4 in (1.63 m) , and Bernadette (Melissa Rauch) stands 4 ft 11 in (1.50 m) . [NOTE: Average male height in the U.S. is 5 ft 9 $$\tfrac{1}{2}$$ in (1.763 m) and average female height in the U.S. is 5 ft 4 in (1.622 m), while the average height of males in India is 5 ft 5 in (1.647 m) .]
 * Sheldon tells Penny that "Leonard has a perfect driving record". It should be noted that, at the end of "The Love Car Displacement", Leonard drives at 120 mph, and is noticed and approached by the police. But, possibly, maybe one single violation of the traffic rules does not affect the "perfect driving record" or the police let him off with a warning.

Mistakes

 * At the end, when Howard is video chatting with Bernadette, he has no idea that he has writing on his face, although you can see yourself on .

Quotes
Penny: Maybe this is a new, better, boring kind of love.

Amy: Just don't tell Leonard anything, or Penny will kill me.

Sheldon: Fine, but FYI, secret-keeping: Hate it. Hand-holding, not a fan. Hammerhead shark, I love that thing. Another fish with a tool on its head.

Bernadette: Being mean is lame. What's cool is being nice.

Howard: Great. I'll say that when I want to be the first guy in space to get a wedgie!

Sheldon: Please don't hurt my friend.

Penny: That is the last thing I want to do.

Amy: If that's all it takes it's a good thing you don't have a dog.

Bernadette: Do you think you'll ever get married someday?

Amy: In exactly four years. But don't tell Sheldon, he's still a flight risk.

Howard: The other astronauts are being mean to me.

Leonard: Amy is causing you to transform into a red-blooded man with sexual desires.

Sheldon: That is literally the stupidest thing I've ever heard.