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"The Electric Can Opener Fluctuation" is the first episode and season premiere of the third season of the American sitcom The Big Bang Theory. This episode first aired on Monday, September 21, 2009.


Sheldon is humiliated by the guys tampering with the data they gathered at the North Pole, while Penny finally shows her feelings for Leonard.

Extended Plot[]

The Electric Can Opener Fluctuation 14

Leonard, you're back!

Following his return from the North Pole, Sheldon is very excited over the prospects that his research has yielded, whereas Raj, Howard, and Leonard are just glad to be home after spending three months at the North Pole in close quarters with Sheldon. Penny is happier than all of them that Leonard has returned as she passionately kisses him after he knocks on her door. Leonard gladly returns the affection while Penny drags him into her apartment. Howard and Raj watched the greeting. Howard laments that he had not been the first to go over there. Raj sarcastically observed that it was first come-first served. After they get into apartment 4A, Howard and Raj confess to Sheldon that the positive results that he received in the Arctic was really static from an electric can opener they kept turning on and off. Furious, especially at Leonard who thought up the idea, Sheldon confronts him at Penny's, much to Leonard's dismay. Leonard explains that he did it because Sheldon was being absolutely unbearable during the expedition when he wasn't getting the results he wanted. Plans to kill him were even brought up and discussed. To make matters worse, Sheldon already contacted everyone at the university that he had positive results. Crushed that his best friend has destroyed his dreams and humiliated him, Sheldon retreats to his bedroom. Penny goes to comfort him; however, she makes Sheldon realize he also missed both Comic Con and the new Star Trek movie.

The Electric Can Opener Fluctuation 16

The gang in Texas fetching Sheldon.

The next day, Sheldon still refuses to forgive Leonard, and is suffering ridicule by everyone in the physics department, especially Kripke. As a result, he resigns and runs home to Texas. Leonard is reluctant to go and wait any longer to hook up with Penny; however, Penny insists that he go help Sheldon and assures him that she will be back in California waiting for him.

At his mother's home, Sheldon becomes increasingly annoyed by his mother's Christian lifestyle. The guys get to her home as Howard annoys her after he goes Texan on her and she tells him to cut it out. She's also happy to realize that Leonard has a girl he's eager to get back to; she's been praying for that. The guys want to bring Sheldon back, even though he is reluctant. Sheldon says that he will stay in Texas to teach Evolution to Creationists. Mary tells him that that is just his opinion. Quickly, he forgives the guys and they prepare to get his things and head back to Pasadena. Out of earshot, Mary indicates that this was the outcome she was praying for.

Back at home, Penny and Leonard finally hook up, but both of them now feel their relationship has gotten weird.



  • "I don’t think this show is in terminal decline just yet. Of course my standards for it and desires for it are different to its producers. But I still think it will stay fresher for longer with a little more care and attention than it currently receives." - The TV Critic's Review
  • IMDb user reviews


  • The title refers to the appliance that Leonard, Howard and Raj used to give Sheldon false results in lieu of killing him.
  • Chuck Lorre's vanity card [1]
  • This episode was watched by 12.96 million people with a rating of 4.7 (adults 18–49).
  • This episode aired in Canada on September 21, 2009.
  • Episode transcript [2]


  • Sheldon's experiment was to track slow moving magnetic monopoles at the magnetic North Pole.


  • Sheldon accuses his mother of having resorted to post hoc, ergo propter hoc, an informal fallacy in the form of "X occurred, then Y occurred, therefore X has caused Y to occur". The error is one of mistaking correlation with causation. In simple language, he is saying "one cannot assert that I came home safely only and only because my mother prayed for my safety". However, Sheldon himself is committing an informal fallacy because there is no evidence that his mother has said "only and only". In fact he is famous for dismissing anything that he himself cannot quantify as "hokum".


  • Sheldon believes his work on Magnetic Monopoles will gain him a Nobel Prize.
  • Howard and Leonard say that Sheldon has Vulcan hearing, referring to the race of people from Star Trek.
  • Sheldon makes reference to emoticons (himself being :D, then Raj noting he became :O following the revelation).

Costume Notes[]




Ames Bros Ray Gun


BDG stripes

Sheldon wears the green Goodnight celestial graphic shirt, his Ames Brothers Flash RayGun t-shirt, and his BDG multi-colored pin striped tee (discontinued from Urban Outfitters).



Red Tiger


Unknown moon/pagota

Leonard wears the Turntable shirt by Heavy Rotation, his red tiger head shirt from Zazzle, and an unidentified olive colored shirt with a moon/pagoda design.

Set/Props Notes[]

New on the set:


The Incident by Eric Joyner


Lgd/Drk Knight #159


The Demon #32


JLA #92

The Incident
by artist Eric Joyner
Bookshelves behind couch
Batman/Dark Knight #159
November 2002 Issue
Comic bins/Sheldon's room
The Demon #32
February 1993 issue
Comic bins/Sheldon's room
Justice League #92
March 2004 issue
Comic bins/Sheldon's room


  • First of eight episodes to have a "Previously on The Big Bang Theory" review of past events. It summarizes "The Monopolar Expedition" (S2E23) and it is narrated by Kaley Cuoco. The other seven are "The Cohabitation Formulation" (S4E16), "The Skank Reflex Analysis" (S5E1), "The Countdown Reflection" (S5E24), "The Date Night Variable" (S6E1) and "The Locomotion Interruption" (S8E1), "The Matrimonial Momentum" (S9E1) and "The Positive Negative Reaction (S9E16).
  • Leonard says, "You can still publish the actual results." Since it was an NSF expedition, it is not simply a decision to publish their results, it is a requirement.
  • Sheldon doesn't seem surprised that Leonard and Penny are beginning to date, as he was the one who correctly hypothesized that Penny wants him in the previous season finale (S2E23), just before the gang's expedition.
  • Penny described a scene from the new movie Star Trek in this episode, meaning she probably saw it even though the others didn't, which could indicate that she has begun to like their geeky things. This time was the only time she knew something about Star Trek that Sheldon didn't.
  • Sheldon's beard looks like the one Spock has in the "mirror universe" episode "Mirror, Mirror". Along with that, Howard and Leonard mention his "Vulcan hearing".
    • Sheldon's hair is pretty much the same length as usual while the others let theirs grow out. In the later episode "The Werewolf Transformation" (S5E18), it was developed that he likes to have it cut by a preferred barber so there isn't really an explanation how he accomplished this, other than knowing that he wouldn't be able to get a trim for two months and planned it out how to do it himself.
  • When Howard says to Mary Cooper he'll take a Diet Yoohoo in the DVD, she says he'll take a Coke, but on TV, she says "you'll take a cola".
  • Raj suggests Howard's hat is reminiscent of Woody's in Toy Story. Laurie Metcalf (who plays Mary Cooper) is in all four Toy Story films as the voice of Mrs. Davis.
  • Howard previously referred to cyanoacrylates in "The Work Song Nanocluster" (S2E18), as Leonard attempts to define them in this episode. 
  • The preserved snowflake from North Pole appears again in the later episode "The Toast Derivation" (S4E17).
  • In the special features for this episode on the DVD release, the actors actually grew real beards for filming, but they were told to shave them so that the make-up department could put fake ones on. It is never stated why this decision was made.
  • This season premiere episode takes place three/four months after the last episode of the previous season (S2E23).
  • Despite his statement to the contrary, Sheldon does mention Howard and Raj in his Nobel Prize acceptance speech in the Stockholm Syndrome, although it was for a different achievement.


Penny: Leonard, you’re back.
Leonard: Yeah, I just stopped by to say… (She grabs him and kisses him passionately.) Yeah, so, hi!
Penny: Hi! (They stumble, kissing, into her apartment and slam the door shut.)
Howard: Dammit, I should have gone over and told her we were back.
Raj: (Sarcastically) Yeah, it was first come, first served.

Leonard: Hey. Listen, since we got, you know, interrupted last night, I didn't have a chance to give you this.
Penny: Oh, Leonard, you shouldn't have. Oh, boy! What is it?
Leonard: It’s a snowflake. From the North Pole.
Penny: Are you serious?
Leonard: Uh-huh. It’ll last forever. I preserved it in a one percent solution of polyvinyl acetyl resin.
Penny: Oh, my God. That’s the most romantic thing anyone’s ever said to me that I didn't understand.

Penny: Well, wait a second, Leonard, come on, how can you not go? He’s your best friend.
Leonard: Yeah, but I already saw him naked. Just come here.
Penny: No. I promise I will be here when you get back. Just go help Sheldon.
Leonard: Really?
Penny: Yeah. We waited a few months. We can wait a few more days.
Leonard: Maybe you can.

(Leonard, Howard and Raj are at Sheldon's mother's place in Galveston, Texas, trying to get Sheldon to come home with them. Howard is wearing a goofy cowboy hat and a mustache. Leonard rings the doorbell.)
Leonard: Can you please take that stupid hat off?
Howard: No, I wanna blend in.
Raj: (he's looking rather puzzled) To what, Toy Story?
(Leonard chuckles at Raj's remark. Mary Cooper opens the door.)
Mary: Hi, boys.
Howard (with Texan accent): Howdy, Ma'am.
Mary: Howdy to you too, you got here quick.
Leonard: Ah, we took the Red Eye.
Mary: Well, come on in.
Howard (with Texan accent): Thank you kindly.
Mary: Can I, can I get you something to drink?
Leonard: Uh, no, thank you.
Howard (with Texan accent): Uh, if ya'll don't mind, I'm hankering for a Lone Star Beer.
Mary: (she's rather cross with Howard) There's no alcohol in this household, stop talking like that and lose the hat.
Howard (In normal voice): Sorry, I'll take a Diet Yoo-hoo if you have it.
Mary: You'll take a coke. (To Raj) What about you, Raj, is it? Oh you still having trouble talking to the ladies? (chuckles) Because you know at our church, we have a woman who's an amazing healer. Mostly she does, uh, crutch and wheelchair people, but I bet she'd be willing to take a shot at whatever third world demon is running around inside of you.
Leonard: Uh, if you don't mind, Mrs. Cooper there's a 3:05 non-stop back to Los Angeles and you have no idea how much I wanna be on it.
Mary: A girl?
Leonard: Uh, yes, ma'am.
Mary: Good, I've been praying for you.
(Sheldon walks into the room.)
Mary: Oh. Sheldon.
Sheldon: What are they doing here?
Leonard: Uh we came to apologize.
Howard: Again.
Leonard: And bring you home, so why don't you pack up your stuff and we'll head back.
Sheldon: No. This is my home now. Thanks to you, my career is over. And I will spend the rest of my life in Texas, trying to teach evolution to creationists.
Mary: (she really is cross with Sheldon) You watch your mouth, Shelly. Everyone's entitled to their opinion.
Sheldon: Evolution isn't an opinion. It's fact.
Mary(she's completley furious for the last time) And that is your opinion
(She now frowns whilst Sheldon is glaring harder at his mother for a few seconds)
Sheldon (Turning to the guys): I forgive you, let's go home.
(Goes to get his stuff.)
Mary: (she chuckles) Don't tell me prayer doesn't work.

Sheldon: (Knock, knock, knock) Leonard. (Knock, knock, knock) Leonard. (Knock, knock, knock) Leonard.
Leonard: (whispering) Do not make a sound.
Sheldon: Whispering "do not make a sound" is a sound.
Leonard: Damn his Vulcan hearing. Not a good time, Sheldon.
Sheldon: (Knock, knock, knock) Penny. (Knock, knock, knock) Penny. (Knock, knock, knock) Penny.
Penny: Oh, this is ridiculous. (Opens door) What?
Sheldon: Hello, Penny. I realize you're currently at the mercy of your primitive biological urges, but as you have an entire lifetime of poor decisions ahead of you, may I interrupt this one?
Penny: It's great to see you too. Come on in.