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"The Jerusalem Duality" is the twelfth episode of the first season of the American sitcom The Big Bang Theory. This episode first aired on Monday, April 14, 2008.


Dennis Kim, a child prodigy, is looking around the university and seems to have outstripped Sheldon's achievements in every way. Sheldon decides to give up his own work and focus on other tasks. It annoys the guys so much that they try to distract Dennis in order to get Sheldon back to normal.

Extended Plot

Dennis Kim is being introduced.

At work, Sheldon and Leonard discuss problems of teleportation. Sheldon is adamantly against being disintegrated even if he is exactly recreated. He simply can't allow the original Sheldon to be destroyed. Dr. Eric Gablehauser introduces Dennis Kim, a new 15-year-old child prodigy and wants the boys to make him feel welcome. Kim is dismissive of Sheldon's work in string theory calling it a dead end. Kim starts explaining to Sheldon about false vacuums, but gets distracted by chocolate milk in the vending machine. Sheldon muses "I sense a disturbance in the force." ala Star Wars.


As Sheldon and Leonard show Dennis around, we see Sheldon's office for the first time. On seeing Sheldon's whiteboards, Dennis comments negatively on Sheldon's work in quantum loop corrections. He questions if Sheldon has considered a field theory approach. Sheldon takes exception, then orders Leonard to get Dennis out of his office. On their way out, Dennis sees Sheldon's Stevenson Award. Sheldon takes great pride in announcing that he is the youngest person to win the award at "fourteen and a half". "You WERE the youngest winner",  Dennis corrects him, strutting out of the office. 

Back at the apartment, Sheldon is fuming about Dennis Kim's presence, upset that at fifteen years old, Dennis is correcting Sheldon's work.  Sheldon adds that he has gone from "being Stevenson Mozart, to being...that other guy". When Howard chimes in with Salieri's name, Sheldon is despondent, noting "Oh God, now even you're smarter than me". Leonard encourages Sheldon to eat something, then he'll feel better. Sheldon doubts this because "In Texas when a cow goes dry, they don't keep feeding it, they just take her out back and shoot her between the eyes". Sheldon always knew that some day someone smarter would come along; but he always assumed that he would have been dead for hundreds of years and that the new smarter someone would have an asterisk beside their name because they were a cyborg. Sheldon determines that the rational thing is to give up fruitless efforts in his own field and point his efforts in a new direction; dedicating himself to scientific research and waiting to die. Penny questions whether they have to WAIT for him to die, or if they get to shoot him between the eyes.

Dinner with the gang.

Later that night, Sheldon has decided that with his own line of research blown up by Dennis, he will instead collaborate with Leonard. He asks Leonard to clarify exactly what he does; he's listened to Leonard talk about his work, but he never really paid attention. Leonard is currently designing an experiment to study the soft component of cosmic radiation at sea level. Sheldon looks at Leonard's design and asks about a laser array in the schematic, questioning why he's using helium lasers instead of argon lasers. Leonard tells him that he's pretty sure it would blow up. Sheldon knocks Leonard's scientific method:  "Pretty sure is not very scientific. It this how you usually work? With hunches and guesses and stuff"?  Leonard finally has enough, telling Sheldon to "GO AWAY!".

The next day, Sheldon attempts to collaborate with Howard in engineering. Sheldon has made it clear over time that he regards Howard in particular and engineering in general to be far far beneath his own level of science.  Sheldon has never visited Howard's work space in the 3 years he'd worked there, so when he shows up, Howard is immediately suspicious of Sheldon's presence. Howard shows Sheldon that he's working on a payload support structure that is going up on the next space shuttle. Sheldon looks it over and declares, "so it's a shelf". He further critiques the design, from the choice of metal to the structural details. Howard reminds Sheldon that he has a diploma in his office that says he has a Masters in Engineering. Sheldon rebuts, picking up a piece of paper on Howard's desk; "You also have a note from your mother that says 'I love you, bubbulah'. But neither of those is a cogent argument for titanium over nanotubes". Howard mimics Leonard's response to Sheldon's meddling: "GO AWAY!" Sheldon wants to know if Leonard told him to say that. Howard retorts that he came up with it on his own. Sheldon walks away, pondering how this cannot be coincidence, and wondering what causal link he's missing.

We don't see the interaction between Sheldon and Raj, but predictably, it ends the same way, and we see Raj angrily throwing Sheldon out of his office with the predicted "GO AWAY!" Sheldon leaves, muttering to himself "Curiouser, and curiouser".

Back at the apartment Howard and Raj show up to discuss the situation with Leonard. Raj tells Leonard that Sheldon watched him work for 10 minutes then started designing a piece of software that could replace him. Leonard isn't sure what CAN be done, as Sheldon will never be able to cope with the fact that a 15 year old kid is smarter than him. Raj wonders what would happen if "something happened" to Dennis so he would no longer be a threat to Sheldon. Howard suggests they use " know....biology" to distract Kim from academics.

Sheldon gets home, excitedly babbling about how, if they all teamed up, they could lick cold fusion in a decade, twelve years tops. They all glare at Sheldon, who seems to be learning, as he asks.."go away?". They all nod and Sheldon is at the brink of an epiphany: "Could it be ME?"

Leonard, Howard, and Raj seek Penny's help. They want to try to "distract" Kim by hooking him up with a girl, so they ask her where to get a hot Asian 15-year-old girl with a thing for smart guys. Leonard points out that Howard's comment was racist, and that ANY hot 15-year-old girl will do. Penny slams the door on them. 

Sheldon applies himself to winning the Nobel Peace Prize for solving the Middle East crisis by creating a second wailing wall (also called the "Western Wall") in the Mexican desert.  Dr. Gablehauser and Dennis Kim stop by. Sheldon explains his concept to them; convinced that, like the baseball movie "build it and they will come", adding that he plans to lure the Jewish people by "making it nice...we'll put out a spread".  His jealousy and hatred for Dennis is still apparent as he asks Kim "You can see ""The Matrix", can't you?" Gablehauser takes Dennis down the hall...explaining that Sheldon "is nuts". As they leave, Sheldon can be heard singing the Jewish folksong, "Hava Nagila".

"Bring Your Daughter to Work Day", a scheme obviously invented by the boys as a means to populate the event with prospective young women to distract Dennis. As the boys plot how to get a girl interested in Dennis, Dr. Gablehauser gives his welcome speech and introduces Dennis. When asked if he'd like to give a few words about his upcoming research, Kim declines, instead leaving the party in his honor to go to the mall with Emma, one of the beautiful daughters in attendance, leaving the boys speechless that he was able to land such a girl on his own. Sheldon steps in to cover the awkward silence left by Dennis' departure. He takes advantage of the situation to announce to the crowd that his own work will continue and that social relationships will continue to baffle and repulse him.

Later at the park, the boys have been playing with model rockets. Howard is annoyed that even with his work orbiting Earth on a space shuttle, he received a ticket for launching his rocket in the park. Leonard points out that it was probably due to Howard's insistence to the police woman that she frisk him. The boys come across Dennis Kim, disheveled, making out with Emma and drinking what appears to be alcohol from a bottle in a paper bag. He gives the impression of being a ruined person. Raj feels bad for what they did to him. Sheldon has no such sympathies, noting: "Screw him, he was weak."



  • "I hope the producers can see the value of telling real stories and giving their characters developed personalities. Otherwise it is going to be a frustrating few years for viewers who crave something more. The show is good enough to survive and entertain but it could be even better. This is a typical effort, I hope one day it will be atypical."[1] The TV Critic's Review
  • IMDb user reviews


  • Title Reference: Sheldon tries to build an exact replica of Jerusalem in the middle of the Mexican desert after his work in theoretical physics seems useless. Sheldon wants to bring peace to the Middle East using this concept.
  • Chuck Lorre's vanity card[2]
  • This episode was watched by 7.69 million people with a rating of 2.8 (adults 18–49).
  • Episode transcript [1]

Costume Notes

Stripes by Urban Outfitters

Sectrum by Urban Outfitters

Black & Grey

Superman logo

Sheldon's shirts in this episode are mostly from Urban Outfitters...all of which are discontinued. If you want these, you're going to have to find them used. Sheldon starts the episode in a gray and purple striped tee with a yellow horizontal accent. When visiting Howard's engineering space at the university, Sheldon sports a gray tee with spectrum bars on it. He works on the New Jerusalem in Mexico problem wearing a black tee with dark gray stripes, and ends the episode with his Superman distressed logo shirt.


Cat/Dog shirt

Atomic Structure


Leonard starts in his orange tee with large tree graphic (Sheldon wears this same shirt in season three), then moves into his half cat/half dog shirt, his red atomic structure shirt, and finally his green shirt with white recycle logo.

Classic Bat buckle

Yellow Vans

45 Adapter buckle

Keyboard belt

Howard sports a Batman classic logo belt buckle. When Sheldon visits his office, Howard is wearing yellow Vans (pretty hard to find these days). At the gathering to honor Dennis, he's wearing a keyboard belt with a 45 record adapter buckle. As the guys see Dennis hanging out at the park, he's got a Celtic/Maltese cross buckle.


  • First episode to feature a scene shot outside.
  • Eric Gablehauser: "And he’s (Dennis Kim) only fifteen years old." Sheldon: "Not bad, I myself started graduate school at fourteen." Dennis: "Well, I lost a year while my family was tunneling out of North Korea." Leonard: "Advantage Kim." Leonard's response does not make sense, as Dennis Kim would have been 14 like Sheldon if he hadn't lost a year. Moreover, since Kim did lose a year, the advantage goes to Sheldon.
  • Dr. Gablehauser refers to Dennis Kim as a doctoral candidate to indicate that he is a potential Ph.D. student of the Caltech Physics Department; however, the term aforementioned applies only to admitted doctoral students who have completed all of the formal coursework and comprehensive examinations required of the degree, but have yet to complete the doctoral dissertation. Hence, Dennis is merely a prospective doctoral student, as opposed to a doctoral candidate.

Dennis Kim examines Sheldon's result for a massless self-energy integral on the two-loop level.

  • When Dennis Kim enters Sheldon's office, his whiteboard features a massless two-loop self-energy diagram and the evaluation of the associated multiloop Feynman integral. Multiloop Feynman integrals appear when quantum-field amplitudes are constructed within perturbation theory. They are integrals over so-called loop momenta. Feynman integrals are usually complicated objects even in a one-loop approximation, so that the number of loops equal to two is already considered big. Feynman invented their graph-theoretic interpretation. (Refer to Graph Theory and Feynman Integrals by Noboru Nakanishi.)
  • First time the Caltech cafeteria is seen.
  • First time Sheldon's office is seen.
  • Sheldon states, "If you’re concerned about sharing credit with me, your name can go first." In "The Cooper-Hofstadter Polarization", Sheldon was not so content with Leonard going first: "I let you think we went alphabet|alphabetically to spare you the humiliation of dealing with the fact that it was my idea. Not to put too fine a point on it, but I was throwing you a bone. You're welcome." In "The Cooper-Nowitzki Theorem", he absolutely refuses to share credit.
  • Second episode where Sheldon perceives guesses as unscientific. The first was "The Loobenfeld Decay".
  • Dennis Kim points out that Sheldon's string theory research is at a dead end. This foreshadows the events of "The Relationship Diremption", where Sheldon finds out his long-time string theory research is going nowhere. Eventually he wins a Nobel Prize for his string theory work.
  • This is the first episode where the guys make an inappropriate question by asking Penny if she can help them find a hot 15-year-old girl into smart guys, not realizing what that sounds like.
  • Strangely, none of the guys seemed to consider what might happen if Dr. Gablehauser found out that they ruined his brightest recruit ever.
  • Sheldon's comment about Dennis seeing "The Matrix" makes the former assume that Dennis Kim is able to detect the "real" reality from which the movie series takes its name; that mankind is actually enslaved by machine machines who live off of human body heat and electrochemical energy and that most people are in a sort of state of hypnosis, living an artificial reality imposed on them.
  • Despite not having a line, Emma in this episode was credited at the end, which in strange because characters who do not have any speaking roles are considered extras and are not usually credited such as Lonely Larry and Captain Sweatpants.
  • Sheldon says to Howard "Oh god, now even you're smarter than me!" This is inconsistent with Sheldon's character given that the grammar he would've used is "Oh god, now even you're smarter than I." Sheldon is shown to have a great understanding of grammar so this is odd.
  • In this episode, we learn that Howard has had his lab for 3 years (2004 or 2005), but he'd been at Caltech longer based on "The Staircase Implementation".


  • Leonard says "A bad feeling I have about this!" doing a Yoda impression. Yoda would probably have said "A bad feeling about this I have!".


Gablehauser: Gentlemen, I’d like you to meet Dennis Kim. Dennis is a highly sought after Doctoral candidate and we’re hoping to have him do his graduate work here.
Leonard: Graduate work, very impressive.
Gablehauser: And he’s only fifteen years old.
Sheldon: Not bad, I myself started graduate school at fourteen.
Dennis: Well, I lost a year while my family was tunneling out of North Korea.
Leonard: Advantage: Kim.

Sheldon: 15 years old—Dennis Kim is 15 years old, and he's already correcting my work. Today I went from being Wolfgang Amadeus Mozart to—you know—that other guy.
Howard: Antonio Salieri.
Sheldon: Oh, God, now even you're smarter than me.

Sheldon: Engineering—where the semi-skilled laborers execute the vision of those who think and dream. Hello Oompa-Loompas of science.

Sheldon: Something remarkable. Since my prospects for the Nobel Prize in physics have disappeared, thank you very much, I've decided to refocus my efforts and use my people skills to win the Nobel Peace Prize. Look, I’m going to solve the Middle-East Crisis by building an exact replica of Jerusalem in the middle of the Mexican desert.
Gablehauser: To what end?
Sheldon: You know, it’s like the baseball movie, build it and they will come.

Penny (opening door): Oh, hey guys, what’s up?
Howard: We need a hot fifteen year-old Asian girl with a thing for smart guys.
Penny: What?
Leonard: Howard, that’s racist, any fifteen year-old girl will do the trick. (Penny slams door.)
Raj: It’s possible she may have misunderstood us.

Gablehauser: You'll have to excuse Dr. Cooper, he's been a under a lot of, um... He's nuts.