The gang is having fun using the X-10 system to send signals across the Internet and around the world from their apartment. Penny who joins them then asks "Why?", only to be met with a unified answer of "because we can". The guys also have a collection of remote-controlled cars in the apartment, equipped with wireless cameras, and these too were being be controlled remotely in other countries. As Penny stands in the doorway, the cars move to her, between her feet with webcams pointed up her skirt. Sheldon recommends that she wear pants. After Penny leaves, disgusted, we learn that Howard was controlling one of the vehicles.
When the gang is cleaning up after their little activity, Leonard finds a letter in the trash addressed to Leonard and Sheldon inviting them to present their research paper at a conference on Paradoxical Moment-of-Inertia Changes Due to Putative Super-Solids. As Leonard ponders how the invitation ended up in the trash, Sheldon clarifies that "There's always the possibility the trash can spontaneously formed around the letter, but Occam's Razor would suggest that someone threw it out." He goes on to explain that he threw it away because he refuses to give a speech to a crowd of unappreciative people. Leonard is angered as Sheldon claims their work's success is largely due to him and as such, he makes the key decisions for it. Sheldon also belittles the audience that will attend the conference, noting that they "wouldn't recognize true genius if it was standing in front of them giving a speech...which if I were there it would be." Despite this argument, Leonard is still keen on presenting their paper at the conference.
Penny comes over to help Leonard pick out a suit to wear to the conference. She finds a closet full of clothes that he has had since he stopped growing in middle school. He also has a "Battlestar Galactica" flight suit that he refuses to wear as a Halloween costume. Leonard also explains to her that his situation with Sheldon has deteriorated. Later, Sheldon and Penny bump into each other while getting their mail, which includes Sheldon's latest copy of Applied Particle Physics Quarterly. On the way up, Penny attempts to mend Leonard and Sheldon's relationship, but instead she worsens the situation. Before Leonard leaves for the conference he makes a final offer to Sheldon asking to present the paper together, he refuses. At the conference, after Leonard finishes presenting, he opens the floor for Q&A, with Sheldon quickly posing a mocking question. These disagreements quickly erupt into a fight between Leonard and Sheldon. After the conference, Sheldon apologized to Leonard for trying to blow up his head with his mind as they did in the film "Scanners".
Suddenly, Howard]and Raj burst in and announced that their fight was posted on YouTube (by Howard). Howard also took a picture of Penny asleep on his shoulder and posted it as a picture of his girlfriend. Penny found it and, mimicking Sheldon, makes the motions of trying to make Howard's head explode. The final scene shows two geeks from "Somewhere in China", who resemble Chinese versions of Leonard (Talbott Lin) and Sheldon (Howard Chan) watching and mocking the aforementioned video. Howard uses the Internet to switch the two guys' lights on and off, much to their excitement.
- Guest starring:
- Teleplay: David Goetsch, Chuck Lorre & Lee Aronsohn
- Story: Bill Prady & Stephen Engel
- "The show is so close to breaking out from the pack and becoming an excellent character comedy, but the writers are missing the point. In the last few episodes, in particular, they have set up well written plots, which fall away rather than making a point. The producers of the show worked for long stretches on "Two and a Half Men", a show more concerned with punch lines than characters. I hope that the producers chose to develop the show in a different direction, because it can be so much more than it is." The TV Critic's Review
- IMDb user reviews.
- Title Reference: The title refers to the opposites sides of the fight that develops between Leonard and Sheldon.
- Chuck Lorre's vanity card 
- This episode was watched by 9.11 million people with a rating of 3.6 (adults 18-49).
- Episode transcript .
Sheldon starts out wearing his "Blue Robots" shirt (which is actually black robots, on a light blue shirt). As Sheldon tries to make Leonard's head explode, he's sporting the green version of the Celestial Graphic tee. As Sheldon and Penny discuss the rift between the room mates, Sheldon wears the Batman Action Duo shirt. Leonard wears his red periodic table shirt and his white recycle logo shirt. While helping Leonard pick out clothes, Penny wears the Celestial Printed Hoodie by Truely Madly Deeply (discontinued from Urban Outfitters). During the conference, she wears a Peacock Charmeuse Top from Free People. Howard wears a silver Batman belt buckle and a reel to reel player belt buckle.
New on the set:
- Penny opens the top-right mail box while Sheldon opens the top-left. In future episodes Penny opens the top-second (from left to right) just next to the boys' mail box. This makes more sense as they reside on apartments 4A and 4B. Based on each floor level apartment doors and knowing that there is a fifth floor, there are still a few extra mail boxes.
- Sheldon feels Leonard's chance of winning a Nobel Prize is non-existent, as he also said in the "Pilot" (S1E1).
- Penny later references Leonard's wearing of his costumes not just for Halloween in "The Ornithophobia Diffusion" (S5E9).
- Leonard confesses that his last growth spurt was in the 8th grade.
- Leonard only has a corduroy suit, but he actually wore a three-piece suit in "The Luminous Fish Effect" (S1E4).
- Leonard has a "Battlestar Galactica"' flight suit.
- The Flash's costume from "The Middle-Earth Paradigm" (S1E6) is seen in Leonard's closet.
- The display prop in front of the Rose Room of the Pasadena Marriott for Leonard's topical conference on Bose-Einstein condensates has an error: "Paradoxical Movement-of-Inertia Changes Due to Putative " should read "Paradoxical Moment-of-Inertia Changes Due to Putative Super-Solids." Leonard's PowerPoint presentation slides and dialogue, on the other hand, are correct.
- After Howard informs Leonard that there are approximately 25 people in attendance for the Institute for Experimental Physics topical conference on Bose-Einstein condensates, Leonard remarks that "in particle physics, 25 is Woodstock". However, Bose-Einstein condensates are at the Condensed Matter/AMO Physics interface, not research in the field of Particle Physics as Leonard indicates. Though, Leonard may have been simply comparing the turnout at this conference to an analogous case from his experience as a participant at particle physics conferences.
- Leonard's spherical chicken joke: "There’s this farmer, and he has these chickens, but they won't lay any eggs. So, he calls a physicist to help. The physicist then does some calculations, and he says, um, I have a solution, but it only works with spherical chickens in a vacuum." This joke is a variation of the spherical cow joke. The point of the joke is that physicists will often reduce a problem to its simplest form in order to make calculations more feasible, even though such simplification may hinder the model's application to reality.
- Leonard received his doctorate at 24 years old, while Sheldon earned his doctorate at 16 years old.
- Though the scene changes from the Marriott to apartment 4A at the end of the episode, the signature transition of the series (a shot of an atom on a colored background) is absent.
- The embarrassing YouTube video of Sheldon and Leonard fighting is underscored with "Three Blind Mice". There are four notable differences between the video and the conference it was shot at: 1) Leonard throws Sheldon against the wall at the conference, but not in the video, 2) Raj turns his head to look at Howard's camera cell phone more obviously during the video than he does at the conference, 3) Leonard says to Sheldon 'Quit it' once at the conference, but in the video he says it twice, and 4) Howard and Penny's short conversation where Penny asks if these physics conferences typically include this behavior is not shown in the video.
- Embarrassing YouTube videos would factor into several more episodes: Sheldon's drunken acceptance speech in season 3's "The Pants Alternative" (S3E18), Raj's way-too-revealing toast at Howard's stag party in season 5's "The Stag Convergence" (S5E22), and Howard's screaming for nine minutes aboard the ISS in season 6's "The Decoupling Fluctuation" (S6E2).
- The "Physicists Gone Wild" YouTube video shown in the episode was actually uploaded onto YouTube by an account named "WOLOWIZARD", but was taken down shortly after presumably for legal reasons.
- The episode was directed by Joel Murray, who appeared on Chuck Lorre's earlier sitcom, Dharma & Greg".
- The Mandarin physicist at the end is wearing a Greatest American Hero t-shirt, the same one Sheldon would later wear in Season 2, Episode 4, the Griffin Equivalency and future episodes.
- First episode after the 2007–2008 Writers Guild of America strike, which lasted from November 2007 to February 2008.
- Longest episode title during season 1.
- First new episode broadcast in 2008.
- In this episode Leonard clearly states that scientists do not apologize, yet Sheldon apologized in "The Big Bran Hypothesis" (S1E2), "The Apology Insufficiency" (S4E7), and "The Parking Lot Escalation" (S6E9). It should be noted that in the first example Leonard told Sheldon to apologize not by choice and in the second and third examples, he apologizes to Howard because he messed something up and making things worse.
- The episode was originally supposed to be filmed during the week of November 5, 2007, however was halted due to the 2007-2008 Writer's Guild of America strike.
- Before the strike, It was rumored on an older version of the Wikipedia list of episodes that the episode would be aired on November 19, 2007.
Penny: So, you know, isn't there maybe some way you and Sheldon could compromise on this whole presentation thing?
Leonard: No. Scientists do not compromise. Our minds are trained to synthesize facts and come to inarguable conclusions. Not to mention Sheldon is bat-crap crazy.
Leonard: Any questions?
Sheldon: Yeah. What the hell was that?
Leonard: Any other questions?
Sheldon: Dr. Sheldon Cooper here. I am the lead author of this particular paper. Thank you. You, sir, you have completely skipped over the part where I was walking through the park, and I saw these children on a merry-go-round, which started me thinking about the moment of inertia, in gases like helium, at temperatures approaching absolute zero.
Leonard: I didn't skip it. It's just an anecdote. It's not science.
Sheldon: Oh, I see. Was it the apple falling on Newton's head? Was that just an anecdote?
Leonard: But you're not Isaac Newton.
Sheldon: No, that's true. Gravity would've been apparent to me without the apple.
Leonard: You cannot possibly be that arrogant.
Sheldon: You continue to underestimate me, my good man.
Leonard: Look, if you weren't happy with my presentation, then maybe you should've given it with me.
Sheldon: As I had explained repeatedly, unlike you, I don't need validation from lesser minds. (to audience) No offense.
Leonard: Really? So why did you come?
Sheldon: Because I knew you'd screw this up.
Leonard: I didn't screw it up!
Sheldon: Oh, please. I admit that "spherical chicken" joke, that was hilarious, but it went straight downhill from there.
Leonard: You know, I've had enough of your condescension. Maybe I didn't go to college when I was eleven, like you! Maybe I got my doctorate at twenty-four instead of sixteen, but you're not the only person who's smarter than everyone else in this room! (Sheldon gestures Leonard to audience; to audience) No offense. And I'm clearly not the only person who is tormented by insecurity and has an ego in need of constant validation!
Sheldon: So you admit you're an egotist?
Leonard: Yes! (to audience) My name is Dr. Leonard Hofstadter, and I could never please my parents, so I need to get all my self-esteem from strangers like you (points to Sheldon), but he's worse!
Sheldon: Okay, that is it! (puts fingers on his head)
Leonard: Stop it. You cannot blow up my head with your mind!
Sheldon: Then I'll settle for an aneurysm!
Leonard: (slaps Sheldon's hands) Stop it.
Sheldon: You hit me. (to audience, points at Leonard) You saw that, he hit me.
Leonard: You tried to blow up my head.
Sheldon: So it was working.
Leonard: It wasn't - it was not -- you're a nutcase!
Sheldon: Oh, we'll see about that! (puts fingers on his head, to audience) Heads up, you people in the front row, this is a splash zone!
Leonard: Stop it! (slaps Sheldon's arms) Quit it! (Leonard slaps Sheldon's arms repeatedly and holds his wrists)
Penny: Is this usually how these physics things go?
Howard: More often than you think.
Sheldon: (Both he and Leonard are on the floor) I'll give you a Vulcan Nerve Pinch!
Howard: Gentlemen, I am now about to send a signal from this laptop through our local ISP, racing down fiber-optic cable at the speed of light to San Francisco, bouncing off a satellite in geosynchronous orbit to Lisbon, Portugal, where the data packets will be handed off to submerged transatlantic cables terminating in Halifax, Nova Scotia, and transferred across the continent via microwave relays back to our ISP and the X10 receiver attached to this (clicks mouse, lamp switches on) lamp. (The others cheer and clap).
Penny: Get anything good?
Sheldon: Uh, just the latest copy of Applied Particle Physics Quarterly.
Penny: Oh, you know, that is so weird that yours came and mine didn’t. (Sheldon looks confused). It was a joke. (Sheldon gives a fake laugh.) Yup, tip your waitresses, I’m here all week.
Sheldon: Libido, one. Truth, zero.
Leonard: Okay, I’m going to ask you one more time, we did the work together, lets present the paper together.
Sheldon: And I’m telling you for the last time it’s pandering, it’s undignified and bite me.
Penny: I really should have brought my own car.
- Sheldon: You could have offered me a ride home.
- Leonard: You’re lucky I didn't run you over.
- Sheldon: I really don’t understand what you’re so unhappy about, you begged me to come, I came, there’s just no pleasing you.
- Leonard: You’re right, I’m the problem, I’m the one that needs help.
- Sheldon: Well that’s not much of an apology, but I’ll take it.
- Leonard: Excuse me. Is there anything you’d like to apologize for?
- Sheldon: Yes. I’m sorry I tried to blow up your head. It was uncalled for.
- Penny: (entering) Howard, would you like to explain to me why your Facebook page has a picture of me sleeping on your shoulder captioned “Me and my Girlfriend"?
- Howard: Uh-oh, here comes “the talk.”
- (Penny tries to make Howard’s brain explode)
|Episodes | Season 1|