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"The Explosion Implosion" is the fourth episode of the eleventh season of the American sitcom The Big Bang Theory. The episode aired on Monday, October 16, 2017.


Howard and Sheldon begin to bond while launching one of Howard's old model rockets while Penny and Beverly bond as they have conversations on the phone, which bothers Leonard.

Extended Plot[]

While waiting to have Bernadette's sonogram, Howard says that it doesn't seem that long since they were doing that. Bernie replies that it hasn't been that long and that he should get a vasectomy. The technician comes in asking if they are ready to find out the sex of their baby. Yes. Howard and Bernadette say that they don't care which sex it is, though they aren't too excited when they hear that it's a boy.

In apartment 4A talking to the gang who are expressing doubts that they can raise a son. Amy wonders if Bernadette wants a little version of Howard. She quips that she already has a little version of Howard. Howard doubts that he can teach a son manly things. Leonard reminds him that he was an astronaut. Howard did build model rockets when he was younger which excites Sheldon.


Putting away Halley's clothes.

Leonard comes down the hall with his Captain Captain Kirk shirt explaining that he has to have it dry cleaned to get the green stain out. Penny was wearing green body paint. The computer rings that Beverly Hofstadter was calling so Leonard runs out the door. Penny talks to Beverly and learns of her Cuban dinner and unsatisfying coitus of the previous night. "Okay," replies a disinterested Penny. Beverly anticipates her next questions with the answers roast pork and sidewise missionary.

Raj, Howard and Sheldon are going through Howard's old rockets. Sheldon used to launch them too; once burning down their garage. Sheldon finds the Saturn V model Howard's Dad got him just before he left Howard's mother. Howard never wanted to use it. Then Howard suggests that he and Sheldon build it now as a bonding experience. Sheldon didn't think that that was a positive.

Raj is talking to Bernadette since Howard and Sheldon were bonding over their miserable childhoods. Bernie is putting away Halley's clothes that she has out grown since their new baby is a boy. Raj tells her how modify some of the clothes for a son.

Sheldon and Howard are driving out to launch their rocket. Howard brought peanuts because at JPL they always have peanuts around as a superstition to have a successful launch. Sheldon doesn't like the peanuts story if it's a superstition, but does like it if it's a tradition. So he wants to get the peanuts.

Penny answers the phone and is surprised to finds out that Beverly called to talk to her. She enjoyed talking to Penny and wants to continue their conversation since she doesn't have a lot of girlfriends. All of her female colleagues are Freudians so all she can complain about her father joked Beverly. Beverly then wants to talk about Penny's life. Penny wants them to find a girlfriend so they can trash talk her behind her back. Beverly wants to be catty. She starts that she finds Amy a bit dour. Meow.

Out in the desert, Howard is preparing the rocket while Sheldon photographs it. First they argue if the countdownshould start T-minus or L-minus. When countdown reaches zero, Howard ignites the launch sequence as the rocket blows up on the launch pad. Sheldon remarks that he thought they went higher. Howard is now upset because he thought this was the one thing he could do with his son. Sheldon finds the video he took when played slow motion is neat. Howard exclaims that he doesn't know anything about raising a boy. Sheldon retorts asking him what he knows about raising a girl.


Why not T minus?

Penny gets a text from Beverly and tells him how she keeps contacting her. Leonard warns that she could be the subject of his mother's next book. It seems that they have really been supporting each other which bothers Leonard since she never did that with him. He was never proud of him.

Back in the desert, the guys are picking up what was left of the rocket. Sheldon is trying to cheer up Howard with reasons like, the launch was terrible, but the explosion was glorious. Sheldon hopes that he won't be mopey all the way home, so he thinks up an amazing trigonometry riddle.

Raj is working on some of Halley's old clothes and his attempt at putting a bat and two baseballs on it looks like the boy's tiny male organ. Bernadette is fine with having a son since she grew up with brothers.

Leonard goes over to talk to Amy who is working on her computer. He is worried that Penny and her mother are talking to each other like they are best friends. Amy assures him that they are since Amy is Penny's best friend. Leonard disagrees causing Amy to wonder if she has been neglecting their friendship. Each of them starts talking about their problem ignoring the other one. Amy concludes that she deserves her own life. Leonard walks out with no real solution.

Heading back home, Sheldon is worried that Howard's emotional problems will distract his driving. Howard adds that irritating passengers causes the same thing. Sheldon asks if he can drive since he has a license. He barely passed his test, but the road was straight and no one was around. And Howard didn't seem to have a reason to live.


Sheldon trying to drive.

Leonard calls his mother who was expecting Penny. Leonard wants to know why she isn't proud of him. Of Penny and the rest of her children's spouses, she is the one she is most impressed with. She's confident, caring and doesn't complain about Leonard. Then she tells Leonard that he married well and she is proud of him for that reason. That drives Leonard to tears.

Sheldon is now driving Howard's car with Howard coaching him. Sheldon thinks that Howard is a good teacher and that his son is lucky to have him as a father. Sheldon then speeds up scaring Howard and ends up getting stopped by a police officer. He knows he was going 112 mph. After the officer asks Sheldon for his license, Sheldon just tells him to keep it.



  • Title Reference: Sheldon and Howard try to launch a model rocket that explodes.
  • Taping date: September 12, 2017
  • This episode was watched by 13.07 million people with a rating of 2.8 (adults 18–49).
  • Total viewers including DVR users 17.71 million.
  • This episode aired in Canada on October 16, 2017.
  • Chuck Lorre's vanity card [1].


  • Caroline Preece at Den of Geek! - One thing The Big Bang Theory had to prove when announcing another pregnancy for Howard and Bernadette was how different it could be from the first. There's the commonly held idea that babies ruin shows, but so far The Big Bang Theory has not only sidestepped a lot of the challenges - chiefly by not ever having to have a baby on set - but also milked the scenario for multiple plot lines and running jokes. So why have Bernadette become pregnant again, rather than Amy or Penny? Well this time they're having a boy, and boys present a lot more challenges for the couple...But as Sheldon says in one of the more interesting pairings of the season, he knows just as little about raising a daughter, and he and Bernadette are doing fine there...I'm a sucker for whenever The Big Bang Theory acknowledges how awesome Penny is aside from how much more traditionally attractive she is than the rest of her friends, so this is a sweet little side story. It also leads to a funny aside from Amy, who becomes manically insecure that Penny could possibly have another friend besides her. It's been a while since we’ve seen this side of their relationship come out, and I'd really love for it to come back in the run up to the wedding. [2]
  • IMDb user reviews


  • Beverly will return in this episode, Leonard Skypes with her.[2] This is the first time Beverly told Leonard she was proud of him and first time they ever bonded.
  • Howard and Bernadette's second child is revealed to be a boy.
  • Sheldon reveals to Howard that he has a driver's license.
  • In this episode, Sheldon is seen driving for the first time; however, in "The Adhesive Duck Deficiency" Sheldon drove Penny to the hospital after she dislocated her shoulder, though it wasn't seen in that episode.
  • So far, Amy and Howard are the only ones who know about Sheldon's license.
  • When Sheldon shows the police officer his license, he tells him to keep it. It is unclear whether he is joking at that point or whether he'll get the license back at some point in the near future.
  • Amy appears in just two scenes in this episode
  • Raj said he had a good relationship with his parents growing up. When he was an adult, sometimes he has an estranged relationship with them and mostly they usually threatened to cut him off if he messes up.
  • When Sheldon tells Howard that he finds his Saturn V model rocket in the box unopened, Howard already has one sitting on the table.


Leonard Hofstadter: [Howard is nervous about having a son] It's okay. We're all here to help.
Sheldon Cooper: Yes. And this baby will have plenty of manly role models. You know, I'm certain that whatever Bernadette can't teach him, Penny can.
Leonard Hofstadter: Uh, she can pee into a bottle.
Penny Hofstadter: Mm-hmm. Anything with a neck wider than a nickel.

Penny Hofstadter: Hey, Beverly.
Dr. Beverly Hofstadter: Oh, hello, Penny.
Penny Hofstadter: Uh, Leonard just left. He's gonna be so upset he missed your call.
Dr. Beverly Hofstadter: Why?
Penny Hofstadter: Because he... yeah, I don't know. How are you?
Dr. Beverly Hofstadter: Did you mean personally or professionally?
Penny Hofstadter: Um, personally? Like, what'd you do last night?
Dr. Beverly Hofstadter: I had Cuban food at the home of a man with whom I shared unsatisfying intercourse.
Penny Hofstadter: Wow. Okay.
Dr. Beverly Hofstadter: And to anticipate your next questions, roasted pork and sideways missionary.
Penny Hofstadter: Sure. Sure. 'Cause you were full.

[first lines]

Howard Wolowitz: [as the doctor's office] It feels like it wasn't that long ago we were here doing this for Halley.
Bernadette Rostenkowski: 'Cause it wasn't. Which reminds me, before we leave, let's get you a vasectomy.
Howard Wolowitz: Oh, that's sweet, but today is all about you.

Dr. Sanders: So, you two ready to find out the sex of this baby?
Howard Wolowitz: Yeah
Bernadette Rostenkowski: Absolutely.
Dr. Sanders: Is Halley hoping for a little brother or a little sister
Bernadette Rostenkowski: Well, she's nine months old, so unless it jingles or is in my bra, she doesn't care.

Raj Koothrappali: Come on, you can't really be disappointed.
Howard Wolowitz: Hey, I barely know how to be a man myself. Now I have to teach someone?
Sheldon Cooper: Hmm. As the saying goes, those who can't do, teach.

Amy Farrah Fowler: Don't you want a little version of Howard?
Bernadette Rostenkowski: I already have a little version of Howard
Howard Wolowitz: Now I'm having a son? I'll have to teach him how to play sports, and... and *watch* sports, and... and... and... and... and... and...
Raj Koothrappali: [to Leonard] He just ran out of man things. He's in trouble.

Bernadette Rostenkowski: Howie, there's a lot of amazing things you can teach a son.
Raj Koothrappali: Yeah. You do always know how to pick just the right antacid.
Howard Wolowitz: I don't know if I can teach that. It's just something I was born with.

Howard Wolowitz: You know, as a kid, I used to make model rockets. That'd be pretty cool to do with a son.
Sheldon Cooper: Model rockets. Finally, something interesting. What is your preferred mode of conveyance?
Amy Farrah Fowler: Sheldon, we're helping our friends.
Sheldon Cooper: And we got to model rockets, yeah? It was a tedious road, but well worth the effort.
Amy Farrah Fowler: So, have you thought of any names?
Sheldon Cooper: Amy, we finally got to model rockets. Why are you turning back?

Penny Hofstadter: Hey, where you going?
Leonard Hofstadter: Back to the dry cleaner. Look at this. They didn't get the stain out of my Starfleet uniform.
Penny Hofstadter: Well, if you didn't make me wear the green body paint in bed, you wouldn't have to get it dry cleaned so much.
Leonard Hofstadter: Nah, it's worth it.

Howard Wolowitz: [in his garage] I haven't looked at all this stuff in years.
Sheldon Cooper: Had it. Had it. Burned down my garage with it.
Raj Koothrappali: I had three model rockets as a kid, and that was the largest space program in India.
Sheldon Cooper: You have a replica Saturn V?
Howard Wolowitz: Yeah. My dad bought it before he, you know, abandoned our family.
Sheldon Cooper: Lucky duck.

Howard Wolowitz: [about a model rocket from his childhood] Could never bring myself to open it without him. It's silly.
Sheldon Cooper: No, it's not silly. I always wanted my dad to build rockets with me, but he wasn't interested.
Raj Koothrappali: Ah, yes, disappointing fathers. Tell me about it. I remember for my sixteenth birthday, my dad bought me a Mercedes. Like, a little one, like a starter Mercedes. He had barely handed me the keys before he had to rush back to work. I didn't see him again 'till, like, pretty late that night.
Howard Wolowitz: Anyway... as angry as I was with him leaving, building this stuff is probably what led me to become an engineer.
Sheldon Cooper: I suppose, in his own way, my dad also encouraged me to pursue science. I mean, he is the one that taught me that flatulence is combustible. And also, polyester gym shorts don't burn. They melt.

Howard Wolowitz: You know what? Forget the past. What do you say you and me build this rocket?
Sheldon Cooper: That sounds like it could be a real bonding experience for us.
Howard Wolowitz: Right?
Sheldon Cooper: Oh, I see. Oh, you think that's a positive.

Raj Koothrappali: What's all this?
Bernadette Rostenkowski: I'm just boxing up all the clothes Halley's outgrown. I guess we won't need them anymore.
Raj Koothrappali: Oh, well, slow down. I'm sure there's some you could re-use for a boy.
Bernadette Rostenkowski: [holding up a onesie] "Daddy's little girl"?
Raj Koothrappali: Okay, well, what if we, uh, change it to say "Daddy's little girl magnet"? Boom! Boy shirt.
Bernadette Rostenkowski: [holding up a tutu] What about this?
Raj Koothrappali: Uh, okay. Uh, pull off the skirt, slap a lightning bolt on the front, and you got baby Flash. Ooh! Stick a long sleeve under it, boom! Baby Sheldon.
Bernadette Rostenkowski: Wow, you're really good at this.
Raj Koothrappali: Oh, please. This isn't my first time turning girl clothes into boy clothes.
Bernadette Rostenkowski: Why? You got your sister's hand-me-downs?
Raj Koothrappali: Yeah, that.

Howard Wolowitz: I should have brought peanuts.
Sheldon Cooper: You can't eat peanuts. You're allergic. If you die, who's going to drive me hom?
Howard Wolowitz: I'm not gonna eat them. It's a thing they do at JPL. When the Ranger mission finally had a successful launch, there were peanuts in the room. Ever since then, they have them at every launch.
Sheldon Cooper: That sounds like a silly supersition.
Howard Wolowitz: It's more of a tradition.
Sheldon Cooper: Oh! I do love a tradition. Pull over at the next peanut store.
Howard Wolowitz: I don't think that's a real thing.
Sheldon Cooper: Oh, don't be pedantic. Any nut store will do.
Howard Wolowitz: I... I don't think we can get peanuts out here.
Sheldon Cooper: Ah, well, then this whole day's ruined.
Howard Wolowitz: Now that I think about it, maybe it is more of a superstition.
Sheldon Cooper: Whew! That was close.

Penny Hofstadter: Oh, uh, hey, Beverly, you called my phone, not Leonard's.
Dr. Beverly Hofstadter: Actually, I was hoping to speak with you. Is this a good time?
Penny Hofstadter: Uh, that depends. What time is it where you are?
Dr. Beverly Hofstadter: [checking her watch] Uh, just after 5:00.
Penny Hofstadter: [taking a wine bottle from the fridge] Yeah, that counts. What's up?

Dr. Beverly Hofstadter: You may find this surprising, but I don't have a lot of what you would call girlfriends.
Penny Hofstadter: [exaggerated surprise] What?
Dr. Beverly Hofstadter: Of course, there are my female colleagues, but, uh, they're all Freudians, so the only boy that I can dish about is my father.
Penny Hofstadter: Uh, well, you know, I'm here for you. What do you want to talk about?
Dr. Beverly Hofstadter: Well, last time, we focused on my life. If we're going to be real girlfriends, we should talk about you, as well.
Penny Hofstadter: Well, you know, if we're gonna be real girlfriends, we should get a third girl we can trash behind her back.
Dr. Beverly Hofstadter: Oh, so we'd be catty. Oh, I like it. What about Sheldon's fiancee? She seems a bit dour.
Penny Hofstadter: Ooh, "dour". Meow.

Howard Wolowitz: All right, here we go. L-minus ten, nine...
Sheldon Cooper: Wait, what are you doing? It's "T-minus".
Howard Wolowitz: I was an astronaut. We used "L-minus".
Sheldon Cooper: But this is a Saturn V, and when they launched those, they said "T-minus".
Howard Wolowitz: It's my rocket! We're doing it my way.
Sheldon Cooper: Fine. I'm not saying I know why your dad left, but I think I'm getting anidea.
Howard Wolowitz: L-minus ten, nine, eight, seven, six...
Sheldon Cooper: 'Cause you're kind of bossy.
Howard Wolowitz: ...five, four, three, two, one... [rather than lifting off, the model blows up]
Sheldon Cooper: I remember them going up higher.

Howard Wolowitz: Well, that's perfect. I mean, the one thing I thought I could do with my son, I can't even do that right.
Sheldon Cooper: Well, if you want to see it again, I got it on video. Looks pretty cool in slow motion.
Howard Wolowitz: Thank you for your support.
Sheldon Cooper: You're welcome.
Howard Wolowitz: I was being sarcastic.
Sheldon Cooper: How dare you!
Howard Wolowitz: Sheldon, what am I gonna do? I mean, what do I know about raising a boy?
Sheldon Cooper: What do you know about raising a girl?
Howard Wolowitz: Oh, my god, you're right.
Sheldon Cooper: Well, I don't know if that was sarcasm or not. So either "You're welcome" or "Hey!".

Penny Hofstadter: [her phone chimes] Leonard, did you really just text me from the couch to put extra mustard on your sandwich?
Leonard Hofstadter: I was worried you might not check your e-mail.
Penny Hofstadter: [her phone chimes again] I swear to god, I will throw this out.
Leonard Hofstadter: That one was not me.
Penny Hofstadter: [checking her phone] Oh, wait, it was just your mom.
Leonard Hofstadter: My mother's texting you?
Penny Hofstadter: Yeah. We've been talking a lot lately.
Leonard Hofstadter: Why? She sick of talking to the magic mirror on the wall?

Penny Hofstadter: Do you not want me to be friends with your mom?
Leonard Hofstadter: Well, let's be clear. I... I married you to hurt her. You're kind of ruining it.

Sheldon Cooper: Reason number thirteen to feel good: as a launch, it was bad, but as an explosion, it was glorious. Reason fourteen: you still have all your fingers, and boys prefer a dad with fingers.
Howard Wolowitz: Thanks for trying, but you're not gonna be able to cheer me up.
Sheldon Cooper: Well, how about this, then? You quit your whining before I give you something to cry about, young man.
Howard Wolowitz: What?
Sheldon Cooper: Those are comforting words my father would often say.
Howard Wolowitz: Did it help?
Sheldon Cooper: I turned out great. You tell me.

Sheldon Cooper: Are you gonna be this mopey all the way home?
Howard Wolowitz: I don't know. Maybe.
Sheldon Cooper: There any chance you'd be cheered up by an amazing trigonometry riddle? [Howard looks at him in exasperation]
Sheldon Cooper: Well, if you can't answer that, there is no way you're gonna get this riddle.

Raj Koothrappali: [using a sewing machine] Oh, hey. Hey, what do you think?
Bernadette Rostenkowski: Just because it's a boy, I don't think you need to put a picture of genitals on his shirt.
Raj Koothrappali: But that's a baseball bat with two little baseballs. [tilting his head]
Raj Koothrappali: Okay, and now I see it.

Raj Koothrappali:: So, you know, I understand why Howard is nervous about having a son, but are you really upset about it?
Bernadette Rostenkowski: No, I'm fine. It's just I grew up with a bunch of brothers, so I thought it'd be nice for Halley to have a sister. Is that wrong?
Raj Koothrappali: Of course it's wrong! You don't know what this little boy's gonna be like. Maybe he'll be rough and tumble, or maybe he'll be sweet and sensitive, or maybe he'll be all those things, like me.
Bernadette Rostenkowski: You're rough and tumble?
Raj Koothrappali: You bet I am, bitch. But I'm also sensitive and regret saying that.

Leonard Hofstadter: You got a sec?
Amy Farrah Fowler: Sure. What's up?
Leonard Hofstadter: Penny's been talking to my mother like they're best friends, and it's kind of freaking me out.
Amy Farrah Fowler: Okay... I am pretty sure they're not best friends. 'Cause you can only have one best friend. And Penny has that, and... [she clicks her tongue]
Amy Farrah Fowler:'s me.
Leonard Hofstadter: Oh, really? Is she FaceTiming with you right now? Because she's FaceTiming with my mom, and believe me, that is not a face you want to spend time with.

[following their own trains of thought]

Amy Farrah Fowler: Well, I have been pretty busy lately. Maybe I've been neglecting our friendship.
Leonard Hofstadter: Penny knows I have a complicated relationship with my mother; it's like she doesn't even care.
Amy Farrah Fowler: And with everything going on at the lab and planning the wedding, I just... I have so little free time.
Leonard Hofstadter: Penny doesn't know how manipulative my mother can be. Did you know there's such a thing as reverse, reverse, reverse psychology? Because... [indicating his head]
Leonard Hofstadter: ...there is.

Sheldon Cooper: You know, studies have shown that people distracted by emotional issues are poor drivers.
Howard Wolowitz: What about people distracted by irritating passengers?
Sheldon Cooper: That would be hard to test, because "irritating" is a subjective quality.
Howard Wolowitz: Strongly disagree.

Sheldon Cooper: Can I drive?
Howard Wolowitz: No. You can't drive. You don't even have a license.
Sheldon Cooper: Actually, I do?
Howard Wolowitz: Really? Since when?
Sheldon Cooper: Three years ago. I went on a bit of a license kick. I'm also a commercial fisherman.
Howard Wolowitz: Then why don't you ever drive yourself?
Sheldon Cooper: Honestly, I barely passed my test. And the one time I drove on my own, I made a U-turn, got dizzy, threw up, and walked home.

Howard Wolowitz: You really want to drive?
Sheldon Cooper: It seems like the perfect time. The roads are straight, there's no one around, and you don't seem to care if you live or die.
Howard Wolowitz: Live, Sheldon. I want to live.
Sheldon Cooper: That makes things a little trickier, but I'll do my best.

Leonard Hofstadter: I want to know, why aren't you proud of me?
Dr. Beverly Hofstadter: Well, isn't the real question why aren't you proud of yourself?
Leonard Hofstadter: No, that is *a* question - and I ask it a lot - but let's stick with the one I asked you.
Dr. Beverly Hofstadter: But why do you think I'm not proud of you?
Leonard Hofstadter: Because you never say it? But two days into chatting with Penny, and you can't stop telling her how great she is.
Dr. Beverly Hofstadter: She is great. Honestly, of all of my children's spouses, she's the one that I'm most impressed by.
Leonard Hofstadter: Seriously?
Dr. Beverly Hofstadter: Yes. She's confident, she's thoughtful, and she never complained about you once. I know what kind of strength that takes.
Leonard Hofstadter: So Penny's your favorite?
Dr. Beverly Hofstadter: I suppose she is. You married well, Leonard, and for that, I am proud of you.

Howard Wolowitz: [letting Sheldon drive] Your hands are at 10:00 and 2:00. Good. Steady on the gas. Okay. Now, you're gonna want to slowly switch lanes.
Sheldon Cooper: Why?
Howard Wolowitz: Because there are only two, and you're not in either of them.

Sheldon Cooper: Do you think I could try going a little faster?
Howard Wolowitz: Go for it, champ. [he gives Sheldon a soft, fatherly shoulder punch]
Sheldon Cooper: Ow.
Howard Wolowitz: Sorry. Just ease on the gas and... [as Sheldon steps on the gas, the car lurches forward]
Howard Wolowitz: OH, TOO MUCH! TOO MUCH!
Sheldon Cooper: Why was I scared of this? This is exhilarating!
Howard Wolowitz: No, it's not! Slow down!
Sheldon Cooper: Don't tell me what to do! You're not my father!

[last lines]

Police Officer: Do you know how fast you were going?
Sheldon Cooper: 112.
Police Officer: Let me see your license.
Sheldon Cooper: [quietly to Howard] Okay, here's the plan.
Howard Wolowitz: No.
Sheldon Cooper: Fine. [handing the officer his license]
Sheldon Cooper: There you go. You know what? You can just keep it.