No. overall No. in season Title Directed by Written by Original air date Prod. code U.S. viewers (millions) 232 "The Proposal Proposal '' Mark Cendrowski Story by: Chuck Lorre & Eric Kaplan & Jeremy Howe Teleplay by: Steve Holland & Maria Ferrari & Tara Hernandez September 25, 2017 (2017 - 09 - 25) T12. 15601 17.65 Amy enthusiastically accepts Sheldon 's marriage proposal. However, when dining with Amy 's colleagues later that night, Sheldon is offended that they are more impressed with Amy 's work than his own. With help from Stephen Hawking, Sheldon later comes to grips with the fact that he will not always be the center of attention in the marriage. Bernadette is shocked to realize that she is pregnant again. She and Howard are not thrilled at the idea of having another baby so soon after their first. They attempt to convince Leonard and Penny to have a child as well, but are rebuffed. Title reference: Sheldon 's proposal of marriage 233 "The Retraction Reaction '' Mark Cendrowski Story by: Steven Molaro & Steve Holland & Maria Ferrari Teleplay by: Dave Goetsch & Eric Kaplan & Anthony Del Broccolo October 2, 2017 (2017 - 10 - 02) T12. 15602 14.06 Leonard gives an interview on public radio where he admits physics research might be at a dead end. The university is furious and, while trying to think of reasons to put in a retraction, he depresses Sheldon into thinking he might be right. Howard and Raj come over and end up just as depressed. Getting drunk with Penny, the guys go to the grave of Richard Feynman and realize there is hope for physics as long as they believe in it. Leonard accidentally sends a drunken email to Human Resources. Meanwhile, Amy and Bernadette agree with each other to keep quiet about the success in their careers so as not to upset Sheldon and Howard. While bragging to each other, they end up arguing which of their fields is better. Title reference: Leonard 's depression while writing a retraction of his statements on the radio. 234 "The Relaxation Integration '' Mark Cendrowski Story by: Chuck Lorre & Steve Holland & Adam Faberman Teleplay by: Maria Ferrari & Andy Gordon & Tara Hernandez October 9, 2017 (2017 - 10 - 09) T12. 15603 13.13 Sheldon can not find the perfect wedding date and begins talking in his sleep, adopting the persona of a laid - back person who goes with the flow. Amy and Penny believe that his subconscious mind is trying to tell him to be more relaxed; his attempt to be so while wearing flip - flops ends in disaster. He decides to leave all the wedding planning to Amy while he wears a Star Trek uniform underneath his tuxedo. Meanwhile, Raj and Stuart both become interested in Bernadette 's new coworker Ruchi. While she likes them both as friends, she does not want a relationship with anyone. Title reference: Sheldon trying to embrace the relaxed side of his personality. 235 "The Explosion Implosion '' Mark Cendrowski Story by: Bill Prady & Maria Ferrari & Tara Hernandez Teleplay by: Steve Holland & Eric Kaplan & Jeremy Howe October 16, 2017 (2017 - 10 - 16) T12. 15604 13.07 Howard and Bernadette learn their second child will be a boy, leading Howard to doubt whether he can be a good father to a son. He and Sheldon go out in the desert to test launch a model rocket, but it explodes, causing him further doubt. On the way home, Howard does a good job coaching Sheldon to drive them home, for which Sheldon tells him he will be a good teacher to his son. Leonard 's mother Beverly begins talking to Penny as a friend and confidant, troubling Leonard, especially when he learns that Beverly told Penny that she is proud of her, a level of praise she never bestowed upon Leonard himself. When Leonard confronts Beverly, he is touched when she says that of all of her children 's spouses, Penny is the one she is most impressed by, and that for this, she is indeed proud of him. Meanwhile, Raj helps Bernadette turn baby girl clothes into boy ones. Title reference: The fate of Sheldon and Howard 's model rocket. 236 5 "The Collaboration Contamination '' Nikki Lorre Story by: Steven Molaro & Steve Holland & Eric Kaplan Teleplay by: Dave Goetsch & Maria Ferrari & Jeremy Howe October 23, 2017 (2017 - 10 - 23) T12. 15605 13.20 Amy and Howard begin collaborating on a neuroprosthetics project, upsetting Sheldon and Raj, who feel they are not spending as much time with them. When they seek solace with an annoyed Bernadette, she exploits the situation to trick Sheldon into doing Howard 's chores. Penny employs the approaches recommended in one of Bernadette 's parenting books to deal with Sheldon with success, but Leonard believes she is coddling Sheldon too much. Sheldon and Raj resolve the issue of missing their significant others by spending time together. Title reference: Amy and Howard 's collaboration contaminating Sheldon and Raj 's moods. 237 6 "The Proton Regeneration '' Mark Cendrowski Story by: Steven Molaro, Dave Goetsch, Alex Yonks Teleplay by: Dave Steve Holland, Andy Gordon, Jeremy Howe November 2, 2017 (2017 - 11 - 02) T12. 15606 14.14 Sheldon 's childhood science show with Professor Proton is being rebooted. After unsuccessfully auditioning for the part, he goes to Wil Wheaton for acting tips for his second audition. However, Sheldon is later dismayed when Wil has somehow taken the role instead. Talking it over with Arthur in his dreams he is still upset his idol is replaced and considers Wil an enemy again. Meanwhile, Howard gets a vasectomy while Bernadette is on bed rest. Penny offers to take care of Halley for them but they insult her by saying Penny is irresponsible. Halley ends up saying her first word by calling Penny "Mama. '' Title reference: The announced reboot of the Professor Proton series. 238 7 "The Geology Methodology '' Mark Cendrowski Story by: Steven Holland & Anthony Del Broccolo & Adam Faberman Teleplay by: Eric Kaplan & Maria Ferrari & Tara Hernandez November 9, 2017 (2017 - 11 - 09) T12. 15607 13.80 Bert asks for Sheldon 's help in a geology research project relating to dark matter. Sheldon secretly agrees, but is too embarrassed to admit he is working with rocks. Bert finds out about this and ends their partnership. After talking with Amy, Sheldon goes to apologize, only to find Leonard has taken his place. Meanwhile, Raj runs into Ruchi again and goes out with her, but she does not believe in romantic love. After Howard and Bernadette tell Raj that he can just have sex with Ruchi, he agrees to keep it casual. Title reference: Sheldon working in geology with Bert. 239 8 "The Tesla Recoil '' Anthony Rich Story by: Chuck Lorre & Eric Kaplan & Tara Hernandez Teleplay by: Steve Holland & Maria Ferrari & Jeremy Howe November 16, 2017 (2017 - 11 - 16) T12. 15608 13.44 After learning Sheldon went behind their backs to work with the military again, Leonard and Howard say Sheldon is like Thomas Edison, taking credit for other 's ideas, while they are more like Nikola Tesla. Leonard and Howard bring in Barry Kripke to help create a better idea than Sheldon 's, but Kripke goes to the military himself cutting all three of them out. Meanwhile, Bernadette fears Ruchi is trying to steal her projects at work while she is on maternity leave, and hires Raj to spy on her. Though he finds proof that Ruchi may be stealing from Bernadette, Raj tries to defend Ruchi like a boyfriend would, pointing out Bernadette 's hypocrisy as she would 've most likely stolen from other people 's projects as well. Ruchi is not happy about this and promptly dumps Raj. Title reference: The guys discussion of Tesla and Edison. 240 9 "The Bitcoin Entanglement '' Mark Cendrowski Story by: Steve Holland & Andy Gordon & Jeremy Howe Teleplay by: Dave Goetsch & Maria Ferrari & Anthony Del Broccolo November 30, 2017 (2017 - 11 - 30) T12. 15609 13.84 In 2010, Leonard, Howard and Raj mined a lot of Bitcoin, worth thousands of dollars seven years later, but leave Sheldon out due to his fear of tax implications. Flashbacks are shown of how the Bitcoin ended up on an old laptop of Leonard 's, which Penny gave to her old boyfriend Zack after she and Leonard broke up. In 2017, Leonard and Penny retrieve the computer from Zack, who first shows them a video of a drunken Penny apologizing for breaking up with Leonard. The Bitcoin is not found on the laptop. Sheldon had moved it to a flash drive on Leonard 's keychain to teach them a lesson, but Leonard lost the keychain years ago. A final flashback to 2013 shows Stuart discovering the flash drive, which he decides to erase and sell for $10. Title reference: The guys trying to find their old Bitcoin investment. 241 10 "The Confidence Erosion '' Mark Cendrowski Story by: Bill Prady & Maria Ferrari & Adam Faberman Teleplay by: Steve Holland & Eric Kaplan & Tara Hernandez December 7, 2017 (2017 - 12 - 07) T12. 15610 14.41 When Raj loses a job interview at a planetarium, his father says he has no confidence because Howard always makes fun of him. Raj distances himself from Howard and later gets the job. Howard is hurt by this (even after apologizing to him) and tries to make amends with Raj after his first talk at the planetarium, but when he sees him get a date, he leaves without speaking to him, thinking that the latter 's life is better without him. Meanwhile, Sheldon and Amy try randomly dividing up wedding tasks, but they keep arguing. The only thing they can agree on is to get married so they decide to just get married at City Hall. However, Sheldon decides that he wants a first dance with his new wife, and they go home to plan their wedding. Title reference: Howard eroding Raj 's confidence. 242 11 "The Celebration Reverberation '' Mark Cendrowski Story by: Steve Holland & Eric Kaplan & Alex Ayers Teleplay by: Dave Goetsch & Maria Ferrari & Jeremy Howe December 14, 2017 (2017 - 12 - 14) T12. 15611 13.74 Howard and Raj are still fighting so Howard dis - invites Raj to Halley 's birthday party. However, when Howard 's designated party planner Stuart pulls out at the last minute, Raj agrees to plan the party, which does n't turn out too well due to Halley being asleep, Bernadette on bed rest and no people turning up. When Howard and Raj get into a shoving match in the party 's bounce house, they end up letting out their frustrations with each other, but also having fun and reconciling. Leonard is depressed upon receiving his successful brother 's Christmas card and attempts to make a list of what he and Penny accomplished this year, but does n't come up with much. This prompts them to think about their plans for the future, so they decide to go on trips and achieve more out of life together before starting a family. Sheldon cooks Amy a Little House on the Prairie - themed birthday dinner, which gives them both food poisoning. They eventually recover enough to attend Halley 's birthday party with the others, where they decide to have fun in the bouncy castle and then have sex in Howard and Bernadette 's house. Title reference: Amy and Halley 's birthday celebrations. 243 12 "The Matrimonial Metric '' Mark Cendrowski Story by: Maria Ferrari & Tara Hernandez & Jeremy Howe Teleplay by: Steve Holland & Eric Kaplan & Andy Gordon January 4, 2018 (2018 - 01 - 04) T12. 15612 16.16 Sheldon and Amy struggle to choose a best man and maid of honor from their friends. They secretly decide to test and score them, allowing everyone to have an equal shot at either role. Once the gang finds out, none of them apart from Bernadette and Stuart want to be in the wedding. Sheldon settles for Stuart as best man, but once Leonard tells Sheldon that as the groom, the decision is his alone, he picks Leonard. Amy is set to call Bernadette but once Penny realizes Amy is her best friend, she immediately pitches herself for the position and Amy enthusiastically chooses her. Amy later makes Penny tell Bernadette the bad news. Title reference: Sheldon and Amy scoring their friends for roles in the wedding. 244 13 "The Solo Oscillation '' Mark Cendrowski Story by: Chuck Lorre & Steve Holland & Anthony Del Broccolo Teleplay by: Eric Kaplan & Maria Ferrari & Jeremy Howe January 11, 2018 (2018 - 01 - 11) T12. 15613 15.93 With Leonard, Howard, Raj and Amy accomplishing so much on their respective projects, Sheldon is forced to admit he has nothing important to work on. He makes Amy leave the apartment for a few days so he can focus, but can not come up with any ideas and calls his mother as a distraction. Leonard and Amy have fun recreating experiments from when they were growing up, boring Penny, so she eats with Sheldon as he mulls over his scientific studies. Penny helps him realize that his study of dark matter is his rebound science from string theory, which Sheldon admits he never forgot about, but explaining string theory to her inspires Sheldon, helping him discover a potential breakthrough in the field. Meanwhile Howard is too busy with his family to be in the band with Raj, so Raj brings in Bert. But when Howard annoys Bernadette by writing an astronaut - themed musical while she is on bed - rest, she makes him rejoin the band. The three are poorly received, after singing Bert 's original song about the boulder from Indiana Jones at a Bar mitsvah. Title reference: A triple entendre to represent Sheldon going into isolation to figure out his future research field only to go back to studying string theory, the vibration of the strings in string theory, and Howard 's oscillation between being in a band with Raj and being solo. 245 14 "The Separation Triangulation '' Mark Cendrowski Story by: Chuck Lorre & Eric Kaplan & Maria Ferrari Teleplay by: Steven Molaro & Steve Holland & Tara Hernandez January 18, 2018 (2018 - 01 - 18) T12. 15614 14.92 Raj hooks up with a recently separated woman, Nell, after one of his lectures at the planetarium. Her husband Oliver confronts Raj at the planetarium and then breaks down over the end of his marriage. After comforting Oliver, Raj talks to Nell and convinces her to give her husband another chance. Meanwhile, after diving once again into string theory and sprawling his work across his and Amy 's apartment, Sheldon approaches a reluctant Leonard and Penny and convinces them to let him use his old room to study for a three - day trial period with an agreement to be quiet and stay out of their way. Sheldon surprisingly sticks to this agreement, being a reasonably good guest, which shockingly frustrates Leonard to no end. After Leonard lets out his frustrations, Sheldon then renegotiates the guest tenancy agreement for an extra few days and resumes being his normal demanding self, much to Leonard 's relief. Title reference: A double entendre that refers to both the love triangle between Raj, Nell, and Oliver, who is upset at his separation from Nell and the roommate triangle that has reformed between Sheldon, Leonard, and Penny, a distinct callback to the show 's initial seasons. 246 15 "The Novelization Correlation '' Mark Cendrowski Story by: Steve Holland & Andy Gordon & Adam Faberman Teleplay by: Eric Kaplan & Maria Ferrari & Jeremy Howe February 1, 2018 (2018 - 02 - 01) T12. 15615 14.69 Sheldon and Amy are surprised to find that Wil Wheaton 's new Professor Proton show is actually very entertaining and that Wil had Howard on as a guest. On Howard 's suggestion, Sheldon apologizes to Wil, mending their friendship, and tells him he wants to be on the show; but Wil asks for Amy. Sheldon tells her to do it, but she says she often does n't do things to avoid upsetting him. Sheldon is horrified when he realises how selfish he has been, especially when he finds out that the guys do the same for him. Sheldon encourages Amy to go on the show to inspire girls to pursue science while trying to control his obvious jealousy for her. Meanwhile, Leonard writes a book about a physicist that solves a murder, the protagonist Logan Dean is based on himself. Bernadette points out Logan 's mean boss Illsa is similar to Penny, who thinks it is based on Bernadette, though Leonard does not correct her. However, Bernadette tells Penny the truth, upsetting her and making her mad at Leonard. After calling his mother for advice, Leonard learns that Illsa is actually like her; but abandons the book when he realizes he wrote romantic tension into the relationship between the characters. Title reference: The uncertainty of which woman in Leonard 's life he subconsciously based the mean boss character in his novel on. 247 16 "The Neonatal Nomenclature '' Gay Linvill Story by: Eric Kaplan & Maria Ferrari & Anthony Del Broccolo Teleplay by: Steve Holland & Tara Hernandez & Adam Faberman March 1, 2018 (2018 - 03 - 01) T12. 15616 TBD 248 17 "The Athenaeum Allocation '' Mark Cendrowski Story by: Steve Holland & Steven Molaro & Tara Hernandez Teleplay by: Dave Goetsch & Eric Kaplan & Maria Ferrari March 8, 2018 (2018 - 03 - 08) T12. 15617 TBD
the big bang theory seson 11 episode 12
The Matrimonial Metric