Leslie Winkle

Leslie Winkle, ., is an experimental physicist at the California Institute of Technology who works in the same lab as Leonard. She is essentially his, equipped with the same black framed  and zippered. Whenever depicted in the, she is always using the inappropriately to prepare , such as  a  with  and then shattering it with a  to put in her , or using a  to heat a  of. She Leonard on-and-off, and later Howard. Because of her  and nature, she is arguably the central  of the second season- although the only true hostility she ever displays is towards Sheldon. Leslie made her final appearance in "The Lunar Excitation" when she rejected Leonard's offer for and left the series after that.

Career
Leslie specializes in, particularly searching for with like-sign. Leslie believes is the future of  and better unites  with  than string theory does. She posits that only loop quantum gravity calculates the entropy of and expects quantized  to manifest itself as minute differences in the  for different.

Personality
Leslie takes her job seriously (when she isn't using the  for  preparation) and is very ; she figured out a problem Sheldon had been working on without difficulty, much to his. She cares so much about that it affects her : her  has to have the same  as her in order for them to stay together.

She is displayed as, , and. When she and Howard started a "" relationship, she would only give him so long as he did as she wanted, admitting she could only be happy if she were in control. It is implied by (and said outright by Sheldon) that Leslie is, as she suggested she tended to have  and mainly craved  instead of a.

Season 1
Leslie makes her in "The Fuzzy Boots Corollary." Leonard, feeling his of his neighbor Penny is pointless, asked her out on a  because he thought she was in his. She him to see whether they have any, and although complementing his , turns the offer down when she feels no. This, and his hopeless with Penny, causes Leonard to go into a state of. In her next appearance, she goes to Leonard's apartment to practice with her. She offers herself to Leonard to have, despite her previous rejection. She also inadvertently starts her with Sheldon when she solves a  he was having and insults his. Assuming he and Leslie are now dating, Leonard goes to her only to find she just used him to satisfy her, which is apparently now covered until.

When the compete in a  bowl and kick Sheldon off the  for his showboating, Howard and Raj want Leslie to join. Leonard is understandably uneasy since she had used him, but agrees. Leslie at first rejects, but reconsiders when she discovers Sheldon has formed an opposing team; when Sheldon realizes she is on their team, his confidence is visibly shaken. They the bowl when Sheldon does not allow one of his partners to answer a, which turned out to be right.

Season 2
After Leonard and Penny decide not to pursue a, Leslie approaches Leonard for a true relationship, despite her previous unwillingness. She allows him to have the " role," despite continuing to and manage their relationship, and goes a bit far when she  Leonard on any  and  he has, and talks about having  on the first. Sheldon is perturbed by Leonard's attachment to Leslie and ponders why, of all the  in all the  in all the, it had to be Leslie Winkle, paraphrasing  in. Following several s by Sheldon during a date she had with Leonard, she interprets the situation as. Later, in an attempt to be and support his  with Leonard as Penny advised, he seems accepting of Leslie's  involvement with him. Sheldon claims to be willing to overlook her faults, but starts an argument that effectively nullifies her romance with Leonard by stating that she is an arrogant scientist, who prefers loop quantum gravity to string theory. She expects Leonard to back her up, but when he sides with string theoretic validation, she dumps him, feeling they are not. ("How will we raise the children?")

In the next episode she suggests Penny's recent {{w|addiction} to an is due to a lack of a. Sheldon agrees, as Penny had already admitted to having not had for a while, making it a rare  that he agrees with Leslie on anything. When Sheldon signs up to use the mainframe in Buckman 204 at Caltech, Dr. Winkle rips the  off the  as he printed it himself and put his name down in every slot for the next six. Sheldon maintains that he was only trying to ensure resources are not being "squandered chasing  ." This particular dispute could only be resolved by meeting with the of the  Department, Dr. Gablehauser. In "The Cooper-Nowitzki Theorem," she makes fun of Sheldon after he gives an insulting, but is derailed and disgusted when a named Ramona Nowitzki shows admiration for Sheldon. She even insults Leslie for Sheldon at one point (Sheldon is horrible at making snarky comebacks). Annoyed, she leaves.

"The Cushion Saturation" sees Leslie beginning a "" relationship with Howard when they are trapped in a during a paintball game. She gives him funds for his work and invites him on a to the CERN  Large Hadron Collider project in. However, this turns out to be just Leslie's way to control Howard. Although initially reluctant to be in this sort of relationship, Howard later happily accepts his as a "/." While Leslie does not appear in "The Vegas Renormalization," she plays a major part in the story line when she calls off her "friends with benefits" relationship with Howard. Having developed genuine for her, he becomes  and goes to  with Leonard and Raj, where he sleeps with a  to get over her.

Season 3
Leslie is completely throughout season 3, only appearing in the finale, "The Lunar Excitation." Leonard shows up at her door and suggests they start their relationship again, and she responds "Let me think about that," before ming the } in his, and he realizes she is not coming back.



Leonard
Leonard tries to ask her out because he considers her to be in his league and they decide to kiss to see if they have . Though Leslie compliments Leonard on his kissing technique, Leslie feels no arousal, and thus, no date occurs. She eventually puts forth an offer of  towards Leonard one   after a string quartet practice in which she plays the   and the two engage in , but she reveals that she only desires sex infrequently while distracted by a difficult pro ject and subsequently dumps him, claiming she'll be satisfied until at least New Year's Eve.

Initially uncomfortable with commitment, she later comes to the realization that "there’s just a time in every  ’s life when she gets tired of waking up on a strange  with a bunch of people she doesn’t know." Leslie briefly tries to rekindle her relationship with Leonard after his failed attempt at dating Penny, stating that she is "fully committed to the traditional relationship  " and "who better to slow things down with than you?" She even considers Leonard as a potential , going so far as asking Leonard how many  they should have. However, it does not work out because of Leslie's  in loop quantum gravity and Leonard's belief in string theory, which is, as she put it, a " ." Leonard later said he did not care about their relationship. In " The Lunar Excitation ", when Leonard appears at her door, Leslie reveals it has been eighteen months since they have seen each other. He asks if she wants to have sex with him just for  like they used to. She quickly deduces that Penny dumped him and says she would like to think about it, before she slams the door. Leonard realizes she is not going to come back. Despite their history of not sustaining a relationship for any significant length of time, Leonard thoroughly enjoys watching Leslie spar with Sheldon, as she is one of the few people who can catch him off-guard.

Sheldon
Sheldon originally had no  towards Leslie, as he was the one who encouraged Leonard to pursue her. After her first dalliance with Leonard, she was able to fix a problem Sheldon was having in showing that  are asymptotically free at high energies by changing the sign of the beta function β(g) of   (QCD) on his , greatly irritating him. When she insulted his intelligence, he came to hate her, considering her his " " &mdash; playing the role of a " Dr. Doom to [his] Mr. Fantastic ." She even, at some point in the past, made Sheldon cry. Sheldon usually stumbled to  her, but had stated he has no respect for her as a scientist or a . Sheldon thinks her research  is sloppy, asserts that she’s unjustifiably arrogant about loop quantum gravity and that the only way she could make a contribution to science would be if they resume sending   into space. Sheldon also conceded that she had an undeniable expertise in the interrelated fields of promiscuity and general . To make matters worse, according to Sheldon, she's often mean to him.

Meanwhile, Leslie Winkle considers Sheldon an "arrogant, misogynistic  doorknob" who one time told her she should abandon her work with high energy particles for   and . She has likewise grimaced that he is a "passive-aggressive East Texas blowhole." More often, Leslie displayed indifference to him, frequently calling him "dumb-ass" and insulting him at every opportunity. A commonly used insult (or a slight variation) by Leslie is "Hello, fellow scientists. Hello, Sheldon." Her favorite  to him is "Hello, dumbass." When Sheldon received a  during a meeting with Dr. Gablehauser, she hoped he wouldn't miss a call from the Nobel committee informing he had been nominated as dumbass   of the year. Similarly, when Sheldon was working toward a breakthrough with his theory of string-network condensates at  in the Caltech cafeteria, she remarked that he was organizing his papers for the   Museum of Dumbassery. The only time Sheldon got the better of Leslie was when he tricked her into breaking up with Leonard, and this was primarily because Leslie was busy arguing with both of them rather than focusing on Sheldon.

Interestingly, during "The Cushion Saturation," neither displayed any animosity towards each other, suggesting they have gotten past it; however, this was probably because Sheldon's temper was currently directed at Penny instead.

Howard
In "The Cushion Saturation", during a Caltech paintball game, she begins an affair with Howard Wolowitz, making her the fifth woman to sleep with Howard without being paid. She allows him access to experimental equipment (like a rapid prototyper) in spite of budget cuts and a research trip to Geneva to check out CERN's supercollider, using some unrestricted grant money Caltech gave her. She essentially controls Howard with new equipment and research trips, so as to avoid a real relationship with feelings, and institutes a "friends with benefits" arrangement instead, which she is more used to. However, in "The Vegas Renormalization", she dumps him over the phone, simply saying "Howard, momma’s a rolling stone."

Trivia

 * Leslie seems to be the only person aside from Dennis Kim, Barry Kripke and Amy Farrah Fowler who may have approximate or greater intelligence than Sheldon.
 * Sheldon became angry when Leslie and Leonard briefly dated, when, ironically, he was the one who suggested Leonard pursue her in the first place. When he did, however, he had no ill feelings towards her.
 * He showed no anger when she and Howard were together, possibly because they were not officially dating. Also, since Leonard is his best friend, he probably didn't mind what Howard did.
 * Leslie's only appearance in the third season was its finale, which was also her last appearance in the series.
 * Out of all of Penny's rivals for Leonard's affection, Leslie was perhaps the smallest threat, as she and Leonard only dated for one episode.  She is really more of a friend to the guys, since she is on their intellectual level and shares their quirkiness.
 * It has not been made clear what became of Leslie after season 3.
 * Leslie is one of the only people who can make Sheldon stutter.
 * Has not been mentioned since the third season (October 2013).

Leslie Winkle