Leslie Winkle

Leslie Winkle is a physicist at the California Institute of Technology who works in the same lab as Leonard, specializing in high energy physics, particularly supersymmetry and dilepton calculations. She is essentially Leonard's female counterpart, equipped with the black framed glasses and sweat jackets, with Penny saying they make a cute couple.

Whenever depicted in the lab, she is always using the equipment inappropriately to prepare food, such as flash-freezing a banana with liquid nitrogen and then shattering it with a hammer to put in her cereal, or using lasers to heat her Ramen noodles. She is the fifth woman to sleep with Howard Wolowitz without being paid. Currently her last apperance was in "The Lunar Excitation".

Personality & Background
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 chemistry. Though Leslie compliments Leonard on his kissing technique, Leslie feels no arousal, and thus, no date occurs. She eventually puts forth an offer of sexual availability towards Leonard one evening after a string quartet practice, and the two engage in sexual intercourse, but she reveals that she only desires sex infrequently while distracted by a difficult project and subsequently dumps him, claiming she'll be satisfied until at least New Years.

Leslie plays the violin in a string quartet.

Sheldon's Arch-enemy
She, at some point in the past, made Sheldon cry. She also is able to fix one of Sheldon's equations in "The Hamburger Postulate"; this act greatly irritates him. Later on, whenever she sees Sheldon, she tries to insult him. A frequently used insult (or a slight variation) is "Hello, fellow scientists. Hello, Sheldon." Her favorite quip to him is "Hello, dumbass." Sheldon usually stumbles to insult her, but has stated he has no respect for her as a scientist or a human being. 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 paradigm" and "who better to slow things down with than you?" She even considers Leonard as a potential mate, going so far as asking Leonard how many children they should have. However, it does not work out because of Leslie's belief in loop quantum gravity and Leonard's belief in string theory, which is, as she put it a "deal-breaker". During a Caltech paintball game, she begins an affair with Howard, allowing him access to experimental equipment in spite of budget cuts and a trip to Geneva to see CERN's supercollider. Interestingly, she serves as Sheldon's ally without insulting him once in that same episode, which might imply that they have settled their differences.