Sheldon Cooper

Sheldon is a theoretical physicist from Caltech who rooms with Leonard in apartment 4A of their rundown apartment building, in which the elevator always seems to be out of order. He is Leonard's best friend and colleague, who appears to have OCPD, beginning with suspicion of it in episode S01E02. A prodigy, Sheldon possesses a Master's degree and 2 PhDs. Recently, he has switched disciplines from bosonic string theory to heterotic string theory and has reconciled the black hole information paradox using a string network condensate approach. Like Leonard, he keeps a whiteboard in the living room for scientific theories, especially for his work on string theory. Unlike Leonard, he embraces his genius fully and doesn't mind sharing details of his life that Leonard finds embarrassing, such as their main weekend activity being Klingon Boggle tournaments until 1 AM. It's indicated that Sheldon's genius is concentrated more fully on science (though, he does have an extensive general knowledge as well, shown by his comments regarding the introduction of the fork into Thailand and his knowledge of history) and that his 187 IQ is higher than Leonard's; he tends to question Leonard's theories and has a larger background full of behavior common to child prodigies.

When he was a child, he conducted experiments involving the height of stairs and deduced that if a step on a staircase is 2 millimeters off or more, a person is likely to trip (this resulted in his father breaking his clavicle). At age 14, he dabbled in lasers and this resulted in his being sent to boarding school; it is heavily implied in a CBS promotional clip that the government took Sheldon's laser away and hushed the college professor who witnessed the experiment. According to his mother, Sheldon also attempted to build a nuclear reactor at a young age in order to provide free electricity for his town; that failed after a government agent informed him that it was illegal to store yellowcake uranium in a shed. (Sheldon may have been about twelve years old when he built the reactor, for, at this time, he wanted a titanium centrifuge to separate radioactive isotopes.) He also built a so-called "Death Ray" and a robotic arm made from substrates cooked in his sister's Easy-Bake Oven. Sheldon graduated high school very early; he asks Penny, in complete disbelief, "It took you four years to get through high school?!" He told Penny he was eleven years old when he was going to college.

Sheldon also has common qualities associated with being a prodigy, such as an inflated ego, social ineptness, and an inability to identify emotionally with others. He fails to understand not only the simplest sarcastic jokes made by Leonard, but also regards Penny's sadness over her break up with blatant disgust. That isn't to say Sheldon doesn't have a conscience; he's simply more likely to do what's scientifically ethical (not donate to a "high IQ sperm bank" because his sperm won't guarantee high IQ offspring) rather than morally and socially ethical (break into Penny's home to organize her things). Sheldon also remains unswayed by Penny's beauty. He also has symptoms of obsessive compulsive personality disorder and Asperger syndrome; when he finds Penny's apartment messy, he sneaks in during the night and cleans it up because he can't stand being in the same hallway with something so disastrous. Also, he refuses to sit anywhere other than his designated spot on the couch. He is calculating and cynical, believing that Leonard is only setting himself up for disappointment as he continues to crush on Penny.

Sheldon's eating habits
Being a person with obsessive-compulsive personality disorder, Sheldon has a a lot of very strict eating habits, which he can't depart from.


 * Sheldon loves to eat at Big Boy, an American restaurant chain.
 * Sheldon eats at the Cheesecake Factory on Tuesday nights (presumably before the occasional Klingon Boggle game), which replaces eating at Big Boy. Big Boy may have moved to Thursdays replacing Souplantation
 * Sheldon sorts his cereal numerically by fiber content.
 * Sheldon neither drinks coffee, nor alcohol, because he promised his mother that he wouldn't do drugs while he resided in California. Instead he likes drinking diet coke. When forced to order a cocktail, Sheldon solves the problem by ordering a "virgin Cuba Libre", which is nothing more than a coke in a tall glass, served with a lime wedge. He then goes on to ask if Penny would make it diet.
 * Sheldon likes Chinese food.
 * Sheldon likes Thai food.
 * Sheldon thinks chocolate pudding is the best one.
 * Sheldon does not believe that three-tined forks are, in actuality, forks, but tridents, and refuses to eat with them.
 * Sheldon doesn't like to go to the cinema if he can't eat popcorn or drink Icees during the movie.
 * Sheldon always eats oatmeal for breakfast on Mondays.
 * Sheldon always has French Toast for breakfast on some unspecified day of the week.
 * Sheldon rewards himself with "Honey Puffs" cereal.
 * Sheldon drinks herbal tea, sometimes with honey.
 * Sheldon prefers red vines over Twizzlers

Trivia

 * Sheldon is 29 years old.
 * Sheldon was born in a K-Mart.
 * Sheldon wakes up at 6:15 every Saturday, pours himself a bowl of cereal, adds a 1/4 cup of 2% milk, turns on BBC America and watches Doctor Who.
 * Sheldon was raised in an aluminum trailer in Galveston in east Texas.
 * Sheldon has a Master's degree and two PhDs.
 * Sheldon went to college at the age of eleven, entered graduate studies at fourteen, and received his first PhD at sixteen.
 * According to Leonard, Sheldon is a Semi Pro masturbator.
 * Sheldon was a visiting professor in Germany at fifteen.
 * Sheldon took four years to write his second Doctor of Philosophy thesis.
 * Sheldon has recently switched his research from bosonic string theory to heterotic string theory.
 * Sheldon conducts research at the California Institute of Technology, primarily in string theory.
 * Sheldon continues to be baffled and repulsed by human relationships.
 * Sheldon has 212 friends on MySpace.
 * Sheldon is allergic to bees and cats (despite having a pet cat as a child).
 * Sheldon has asthma.
 * Sheldon knocks on the doors three times before he actually enters, repeating in between each knock the person's name who is inside.
 * Sheldon cannot detect sarcasm, but frequently asks if the comment made was.
 * Sheldon showers twice a day and washes his hands as often as he can.
 * Sheldon loves Star Trek, Battlestar Galactica, Doctor Who, and Scrubs, although he hates Babylon 5.
 * Sheldon's IQ is 187. (Though Sheldon says that his IQ is incapable of being accurately measured by any IQ test)
 * Sheldon considers himself to be a "Homo novus." A new, evolved species of homo sapiens.
 * Sheldon and his friends play Age of Conan where he is most likely a Conqueror by the name of Sheldor the Conqueror and has reached Level 80.
 * Sheldon and all of his friends play multiplayer online games. He is a rogue night elf in World of Warcraft.
 * Sheldon and his friends play Halo every Wednesday night, they call this ritual "Halo Night".
 * Sheldon doesn't believe in luck or coincidence, instead citing the Law of Large Numbers (LLN) in statistics as the explanation for such phenomena.
 * Sheldon was sick a lot as a child.
 * Sheldon agrees with the theory that 75-80% of any Rock-Paper-Scissors games you play with a person you are familiar with end up in a tie, and accordingly he prefers the variation Rock-Paper-Scissors-Lizard-Spock (http://www.samkass.com/theories/RPSSL.html).
 * Sheldon has two siblings, one of whom is a (fraternal) twin sister who hostesses at Fuddruckers and the other, an older brother.
 * Sheldon has a red toothbrush that is kept in a Plexiglass case under a UV lamp.
 * Sheldon used a Doppler Effect costume for Halloween.
 * Sheldon loves superheroes, especially Batman, Green Lantern, and The Flash.
 * Sheldon likes to wear vintage t-shirts adorned with superhero logos.
 * Sheldon has a t-shirt of The Greatest American Hero's costume.
 * Sheldon goes to the Comic Book Store every Wednesday so he can see all the new comics on, "New Comic Book Day"
 * Sheldon uses his Green Lantern action figure as a safe place for his emergency money.
 * Sheldon wears briefs.
 * Sheldon knows Morse code very well.
 * Sheldon is terrible and constantly asks for things when he is ill. His friends have a protocol to hide themselves from him when it happens.
 * Sheldon has to sit on the left side of the couch. Wherever he goes, he has to choose the best sitting location based on such things as optimal television viewing, lighting, airflow, and cushion density.
 * Sheldon hates it when someone stops him when he is trying to explain something. If this happens: a tic starts on his face until he can complete what he wants to say.
 * Sheldon doesn't know how to lie or how to keep a secret.
 * Sheldon has Leonard Nimoy's DNA and signature on a restaurant's napkin.
 * Sheldon does his laundry every Saturday night at 8.15 p.m.
 * Sheldon's favorite amino acid is Lysine.
 * Sheldon thinks that his very strong attention to hygiene and his skill in writing Java Applets are main reasons why his friends like him.
 * Sheldon can play the piano.
 * Sheldon labels all home utensils, appliances, etc.
 * Sheldon loves trains and monkeys.
 * Sheldon fears birds.
 * Sheldon had a cat named Lucky when he was a child, and this cat died because it was hit by a train. Sheldon couldn't see the irony of the hit cat named Lucky.
 * Sheldon learned how to swim (on the floor) online.
 * Sheldon hates people who hiss at home.
 * Sheldon cannot stand whistling.
 * Sheldon doesn't like to go to the cinema alone because there is no guarantee that someone can help him with the Heimlich maneuver in the case he chokes on his popcorn.
 * Sheldon doesn't condone anyone to sit on his place on the sofa (left side).
 * Sheldon's arch-enemy is Leslie Winkle.
 * Sheldon thought about creating a griffin when he was a child.
 * Sheldon loves to play Super Mario Bros.
 * Sheldon would like to control people in the same way he can control Mario in the video game Super Mario Bros.
 * Sheldon's favourite Star Trek movie is: Star Trek IV: The Voyage Home.
 * Sheldon thinks that having more than four friends at the same time is much too stressful for him.
 * Sheldon was very busy in his teenage years examining the range of diffusion in the $$\mathcal{N}=4$$ supersymmetric theories, which brought him to re-examine the ultraviolet properties of supergravity $$\mathcal{N}=8$$ a loop.
 * Sheldon's expenses account for 46.9% of his after tax income.
 * Sheldon cannot and will not drive. Someone must drive him always.
 * Sheldon likes the movie Saturn 3.
 * Sheldon loves Star Wars but thinks the latest stuff by George Lucas is not so good.
 * Sheldon imposes and teaches behavior lessons to any friend of his who disappoint him for 3 consecutive times.
 * Sheldon's nickname is "Shelly" (although he only allows his mother Mary Cooper, his sister Missy, and Leonard to call him this).
 * Sheldon thrives off his work, and if left jobless he loses all focus and moves onto a new experiment/obsession every day.
 * Sheldon does not like teddy bears because he thinks bears are terrifying.
 * Sheldon is considered 'one lab accident away from becoming a super villain'.
 * Sheldon loves having his brain scanned.
 * Sheldon hates when people pronounce the "t" in often.
 * Sheldon only shows genuine affection for one person, his grandmother (or Meemaw), who he writes to.
 * Sheldon only condones one of his nicknames, "Moonpie", which his grandmother calls him.
 * Sheldon plays bass guitar on rock band.
 * Sheldon is a Taurus placing his birthday between 20 April and 21 May.
 * Sheldon, though unwilling to fight, is physically the strongest of the group, easily holding his own against Raj in an arm wrestle, and once referred to Leonard and Howard as 'tiny tiny men'.
 * Sheldon's little toe is degenerated, purportedly due to his high level of evolution which keeps him from using a motor vehicle.
 * Sheldon once got chased up the elm tree at the front of his house by his neighbour's chicken.
 * Sheldon once took a bet with Howard about a species of cricket, but lost and had to give Howard his Flash comic book.
 * Sheldon's middle name is Lee, according to his Stevenson Award.
 * Sheldon went to a Science Fiction convention on a bus for 10 hours and violated his personal rule of not urinating on buses twice to see Wil Wheaton, who didn't show up at the convention.
 * Sheldon has actually been kind to Penny; in one episode he actually drove her to the hospital because she dislocated her shoulder.
 * Sheldon is terrified of being sick.
 * Sheldon buys his t-shirts at Comic Book Store.
 * Sheldon's favorite actress playing Catwoman is Julie Newmar and his least favorite is Halle Berry.
 * Sheldon was once offered a position at a secret military base, but was later rejected due to his inability to keep secrets.
 * Sheldon hates it when people change the contrast of the TV settings, talk to him through the bathroom door, change Band-Aids in front of him, buy generic ketchup, forget to rinse the sink, adjust the thermostat, or cook with Cilantro.
 * Sheldon thought that the trip he and his friends took to the North Pole in Season 2/3 was "a hoot and a half."
 * It was mentioned that Sheldon and Leonard once had (before they were robbed) "A TV, 2 laptops, 4 external hard drives, a PS2, PS3, Xbox, Xbox 360, a classic Nintendo, a Super Nintendo, a Nintendo 64, a Nintendo Wii, Halo 1-3, Call of Duty 1-3, Rock Band 1-2, Final Fantasy 1-9, Legend of Zelda, Legend of Zelda: Ocarina of Time, Legend of Zelda: Twilight Princess, Super Mario Bros., Super Mario Galaxy, Mario and Sonic at the Winter Olympics, and Ms. Pac-Man.
 * Sheldon has adhesive ducks holding umbrellas in his bathtub to prevent slipping.
 * When Sheldon was 12, he had to be flown to a hospital by helicopter and be treated for radiation damage following a mishap when he built a CAT scan which also resulted in the death of his sister's guinea pig, Snowball.
 * Sheldon keeps a daily log of social interactions called Sheldon's Log ( in place of Captian's Log)
 * Sheldon doesn't trust banks because he believes that ATM machines will lead the robot armies when they revolt against humans.
 * Sheldon keeps band-aids with him at all times as well as in his kitchen, top desk drawer, etc.
 * As of The Excelsior Acquisition, Sheldon has a restraining order from Stan Lee as well as Leonard Nimoy.
 * Sheldon has an in depth knowledge of American Football

Relationships
Of all main characters of the show, Sheldon has displayed the least interest in pursuing a sexual relationship. He has, however, had a few opportunities, although he never seemed to realize it.

Lalita Gupta
Lalita was arranged to be married to Raj. They went on a date together which gradually deteriorated as alcohol made him obnoxious. When Sheldon arrived at the bar, he thought she looked similar to an Indian fairytale princess from a bedtime story his mother used to read to him when he was sick. When he told her, she was flattered and ended up dumping Raj and going out for dinner with Sheldon. When he was asked about it the next day, he simply said that they ate and discussed dental hygiene. He didn't seem to realize that he technically was on a date with her.

Ramona Nowitski
Ramona was a huge admirer of Sheldon and had an obvious crush on him, which he didn't seem to notice. In The Cooper-Nowitski Theorem, she asked him out for dinner at his apartment. After that, she began spending more and more time with him, preventing him from doing anything recreational like playing Halo, paintball or watching Battlestar Galactica so he could focus on his work. Eventually, he made a breakthrough. When she suggested they share credit, he simply responded "Get out", after which she angrily left.

Martha
When Raj brought Sheldon to a faculty mixer to act as wingman, they picked up a girl named Abby and her friend, Martha, brought them to Sheldon and Leonard's apartment and played Rock Band with them. While Abby and Raj hit it off, Martha became interested in Sheldon. The two enjoyed a few stimulating discussions together at their second meeting, during which Raj and Abby "[got] busy", Martha visited Sheldon's room in the middle of the night and asked to come in, hoping for sex. Misinterpreting this, Sheldon went to sleep in Leonard's room and left Martha alone in his. She apparently lost interest in him after that.