The Big Bran Hypothesis - S1-E2
Character mistake: In his argument with Leonard regarding Superman's ability to fly, Sheldon states that in Superman 1, Lois Lane is two feet off the ground when Superman catches her as she falls from the helicopter. Not so. Superman catches Lois at least ten stories up. Additionally, both Penny and Sheldon say Superman "swoops down" to save Lois. Penny can be forgiven, but Sheldon would know better: Superman flies UP from ground level to catch Lois. (00:02:30)
The Big Bran Hypothesis - S1-E2
Character mistake: Sheldon does not do his 3x OCD knock on Penny's door.
Suggested correction: That quirk wasn't brought into the series until halfway through the first season. The one-knock Sheldon happened a couple of times before it became the three knock habit.
The Hamburger Postulate - S1-E5
Character mistake: Leslie states that heroin causes pupils to dilate, like when Leonard sees Penny. Opiates cause pupils to constrict. (00:06:20)
The Hamburger Postulate - S1-E5
Character mistake: When Sheldon knocks on Penny's door to seek advice about the tie on Leonard's doorknob, he does not use his typical triple knock. (00:07:43)
First time he knocks 3 times is in Episode 2 of Season 1. First time knocking 3 times followed by saying the name is episode 10 of Season 1. The ritual of 3 knocks and 3 times saying the name and then stopping is Episode 5 of season 2.
Sheldon knocks three times because he once walked into his parents bedroom and saw his father with another woman. He's been doing the triple knock since he was a teenager.
Yet, he didn't in the show till Season 2. Funny ain't it?
Suggested correction: A one-time lapse in someone's usual behavior does not count as a "character mistake", even in the case of someone given to ritualistic behavior as Sheldon is.
Ah, but in an episode he explains he had developed this particular ritual at age 13 after walking into his parent's bedroom without knocking and seeing his father having sex with another woman. He says he started knocking 3 times since then and would never forget. So its not consistent and a mistake as this is not the only example one can name.
Character mistake: Wolowitz warns his fellow halo players that their enemy is "charging his Plasma Rifle". This is impossible since only the plasma gun can be charged up. (00:20:00)
Character mistake: Raj cannot talk with a woman around, but when Leonard claims they'd have to cut him in half to play teams, he blatantly argues back, and Penny is present with them. Regardless of if he was facing her or not, he shouldn't have said anything.
Character mistake: Sheldon is a well-documented and self-proclaimed germophobe. It is completely out of character for him to retrieve the bag of chicken from the trash.
The Nerdvana Annihilation - S1-E14
Character mistake: Being the first to play in the "time machine," Leonard says he will set the date for March 10, 1876. Howard says "Good choice. Alexander Graham Bell invents the telephone and calls out for Doctor Watson." Bell's assistant, Thomas A. Watson, was an experienced electrical designer and mechanic, but he did not hold an advanced degree. It is well documented that the first words transmitted over the telephone identified him as Mister Watson.
The Pork Chop Indeterminacy - S1-E15
Character mistake: In his conversation with Missy Sheldon makes it clear that his superior intelligence is a result of a random, mutated gene. Since Missy isn't similarly intelligent she obviously isn't carrying this mutated gene (which would be a billion to one shot anyway) so her offspring wouldn't inherit it. Sheldon would know this - his offspring would carry the mutated gene for superior intelligence, Missy's would not. Anyone knowing enough about genetics to use the term 'randomly mutated gene' understands enough to know that the mutated gene would only be expressed in a direct line from the carrier - Sheldon. Also bear in mind he has a model of the DNA molecule in his living room - it is obviously an interest.
Suggested correction: Genes can be dormant. Which allows them to skip generations. Therefor Missy's children could actually get the "mutated" gene. This is especially true since Sheldon and Missy are twins. Also, since the episode is about who out of Leonard, Howard or Raj, Sheldon would allow to "mate" with his sister, there is the added "insurance" of getting any smart genes from any of the 3 Lothario's mentioned above.
If you are going to try to argue with a geneticist about genetics, please use the correct terms. Sheldon is not referring to a recessive gene - there is no such thing as a dormant gene - he is speaking of a randomly mutated gene. Those are the words he used. If he had inherited a homozygous recessive karotype - one recessive gene from each of his parents - then somewhere in his family tree there would similarly gifted people, in which case he would use the correct term - a recessive gene. If Missy is a heterozygotic dominant karotype possessing the recessive gene for super-genius and the dominant for ordinary intelligence then mating her with Howard, Raj or Leonard would be a waste of time as their dominant genius gene would prevent the recessive super-genius gene from being expressed in the phenotype of the resulting child. The child would be highly intelligent but not on Sheldon's standards. It doesn't matter if Sheldon does not know any of this as he refers several times to a randomly mutated gene, not a recessive one. Missy does not carry the super-genius gene. The posting is correct.
Sheldon is prone to magical thinking when necessary to preserve his obsessive need to control his environment. He may have simply ignored the flaw in his reasoning, as even the most intelligent humans do when venturing outside their ares of expertise. He may be interested in the science of genetics, but his Ph.D. in physics doesn't qualify him as an expert in that field.
The Pork Chop Indeterminacy - S1-E15
Character mistake: Through the whole episode, Missy's accent is sometimes completely missing in scenes and then stronger and more noticeable in others.
Character mistake: When Leonard and Sheldon sit down for lunch at work, Sheldon grabs the salt and pepper and begins to shake the "shakers" over his food. However, these are grinders and not shakers. He would have had to twist the tops in order to get any salt or pepper. (00:16:10)
Character mistake: At the very beginning of the episode Leonard says "So you see what you're eating is not technically yogurt because it doesn't have enough live active acidophilus cultures." He is implying this is a scientific fact (he's not just giving his opinion on yogurt.) But to meet the U.S. standards for yogurt, only the starter cultures Lactobacillus bulgaricus and Streptococcus thermophilus are required, not Lactobacillus acidophilus. The presence or absence of L. acidophilus does NOT determine a food's identity as yogurt (which Leonard's line is implying). (00:00:05)
Character mistake: When Sheldon arrives at the apartment with his Nintendo 64 in the box, he tells Leonard that they can play Super Mario 64. He then proceeds to say, upon finding a memory card, that they can pick up where he left off. Super Mario 64 does not make use of the memory card for progression, all of that data was saved on the cartridge. (00:07:25)
The Maternal Capacitance - S2-E15
Character mistake: Leonard has his phone on his left ear. Sheldon says "Since ears don't cross hemispheres..." This is an error. The vast majority of the input to the left (or right) ear crosses over to the opposite hemisphere.
The Gothowitz Deviation - S3-E3
Character mistake: Sheldon refers to using the spray bottle as negative reinforcement when it is in fact positive punishment. Reinforcement involves encouraging a behaviour by either adding or removing a stimulus whereas punishment involves discouraging a behaviour by adding or removing a stimulus. Sheldon would know the difference.
The Adhesive Duck Deficiency - S3-E8
Character mistake: When Sheldon is placing his order near the beginning of the episode, he states "In the mid-18th century, King Rama IV of Siam..." King Rama IV was born 18th October 1804 and died 1st October 1868. His reign was during the mid-19th century (1851-1868).
The Vengeance Formulation - S3-E9
Character mistake: When Leonard, Sheldon, and Raj are watching Kripke entering his office with the board of directors, Kripke says "President Siebert", yet Siebert is not among the people standing with him.
The Einstein Approximation - S3-E14
Character mistake: When working in the Cheesecake Factory, Sheldon says "Bonne appétite," with a hard T at the end. He should know that this is incorrect and would be the first to remind others that the correct phrase is "Bon appétit" (pronounced "appéti" - it is masculine and the t at the end is not pronounced).
The Einstein Approximation - S3-E14
Character mistake: Sheldon is an extreme germophobe to the extent he doesn't even shake hands. There is no way he would be climbing around in a ball pit.
Suggested correction: If he was acting normally (for Sheldon), he wouldn't. However, Sheldon isn't acting as he normally would due to lack of sleep, and his obsession with solving a problem.
The severity of his phobia would not be minimized by lack of sleep.
Sheldon's mind is distracted by the problem he is trying to solve. He grabs other people's food, he allows Raj to touch his food, he handles dirty cutlery at the cheesecake factory, All characteristics that would be present if he was acting normally. The fact that he is in the ball pit is simply an extension.
Severe sleep deprivation could certainly affect how Sheldon reacts to phobias. The brain requires sleep to function and with a severe lack of sleep, the brain is no longer able to send the signals that alert Sheldon to his fear of germs.
The Excelsior Acquisition - S3-E16
Character mistake: When Howard finds the stack of paychecks in Sheldon's drawer and wonders why Sheldon hasn't cashed them, Sheldon explains that he's saving them to purchase items that have yet to be invented and he doesn't trust banks. But just keeping them in his drawer doesn't do anything, because checks are voided after a set period of time and they would eventually become worthless.