Cultural Error

In Season 1 Episode 11, Sheldon is concerned that he is coming down with a cold/flu virus transmitted through Penny from her sick relatives in Nebraska. He makes up some cultures out of lime Jell-o to find out exactly what bug he has caught.
In fact, viruses don’t grow in a culture (or, at least not on their own). They have no reproductive mechanism of their own and only replicate by taking over the cellular machinery of a living organism. You can only culture bacteria, and bacteria do not cause colds or flu.

Fluid Consistency

In Season 1 Episode 11, Leonard tells an ill Sheldon to “drink plenty of fluids”. Sheldon replies by saying, “What else would I drink? Gases? Solids? Ionized plasma?”. Any high school chemistry student would be able to tell you that gases are, in fact, fluids. Any Sc.D would be able to tell you that plasmas are also fluids. ‘Fluid’ is often assumed to be synonymous with ‘liquid’, however, this is not the case. The definition of a fluid is a substance that has no fixed shape and yields easily to external pressure e.g. liquids, gases and plasmas. Sheldon’s implication is that a fluid is a state of matter separate from other states. Meanwhile, all four states of matter can, in fact, be fluids.

For a regular Joe, this is an honest mistake; the term “drink plenty of fluids” is rather colloquial. Technically, you are inhaling fluids as we speak. However, Sheldon’s response furthers the technical ignorance of their conversation.

Thanks to David Grounds for the submission.

Average Look

In season 6 episode 8, Sheldon says that, statistically speaking, Leonard should worry about Penny’s friend.

Well, if we assume your looks are average, yeah, right off the bat, fifty percent of men on Earth are more attractive than you. That’s one point five billion handsome lads standing by, waiting to rain on your parade.

Sheldon assumes that if Leonard’s appearance is average, 50 percent of men are more attractive than him. He makes the classic statistics mistake by confounding the average (mean) and the median. Leonard being “average” does not define his location on a scale of appearance. Average ≠ middle.

For example, in Fig. a, 


the red bars represents members of the male population who are less attractive than Leonard. The blue bars represent members of the population who are more attractive. As you can see, Leonard is the exact average, being in the middle. This is an idealized situation where Sheldon would be correct (because there are 9 less attractive and 9 more attractive). 

However, consider Fig. b,


In this example, there are 16 men less attractive than Leonard and 2 men more attractive. Yet, Leonard is still in the average. Despite being in the average, he is not in the middle, with 11% of men more attractive than him.

Doctor Who?

In season 5 episode 14, Amy makes the unforgivable mistake of referring to the main character of “Doctor Who” as Doctor Who (as opposed to his title, The Doctor or Doctor). Even worse, in the room full of nerds, no one corrects her. No one.

For someone who has a machine that can travel anywhere in time and space, Doctor Who sure does have a thing for modern-day London.

As for Amy’s comment, I think he spends a fair amount of time in places aside from London.

  • space station orbiting Earth (‘The End of the World’)
  • Cardiff (‘The Unquiet Dead’, ‘Boom Town’)
  • Utah (‘Dalek’)
  • Satellite 5 (‘The Long Game’)
  • Gamestation (‘Bad Wolf’/’The Parting of the Ways’)
  • New Earth (in ‘New Earth’, ‘Gridlock’)
  • Victorian Scotland (‘Tooth and Claw’)
  • 18th century France (‘The Girl in the Fireplace’
  • A random planet orbiting a black hole (‘The Impossible Planet’/’The Satan Pit’)
  • Manhattan (‘Daleks in Manhattan’/’Evolution of the Daleks’)
  • A spaceship (‘42’)
  • a space cruiser (‘Voyage of the Damned’)
  • Pompeii in AD79 (‘The Fires of Pompeii’)
  • The Oodsphere (‘Planet of the Ood’)
  • Messaline (‘The Doctor’s Daughter’)
  • The Library (‘Silence in the Library’/’Forest of the Dead’)
  • Midnight (‘Midnight’)
  • Shan Shen (‘Turn Left’)

Thanks to somedielookinforahandtohold for the mistake.

Acronyms & Initialisms

In season 4 episode 14, Sheldon makes the mistake of calling “KMN” (Kill me now) an acronym, when it is, in fact, an initialism. Sheldon, being the type to correct regular folk on simple semantics, should know this.

Oh, tweets about my lecture. Hmm. That’s rather unfair. That’s downright cruel. Plus, insects have six legs. Yeah, I’m not familiar with the acronym KMN.

Submitted by: Gerry

Oxygen Availability

In season 3 episode 9, Sheldon’s voice becomes high-pitched when helium is pumped into his enclosed room. If Sheldon’s larynx were to be noticeably affected by the gas, the average volume of helium per cubic area of the room would have to be at least 23.8% greater than the amount of available oxygen. If this were the case, Sheldon would be metabolizing less than 1/20th the amount of required oxygen in one minute, resulting in rapid asphyxia and unconsciousness. Critical brain damage would occur after a few minutes followed by brain death.

Scientific Panels

There is no way Sheldon, Leonard, Raj, Howard, Bernadette, and Amy Farrah Fowler would be on the same scientific panel at conferences they attend. I can see them at the same conference (as they all research at the Caltech), but definitely not on the same panel.

Leonard and Sheldon are both physicists, however Sheldon is a theoretical physicist and Leonard is an experimental physicist.
Howard is an engineer. Raj is an astrophysicist. Bernadette is a microbiologist. Amy Farrah Fowler is a neuroscientist.

None of them do the same research.

Schrodinger’s Cat

You probably thought you knew what Schrodinger’s Cat is. You aren’t one of those people that think it’s about about a zombie cat or something. However, it’s likely that you are misinformed, just like a lot of high school history teachers, almost every Youtube video on the topic, your smart-ass friend and the Big Bang Theory.

In season 1 episode 17, Leonard and Sheldon are discussing Leonard’s relationship with Penny. Sheldon explains the simultaneity of his relationship with Leonard with a reference to Schrodinger’s Cat. This famous thought experiment has been more or less popularized by the show, however described incorrectly.
Sheldon is using this quantum physics concept to explain how he is both friends and enemies with Leonard, simultaneously. He explains Schrodinger’s cat by saying, “In an attempt to explain the Copenhagen interpretation of quantum physics, “[Erwin Schrodinger] proposed an experiment where a cat is placed in a box with a sealed vial of poison that will break open at a random time. Since no one knows if the poison has been released, until the box is opened, the cat can be thought of as both alive and dead.”
The show’s explanation of Schrodinger’s Cat grasps the general idea (many physics teachers would tell you that there is nothing wrong with this explanation). However, it is patently false.
As mentioned in the quotation, Edwin Schrodinger lived in the time of the proposition of the Copenhagen interpretation of quantum physics, which dictated a level of simultaneity when uncertainty is present. When you don’t know if something is A or B, it’s both. Although widely believed, Edwin Schrodinger did not invent his famous thought experiment to better explain quantum mechanics, but to point out how absolutely ridiculous it is. Schrodinger was showing that the uncertainty principle is silly and cannot be applied to classical physics.
Do not be fooled; Schrodinger was correct. As Einstein said, “The more success the quantum theory has, the sillier it looks.”


In season 5 episode 16, Amy tells Sheldon to wash a tray of “beakers”, but in fact only one of the items on the tray is actually a beaker; the rest are flasks. Beakers (aside from Dr. Bunsen Honeydew’s assistant on The Muppet Show) are straight-vertical-sided containers like a cup or mug but without a handle. Flasks are angled-sided or round containers with a narrow neck at the top.

NASA Space Program

In season 5 episode 18, Howard is accepted into the NASA space program to go into space. He passes the physical and proceeds into astronaut training. It is impossible for Howard to pass the physical examination as Howard has a heart condition. NASA has extremely rigorous health checks and, although his fatal allergy to peanuts may be overlooked, a heart condition is a spaceflight deal-breaker.

On the same topic, Howard, at one point, failed an FBI security check to participate on a secret government project. Failing a government security check would either parallel or nullify all chances of being sent to space.

Furthermore, Howard’s design for a toilet failed in action aboard the space station when the waste was ejected into the inside of the quarters. Not only would this be detrimental for the crew (as waste is processed into necessary drinking water), but it would also void Howard’s chances of being sent to space as a payload specialist for his own previously malfunctioning components, after the fact.

Thanks to Matt for the correction on FBI vs. CIA.