The Big Bang Theory Plot Hole That Should Have Led To Sheldon's Death

Even though the main purpose of CBS sitcom "The Big Bang Theory" was to entertain, the show about socially awkward Ph.Ds living in Los Angeles also prided itself on bringing some scientific accuracy to network prime time. As in any good workplace comedy, the show's main characters Sheldon (Jim Parsons), Leonard (Johnny Galecki), Raj (Kunal Nayyar), and Howard (Simon Helberg) often mixed their professional and personal lives. This created a mix of experimental physics and dating experiments that had viewers hooked.

However, just because the show tried its best to add some realism to the scientific aspects doesn't mean the writers didn't err during the series' impressive 12-season run. The show had its share of typical sitcom plot holes, such as drifting birth dates and relatives whose names changed between seasons. There was also one glaring inaccuracy that had fans more up in arms than usual. While the mystery of how Penny (Kaley Cuoco) affords her own apartment in LA on a waitress' salary may have irked viewers, the "Big Bang Theory" plot hole in question is so large that it should have led to the untimely death of one of the show's central characters.

In the Season 3 episode "The Vengeance Formulation," Sheldon is feuding with his nemesis Barry Kripke (John Ross Bowie) after Kripke ruins Sheldon's surprise announcement that he's going to be interviewed on NPR. Fuming, but determined to deliver a professional interview, Sheldon readies his talking points and sits in his office to call into the interview.

Unbeknownst to him, Kripke already has a plan to sabotage his appearance. As Sheldon speaks he notices his voice is getting higher and higher, until he goes full on cartoon character. Kripke had inserted a nozzle attached to a helium tank through a hole in the wall and filled his office with the inert gas. 

It's worth noting that Kripke also has an oxygen tank right next to the helium tank; if he used both those gases, it would have made heliox, a breathing gas often used for medical purposes and in commercial diving (via ScienceDirect). However, it looks like Kripke only places his hand on the knob of the oxygen tank and sort of mimes twisting it — it's difficult to see if he actually turned it. Comparatively, one can easily see Kripke cranking the knob on the helium tank. It does appear that the nozzles on both tanks join together to the one that flows into Sheldon's office, but that wouldn't matter if Kripke had used only helium.

Heliox still would have made Sheldon's voice squeaky, but pure helium has a far more devastating consequence.

Even though helium is a relatively benign gas when used for its intended purposes (aka party balloons), it can be extremely deadly to humans when used incorrectly. Daniel Engber, writing for Slate, explains exactly why: "When [helium] fills your lungs, it creates a diffusion gradient that washes out the oxygen... After inhaling helium, the body's oxygen level can plummet to a hazardous level in a matter of seconds."

He clarifies that inhaling a small amount from a balloon to make your voice squeaky is fairly innocuous (as long as you don't overdo it), but that sucking it straight from a nozzle or being completely immersed in helium can prove to be deadly extremely quickly. There have even been several cases over the years of people dying after sticking their entire heads inside large helium filled balloons.

Another factor in Sheldon's would-be demise is that once there was enough helium in the room for his voice to turn Alvin and the Chipmunks, the inert gas would have already displaced the oxygen in the room. Under the laws of the real world, this would mean that Sheldon would have been dead in seconds, and he would have gotten no vengeance (unless Kripke getting arrested on manslaughter charges counts).

Considering what a fuss "The Big Bang Theory" makes over its scientific accuracy, fans were miffed that the writers missed such an obvious error in service of a bit that was only just OK to begin with. But it's not even the last time they opened up a fatal plot hole for one of their characters.

In the Season 5 "Big Bang Theory" episode "The Countdown Reflection," Howard takes a trip to the International Space Station. This seems like pretty typical "five seasons in and jumping the shark" plotting for a sitcom about scientists, but as ScreenRant points out, Howard's myriad of previously disclosed health issues make him a particularly poor candidate to face the rigors of space travel. It's unlikely he would even be allowed to even board a spacecraft — and if he was, his heart issues and asthma would have put him at serious risk of not making it back to earth alive.

We should specify that this one is only a plot hole if you don't subscribe to the theory that after asphyxiating in the helium room, the rest of the series is one long Sheldon coma dream.