Young Sheldon Season 6, Episode 4 Isn't The First Time Viewers Have Seen Sheldon In An All-Consuming Scientific Crisis

One of the many enjoyable qualities of "Young Sheldon" is the prequel's ability to lovingly call back to "The Big Bang Theory." This often contextualizes one of the titular character's many quirks that he consistently explains at length like his iconic spot on the couch. In "Young Sheldon," we witness the adolescent scientist (Iain Armitage) grow and develop into the zany physicist we fell in love with on "The Big Bang Theory" through events that sometimes mirror the original series.

In Season 6 Episode 4, The Cooper family continues adjusting to their new life, which is chock full of family complications. Georgie (Montana Jordan) and his expecting not-girlfriend Mandy (Emily Osment) are struggling financially while Georgie still attempts to woo the unimpressed mom-to-be. Meanwhile, Sheldon's twin sister Missy (Raegan Revord) is facing a mean girl at school and is dealing with accompanying boy problems, leading to her own identity crisis and a hair-raising makeover. Missy confides in Mandy instead of her mother (Zoe Perry) or grandmother (Annie Potts), sending them both into their own contemplations of identity. 

Sheldon's mind remains busy as always when his new tutoring gig brings about an unexpected and unsolvable problem. His next-door neighbor Billy (Wyatt McClure) proposes the question: what is zero? Sheldon scoffs at this and attempts to explain it but then falls deep into his first scientific existential crisis reminiscent of his insomniac nightmare on "The Big Bang Theory."  

This tutoring session on "Young Sheldon" evokes comical memories of adult Sheldon (Jim Parsons) teaching Penny (Kaley Cuoco) physics on "The Big Bang Theory" with unexpected results in Season 3, Episode 10. Penny actually learns some useful physics knowledge quite like Billy, who passes his math test thanks to Sheldon's mentoring. It even paves the way for another delightful callback due to Sheldon's obsessive personality.

At the university, Sheldon asks Dr. John Sturgis (Wallace Shawn) and Dr. Linkletter (Ed Begley Jr.) for assistance, all resulting in the same effect. Billy's mind-numbing question even stupefies Sheldon's professors when he recruits their expertise, producing the same result each time. At first, the scientists are smug and righteous then quickly fall into hopeless confusion with an iconic trombone shot (or dolly zoom) depicting their drastically changed state of emotion. The three even take turns vomiting into a trash bin to illustrate their deep unease at the concept of zero not actually existing.

This is extremely evocative of Sheldon's insomniac state when he's stumped by a troubling physics problem. In Season 3, Episode 14 of "The Big Bang Theory," he follows Albert Einstein's brilliant footsteps by taking a routine job at the Cheesecake Factory to help free up his mind. This extreme reaction is reflected in the younger Sheldon's dramatic response to the possible nonexistence of zero with hilarious results, adding yet another layer to his multifaceted character.