The Star Trek franchise, which began with The Original Series in 1966 and is still popular today, was a huge influence on the long-running sitcom series The Big Bang Theory - which definitely makes sense, at least considering the latter's main focus of exploring nerds and aspects of nerd culture. Because of this connection, the characters in TBBT (especially the four guys, who are die-hard fans) have referenced Star Trek literally dozens of times; these references range from casual callbacks spouted during a rant to full-on homages (some of which have featured actors from the Star Trek franchise itself).
Here are 10 of the best Star Trek references found throughout the show.
Napkin
In the Big Bang Theory episode "The Bath Item Gift Hypothesis", Penny decides to get Sheldon a Christmas gift, which - despite Sheldon's dislike for the holiday - compels him to get her something equal in return.
On Christmas Day, Sheldon opens the gift and finds that it's a napkin both signed by Leonard Nimoy (the actor who played Spock on Star Trek) and containing his DNA. Sheldon is overjoyed, and plans to use the gift to clone his hero.
Action Figure
In the season 5 episode "The Transporter Malfunction", Penny gets Sheldon and Leonard mint in box Star Trek toys, but Sheldon breaks his after being advised to play with it by a talking Spock action figure (voiced by Leonard Nimoy himself).
He tries to switch it out with Leonard's, but he's not exactly the best liar, and the truth is soon revealed.
Renaissance Fair
In the season 2 episode "The Codpiece Topology", Sheldon, Leonard, Howard, and Raj go to a Renaissance Fair set in the Middle Ages.
Sheldon, after complaining repeatedly about the numerous historical inaccuracies found throughout the displays, decides to show up dressed in a Spock costume.
Where No Sheldon Has Gone Before
In the season 4 episode "The Thespian Catalyst", Penny is trying to give Sheldon acting lessons, so she has him act out a couple of different scripts - including one based on a Star Trek fan fiction piece he wrote at the age of 10 called "Where No Sheldon Has Gone Before".
The piece ends up becoming surprisingly emotional for Sheldon, forcing Penny to call his mom to reassure him.
Klingon Boggle
Klingon Boggle is a game first referenced in the series' pilot episode. It follows the traditional rules of the Hasbro game Boggle, except that Klingon characters are used instead of the traditional alphabet.
Apparently, to make the game easier, you're allowed to use a copy of The Klingon Dictionary by Marc Okrand (inventor of the Klingon language) to help you find words.
Rock, Paper, Scissors, Lizard, Spock
Another Star Trek-modified game played by the gang is Rock, Paper, Scissors, Lizard, Spock. The game works like a standard game of Rock, Paper, Scissors, just with two extra weapons. The game was invented by Sam Kass and Karen Bryla to expand on both the psychological and the luck elements on its predecessor.
The rules are as follows: Scissors cuts Paper, Paper covers Rock, Rock crushes Lizard, Lizard poisons Spock, Spock smashes Scissors, Scissors decapitates Lizard, Lizard eats Paper, Paper disproves Spock, Spock vaporizes Rock, Rock crushes Scissors. Pretty simple, right?
Spockumentary
In the ninth season episode "The Spock Resonance", Sheldon is interviewed as part of a "Spockumentary", created by Leonard Nimoy's son, Adam (who plays himself), about the effect of the character on culture and the entertainment industry.
However, Sheldon's recent breakup with Amy makes it hard for him to concentrate on the interview.
Wil Wheaton
Actor Wil Wheaton, known for his role as Wesley Crusher on the series Star Trek: The Next Generation, appears in multiple episodes of The Big Bang Theory.
Perhaps most memorable was his season 3 appearance in the episode "The Creepy Candy Coating Collorary", in which he becomes Sheldon's main rival in a high-stakes tournament of the (fictional) trading card game Mystic Warlords of Ka'a.
Leonard Nimoy Restraining Order
Maybe Sheldon just obsesses too much over his heroes. After all, it's just a little bit concerning that astronomer Carl Sagan, television personality Bill Nye, comic book writer Stan Lee, and actor Leonard Nimoy all have restraining orders against him.
The existence of Nimoy's restraining order against Sheldon was revealed in the season 3 episode "The Excelsior Acquisiton".
The Bakersfield Expedition
Perhaps the biggest tribute made to Star Trek over the entirety of The Big Bang Theory's run was the season 6 episode "The Bakersfield Expedition", which follows Sheldon, Leonard, Howard and Raj as they go on a road trip to Bakersfield Comic-Con.
However, after they decide to pose for photos in costume at Vasquez Rocks Natural Area Park (the filming location of many Star Trek episodes), Leonard's car is stolen, and the four have to go on a trek of their own to make it to the convention in time.