J. Robert Oppenheimer's 'Q clearance' is on the line in 'Oppenheimer' — here's what that means

• Much of the action in the 2023 film "Oppenheimer" is focused on a 1954 security hearing.
• Oppenheimer is accused of being a spy for the Soviet Union, and his Q clearance is on the line.

Warning: This story references a major plot point in the movie "Oppenheimer."

If you've seen "Oppenheimer," Christopher Nolan's 2023 biopic of J. Robert Oppenheimer, the father of the atomic bomb, you might be wondering exactly what Oppenheimer lost after the 1954 hearing spliced throughout the film.

His "Q clearance" — which is uttered a few times during the film by various characters — was revoked after he lost his appeal, as shown in the film. But what exactly does that mean?

What is Q clearance?

As a habit, Nolan doesn't always spell things out to viewers, and all the film makes clear is that this was a professional blow that Oppenheimer was never able to recover from. He died 13 years later, and by all accounts, was never the same after this.

Q clearance is the level of security clearance issued by the US Department of Energy that's required to access Top Secret Restricted Data, Formerly Restricted Data, Secret Restricted Data, and National Security Information.

Oppenheimer was given this security clearance during World War II when he worked on the Manhattan Project in Los Alamos, New Mexico, which is shown during the film.

For context, this is the same level as the US Department of Defense's Top Secret clearance.

Due to suspected ties to the Soviet Union — a letter from a Manhattan Project engineer, Kenneth Nichols, claimed that Oppenheimer was "a Communist in every sense except that he did not carry a party card" — Oppenheimer lost his security clearance, was removed from the Atomic Energy Comission, and was essentially cut off from influencing any policy decisions regarding nuclear energy.

In 2022, Oppenheimer was cleared of any ties to the Soviet Union by the Department of Energy, 55 years after his death in 1967.

"History matters and what was done to Oppenheimer in 1954 was a travesty, a black mark on the honor of the nation," Kai Bird, a co-author of the biography "American Prometheus," on which the film was based, told The New York Times in 2022.

What does this have to do with QAnon?

In short, Oppenheimer doesn't have anything to do with QAnon — but Q clearance does. The conspiracy takes its name from it; the person behind the conspiracy, known to followers as "Q," claims to be someone who has Q clearance.

This contributes to why the conspiracy theory, which posits that Trump is fighting a "deep state" cabal of human traffickers, has only grown in popularity since it first popped up on the internet in 2017. Followers believe that they have a direct line to someone high up in the government.

Another reason it persists is that people in government, like US Representative Marjorie Taylor Greene have publicly endorsed the conspiracy, even though QAnon has been disproven time and time again.