It was Mr. Oppenheimer’s opus, and it was based in theory.

J. Robert Oppenheimer (Cillian Murphy), a renowned theoretical physicist, had a theory that an atomic bomb could be developed; the U.S. military had a theory that a big enough bomb would end World War II. Both parties were proven correct in 1945, after America dropped two newly developed atomic bombs on Japan, leading to its surrender.

In his first historical film since “Dunkirk,” Christopher Nolan’s new biopic “Oppenheimer” takes on the story of the man who changed the course of history by leading a tightrope race to peace through God-like destruction. Worried that Hitler might have his scientists working toward the same goal, the U.S. military recruited Oppenheimer to work on the Manhattan Project, appointing him director of the Los Alamos Laboratory that would develop the bomb.

Moving from theory to creation was anything but simple, as time was not the only challenge his teams faced. There was a constant risk of their research being smuggled out to the Soviets. Though technically an ally against the Nazis—Americans didn’t like the idea of Stalin having such weaponry at his disposal.

Never before had such a powerful weapon existed. Scientists had a lot to figure out before they could actually test it. And when they did, they weren’t certain it wouldn’t set off a chain reaction of explosions that ignited the atmosphere and destroyed the entire planet.

There was also moral uncertainty. By the time the bombs were completed, Germany had lost the war, and Japan was barely hanging on. Some felt it was a matter of time before Japan surrendered. Should the bomb be used at all?

Early in his work, Oppenheimer believed that bombing Japan was essential; he thought the fear of such a weapon would lead to a peace the world had never known. But when he sees the first atomic bomb tested in the New Mexico desert, we hear him think of a line of Hindu scripture: “Now I am become Death, the destroyer of worlds.” He saw the power of his creation.

After the bombs were used on Japan, Oppenheimer became less certain that a better option hadn’t existed. The complicated moral fallout of the atomic bombs dropped on Japan has been debated ever since. The war ended, yes, but at the cost of more than 100,000 Japanese casualties—mostly civilians. We can never know how many lives the bombs saved from a continuing war.

The film builds to the conclusion that while the atomic bomb ended World War II, it simultaneously formed the foundation of the Cold War. It was a matter of time before the Soviet Union—then other countries—had these world-destroying weapons pointing at one another with fingers resting on the launch buttons.

Viewed as a hero after the war, Oppenheimer was vocal in his later years about the importance of control and limitation of nuclear weapons worldwide and was strictly against the hydrogen bomb, opinions that government officials like Lewis Strauss (Robert Downey Jr.) didn’t care for and tried to bury Oppenheimer over.

“Oppenheimer” is a hugely ambitious film, and it’s pretty remarkable that it hits all of its marks. It’s a massive movie (three hours) from a massive director with a massive cast about a massive bomb with massive repercussions.

It was made more massive by viewing it at the Indiana State Museum’s IMAX—one of only 30 theaters in the world to show the film as Nolan intended, on IMAX 70mm film (the frames weigh 600 pounds, and its film is 11 miles long). The experience was best summed up by the random dude next to me who at the sight of the opening scene stretching across the enormous screen gave a breathy, “Whoa.”

In typical Nolan fashion, the music is truly unique—and loud. The volume grows nearly unbearable at times, leaving the audience anxious, on the verge of discomfort—which seems fitting, considering the gravity of the work the scientists were undertaking. I don’t think there’s a drum used in the soundtrack, instead replaced by the percussion of feet stomping and explosions.

In one scene I heard a subtle metallic ticking in the right of the theater. It started to bother me; I thought someone in the audience was kicking something. Surely I wasn’t the only one hearing it. Then I realized everyone was hearing it because it was in the movie: the pestering clock buried behind the chaos of the race against the Nazis.

It’s long and it’s slow at times, which could bore the impatient viewer. But it’s stunning to look at and beautifully acted by an impressive list of actors who lined up to be in a Christopher Nolan movie (Matt Damon promised his wife he’d take a break from acting unless Nolan called). Cillian Murphy should expect award nominations for his portrayal of Oppenheimer as the confident yet fluid “father of the atomic bomb.”

“Oppenheimer” intensely captures the moment the world changed forever—for better and for worse—setting off a different type of chain reaction that we feel to this day.