The new trailer for Christopher Nolan's Oppenheimer wonders 'if we can be trusted with such a weapon'

Melinda Sue Gordon/Universal Pictures Cillian Murphy front and center in 'Oppenheimer.'

Get ready to stare into the sun. A full-length trailer for Oppenheimer makes clear that Christopher Nolan's upcoming film will gaze into the cosmic energy of nuclear fission as it tells the story of the invention of the atomic bomb.

Oppenheimer stars Cillian Murphy as J. Robert Oppenheimer, the leading theoretical physicist of the Manhattan Project and "father of the atomic bomb." The new trailer finds him pondering a nuclear future — and he doesn't exactly sound happy about it.

"We imagine a future, and our imaginings horrify us," Murphy's Oppenheimer says in narration, over footage of explosions and the desert location of the Los Alamos Laboratory. "They won't fear it until they understand it, and they won't understand it until they use it."

Although Murphy takes center stage in the new trailer, Oppenheimer is stacked with stars. To name a few: Emily Blunt plays biologist and botanist Katherine "Kitty" Oppenheimer; Matt Damon plays Manhattan Project head General Leslie Groves Jr.; Robert Downey, Jr. plays U.S. Atomic Energy Commission founder Lewis Strauss; Florence Pugh plays psychiatrist Jean Tatlock; Benny Safdie plays physicist Edward Teller; and Josh Hartnett plays nuclear scientist Ernest Lawrence. Rami Malek, Dane DeHaan, Dylan Arnold, David Krumholtz, Alden Ehrenreich, and Kenneth Branagh (who previously collaborated with Nolan on Dunkirk and Tenet) are also in the cast.

Melinda Sue Gordon/Universal Pictures Christopher Nolan directing 'Oppenheimer.'

More Oppenheimer footage can be seen in a sneak peek playing before IMAX showings of Avatar: The Way of Water. That footage includes dialogue with Damon, and makes clear that the film will oscillate between color photography and black-and-white.

As an indication of why the explosions in this Oppenheimer trailer look so terrifyingly majestic, Nolan recently revealed that he and his team recreated a nuclear explosion "without the use of computer graphics."

Oppenheimer is currently set to hit theaters on July 21, 2023 — the same day as Greta Gerwig's Barbie, which also just released its first trailer.

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