It's natural that a film set around the world's first atomic testing would focus on the build-up and—quite literally—the fallout of such an event, and that's what Christopher Nolan's latest film, Oppenheimer, sets out to do as it follows the lead character of American physicist J. Robert Oppenheimer (who will be played by Cillian Murphy in the movie).

The first ever test explosion was code-named 'Trinity' and it took place in a desert in New Mexico in early 1945. Onlookers at the time described the event as "amazingly bright", adding that the lights turned yellow, then red, then purple, before noting it rose in a "toadstool effect" - which is where the infamous "mushroom cloud" expression came from when referring to nuclear detonations. To capture such an event for the film would require a lot of logistical planning, or the heavy use of CGI to achieve a similar effect, but for Nolan, practicality has always been the way forward.

Speaking with Empire Magazine, in an in-depth piece on the film, Nolan has expanded on the revelations that he chose to do it all without the use of CGI. The director described the visceral feeling of being among a group of colleagues and peers, watching fire rise into the sky. Having worked with his visual effects supervisor, Andrew Jackson, to best achieve a practical recreation of the original test, the director believed it was the most surefire way to ensure authenticity within the filming process.

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Image via Universal 

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Setting Fire to the Atmosphere

Nolan continued by saying that the sensation of hearing the noise and feeling the heat brought him back in time alongside the scientists watching the events unfold for the first time, both in awe and terror, as they never knew for certain that their decision to work with nuclear material wouldn't end up scorching the atmosphere of the planet.

"I mean, I've done a lot of explosions in a lot of films. But there is something very unique and particular about being out in a desert in the middle of the night with a big cast, and really just doing some enormous explosions and capturing that. You couldn't help but come back to this moment when they were doing this on the ultimate scale, that in the back of their minds they knew there was this possibility that they would set fire to the atmosphere. It was pretty amazing to engage in that kind of tension."

Oppenheimer is set to be released in theaters on July 16. Nolan recommends you watch the film in IMAX 70mm if you can. For more information on that limited release, check this link here. You can see the trailer for the film down below.