Oppenheimer, Christopher Nolan's latest film, has already grossed $500 million worldwide, making it one of the highest-grossing films of 2023 so far. Nolan often makes movies that blend science in storytelling and require a basic understanding of science, some of which he explains through dialogue and the rest he assumes the audience already knows. In his latest movie, lack of understanding of science won't prevent the viewer from following the screenplay (which was not in the case of interstellar, for example). However, if you know a bit of school grade science, you'd be able to appreciate one of the defining scenes of the movie better.
Spoiler Alert: If you haven't seen Oppenheimer and plan to, then stop reading now. If you have already seen it, you will appreciate this explanation of a key scene.
Towards the end of the film, Oppenheimer's team tests the bomb they have created. The detonation is successful, and Oppenheimer is informed of this over the phone. He is miles away from the detonation site, as is the rest of the team.
We see the mushroom cloud rise from the detonation site, and everyone congratulates each other on the success of the project. However, there is no sound when the fire appears on screen. One would expect a loud explosion with a mushroom cloud of that magnitude, but there is none as the screen fills with fire from the bomb.
It is only after a while that we hear the sound of the detonation. For a moment, if you are watching the film, you might think that they have detonated another bomb. Or perhaps, an oversight by the director. However, this is not the case.
This is where the signature touch of Nolan comes to play as he tries to keep the structure of the scene true to everyday science.
Light travels faster than sound, as we learn in school. The deafening sound is intentionally delayed, subtly mirroring the time lag between light and sound real-life situations. As we wait, the distant rumble finally reaches us, just as it would happen in real-life.
The movie is perhaps Nolan's best work yet and is less about science of physics of the bomb and more about the politics of science where genius is not the guarantee of wisdom!