Oppenheimer review – relentlessly gripping and gargantuan account about the weight of genius

With his twelfth film Christopher Nolan has delivered a dense, talky and morally queasy payload about the destructive weight of genius – a film that pulsates and explodes with the force of an atomic bomb, even when its characters are merely scratching equations on a white board. A major step-up from the cinematic head-scratcher that was Tenet, Oppenheimer – based on the non-fiction work American Prometheus: The Triumph and Tragedy of J Robert Oppenheimer by Kai Bird and Martin J. Sherwin – is Nolan's first biopic, though one could also argue there's a flash of autobiography here, too, revealing as much about the man behind the camera as it does its controversial subject.

That's to say, there feels like some cosmic inevitably about the pairing of Nolan and J. Robert Oppenheimer, “Father of the Atomic Bomb,” played here in a mysterious, somewhat opaque, though never not utterly riveting performance by Nolan regular Cillian Murphy. In Murphy's thoughtful blue eyes, we glimpse the American physicist's brilliant but increasingly disturbed mind; his groundbreaking breakthroughs and his moral confusion. What truly makes him tick, the movie can't quite calculate. But Murphy's haunting turn holds this gargantuan slice of historical speculation together; his thousand-yard stare, his skinny frame constantly at war with the size of his mental achievements.

Nolan, unsurprisingly for the director of The Dark Knight, is interested in Oppenheimer as a subject of myth. Positioning his hero at the centre of a Greek tragedy, the movie unfolds as a muscular, star-studded, and never-not-moving epic with shades of Oliver Stone's JFK. Nolan's dialogue-heavy script leans on the idea of men as self-made Gods. “Now I Am Become Death, the Destroyer of Worlds,” mutters Oppenheimer during a sex scene untypical of this usually rather sexless director – his most famous line, repurposed as to highlight not only his infamous legacy, but the destructive nature of Oppenheimer's personal life, namely his involvement with biologist and psychiatrist Jean Tatlock (Florence Pugh).

Could Nolan, master of many universes, make such a declaration, too? As Oppenheimer assembles his crack team in the remote desert of Los Alamos, New Mexico to work on what would come to be known as the “Manhattan Project,” the film appears to meditate on the process of filmmaking itself; one mad genius and his highly skilled team pitted against massive, insurmountable odds.

Like Oppenheimer, Nolan brings in his most trusted collaborators to help him pull off the task. Hoyte van Hoytema, whose lush, IMAX cinematography relishes in both the scope and the finer details, while Ludwig Göransson's sublime and cerebral score seems to find everything – past, present, and future – at an atomic level, translating the weight of history to the screen, its clock-like rhythms positioned as though counting down to our own extinction. Yet in spite of the film's score-heavy nature, Nolan pulls a brilliant trick in the film's most explosive moment, opting for complete silence after we've become so accustomed to the pounding, incessant noise of progress.

As biopics go, it's an undeniably awesome affair: gripping, intelligent, and brilliantly acted from a cast list too long to mention here. If it suffers at all, it's thanks to the bomb. Not because Nolan fails to translate its terrifying power to the screen: the “Trinity” test sequence is arguably the film's great moment – a triumph of intricate editing and molecular sound design that makes you palms sweat, even as you know just how it will turn out. But after you detonate an atomic bomb, anything else seems like small potatoes. As such, the back half of Oppenheimer, which falls into a courtroom drama about Oppenheimer's post-war battle with Atomic Energy Chairman Lewis Strauss (an excellent Robert Downey. Jr), grips well enough, but can't locate the same level of gravitas as the road leading up to the invention of the weapon.

In a film that feels divvied up three ways, into the personal, the political, and the professional, Nolan is keen to highlight Oppenheimer as a younger, left-leaning man – a choice that comes back to haunt him when he later rallies to slow the arms race between the US and Russia, leading to his blacklisting as a communist sympathiser. But ultimately this portrait wants us to see Oppenheimer as an “American Prometheus” – a genius who would set himself alight in the process, and whose ominous conversations with Einstein (Tom Conti) suggest a man whose anxieties and ambitions were overlapping from the start. What else was he to do, as a Jew caught at arguably the most important crossroad in human history? But did Oppenheimer ever truly want the Americans to use the bomb? The film, like its protagonist, doesn't settle on a firm answer. But Nolan clearly views his subject with understanding, empathy, and admiration – perhaps even as a kindred spirit.

Importantly, consciously, the bombings of Hiroshima and Nagasaki are never seen, just as they were never seen directly by Oppenheimer; only in his nightmares do we get a sense of what it might have been like to be there, as Nolan's film segues into something stranger and more surreal, drowning us in oppressive sound design packed with fervent footsteps and screaming voices; the movie, initially shot with such scope and clarity, becomes increasingly more claustrophobic, all but dissolving around us.

Despite its three-hour runtime and a narrative that leaps back and forth through time, Oppenheimer never loses its sense of hurtling towards something that can never be taken back. The movie tells us, repeatedly, that this is the most important thing to have ever happened, and – stunned into a stupor by the editing, sound design and visual flourishes – we stumble out into the street afterwards, genuinely believing it. While Tenet seemed to turn back the clock on Nolan's career, Oppenheimer shows a filmmaker in flux, this movie serving as the most definitive statement yet on his most common theme: that with everything, it's only a matter of time.

Oppenheimer is released in UK cinemas on 21 July.