F9 Fast and the Furious © Universal

Fast and Furious 9: The insane real-life science behind that magnet scene

With the help of magnet expert Prof Dominic Ryan, here's a crash course into the physics behind the Vin Diesel blockbuster.

Realism isn’t exactly something the Fast and Furious franchise takes too seriously.

Advertisement

You want gravity? These are the films that feature cars parachuting from airplanes. You want physics? These are the films that once saw a car jump from one giant skyscraper to another giant skyscraper. You want cars? Well, yes, there are plenty of cars. But as far as accurate science is concerned, let’s just say the Fast and Furious has quite a few points on its artistic licence.

Even so, the latest film in the series, Fast and Furious 9, might just be its boldest entry yet. For not only is this movie where Vin Diesel and co. launch into space, but it is also the movie that features several scenes involving some seriously seriously strong electromagnets.

One moment, for example, sees a plummeting car plucked out of the air by a plane with a huge magnet attached to its hull – a stunt that was dreamed up by director Justin Lin’s nine-year-old son. But just how childish an idea is it?

“Electromagnets are routinely used to pick up cars in junkyards,” says Dominic Ryan, professor of physics at McGill University in Canada, “but you need good clean contact to a lot of steel for it to work so hitting a car in flight would be tough.”

And even if it did work, Ryan doesn’t fancy the chances of the plane surviving the stunt.

“My primary issue would be the abrupt addition of around 1000kg to the aircraft – managing that sudden change in load without crashing might not be possible, even in principle. Plenty of helicopters can lift tanks, but they do it really slowly.”

Not content with strapping magnets to planes, however, Fast and Furious 9 also sees them strapped to the sides of cars too. In one of the film’s major action sequences, these magnets are used to ‘suck in’ other cars before – with the turn of a dial – repelling them away into oblivion.

According to Ryan, it is technically feasible that a magnet could suck in a car at a short distance. Yet the magnet required to generate that kind of pull would not only be far too big for a car to carry, but would also require an absurd amount of power.

“One of the magnets I’ve used produced 25 Tesla, which is about ten times what you can get from a standard electromagnet,” he says. “It produced that field in a magnet the size of a beer barrel.

“We put 10 megawatts into it. That’s 10 megawatts that appears as heat, so there’s also a 10 megawatt cooling system to get that heat out.

“The power supplying this thing was a building. The cooling system was another building.”

Read more about the science of magnets:

As for the idea that a magnet can be reversed, therefore repelling a steel car, Ryan’s eyes nearly roll out of his skull.

“Magnets don’t repel steel objects,” he says. “There are a small number of materials that are diamagnetic, which means it magnetises the opposite. But it’s typically a very small effect.

“It would not work on fancy expensive Italian lumps of steel. And even if steel [was diamagnetic], those things weigh a ton!”

Perhaps the most outlandish scene for Ryan is the incredible sequence involving a magnet so strong that it manages to drag a car through a building – all the way from another street. Leaving aside the fact that building a magnet this powerful is practically impossible (“it would involve some insane numbers!”), there’s also the issue of it functioning like some sort of tractor beam: targeting one specific car from distance.

“A feature that is always quietly ignored in these movie-magnet situations is that the magnet is not directional in any meaningful sense,” says Ryan.

“If it can grab a car from across the street, every loose iron object at a similar or shorter distance will be pulled in too. The people in the film, they’ve got belt buckles, they all have guns, so those would all stick to the magnet immediately.

“There’s so much steel floating around that would just come in. It would just be a mountain of steel.”

Advertisement

So there you have it: proof, if any should be needed, that the only raw magnetism worth taking seriously in the Fast and Furious films is the charismatic screen presence of Dwayne ‘The Rock’ Johnson.

About our expert: Prof Dominic Ryan

Dominic Ryan is a professor at the department of physics at Canada’s McGill University, where he uses nuclear methods to study a wide variety of problems in magnetism. His work has featured in several peer-reviewed journals, including ACS Omega and AIP Advances

Read more about the science of magnets: