“Jets of compressed air will also lift land vehicles off the highways, which, among other things, will minimize paving problems. Smooth earth or level lawns will do as well as pavements. Bridges will also be of less importance, since cars will be capable of crossing water on their jets, though local ordinances will discourage the practice.” - Isaac Asimov, 1964
In 1964, Isaac Asimov penned a now-famous essay in the New York Times in which he made predictions for the 2014 New York World’s Fair. In keeping with the time-honored tradition of future predictions, Asimov was very close to right in some ways, and really, really wrong in others. One of the ways in which he was wrong was his prediction for the way we’d drive in 2014. His vision of tomorrow involved “fewer tires, more flying.” So, why was he wrong?
For the most part, it comes down to the fact that driving planes and flying cars are both pretty inefficient means of transport. Though Asimov’s idea that hovering above the highway instead of driving on it would save some wear and tear on our infrastructure, it turns out that flying cars just don’t make a lot of sense.
Physicist and sci-fi author Gregory Benford recognizes that planes and cars are fundamentally different beasts, and has pointed out that attempts to make some kind of hybrid have always proven unsuccessful.
“It turns out that if you optimize the performance of a car and of an airplane, they are very far away in terms of mechanical features,” explains Benford. “So you can make a flying car. But they are not very good planes, and they are not very good cars. The military developed one. They found out it didn’t perform well in either element.”
Beyond that, there are questions of safety and infrastructure. Popular Mechanics’s Rachel Feltman points out that with “flying” cars, even those that might theoretically use some kind of room-temperature superconductors, comes new demands for infrastructure, licensing, regulation, and design. Those demands translate to money. I’m not sure if you’ve driven on a highway recently, but it’s not as if the DOT is exactly rolling in cash to throw at new nationwide infrastructure. From a practical perspective, it seems like a non-starter.
But just for the hell of it, let’s talk about those superconductors once more. Sure, a car that works using superconductors isnt a “flying” car in the way that Asimov imagined, but it does hover. And the concept is dead cool. It works thanks to the Meissner effect, which, simply put, refers to the fact that when superconductors and magnets hang out, superconductors expel the magnetic fields of the magnets, bend the fields around themselves, and thus hover just above the source of the magnetic field. It’s called quantum levitation” and it’s as cool as it sounds.
Even cooler? A process called “quantum locking.” Quantum locking is what happens when, as Quantum Researcher Boaz Almog explains, “strands of a magnetic field are trapped inside of the superconductor…and it turns out they behave like quantum particles.”
So … what does that mean? Basically, the superconductor locks the flux lines of the magnetic field inside of itself. That locking prevents the superconductor from moving in space. In his TED presentation, Almog demonstrates that moving the magnet and superconductor in space doesn’t affect it — it’s not just hovering, but is locked in place. The logical extension? A track of magnets, a superconductor and a little push.
Because the superconductor is locked in place, its location above the magnet is constant. Even as it rotates above a circular magnet or travels around a magnetic track, it remains in the same location relative to the magnet, even though its location in space is changing. Eureka! Frictionless motion.
For now, superconductors don’t make sense as a method of bringing about “flying” cars. They work at hard-to-achieve critical temperatures, and, as Feltman said, it becomes a problem of infrastructure. But there are loads of possibilities, and superconductors remain extremely cool (no pun intended.)
Maybe if Asimov had understood that planes and cars both have their parts to play but that hybridization is a fool’s errand, he would’ve shirked the idea of flying or hovering cars. Maybe if we were committed to waterways and aqua foils instead of cars and roads, he would’ve been closer to correct, just not in the way he expected (and also that sounds like an awful idea — can you imagine the traffic?). Maybe in an alternate future.