THIS WEEK, LEXUS introduced a short teaser video for SLIDE, a hoverboard that appears to not just live up to our Back to the Future II dreams but, at least stylistically, improve on them. Better yet, it’s more science than science fiction. Here’s how it works—and why you won’t find one at Toys’R’Us any time soon.
Let’s start with that teaser video, a scant 37 seconds of hoverboard hype that almost prompts more skepticism than excitement. A bamboo and carbon fiber skateboard, emitting wisps of smoke, levitates an inch or two off of what appears to be a concrete surface. A foot approaches as if to mount and ride—and then nothing.
That’s not a lot to put one’s faith in. We’re barely a year past the most recent hoverboard convincing hoax—a Funny or Die promotion, it turned out—and are halfway through the year in which BTTFIItook place, a ripe time for attention-grabbing tie-ins .
Even the information Lexus did provide at the time didn’t jibe with what the teaser shows. According to the company’s briefly stated promotional materials, the device employs “magnetic levitation” to achieve (and maintain) lift-off, which would be well and good if it weren’t for where it was levitating.
“It’s a tease, right? It gives you the impression that this thing is floating on top of concrete,” says Mike Norman, Director of the Materials Science Division at Argonne National Lab. “Which it’s not.”
Fortunately, the bad news stops there. Surface trickery aside—there are probably magnets or steel mixed in or just underneath that concrete—the Lexus hoverboard really does live up to its name.
How It Works
Magnets. That’s the short version. The long version means steeling yourself for a light dose of physics.
According to Lexus, its hoverboard relies on superconductors and magnets, which combine to repel the force of gravity and lift an object—like, say, a fancy skateboard and its rider—above the ground.
That may sound familiar to anyone who recalls the Hendo hoverboard , which debuted as a Kickstarter last fall. You can read about the physics behind the Hendo in great depth here, but the key difference between it and the Lexus project is that Lexus opted for a superconductor—which creates a different kind of magnetic field—instead of a plain ol’ conductor.
“With a superconductor you don’t need to have an oscillating magnetic field [like Hendo’s],” explains Eric Palm, Deputy Laboratory Director at FSU’s National High Magnetic Field Laboratory. “Instead you have something called the Meissner effect, which essentially says that when you take a magnetic field near the superconductor, it induces current in that superconductor, and creates essentially an image magnetic field on the other side of the superconductor. You create current, but since it’s a superconductor, the currents don’t die away. So you don’t need oscillating magnetic fields. You can have a magnet that levitates above a superconductor or vice versa, a superconductor that levitates above a magnet.”
If that all sounds a little technical, try to picture a maglev train, which relies on similar principles to achieve speeds of, in the case of Shanghai’s Transrapid, over 300mph. Or better yet, watch this video, recommended by Norman, of a superconductor locked in a magnetic field:
Watch the teaser below, and get ready to cruise around the city like Marty McFly from Back to the Future.
As for the wisps of smoke you see rising from the sides of the Lexus board? That’s not just for effect (although as effects go, it ain’t bad). That’s liquid nitrogen, cooling the superconductors below their transition temperature—the temp at which it becomes superconducting . Just how cold are we talking? -321 degrees Farenheit, says Palm, who also cautions that it’s not quite as extreme as it sounds. “That sounds very cold,” Palm explains, “but liquid nitrogen is actually a byproduct of the steel industry, so it’s pretty inexpensive.” It’s the same principle as the dry ice you played with in AP Chemistry, just around three times as cold.
When the liquid nitrogen runs out, the superconductors warm up and the hoverboard stops, well, hovering, until you top it off again.
Here’s one last barebones , layman’s definition that might help, compliments of Norman. “There’s interaction between the superconductor and the magnet that repels the force of gravity and allows the thing to levitate,” Norman says. That’s why it can’t be pure concrete in the video; there has to be something magnetic there as well. When you apply the same principles to a human-bearing board, “it really is like you’re floating.”
He would know; while he hasn’t ridden the Lexus hoverboard , he’s spent time on a similar contraption in a lab. As it turns out, for all the anguish and anticipation around making hoverboards real, they have existed for some time. And they’re not all that hard to make.
And yet! A brief teaser of the Lexus version has racked up well over three million views in just two days, a response that surprised few more than Lexus itself.
As for the wisps of smoke you see rising from the sides of the Lexus board? That’s not just for effect (although as effects go, it ain’t bad). That’s liquid nitrogen, cooling the superconductors below their transition temperature—the temp at which it becomes superconducting . Just how cold are we talking? -321 degrees Farenheit, says Palm, who also cautions that it’s not quite as extreme as it sounds. “That sounds very cold,” Palm explains, “but liquid nitrogen is actually a byproduct of the steel industry, so it’s pretty inexpensive.” It’s the same principle as the dry ice you played with in AP Chemistry, just around three times as cold.
When the liquid nitrogen runs out, the superconductors warm up and the hoverboard stops, well, hovering, until you top it off again.
Here’s one last barebones , layman’s definition that might help, compliments of Norman. “There’s interaction between the superconductor and the magnet that repels the force of gravity and allows the thing to levitate,” Norman says. That’s why it can’t be pure concrete in the video; there has to be something magnetic there as well. When you apply the same principles to a human-bearing board, “it really is like you’re floating.”
He would know; while he hasn’t ridden the Lexus hoverboard , he’s spent time on a similar contraption in a lab. As it turns out, for all the anguish and anticipation around making hoverboards real, they have existed for some time. And they’re not all that hard to make.
And yet! A brief teaser of the Lexus version has racked up well over three million views in just two days, a response that surprised few more than Lexus itself.
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