We’ve all seen the above video by now: The single most famous skateboarder in the world riding an actual, honest-to-God hoverboard is like the dream of every ’90s kid suddenly, brilliantly, made flesh. But in truth, since Back To The Future II introduced the idea, a mix of artists, scientists, and straight-up weirdoes have been trying to make the hoverboard a reality.
Believe it or not, the hoverboard is a relatively new concept, as these things go. Its first real mainstream introduction was, in fact, Marty McFly leading the Biff of the future right through a plate glass window. It’d been seen off and on in comic books and animation, but the combination of Robert Zemeckis’ staging and the hoverboard being front and center in an action sequence made people wonder if we could actually get a few inches off the ground.
Zemeckis didn’t help matters; according to legend, he got so sick of being asked about the hoverboard he started telling people they were real. Mattel was just keeping them off the market because of hand-wringing parents’ groups. That started the rumor, and that, in turn, started the race to make it real.
The first “hoverboards” were nothing of the sort. They were hovercrafts, and while they’re actually a pretty fun project to build on their own, they’re not what most people expect; they don’t defy gravity, they’re extremely loud since they need a cushion of air to ride on, and, well, they’re a bit inelegant. They’re fun to ride, but they’re no hoverboard, and even as the Mythbusters and various gadget shows tried to refine it, mostly for laughs, people were focusing on another technology… specifically maglev.
Maglev is short for “magnetic levitation”, and if you played with magnets in grade school, it’s a pretty simple concept to understand. You just create two surfaces with the same magnetic polarity and ride one across the other; the fields repel each other and create a smooth, frictionless ride. Maglev trains are moving at 311 miles per hour in recent Japanese tests.
The problem, from a hoverboard perspective, is that creating maglev surfaces is ridiculously involved. Generally, you use superconducting magnets, which are coils of superconducting wire reduced to cryonic temperatures with liquid helium; it’s the only way they can handle the sheer amount of power you have to run through the magnet. It also needs DC power, so you can’t just hook this thing up to the outlet and call it a day. Did we happen to mention that superconducting wire is extremely rare and expensive, and that liquid helium is $14 a liter?
That’s not the only engineering problem, either. Earnshaw’s theorem, for example, states that you can’t keep two point charges (i.e. two magnets) in equilibrium in most situations. Ten seconds with two strong magnets illustrates the point; they won’t just balance on each other, not without help, and as a result maglev devices tend to constantly switch polarity to get around the issue.
And even if you manage to get around it, that’s not the only practical issue. For example, in 2011, artist Nils Guadagnin created a perfect replica of the hoverboard that floats using maglev. The problem? It couldn’t move away from its stand, and it couldn’t carry a load. If you stood on it, it’d plunge to the ground.
That said, though, it wasn’t long before the French managed to deliver an actual, honest-to-God, working hoverboard. Developed at Paris Diderot University, the Mag Surf debuted in 2011. It was confined to a track, but it could carry up to 220 pounds.
And now, of course, there’s the Hendo Hoverboard, as featured above. The Hendo is easily the most advanced hoverboard we’ve yet seen: It has four independent engines to allow spin and apply thrust under user control, for example, and doesn’t need a rail. And it can be yours for just $10,000!
That said, there are some drawbacks. It needs a nonferromagnetic surface, like a floor sheathed in aluminum or copper, to float due to the physics involved, and the charge doesn’t last long. Currently, the board is able to float for roughly five to seven minutes before the batteries crap out. And even Hendo admits this is little more than a publicity stunt to demonstrate their maglev technology, which they view as having an enormous number of practical uses. You can even buy a small set of their engines called a Whitebox to experiment with.
Still, it’s what we’ve dreamed of since 1989; a real, working hoverboard. Now we just need to sheath every public flat surface in aluminum. Or, uh, perhaps work on expanding the technology a bit.