The Hoverboard is Not So Hot (Supercool!)
OK, so you all know that I really really want a jetpack. However, I have decided that under the circumstances, I’ll settle for a hoverboard. Specifically the one in this viral video from Lexus.
Is that not the most amazing skateboard ever? It’s straight out of science fiction. The hoverboard has high temperature superconducting blocks which are housed in cryostats: reservoirs of liquid nitrogen which cool the superconductors to -197°C (that’s -321°F).
Now I’m not going to pretend that I can explain the physics of quantum locking but luckily, it’s been discussed before — off the back of a video demonstrating levitation that went viral a few years back.
Joe Hanson of It’s Okay To Be Smart posted an explanation in response.
It’s Okay To Be Smart • If this video doesn’t make your jaw drop…
What you start with is an inert disc, in this case a crystal sapphire wafer. That wafer is then coated with a superconductor called yttrium barium copper oxide. When superconductors get very cold (like liquid nitrogen cold) they conduct electricity with no loss of energy, which normal conducting materials like copper can’t do.
Superconductors hate magnetic fields (when cold enough), and normally would just repel the magnetic force and float in a wobbly fashion. But because the superconductor is so thin in this case, tiny imperfections allow some magnetic forces through. These little magnetic channels are called flux tubes.
The flux tubes cause the magnetic field to be “locked” in all three dimensions, which is why the disk remains in whatever position it starts in, levitating around the magnets.
Supercold, superconducting hoverboards … HERE WE COME!
That was in 2011 and now we have them!
It’s not quite what it seems, unfortunately. This skate park was built specifically for the hoverboard, so the hovercraft isn’t quite the freewheeling vision as implied in the video. The skate park has a track containing permanent magnets and as long as the board is supercooled, the quantum locking keeps the hover board at a specific height.
Lexus have also released a five-minute documentary about making the hoverboard with a look at the physics involved:
So not quite as good as it looks at first glance. It requires a custom track and apparently it can only run for half an hour at a time.
I’d probably just fall off anyway. I guess I’ll hold out for that jetpack.