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Comment by bsaunder | Hacker News Reader

The problem is, there's no friction (as the article states) for the board. What would the board push against to adjust itself? In the Segway, the wheels touch the ground and provide something for the motors to act against. This is more like an astronaut in space (if I'm understanding the situation correctly).

I like the idea (my kids would love it). It certainly has marketing value and calls up dreams of an amazing future, but there do seem to be some real practical problems (as the parent alludes to). Stopping seems particularly exciting.

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Dynamic instability? E.g., give the board some extra electromagnets near the edge, which "balance" the same way humans to, by constantly pulsing back and forth. When you want to move, you exaggerate one half of the pulse cycle.

I think you're on to something. There's enough magnetic field there to levitate a couple hundred pounds. It you can shape that field electronically, or even by interposing the right kind of material, it might be possible to create some lateral force.

The board is pushing against the ground (and the load!). If you adjust that force depending on the tilt of the board, you can move it (up to a certain point) to stay under the load.

As others have pointed out, it depends a bit on how much lateral force you can achieve through tilting and reaction forces, but if you can balance a quadcopter, you can balance a hoverboard. It gets a lot easier if your load is attached to the platform.

Now, I have close to no knowledge in super conductivity and how those puck manage to somehow stick to the rails centimeters away from the surface, but could we create some sort of directional friction? Sort of like a snowboard would work, so you could at least rely on one axis to balance yourself properly?

From what I gather, the board would apply a single linear resistance (vertical) aswell as resistance from every rotation axis. So theoretically, we enough skill, you could balance yourself on the board purely by using rotational resistance, even without the directional friction I just mentioned. You couldn't jerk your legs forward and backward, but you could push on the ball of your feet to shift backward, and push on your right foot to shift to your left.

Am I making sense?

> The problem is, there's no friction (as the article states) for the board.

Where'd you read that? All I read was that they are working on a friction-free car.

It uses super-conductivity to facilitate levitation. Flux pinning creates an 'on-rails' movement between the two components (the superconductor and the magnetics on the ground).

Defects in the magnets and gaps would create areas of resistance, much like they do in toy-scale versions of this same concept, but you'll still be pinned to the magnetics as long as that superconductor stays cold.

There will be no 'astronaut-in-space' movement, because the board will only be able to achieve quantum levitation over a bed of magnetics, which will be many pieces and not defect-free.

http://quantumlevitation.com/the-physics/

http://www.ted.com/talks/boaz_almog_levitates_a_superconduct...

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