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Indistinguishable from magic - Input Junkie
October 18th, 2011
11:54 am


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Indistinguishable from magic

A fast googling turns up people with science blogs saying they can't explain it. I'm hoping an explanation comprehensible to the lay reader will turn up. It's got to be simpler than the proof of Fermat's last theorem, right?

My first incoherent thought was that this phenomenon might be Offensive to Relativity, but I guess it's no weirder in that sense than matter being more or less rigid, or is it?

Link thanks to [personal profile] andrewducker.

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[User Picture]
Date:October 18th, 2011 04:11 pm (UTC)
There's another video that does a better job of explaining it, though it still may not satisfy you. See http://www.youtube.com/watch?v=VyOtIsnG71U

Also see the site of the Tel Aviv University superconductivity group.

Apparently the layer of superconductor is so thin that the Meissner Effect does not succeed in flinging all the magnetic flux out of it. Flux tubes get "pinned" to defects, or weak spots, here and there within the superconductor. If the position or angle of the object is perturbed, currents arising in the superconductor try to push it back to its original state; thus it is somewhat stable or, as the videos call it, "locked."

I may have garbled this but it's the best quick answer I can offer.
Date:October 18th, 2011 04:51 pm (UTC)
It's simple enough. The material is superconductor, which means that the magnetic field inside it is 'confined', ie, it can't move. Due to the spin orbitals of the electrons being energetically limited, [i.e it's freaking cold!] so they don;t have sufficient energy to change their spin state, and alter the induced magnetic field. [which is caused by the electron orbitals lining up in the bulk material under the influence of the external field.]

Since it can't easily change it's internal magnetic field, then any action to do that is resisted. In the video the demonstrator points out it can move as long as the field stays symmetrical. Kinda like circling around a hill at the same height, you're not gaining or losing potential energy.

Evidently, gravity itself isn't sufficient to overcome the locking effect, although the demonstrator can apply sufficient force to overcome it.
[User Picture]
Date:October 20th, 2011 12:05 am (UTC)
I had seen the title of this video on Reddit or someplace but hadn't gotten around to looking at it. (I figured it was superconductive levitation.)

I found myself laughing when I watched it. So cool!
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