By David Pescovitz at 11:27 am Tue, Oct 18, 2011
Here's a magical demonstration of superconductivity from Tel-Aviv University. Of course, superconductors are key to the future vision for high-speed maglev trains. (Thanks, Ariel Waldman!)
Mag-lev? Pshaw! I want my Mattel hoverboard!!!!
Your Mattel hoverboard is a Type II superconductor shaped into a longboard and encased in an extremely lightweight carbon fiber shell. It is kept in a flat board-shaped freezer until ready to use. NuCrete sidewalks contain embedded, aligned magnetic particles for you to ride over. In some towns, there are freezers at Malls for people to keep their boards cool before the trip home. Insulated flip-flops keep your toes warm, but on hot days, the cold board and the cool breeze drifting by are a godsend.
BoingBoing pageloads are now freezing my browser. Thanks!
Of course you need superconductors on a maglev. At 500+ mph, punching tickets becomes nearly impossible for any ordinary conductor.
Also, that way if the maglev jumps the track, the superconductor can fly out and catch the train. A normal conductor couldn’t do that.
Now I have so many questions…
Holy crap. I expected to see something like a normal magnetic repulsion… not at all something like that “locking” he demonstrates.
Is he changing the position just by pressure, or each time is he doing something to the field that allows the change, analogous to engaging the clutch in a stick shift? If not, why doesn’t gravity exert force in the same way – is there something specific about gravity that it works against as opposed to any other source of force?
You can see it bouncing around some just from its own momentum; it’s likely that just by holding it in a specific location for a moment, rather than letting it bounce back, you get changes in the magnetic field as it interacts with the supporting metal/magnets, which aren’t superconducting.
The math and theory on superconductors is way beyond me, though, so I definitely can’t verify this. Anyone know their stuff on this one?
I think it’s just that the disc is very light, so its weight and inertia don’t shift it, but he can apply a greater force with his hand.
Holy shit that’s cool.
I need to go buy some magnets and some liquid nitrogen.
How was that guy able to touch the cooled piece without hurting his hands? I was always under the impression that coming into contact with something that cold would not end well.
F*ckin’ nitrogen, how does that work?
It looks like some dry ice has formed on top of the puck. When you touch dry ice or liquid nitrogen, it immediately boils. That boiling gas (which is very cold) keeps your skin from touching the even colder material, and that’s what saves you. I’ve put a piece of dry ice in my mouth, and it doesn’t hurt at all – it feels like pop rocks candy. But still, try this at your own risk.
Cool … not only can we have hoverboards, but they come with built-in smoke effects.
Isn’t this old news? I thought I remember seeing demos of high-temp superconductors like 5+ years ago, that’s very similar to this. Is there something new here that i’m missing?
Ok Santa, this year I want a liquid nitrogen-electromagnetic train set for Christmas. You know, to go around the tree! :)
Actually it it is flux pinning: http://en.wikipedia.org/wiki/Flux_pinning
Every Juggalo on Earth needs to see this.
Game over. This kid definitely wins this science fair.
Jeff Goldblum knows not just about Chaos theory but magnets too?
The video is amazing to me, but not as amazing as the fact that only chellberty is made an Ian Malcolm reference.
So is this a distinctly different phaenomenon from the Meismer Effect (e.g. http://www.youtube.com/watch?v=94-Z2QgHl-s&feature=related ) and if so how? And what exactly makes it “Quantum”?
Someone call ICP, tell them we have a f-ing miracle here.
Can someone explain how this works? It seems similar to the Meissner effect, but my (limited) knowledge of that doesn’t let you do something this impressive. I presume this is somehow using some sort of similar trick with how superconductors don’t like magnetic fields but I’d be curious how exactly this works.
This is amazingly cool. However, I am not quite clear on the “quantum” aspect of it. It appears to be doing one thing, very well, not entangled in multiple states of being.
Cure cancer please. Thank you.
It’s cool, we can do both, actually.
Research into superconductivity has done much towards fighting cancer: look up the physics of magnetic resonance imaging.
forget trains. hoverboards would be cool. but i want this technology in rollercoasters before anything else.
No. You actually *dont* want it in rollercoasters. That would cut out all the noise and vibration and take about 3/4 of the fun out of it….
Witches! (Prove me wrong.)
First, we see a demo of it spinning off-center on the little circular magnet, which imples that there’s no torque being generated by the fact it’s off-center (otherwise, the disk would tend to twist or precess) Then when we see it go around the track on an angle, it changes its angle as it goes around – which implies a torque *was* generated.
This stuff is a lot more subtle than it looks.. ;)
These are the folks from Tel Aviv University who created that video: http://www.quantumlevitation.com/levitation/Quantum_Levitation.html
Their site includes explanations – both text and video – of how this works, what the quantum pinning is all about, and more.
My brother and I used to do this whenever Mom forgot to lock up the liquid nitrogen. Ah, good times!
It must be a high-temp ceramic type superconductor because normal metals only become superconducting as temps well below those of liquid nitrogen.
The magnetic field in the superconductor is induced and will repel the other magnet. It will travel around that table because it is constantly opposing the field just behind it as it is induced.
Um, no. It’s not magnetic repulsion – if it were, the puck would fall off when the track is turned upside down.
It’s flux pinning (of quantized magnetic flux, hence “quantum”).
The videos cited by @google-e8a5b25e14712f202d2d0e478c9af377:disqus above (http://www.quantumlevitation.com/levitation/Quantum_Levitation.html ) do a fairly good job of explaining what’s going on.
Bah. They stole a term that sounded cool on Dr. Who. Just because the “tubes are discrete” doesn’t make it quantum.
May I also say:
Yay! They stole a term from Dr. Who!
It’s quantum if there’s no way to explain this effect using classical electromagnetism, so you absolutely need quantum physics to explain why it works. That’s all that “being quantum” means.
BTW, “Quantum locking” as used in Doctor Who (to explain the fact that the weeping angels can’t move when you look at them) is actually pretty similar to a real thing called the quantum Zeno effect, where a system is “frozen” when it’s being observed. Except it doesn’t depend on it being a conscious being doing the observing, any interaction with the outside world that continually carries off information about the state of the system would do it (so if the weeping angels worked the same way, ordinary interaction with air molecules and such would keep them frozen).
Trains would be awesome, as would roller coasters. But does anyone else look at that perfectly floating puck and imagine the world’s awesomest air-hockey table?
Um…love the video, but…
Isn’t ‘quantum locking’ a technobabble term from Dr. Who???
Here’s an Am J Phys article from 1990 explaining the phenomenon:
“A high‐Tc superconductor floating freely above a magnet of low symmetry remains rigidly suspended in the air in almost any position and orientation as if stuck in an invisible heap of sand. This striking effect is due to pinning of the magnetic flux lines inside the superconductor and is often overlooked, since usually magnets with rotational symmetry are used for levitation. Magnets with rotational symmetry allow for nearly undamped orbiting and rotation of the superconductor about the magnet’s symmetry axis. But even in this geometry, flux‐line pinning can be seen, since it forces the orbiting superconductor to turn the same face toward the axis. Superconductors with sufficiently strong pinning may even be suspended below a magnet.”
The upshot of the article is that flux pinning is NOT the Meissner effect (seen in the type I superconducting metals–and the demo I think we all know and love from high school), and instead replies on imperfections of the crystal structure in a type II superconductor (ceramic). These imperfections allow little tubes of magnetic fields to permeate the superconductor, and it is these little tubes that result in flux pinning.
I’m visualizing it as a zillion little holes with threads going through each of them.
Thanks. That sort of makes sense. I wish I knew enough physics to get this. It seems to me to be sort of like the Meissner effect because the reason the lines get stuck is they can’t go through the perfect areas of the superconductor sort of. I’m not sure. This may be a bad analogy. The math behind this looks difficult and I don’t feel comfortable enough with it to really tell what is going on beyond the very rough analogy given.
Searching Google Scholar for “quantum locking” (with quotes) returns 44 results in legitimate physics-y and electronic journals.
Scientists tend to be the sorts of people who like Dr. Who. Is it a crime for them to geek out a bit when they name something?
Could gravity have a similar effect?
1. Specifically, does quantum relativity require an electromagnetic force to entwine relative physicality?
2. Would such an effect dampen inertia through unifying the way gravity relates to the overall mass of the objects in its proximity?
3. Out of both curiosity and hope for a test-bed, could a similar effect, for example, secure objects on top of a tectonic plate?
oh. my. sack. that is awesome.
OK, the the basic research is here:
They want to make superconducting wires. They coat sapphire with the type II superconductor YBCO, which gives you the flux pinning. (A thin film of YBCO is below the london penetration, which means field lines travel thru it instead of being deflected at the surface like a metal). That explains the video.
What I NOW want to understand is what happens to the (normally dull, inert) sapphire inside? Does it help somehow? Or cooperate once it’s coated?
Edit: I think the sapphire is just a nice growing matrix for teh YCBO, with attractive dielectric and bendy properties. Right?
Even a lifelong familiarity with Arthur C. Clarke’s famous dictum, that “Any sufficiently advanced technology is indistinguishable from magic,” has left me unprepared for what I think I just saw. What an amazing feeling!Do it again!
(studying her for a moment)
Tell me, Hilda — does all this frighten you —
does it make you feel insecure?
Yes, sir — it certainly does!
(nodding with a bland little smile)
That’s good, Hilda. I’m glad.
Is it possible that this is being referred to as ‘quantum’ locking, because the magnetic field is using something like quantum tunnelling to pass through the thin film of superconductor?
no quantum tunnelling is necessary to describe the London penetration:
srsly, they just make the term up because it sounds cool. And it does!
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