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Video: Quantum Levitation

572 pointsby jasonadriaanover 13 years ago

24 comments

MarkMcover 13 years ago
Reminds me of a great quote by Benjamin Franklin:<p>"The rapid progress true Science now makes, occasions my regretting sometimes that I was born too soon. It is impossible to imagine the height to which may be carried, in a thousand years, the power of man over matter. We may perhaps learn to deprive large masses of their gravity, and give them absolute levity, for the sake of easy transport. Agriculture may diminish its labour and double its produce; all diseases may by sure means be prevented or cured, not excepting even that of old age, and our lives lengthened at pleasure even beyond the antediluvian standard. O that moral science were in as fair a way of improvement, that men would cease to be wolves to one another, and that human beings would at length learn what they now improperly call humanity!"<p>-- Letter from Benjamin Franklin to Joseph Priestly (8 Feb 1780), quoted in "How Mumbo Jumbo conquered the World" by Francis Wheen
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sbierwagenover 13 years ago
Pure marketing. "Quantum levitation" is just flux pinning[1] as seen in all "high temperature" superconductors. All you need a chunk of type 2 superconductor, a strong magnet, and some liquid nitrogen. Note the 852 videos on youtube: <a href="http://www.google.com/search?q=superconductor+levitation&#38;source=univ&#38;tbm=vid" rel="nofollow">http://www.google.com/search?q=superconductor+levitation&#38...</a><p>You can shell out 80 bucks and do it yourself: <a href="http://sargentwelch.com/superconductivity-suspension-and-levitation-kit/p/IG0038153/" rel="nofollow">http://sargentwelch.com/superconductivity-suspension-and-lev...</a> (LN2 not provided.)<p>There doesn't appear to be any novel physics here at all.<p>1: <a href="http://en.wikipedia.org/wiki/Flux_pinning" rel="nofollow">http://en.wikipedia.org/wiki/Flux_pinning</a>
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fybrenover 13 years ago
This is very cool. Another video with a bit of an explanation as to why - <a href="http://www.youtube.com/watch?v=VyOtIsnG71U" rel="nofollow">http://www.youtube.com/watch?v=VyOtIsnG71U</a>.
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sliverstormover 13 years ago
Quick question: If the object is the temperature of liquid nitrogen, how can he touch it for so long?
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skeletonjellyover 13 years ago
When I came into work this morning this was at the top of reddit.com/r/all (got to get the procrastination out of the way first thing right!)<p>A guy spoke up regarding his father who works in the field. Currently doing Q&#38;A<p><a href="http://redd.it/lfsjn" rel="nofollow">http://redd.it/lfsjn</a>
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colandermanover 13 years ago
So, the electrical engineer in me says that this is because any movement of the magnet would induce an electric potential in the superconductor. But because such a potential would create an effectively infinite amount of current requiring an infinite amount of work, the magnet is unable to move.<p>Or from a "cause-and-effect" viewpoint, movement of the magnet induces a current loop in the superconductor, the creation of which creates an opposing magnetic force.<p>Either way I believe this is the same principle behind electric motor braking (e.g. when you short-circuit the inputs of a motor). I believe you would also see a similar effect by dropping a magnet down a tube encircled with many (or perhaps one spiral) loop of wire -- the magnet's descent will be slowed by eddy currents in the loops.<p>Edit: Aha, this is just half the story. The superconductor is prevented from spinning due to flux pinning: <a href="http://en.wikipedia.org/wiki/Flux_pinning" rel="nofollow">http://en.wikipedia.org/wiki/Flux_pinning</a> (or what the researchers call quantum trapping / quantum locking)
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mattyoheover 13 years ago
Is this "quantum locking" just a rebranding of the Meissner Effect?<p><a href="http://en.wikipedia.org/wiki/Meissner_effect" rel="nofollow">http://en.wikipedia.org/wiki/Meissner_effect</a>
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jeffoolover 13 years ago
On a more serious note, I'd love to find out more about just how much weight they think this tech could support in the future. Those implications could be insane.
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arsover 13 years ago
Direct link: <a href="http://www.youtube.com/watch?v=Ws6AAhTw7RA" rel="nofollow">http://www.youtube.com/watch?v=Ws6AAhTw7RA</a>
atteover 13 years ago
As a thought experiment, could the effect demonstrated here be used for a transport system on a much colder planet with a much stronger magnetic field (I do realize that these two properties tend to correlate in opposite directions)? What about in our arctic regions, potentially over a magnetic track to interconnect enclosed "settlements"? I'm guessing it would be less cost-effective than other types of transport if even possible, but many times cooler.
ck2over 13 years ago
Will this scale to train cars weighing a few tons each?<p>So if this was demonstrated live to congress, do you think they'd finally fund a few miles of super-conducting trains for research?
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joshuover 13 years ago
blogspam.
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Tichyover 13 years ago
Hm, I remember getting excited about this about 23 years ago, when I was still at school.<p>Can't help wondering if perhaps 50 years ago people were also getting excited about it and expecting to see cool things to come out of it in the near future.<p>Not saying that there couldn't, but I can't help feeling vary about the "technology of the future claim".
hugh3over 13 years ago
Not particularly quantum mechanical.<p>Well, no more so than everything else you might happen to see in your everyday life.
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Pointslyover 13 years ago
Am I really the first one who immediately thinks about Hoverboards???
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DanBCover 13 years ago
Isn't there already a shortage of rare earth minerals, used to make strong magnets? Is that going to be a problem for extending uses of this outside a lab?<p>But: really cool video.
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latchover 13 years ago
how much force (if any) is required to break it off the track? Could that disk be slingshotted around at hundreds of miles per hour and stay on tack?
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Duckpaddle2over 13 years ago
That has to be one of the most engaging conferences I have ever seen. The science demos are just too cool. If I have the time I'm going next year!
zerostar07over 13 years ago
Quantum physics professors do that in their first lecture, it's getting old.
DrDataover 13 years ago
Put this in a vacuum... perpetual motion?
GraffitiTimover 13 years ago
How does this work?
coldarchonover 13 years ago
At 1:30 the disc on the tracks stops without any outer interference, am I missing something in the video?
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marcamillionover 13 years ago
Flying cars here we come?
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bgramerover 13 years ago
How much longer before we all drive landspeeders?
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