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Researchers Demonstrate Quantum Levitation
UnknownSoldier writes "Wired reports that researchers at Tel Aviv University have discovered you can 'lock' a magnetic field into place with a superconductor. They have a very cool demonstration of a frozen puck and some of the neat things you can do with it while its orientation remains locked but its location is movable. Might we someday see high speed trains that will be 'impossible' to tip over, or a new generation of batteries with this technology?"
This isn't new is it? It's a very cool demonstration, but unless I'm mistaken they didn't discover this--the actual article doesn't say it was a new discovery and I'm fairly sure my physics teacher showed me this a year or two ago. It is really cool, and the physics behind how it works is very interesting. It's pretty accessible too, don't be discouraged from reading up on it because you think it will be too hard to understand.
SUPERCONDUCTOR not semiconductor !
This is flux pinning, and apparently, is a different phenomenon than the Meissner effect.
Try this longer video instead. It has construction details, explanations, double levitation etc.
Also, "semiconductor"? Jeez, that is a lame mistake even by Slashdot standards!
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The problem is not that this isn't amazing, it's that the Slashdot editors (and Wired) are presenting an 80-year-old discovery as something new -- and then describing it using the wrong terminology.
"They redundantly repeated themselves over and over again incessantly without end ad infinitum" -- ibid.
Using "quantum" in the description makes it sound like a cool new discovery, rather than simply a demonstration of magnetic levitation using the Meissner effect and flux pinning.
"They redundantly repeated themselves over and over again incessantly without end ad infinitum" -- ibid.
I guess I just can't tell if the rising cynicism here matches the degrading quality of editing.
They go hand in hand, in part because of the number of ignorant people responding to this story saying "WOW THAT IS SO AMAZING!", which just announces that they have somehow managed to preserve their ignorance of this effect for long enough to be old enough to post on /. but are still posting on /. It makes those of us who have an actual interest in science and technology feel like this isn't really the place we should be.
As well as presenting an 80-year-old effect that has been a stock benchtop demonstration for 20 years as something "new" and "exciting", the marketers (not scientists or engineers) behind this have added the word "quantum" to it, which is so obviously catering to the ignorant it is just sad. I've even seen this described as using "quantum superconductors", which nicely distinguishes them from all the classical superconductors out there...
Blasphemy is a human right. Blasphemophobia kills.
This is flux pinning, and apparently, is a different phenomenon than the Meissner effect.
Yes, but this was already well known in the late 1980's when type II superconductors hit center stage in the solid-state physics world. And 30 seconds later every single person in the field thought "hey, we could SOOO build a sweet maglev train with this". But it's still not practical by any stretch of the imagination except as a neat toy.
So /. is only 20+ years late instead of ~80 years with the Meissner effect.
This is not the Meissner effect! If it were you wouldn't be able to do the stunt where they move the disk to a different angle and it stays there. This is more subtle. The Meissner effect involves superconductors not letting magnetic field lines pass through the superconductor. This involves special superconductors that allow magnetic field lines to pass through but make the field lines get trapped in imperfections in the superconductor. The name of this effect is "flux pinning" http://en.wikipedia.org/wiki/Flux_pinning. Here is the website of the group who made this video where they explain it http://www.quantumlevitation.com/levitation/Quantum_Levitation.html
every physics student gets a demonstration of this effect in his solid state physics lecture. But usually the superconductor is rather small and is put into a small matchbox type car to drive it around a track. Here they used a relatively large and bulky superconducting disk, so the orientation locking is more visible. Although not new, it never gets old and I'm always fascinated by it. Just don't use the word "discovery" here!