Quantum levitating (locking) video goes viral

Oct 19, 2011 by Bob Yirka weblog

(PhysOrg.com) -- A video created by researchers at Tel Aviv University in Israel has the Internet buzzing. Though rather simple, it just looks really cool, hence all the attention. It’s a demonstration of quantum locking, though to non-science buffs, it looks more like science fiction come to life. In the video a disc, obviously frozen due to the vapor rising from its surface hovers over a surface.

This is nothing new of course, everyone’s seen it in science class. What is new is that when the demonstrator turns the disc, it stays hovered at that angle. This is in contrast to the wobbling we’re used to in such demonstrations. Next, the disc is set over a different surface where it is made to spin. But that’s only the beginning. The disc is then set on a track where it zips around in midair. And again, it can be made to do so at whatever angle is desired. Then, the track is turned upside down and the disc hovers below it, again zipping around.

This video is not supported by your browser at this time.

Most of the web sites out there seem stumped as to how these guys pulled off this little trick. Fortunately, the researchers explain it in detail. And even more fortunately, it’s not that hard to understand.

First a thin sapphire wafer is created. It is then coated with a very thin ceramic layer of yttrium barium copper oxide which becomes a superconductor (materials that conduct electricity with no loss of energy) at very cold temperatures. The result is a frozen disc. When it is placed over a magnet, the superconductor material and magnet repel one another due to the Meissner effect (the expulsion of the magnetic field from a material when it goes into a superconducting state). But, because the layer of superconducting material is so thin, some of the magnetic force is allowed through at certain particularly weak points. These paths through are called flux tubes, and they are the real secret to the whole trick. Because there are many of them they cause a three dimensional holding or locking effect, which is what viewers see when watching the video.

Upon viewing the video, a lot of commentators refer to the scene in Back to the Future 2 when Mary McFly rides a hoverboard for a few minutes. Unfortunately, the science demonstrated in this latest video holds no hope for that; not unless someone figures out how to keep such boards frozen indefinitely (and embeds magnets everywhere) or better yet, figures out a way to make a superconductor that works at room temperature.

Explore further: Scientists in search of explanation of high-temperature superconductivity

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User comments : 47

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Husky
not rated yet Oct 19, 2011
i like how it levitates yets stays attracted to be stationary
rawa1
1 / 5 (1) Oct 19, 2011
At YouTube are many other videos of Meissner effect, which have a much large traffic in addition.

Meissner effect

http://www.youtub...AAhTw7RA
Isaacsname
1 / 5 (2) Oct 19, 2011
I don't know why this went viral, there's all sorts of videos of this that are years old, this one's 3.

http://www.youtub...=related

Seems like dipping SC's/USC's in LN is a rather crude way to cool them/keep them cool.

Eikka
1 / 5 (2) Oct 19, 2011
One thing I don't understand is how it's possible to move the disc relative to the magnets without it bouncing back to the previous position, as if switching the effect on and off.

Surely whatever keeps it in one spot should stop if from being moved from that spot, yet in the video the disc moves freely when moved.

Or is there some sort of a breakdown effect where applying enough force breaks the superconductivity and allows the eddies to reconfigure.
antialias_physorg
5 / 5 (10) Oct 19, 2011
At YouTube are many other videos of Meissner effect, which have a much large traffic in addition.


I don't know why this went viral, there's all sorts of videos of this that are years old, this one's 3.

Superconductivity levitation / Meissner Effect (or even the upside-down levitation) is not the reason this is going viral. The reason this is different is the quantum locking (the part in the very beginning where the person just tilts the object any which way and it stays right there)

This is achieved because this object (unlike all the other videos on youtube) uses as thin layer with 'defects' (or weak spots) where individual 'field lines' can penetrate. Since these flux tubes are prohibited from moving to adjacent areas (because of the Meissner Effect) they create a force against any shift in position and therefore lock the disc in place.
Callippo
1 / 5 (1) Oct 19, 2011
how it's possible to move the disc relative to the magnets without it bouncing back to the previous position
The energy is dissipated during this in irreversible way, probably because of low thickness of superconductor layer. Inside of such thin layer the current density of eddy currents may exceed the limit, above which the Cooper pairs are getting separated with their own magnetic field and all excessive eddy currents will get dissipated.

On the another video you can see, the system of magnet and bulk superconductor exhibits apparent elasticity.

http://www.youtub...sSdngzLs

The reason this is different is the quantum locking
But the quantum locking can be observed even at the case of bulk semiconductor - compare the old video linked in the second part of my post. These two samples differ just with thickness of superconductor, but their qualitative behavior remains the very same.
Isaacsname
not rated yet Oct 19, 2011


This is achieved because this object (unlike all the other videos on youtube) uses as thin layer with 'defects' (or weak spots) where individual 'field lines' can penetrate. Since these flux tubes are prohibited from moving to adjacent areas (because of the Meissner Effect) they create a force against any shift in position and therefore lock the disc in place.

Thx for the answer. So it comes down to being able to design a material that pinches flux tubes (?), or being able to build an ordered material with specific geometry of pinched lines of flux ( tubes ? ) in order to control orientation of "locked" objects ?
antialias_physorg
3.7 / 5 (3) Oct 19, 2011
The orientation doesn't matter since field lines (which are a bad way of looking at magnetic fields, but which will have to do for now) can be bent any which way. They don't have to be straight. So there's no need to create specific pinch geometries. Just a material with small holes/defects (which is what you get if you just put a very thin layer on top of an object without much quality control: some parts will be thicker than others and some points won't have any material at all)

compare the old video linked in the second part of my post.

The video does not show bulk material.
Skultch
1 / 5 (1) Oct 19, 2011
The orientation doesn't matter since field lines (which are a bad way of looking at magnetic fields, but which will have to do for now)


Can you recommend a link for a better way of visualizing mag fields?
Callippo
1 / 5 (1) Oct 19, 2011
The video does not show bulk material.
Do you mean this video? http://www.youtub...sSdngzLs

It demonstrates a nice pellet of YBaCuO.
javjav
1 / 5 (1) Oct 19, 2011
One thing I don't understand is how it's possible to move the disc relative to the magnets without it bouncing back to the previous position


Read about the Meissner effect and you will understand it.
Callippo
2.6 / 5 (5) Oct 19, 2011
Read about the Meissner effect and you will understand it.
Don't play too smart at public forums. If you would understand it by your own method, you would be able to explain it already. If you're not able to explain it even after reading it, then your method apparently failed.
CapitalismPrevails
1 / 5 (2) Oct 20, 2011
This is probably the closest thing mankind has which resembles a tractor beam!!!
antialias_physorg
3 / 5 (2) Oct 20, 2011
Can you recommend a link for a better way of visualizing mag fields?

There is no really good way of visualizing fields. The best way is just getting used to field equations.

One thing I don't understand is how it's possible to move the disc relative to the magnets without it bouncing back to the previous position

This is because of quantum locking. In bulk materials you do get the bounce effect (i.e. without the flux tubes you cannot position the magnet at arbitrary distances). Though often you can see in videos that you can even position bulk materials at various angles and they will stay there. I'm not hip to the materials so my hypothesis is that you will get quantum locking at the edges/corners where the path through the material is so small that it's akin to having a thin layer (as in this article) so that a little bit of locking force will be exerted.

Do you mean this video? http://www.youtub...sSdngzLs

That video shows bouncing.
Callippo
1 / 5 (1) Oct 20, 2011
This is because of quantum locking. In bulk materials you do get the bounce effect (i.e. without the flux tubes you cannot position the magnet at arbitrary distances)
? Why the "quantum locking" doesn't occur in bulk materials?
antialias_physorg
1 / 5 (1) Oct 20, 2011
Because you don't get the flux tubes (this is explained in the article)

Flux tubes happen when 'field lines' can penetrate the object through weak spots. The thin layer object in the article has those weak spots. Bulk materials don't.

Though you could probably approximate something like this with bulk materials by drilling very small holes into them.
Callippo
1 / 5 (1) Oct 20, 2011
Because you don't get the flux tubes
How the existence of flux tubes is related to the absence of bouncing, as observed in bulk material?
antialias_physorg
not rated yet Oct 21, 2011
The flux tubes are (the way I understand it) field lines which can penetrate the material at these weak spots
(which are effectively small holes in an otherwise 'bulk' superconductor). The flux tubes cannot move into the material because of the Meissner effect but they also cannot move out of the entire object because they are surrounded on all sides by material. The flux tubes (the magnetic fields) just have nowhere to go and will resist any change in position.

In bulk materials all the magnetic field is pushed outside the object. There are no locking lines/tubes through the object (other than at the edges/corners - which is why I suspect you you can tilt bulk material to some degree and have them stay that way). The magnetic field outside bulk materials is free to deform any way it wants to - hence the 'bounce'.
rawa1
1 / 5 (1) Oct 21, 2011
I'm using the conceptual, i.e. high level thinking often and from this way of thinking follows, you cannot (completely) explain some dynamic effect with static geometry. It means, while I do agree, the penetration of flux tubes into (thin layer of) superconductors could affect its motion, the connections of these two phenomena remains unclean because of presence of logical step. And it definitely wouldn't enable you the quantitative description of the phenomena with respect to dimensional analysis of equations involved. You should consider some quantity, which involves the time dimension for description/explanation of the effect, which manifests in time, not just space.
rawa1
1 / 5 (3) Oct 21, 2011
"of presence of logical step" should be "of presence of logical gap".

Many people do believe, they can understand the phenomena if they manage its description, but they often ignore the tiny logical gaps, which are prohibiting them in complete understanding ("Fu*ing magnets? How do they work?")

http://www.youtub...Pe-DwULM

Mainstream physicists are often trying to evade the direct answer with reference to philosophic subtext of such questions - but I do believe, this way of questions is still completely relevant.

So, HOW EXACTLY the penetration of flux lines into superconductor prohibits its motion in magnetic field?
antialias_physorg
5 / 5 (3) Oct 21, 2011
If you don't like my explanations then go look them up. Search terms are:
- Quantum locking
- Flux pinning
- Type II Superconductors
rawa1
1 / 5 (1) Oct 21, 2011
Compare my [Callippo Oct 19, 2011] comments above - especially this very last one. If you cannot present the explanation of phenomena in sequence of robust logical steps, then the reference to even more vague sources of information will not improve your situation at all. We all know, where to find the relevant info about Meissner effect.

BTW As anonymous poster pointed out correctly, the flux pinning is an effect of Type II superconductors, regardless of the thickness. Which means, this flux pinning cannot be used for explanation of the "quantum locking". After all, this locking has nothing to do with quantum effects anyway, because it's not essentially quantized.

http://io9.com/58...comments
antialias_physorg
5 / 5 (2) Oct 21, 2011
I have given you an explanation as I understand it. In 1000 characters or less (which is no mean task for such a complicated subject).
If you cannot follow that condensed explanation then that's not my problem. I am not responsible for your ability to understand logical arguments or not or your inability to use the interent.

There are plenty of sites which explain the phenomenon in detail. If you are REALLY interested in what's going on I suggest you google the relevant papers.

(BTW: I have reported your accounts for abuse because you are using sock-puppets. Again.)

rawa1
not rated yet Oct 21, 2011
I have reported your accounts for abuse because you are using sock-puppets
I'm not using my two accounts for congruent posting, the downvoting and reporting of people the less. Instead of this, many posts of mine are massively downvoted with sock-puppet accounts created just recently for the dedicated purpose: to abuse the voting system here. If you cannot argument in logical way, then the attempts for censorship will not help you both morally, both politically.

I'm just used your exaplanation for demonstration, how superficial is the understanding of physical phenomena in layman public and how every attempt for their deeper explanation are censored just with people, who cannot provide the more relevant explanation.

Why do you mean, the first post of Callipo was downvoted here? Because of this explanation was wrong? Of course not - just because it was deeper, then the explanation provided in article. This is just the way, to which the halfcompetent people are allergic naturally
antialias_physorg
5 / 5 (1) Oct 21, 2011
If you cannot argument in logical way, then the attempts for censorship will not help you both morally, both politically.

The two actions are independent of each other.

1) I gave you enough pointers to where you can get the info you (purport to) seek.
2) I don't know why your (Calippo-)post was downvoted by someone - but the first part seems muddled and the last part is just wrong (IMO).

Independently of this: Do you really think that using a different name will result in posts being 'higher quality' from one account than from the other? Checking your average ratings I'd say people have the same (low) opinion of the quality emanating from either.
So why would you switch? You'll get downvoted for posting BS no matter what name you give yourself. It's not the names that earn you your ratings: it's the content.

Accept it. Or start posting better stuff. Whatever.
rawa1
1 / 5 (2) Oct 21, 2011
I'm using the multiple accounts simply because I'm using a different computers. If you care about quality of posts here, you should avoid all personally oriented discussions and name calling for future.
but the first part seems muddled and the last part is just wrong (IMO)
OK, can you explain it (I mean in sequence of logical steps, not with fuzzy reference to some keywords of internet search again)?

antialias_physorg
5 / 5 (1) Oct 21, 2011
Not in any other words that I haven't used before.

1) Meissner effect pushes field lines (magnetic fields) outside the superconducting material.

2) The thin layer used in the experiment has weak spots (holes) in the material which are areas that are not superconducting. These holes are therefore fair game for magnetic field lines (i.e. they are 'outside' the superconducting part of the object)

3)If the object wants to move (e.g. wobbling as in with bulk material). Then those field lines/flux tubes are deformed. They cannot move because they are forbidden from going into the material surrounding the hole (again Meissner Effect).

4) Deformed field lines create a force that wants to 'straighten' (like misaligning a piece of metal in a magnetic field). Thereby locking the object in place

Other topic: You are perfectly able to use the same account from two computers. That's a pretty lame (and unbelievable) excuse. I call sock-puppetry as I see it.
Skultch
5 / 5 (2) Oct 21, 2011
I'm using the multiple accounts simply because I'm using a different computers.


Bullshit. This is why I usually ignore your posts.
Callippo
1 / 5 (1) Oct 21, 2011
You are perfectly able to use the same account from two computers.
Nope, as I forget its passwords already. These accounts are remnants of times, when I was forced to create new login nearly each day because of intensive moderation of physorg discussions, so I didn't care about password management too much. After then the moderator was fired or he got married or tired or whatever else and I remained with two accounts, which I'm using right now. When I'll delete cookies, I will be forced to create some new account anyway. Actually, for my personal glory it would be more advantageous to use my original account (Zephir), don't you think?
why would you switch? You'll get downvoted for posting
Nope, the people who are downvoting me are downvoting me because of my ideas, not because of multiple accounts (experimentally tested with many forums under single account). But I don't care about, who the posters are - I'm just responding the posts. Names aren't important here.
Callippo
1 / 5 (1) Oct 21, 2011
Then those field lines/flux tubes are deformed. They cannot move because they are forbidden from going into the material surrounding the hole
The flux pinning makes no difference in thin or thick superconductor. Actually, the more thick superconductor, the stronger pinning effects we should expect, the stronger brake should follow. Whereas at the example of demonstration, exactly the opposite relationship has been observed.
4) Deformed field lines create a force that wants to 'straighten' (like misaligning a piece of metal in a magnetic field). Thereby locking the object in place
OK, the braking effect is all about this force. Which is the exact mechanism of this force?
kochevnik
1 / 5 (1) Oct 21, 2011
So 1983...
thales
not rated yet Oct 21, 2011
Upon viewing the video, a lot of commentators refer to the scene in Back to the Future 2 when Mary McFly rides a hoverboard for a few minutes.


flux tubes... are the real secret to the whole trick.


I'm not saying you can build any kind of capacitor out of this thing, but... does anyone know how to generate 1.21 gigawatts?
antialias_physorg
not rated yet Oct 21, 2011
The flux pinning makes no difference in thin or thick superconductor.


In thick materials you don't get flux tubes at all. (There is no path for the field lines to go through the material). You may get a bit at teh very edges because the path through the edges is 'thin' enough to have holes/defects. That's why you can even align bulk material a little bit in a magnetic field.

OK, the braking effect is all about this force. Which is the exact mechanism of this force?
Meisner effect. As stated numerous times already.
Callippo
1 / 5 (1) Oct 22, 2011
In thick materials you don't get flux tubes at all. (There is no path for the field lines to go through the material).
This is just a point, in which your theory and mine can be distinguished and falsified. Because at the case of Type II superconductors the magnetic field lines always penetrate the superconductor, no matter how thick the sample actually is. The interior of quantum vortices serves there as a path for flux tubes.
Which is the exact mechanism of this force .. Meisner effect
LOL, it's the denomination of this force, not the mechanism of it. Which is the mechanism of Meissner effect?
antialias_physorg
not rated yet Oct 22, 2011
For a type II superconductor it depends on what temperature we're talking about (is it in a pure superconducting state or in a mixed Meisner state).

If it is in the pure superconducting state then the weak points could be thinner than the London depth (so this demonstration might actually also work with type I superconductors - though for those you probably need something better than liquid nitrogen)

Ethelred
1 / 5 (1) Oct 23, 2011
I'm using the multiple accounts simply because I'm using a different computers.
Since you have used multiple accounts to uprate yourself and to make it look like there was more than one person in more than one of your series of postings under two or more logins that claim is clearly false. And it doesn't make any sense at all since you could login under single name from as many computers, tablets, phones or whatevers as you want.

So that excuse for multiple logins is just as much a bunch of crap as it was when you first used it. Which was a long time and many sockpuppets ago.

Ethelred
Callippo
1 / 5 (1) Oct 23, 2011
Some people are just a-socially oriented and they cannot contribute with anything to discussion but with enforcement of their understanding of justice. This is why your last comments in scientific threads deal with personal data and attacking of various people here - but never with science. Do you know, which kind of personality the Hitler was? He was strongly oriented to maintaining social justice at any price and its seeming violation by Jews.

I'm not attacking or even downvoting anybody here, with using of multiple accounts the less, my own posts the less. You're just inventing the stuffs for the sake of your psychopathic vision of reality.

After all, if everyone of you would keep strictly the topic and use only arguments, which are intersubjectively testable, then it would become completely irrelevant, which account each of us is using because all of them would became equally relevant. The voting and naming system is just a reaction to imperfection of people.
Callippo
1 / 5 (1) Oct 23, 2011
After all, what else one can expect from egomaniac and socially unsure person, which subscribes each post with his own name, albeit its author is clearly apparent from post label?

Such people are judging the posts by their authors instead of real content exclusively, because they're basically stupid, they have black and white vision and the distinguishing of comments by their authors is the only way, how they can navigate in this complexity. When they're judging the posts, they think about them in context of their membership in political coalitions ("he is commie", "he is crackpot", "he is true scientist"), etc. Without this subjective labeling whole the discussion appears broken for such people.

Such people are indicating their personality with their redundant signatures better, than with anything else.
Isaacsname
not rated yet Oct 23, 2011
Once again the train of thought is on fire, full of screaming babies and headed over the cliff O:

So in bulk materials, in order for the flux tube to penetrate the material there has to be an " allowable path " ( I use that for lack of better terms ) based on inclusions in the material ? Something with an ordered geometry but not periodic, like the structure of a quasicrystal ? I guess basically what I am asking is if it's possible to build a material from the bottom up that has ordered inclusions ?
Callippo
not rated yet Oct 23, 2011
You should understand, how the superconductors are working first. The superconductivity arises, when movable electrons are squeezed between atoms in such a way, their repulsive forces compensate mutually. The type I superconductors are squeezing electrons with attractive forces of their d- and f-orbitals, which doesn't provide very high temperatures of superconductive transition. Type II superconductors are using the attractive forces between whole groups of atoms in layers, which enables them to squeeze electrons more. They're forming the superconductive paths not at the atomic level, but at the lattice level. Which means, there are conductive stripes of electrons separated with many layers of "inert" atoms, the only purpose of which is to keep the electrons together.

Just these "spacer" layers enable to penetrate the magnetic flux lines inside of superconductor. At the case of Type I superconductor the superconductive phase is much more compact and it doesn't enable flux pinning.
Callippo
not rated yet Oct 23, 2011
Something with an ordered geometry but not periodic, like the structure of a quasicrystal ?

Yes, there is such a connection. To prepare effective superconductor you should manage the preparation of highly aperiodic hyperlattice, where the one layer of superconductive stripes alternates with three or more spacer layers in a scheme -SC-SP-SP-SP-SC-SP-SP-SP (actually, the more spacer layers per one superconductive layer, the better, as Rosser semiempirical formula indicates clearly).

http://jpsj.ipap....77SC/142

It's still not the quasicrystal structure in common sense, but some connection exists here. Such structure is nothing natural for common crystals, because they tend to form the lowest entropic state with alternating layers -SC-SP-SC-SP-SC-SP- ...
Isaacsname
not rated yet Oct 23, 2011
Yes, thank you, that's what I was looking for. I get it now, I think. Fascinating, absolutely fascinating.
jnjnjnjn
1 / 5 (1) Oct 24, 2011
... Other topic: You are perfectly able to use the same account from two computers. That's a pretty lame (and unbelievable) excuse. I call sock-puppetry as I see it. ...


Thanks for the explanation, I think I understand it somewhat now.
Regarding the other topic: I have used several accounts sometimes because I didn't know the password on another computer, and created an ad hoc account to be able to post a comment.
So its perfectly believable.

J.
cees_timmerman
not rated yet Oct 24, 2011
This is probably the closest thing mankind has which resembles a tractor beam!!!


It certainly looks more macro than circularly polarized light.
Ethelred
3.7 / 5 (3) Oct 24, 2011
So its perfectly believable.
Plausibly deniability is not the same as believable. Especially with Zephir-Xaero-hodzaa-MustaI-Alizee-Zephir-wiki11-slotin-Alexa-jigga-Sirinx-kaixin-rphy-sckavasallis-gravityphd-Citinex-TDK-CTD1-smk9-VK1-beelize54-undo-Telekinetic-A2G-KwasniczJ-tamang and most likely other logins as well. He made up bogus profiles with fake addresses and nationalities to go with those names in some cases.

He was using multiple accounts exactly as I said . He has only stopped doing so because so many of us have gone to war with the bastard. Some of us went so far as to create counter attack logins. That seems to be what finally stopped his FREQUENT use of sockpuppets to downrank his opponents.

He was caught red handed multiple times pretending to be several people in a conversation himself. He is just plain lying about his behavior to con people that didn't see him do it time and time again.

Ethelred

Ethelred
1 / 5 (1) Oct 24, 2011
Signing posts is STANDARD on most forums. That reply of Zephir's is pretty standard for him. Get caught being naughty, hmm, attack, Attack, ATTACK and don't bother using truth as that is for sissies.

Ethelred
RandomReason
5 / 5 (2) Nov 03, 2011
The attitude in this review and many of the comments is inexplicable. The video has sparked lay interest in physics, and the researchers website makes explicit that they are using this technique as an educational demo, offering kits to schools and promoting interest in science in general and physics in particular.

They should be applauded, and the fact of this video going viral should be greeted with support not condescending disdain.