I'll field this one. If you've ever tried to press two negative or two positive poles of a magnet together you should know that they oppose each other in the most sporadic of ways. In other words, they resist contact and also tend to fly off from each other. Mag Lev simply uses this property in such a way that the repulsion effect is obtained without the problem of the two magnets to fly away. For example, in Mag Lev, the magnetic rails simply won't budge because they're nailed down. And the train itself won't budge because the gravitational force properly attains equilibrium with the sporadic tendency for the two magnets to fly away. No cooling effects needed in this case. Only properly balanced weights and magnetic strengths with well designed mechanical constraints.
The other effect is different. It's a property of the superconductor. I read all this on Wiki, so I don't know what I'm talking about. But I can take a stab at it.
The thing you see hovering above the magnet is a superconductor. The word conductor simply means that the substance conducts electricity. In other words, it allows electrons to move freely about the substance. This property is most often found in metallic substances. Other non-metallic substances are often not conductors in the sense that their electrons stay put, often because they are integral to the stability of the substance.
A superconductor is a substance that allows electrons to move freely about without any form of resistance what so ever. In the case of a normal conductor the electrons meet with small forms of resistance. But not so with the superconductor. The superconductor is brought to a very low temperature. When it approaches the state where the electrical conductivity of the substance is nearly absolution, the magnetic field within the substance is diametrically expelled.
Normally, a magnetic substance forms a field of magnetism that emanates from the very core of its existence, locking and trapping other magnetic things in a very horrible way, I'm sure. But when it gets very, very cold magnetism decides it's had enough, says, "righto. We've had enough. If you're not going to come out of the cold, we're leaving!" And just like that it's gone and the electrons rejoice for their magnetic over lord of clinginess has given up total power.
But then this very cold object is put inside the context of another magnetic field, like the object above or below which the superconductor in the video is "pinned". Here the magnetic field of the other object attracts the superconductor and holds but not as it would were the substance to still be in the bond of its own magnetic field. So this is why the superconductor is trapped above or below the other object.
Another brilliant form of levitation can be seen in the night sky. The moon levitates above the earth in a similar fashion according to the mutual bond of gravity. How exactly these objects stay in relative position with one another is still a topic of discussion among scientists and lay men alike. However, one thing is clear. The moon and the earth are like atoms. Anyone can see that though gravity binds them, there is truly no contact betwixt the two. Like the atoms in our being, no contact exists, though consciousness binds us to the material fabric.
Like the three marks of conditioned existence, this world in itself is filthy, hostile, and crowded
For those who don't understand what has been said because it is too technical but still would like to know about the basic difference between maglev and quantum levitation I think the answer is that they both rely on magnetism as the force to do the lifing.....the difference is just in the way the magnetic force is made.....the main difference from a practical standpoint is that existing maglev trains rely on magnets which have electrical resistence and thus create a residue of heat (which is wasted energy) while the quantum levitation relies on magnets which have no electircal resistence and so create no residue of heat.....as Buddhists we might think of this as "magnetism with residue" and "magnetism without residue".
chownah
As Pondera points out there is also a difference in the arrangement of the magnetic fields....existing maglev technology utilizes the repuslion of two like poles (a north magnetic pole will repel another north magnetic pole and a south magnetic pole will repel another south magnetic pole....we say "like poles repel".).....I can not do videos on my internet connection so I'll have to rely on Pondera's description which seems to indicate that in quantum levitation they have arranged things so that opposite poles work together to do the lifting (a south magnetic pole will attract a north magnetic pole and visa versa...we say " opposite poles attract".) You can do lifting by either repelling (pushing) or attracting (pulling) so its a matter of engineering to determine which to use and for what reasons.
Also I want to point out that it is very possible to build a maglev with magnets with no residue of waste heat by using superconducting magnets but the technology to do this is not yet cost effective but it is heading in that direction and in the future it very well may be possible to do that.
chownah
That's true. When the substance approaches its superconducting level all magnetism is expunged. However, and the phenomenon is still not quite well understood, the action of the electrons at the surface of the superconductor ... That's true. Or, I really don't know. It's pretty weird. The weirdest thing is that the person in the video doesn't seem to have a problem with handling that piece of superconductor, which I'm assuming is as cold as ice, or perhaps even colder than ice. Why aren't his fingers freezing?
Like the three marks of conditioned existence, this world in itself is filthy, hostile, and crowded
The damage from hot or cold things is a matter of heat conduction, not just temperature. That's why you can put your hand in a hot oven (as long as you don't touch the metal parts!) or walk on hot charcoal and not get burned (don't try it at home without an experienced guide!!!).
Pondera wrote:And...and...with Mag Lev the polarity of the magnets are the same.
And with quantum pinning they're not. They're opposites.
The superconductor isn't really magnetic at all (apart from the pinned flux lines).
Mike
I guess then some of what I said is wrong....I wish I could watch the video (but can't)....can you describe what it shows briefly...and perhaps some explanation...or where I could go on the internet to find something equivalent in text?
chownah
mikenz66,
Thanks for the links...sorry that you had to produce them a second time....I looked and the flux pinning page and it really doesn't have much so I looked at some related stuff and when I looked at the topic "Pinning Force it talked about vortex pinning. Are these magnetic vortices which interact with the field lines of the intruding magnetic flux? It seems to me that since type II superconductors do interact with magnetic flux then they must be doing that via magnetic flux so I'm looking for what is in the type II superconductor that facilitates this interaction and expecting to find some kind of magnetic structure....is this "magnetic structure" the vortex?
chownah
My rough understanding is that the vortex lines get pinned ("stuck") at defects. To move the superconductor they have to be detached and moved to a different defect. It takes some energy to "unstick" them, so the superconductor tends to stay where it is.
My rough understanding is that the vortex lines get pinned ("stuck") at defects. To move the superconductor they have to be detached and moved to a different defect. It takes some energy to "unstick" them, so the superconductor tends to stay where it is.
Mike
Mikenz66,
I can get to about that level of understanding too....I guess it is my assumption that a magnetic field only interacts with other magnetic fields...do you know if this is correct?...aren't diamagnetic, paramagnetic, and ferromagnetic effects the result of some large magnetic field interacting with atomic scale magnetic fields?....it seems that something must be interacting with the magnetic field in order to pin it.....
chownah
