Tag Archives: physics

Levitation by Superconducting Materials

File:Levitation of a magnet on a superconductor.jpg

Here is a photo of a magnet levitating above a super conductor.
via Wikimedia user Judobroff

Above you see a photo of a magnet that is “magically” floating. This photo raises many questions. How is this magnet floating? Could this lead to floating objects in real life? Could we float cars? Well here are your answers:

The magnet floats because of the surface composition. The surface is made of sapphire crystals, an aluminum oxide compound, which are poor conductors. Then it is coated with yttrium copper oxide which is a super conductor. Super conductors are compounds that will conduct electricity without resistance below a certain temperature.

More over, Super conductors hate magnetic fields due to the Meissner Effect. They allow electric current to flow easily. When this surface is put near a magnetic field currents are created to expel the field inside. Then the magnet doesn’t move because the surface doesn’t want to change it’s magnetic field. The magnet is held above the surface because of tiny gaps in the surface that the magnetic field seeps into.

Here is an example of what happens when the super conductor is made into a disc and is placed above magnets.

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via youtube user newscientistvideo

In this video you see that the disc is suspended about the magnets just as the magnet is suspended in the photo above. This happens for all the reasons are listed above.

So the questions remains, is this going to be the new technology that leads to hovering objects or even hovering cars? Well firstly, the superconducting surface only works because it is cooled with liquid nitrogen. Therefore we would have to have our roads covered in liquid nitrogen which is not quite possible yet. In addition, these cars would have to be completely made of magnets. So unfortunately, no. I don’t think this is going to lead to hovering cars anytime soon.

This is unfortunate because hovering cars could be useful to us in life. If the magnets were powerful enough and the technology was advanced enough we could have more freedom on the roads. Cars would no longer have to stick to the road and stay behind each other. We would have the freedom to float anywhere and maybe even fly under or above other cars. For now though, we are going to need to stick to the same old technology of wheels rolling along the pavement.