Magnetic Levitation, What is it?
Posted on May 3, 2017 by Marina Daniella Reyes
It is often said that opposites attract. Using that old adage then it would be expected that the things which are the same should repel each other and that’s where magnet levitation is possible. It means exactly what it says, levitation via magnetism, where one magnet or a metal object is held suspended above another.
How is that possible?
To understand magnetic levitation one must first understand what a magnet is. Magnets are any material that generates a magnetic field. This field has the ability to interact with other material considered magnetic. On a molecular level these materials generate said field from the alignment of their electrons. Non-magnetic items have electrons that spin randomly, but should they all start to spin in the same direction this energy generates a force termed as magnetism. This field can attract or repel other objects possessing the same characteristics.
Magnets themselves can be grouped into three, permanent, natural and electronic. Natural magnets are called ferromagnetic and have a fixed electron arrangement. Electro-magnetism occurs when an electronic current is passed through the material making its electrons align to create magnetic force. This does not have to be a fixed state. Permanent magnets can be either natural or man-made. All natural magnets are permanent, however some materials once magnetized via electronic means retain the necessary electron alignment.
Not a magic trick magnetic levitation
The process of magnetic levitation is firmly based in the rules of physics. The magnetic field is created with concentrations of electrical alignment, positive and negative, known as poles. The polarities of the fields determine how they interact with like fields, for example positive and positive, repel each other and opposite poles, positive against negative, attract. The other side of the magnetism is the elements that respond to these magnetic forces. Ferromagnetic materials are strongly attracted to both the positive and negative fields, and paramagnetic substances react weakly.
Logic would then indicate the basic operation of magnetic levitation, trapping one of these materials within the magnetic fields of opposing polarity. This dual magnet levitation takes a small piece of ferromagnetic or paramagnetic substance placed between magnets above and below. The magnetically charged opposite fields cancel out the natural push and pull behavior thus keeping the object suspended untethered.
It doesn’t end it there. Magnetic levitation can be performed with a single magnet, a more amazing display over the dual field process. This is based on several bits of physics theorem starting with diamagnetics. These substances adhere to Lenz’s law and exhibit the Meisser effect, by resisting the change being made to them by external magnet fields. This translates into a something that is repelled by both the positive and negative attraction forces of a magnet. That repulsion is caused by mirror magnet fields created within the diamagnet itself. This key property is why diamagnets are called ‘anti-magnets’ in the physics business. As the force is being countered on both poles of the external object, given the right circumstances, will cause it to push away suspending it above the diamagnet creating the levitation.