Eddy currents

The Raw Power of Permanent Magnetism Magnetism remains one of the most visible yet mysterious forces in our physical world. Most people interact with weak refrigerator magnets, but industrial-grade permanent magnets represent a different tier of physics altogether. These objects generate consistent magnetic fields without requiring an external electrical source. The strength of these fields allows for interactions that seem to violate the standard laws of motion. When a magnet possesses enough pull to oppose gravity, it transforms from a simple tool into a laboratory for fundamental physics. Eddy Currents and the Aluminum Paradox One of the most counterintuitive interactions occurs between powerful magnets and aluminum. Under normal circumstances, aluminum is non-magnetic; a common magnet will not stick to a soda can. However, when an extremely powerful magnetic field moves near a conductor like aluminum, it induces electrical loops called Eddy currents. These internal currents generate their own magnetic fields that oppose the original source. This creates a visible braking effect, effectively turning the air into a thick liquid that halts the motion of the metal. Engineering for Extreme Longevity The longevity of these super magnets is equally impressive. High-quality Neodymium magnets lose less than one percent of their flux density over a decade if maintained properly. Projections suggest these materials can retain up to eighty percent of their original power for a millennium. This durability makes them essential for long-term applications in renewable energy and aerospace where replacing components is difficult or impossible. Scaling the Impossible Historically, witnessing the dramatic repulsion of non-ferrous metals required massive, liquid-cooled electromagnets found in research facilities. The evolution of material science has compressed this capability into handheld form factors. Today, a single solid-state magnet can replicate effects that once required thousands of watts of power. This shift enables researchers and hobbyists to explore complex field interactions and magnetic levitation without the infrastructure of a high-energy physics lab.