479. Can magnetic energy be used to power a vehicle?
When you talk about "magnetic energy," you are referring to magnetic potential energy. A potential energy is energy stored in the forces between objects. In the case of magnetic potential energy, that energy is stored in the forces between magnetic poles. But there is only so much potential energy in any given collection of objects. Potential energy is released by allowing the forces between objects to push the objects around and once it is used up, there isn't any more available. That's because energy is a conserved quantity—something that can't be created or destroyed and that can only be transferred between objects or changed from one form to another. While you can store energy in a collection of magnets, that potential energy is limited by how much was put in in the first place. So to answer to your question: yes, magnetic energy can be used to power a vehicle, but not indefinitely. The only practical magnetic energy storage proposals I'm aware of are ones that suggest using huge superconducting magnets to store electric power. While such devices might be practical for an stationary power company, they would be impractical or even dangerous in a vehicle—picture cars containing incredibly strong magnets driving down the road, repelling or attracting one another as they pass.