How does a superconductor minimize its losses?

Answer 1

One feature of the universe is that energy can only be transferred (via exchange particles, or "virtual particles") in discrete units. In the quantum world, by definition, there is no such thing as "half" an exchange particle.

In a normal conductor, the ambient heat, plus the energy of moving electrons, is enough to create exchange particles. These hit the conductor lattice and are turned to heat. (Emitting exchange particles is the quantum way particles "bump" off of things).

In a superconductor, it is so cold, there is almost no thermal energy. There is no heat present to "help" with the creation of these exchange particles. When added to the energy of the electron's flow, there is still not enough energy to create an exchange particle, so the electron can't spend any energy. You could say that the electrons "bump" off the lattice, but nothing is exchanged, so the electrons continue on with the same amount of energy.

The one exception is when the electrical current gets higher -- then, the increase electron energy can actually start creating exchange particles, which then create heat, which provides enough energy to help other electrons create exchange particles, and so-on, and whammo, suddenly you have a warm ex-superconductor.