Break in of a wire is, as I currently understand it, the reorientation of molecules in conductor (inner layers more than skin) and especially insulation to allow current to pass more efficiently. They stay in the same position but flip around until the charges on their surface are most compatible with the surrounding molecules and dynamic fields. The electric field in the conductor manipulates the orientation of the molecules within the field (conductor, dielectric, metal case and even air) and the molecules respond by finding an orientation that is most "comfortable" in accordance with 1st law of motion (inertia.) Just like trash on the road eventually finds its way to the gutter through the force of passing cars, then stays there unless acted by another randomizing force like wind. Same road, same trash, different orientation, allows traffic to pass more efficiently. Another analogy would be a 4x4 beam in the road will be knocked around until it lies in the centerline pointing in the direction of traffic. It is still in the same location, just reoriented so that it can rest and avoid the passing force. Some materials will change slower than others, so break in time varies. Like teflon caps take a long time, they better resist the field, require more energy to spin the molecules around or alter their shape with a huge molecule like teflon. But this is not truth, just my version of dogma, you are encouraged to be skeptical, I have never seen this happen with my own eyes, although I have seen trash on the road
Mains power and musical signals are alternating current not direct current. The electric field that moves electrons oscillates through the conductor in both directions like a piston, not in one direction like a water hose. Electricity in either is always moving in two directions, each in the exact same amount. Hot and neutral conductors both oscillate in both directions, just like positive and ground in a signal wire. DC current will actually cause electron migration, but that is still just charges, not atoms or molecules moving so there is really no mode by which a preference to flow electricity in either direction can be formed.
If I made cables I would paint arrows on them too, to avoid phone calls from the people who believe direction matters bugging me to explain which direction is "right."
Rich
