Cable directionality


I'm sure this has been discussed before but I missed it, so what is all this stuff with the direction of voltage flow with cables? Every cable you see any more has a little arrow on it. Since the signal is AC and travels one direction as much as it travels the other, what difference could this possibly make. I have talked to numerous co-workers (all electrical engineers) and they ALL say this is the biggest bunch of bunk they have ever seen. Since I am the only "Audiophile", I try to keep an open mind(I'm also the odd man out being mechanical.) Skin effect, resistance, capacitance, etc. are true issues. You pass power through a wire and it creates a magnetic field. You do deal with impedence and synergy with the driving source. How about a few technical answers from the audiophile community.
bigtee
I'm glad we have a cable designer here--welcome Orbeck. As a physicist I like hearing the scientific explainations, when I can only surmise the bits I know about cables. It's certainly refreshing to the hocus pocus.
BigTee,

Please don't confuse voltage with current. In order to drive your amplifiers to drive your speakers current must flow. The same thing happens in your AC line analogy. The cable shield issue that you are raising is real. Current will flow through the shield if the circuit driver and receiver are at a different reference potential.

Regards,

John
OK so interconnect shielding is grounded at one end only, hence the cable is "directional".
But I have seen "directional" speaker cable, and I cannot think of any possible explanation for this. Can anyone offer a plausible explanation?
John, But what if the shield is only connected at one end as some other folks are saying? Now, how does flow occur? I agree with the "Possibility" of potential on the ground circuit but I also know that electricity takes the path of least resistance (both voltage and amps---since volts do push amps.) You can see a ground wire (white wire---not the copper ground) spark at the breaker panel when it is connected to a load such as a motor but it has NO potential. Ground faults help with large, potentially dangerous shorts to ground as through your body. You are always going to have a difference in ground potential between a large amp drawing component and something less. You certainly cannot have voltage potential(and flow) without some sort of current, ever how small. No current, no flow.
So, I guess my question remains, since we are dealing with AC, how can wire be directional?
BigTee, you are confusing a "shield" with a "ground". They can be two different things. In some cables a "shield" is connected only at one end. There are still two other conductors to carry the signal. There is no mystery here to anyone who has ever worked in a calibration lab!