Yes, give up. Why should he take time to validate your point when it is not important to HIM? Most engineers I know who are also audiophiles start out as skeptics, and only come around to the value of cables (if they ever do) when faced with the empirical evidence from their own ears that they can improve the subjective performance of THEIR OWN SYSTEM. Suspension of belief and years and years of formal training and successful application of physical principles requires a significant reward!
The best lay explanations of why cables "improve" sound reproduction has more to do with what they don't allow to happen to the current and signals coursing behind your sound system than what they actually DO or DON'T DO to the SOUND in the absence of complex EM fields, i.e. are they acting as active antennas or passive pipes. With that said, my experience is that silver has a "different" sound signature than copper, but that may be beyond mine or your ability to explain to the good Doctor. I am sure it has something to do with "skin effects", but may also just be that silver wire makes a different kind of antenna than a copper wire???
The best lay explanations of why cables "improve" sound reproduction has more to do with what they don't allow to happen to the current and signals coursing behind your sound system than what they actually DO or DON'T DO to the SOUND in the absence of complex EM fields, i.e. are they acting as active antennas or passive pipes. With that said, my experience is that silver has a "different" sound signature than copper, but that may be beyond mine or your ability to explain to the good Doctor. I am sure it has something to do with "skin effects", but may also just be that silver wire makes a different kind of antenna than a copper wire???