Speaker wire is it science or psychology

I have had the pleasure of working with several audio design engineers. Audio has been both a hobby and occupation for them. I know the engineer that taught Bob Carver how a transistor works. He keeps a file on silly HiFi fads. He like my other friends considers exotic speaker wire to be non-sense. What do you think? Does anyone have any nummeric or even theoretical information that defends the position that speaker wires sound different? I'm talking real science not just saying buzz words like dialectric, skin effect capacitance or inductance.