"Are you that certain that you're right?"
Tubegroover, that's a damned good question! The answer is that I haven't seen (or heard) any compelling evidence that my assertion is wrong. If you boil it down far enough, what we think we "know" about the universe and the way it operates exists only because we hypothesize about the way the universe works, and then we devise tests that either prove or disprove our guesses. For some physical phenomena the guesses do change over time a little bit. Sometimes a lot, but not often. I blame it all on Einstein for so famously changing some guesses made by Newton in such a big way, because it gave people the impression, I think, that other guesses we've made are subject to just as much change. That our understanding is somehow superficial. That might be true in quantum physics, certainly so in some areas of biology, but electricity is a lot different.
Not that electricity and electromagnetism are so simple. A friend of mine specializes in electromagnetic interference effects for multi-gigahertz electronics, and the math he uses is formidable. There's also a lot judgement involved sometimes in product development that makes laymen wonder about "understanding". For example, high-volume production circuit boards are typcially made from a material called "FR-4". It's green, fiberglass, and it's cheap. If you look inside of your PC you'll see a lot of it. Anyway, 10 years ago some of the best analog electrical engineers were of the opinion that for signals with a clock frequency of greater than 500MHz we just might have to drop FR-4, and go to more expensive materials like teflon (due to noise levels, among other things). Anyway, 10 years later we're still using FR-4 for signals well into the multi-gigahertz range. The engineers recommending teflon back then were "wrong". Was this due to a lack of understanding? Did we learn new things about electricity since then?
No, to both questions. Engineers learned more about developing what are called "design rules", that more stringently specified high-speed circuitry to function on FR-4. More was learned about how to manage noise and EMI in physical designs. The engineers were actually correct, using the old rules. So now we have cheap multi-gigahertz circuitry, and nothing I'm aware of was learned about electrical theory. Much was learned about how to engineer products, but it's the same theories, proven over and over again, thousands of times per day, by observations called ultra-precise measurements under controlled conditions. We know how electricity functions because everytime we properly construct a given scenario it works EXACTLY as predicted. Every time.
Do I KNOW that two properly functioning and spec'd power cords are not going to sound audibly different? Anyone who has studied philosophy understands that KNOW is a heavyweight word. I don't KNOW. But if there were audible differences the physical effects that caused the audible differences - that we can't currently explain -would surely show up as anomalies in other areas where low-level currents or signals are incredibly important. (They are not in 120v AC power.) Microchip design, test equipment, 10GHz bit-serial signalling on copper cables... somewhere. And nothing has been detected. Sometimes you need really, really clean power, but you use active devices to achieve it. Our ears are not sensitive devices compared to certain test equipment. Some people don't want to believe it, but it is true.
So in the end, yes, I'm pretty damn certain.
Tubegroover, that's a damned good question! The answer is that I haven't seen (or heard) any compelling evidence that my assertion is wrong. If you boil it down far enough, what we think we "know" about the universe and the way it operates exists only because we hypothesize about the way the universe works, and then we devise tests that either prove or disprove our guesses. For some physical phenomena the guesses do change over time a little bit. Sometimes a lot, but not often. I blame it all on Einstein for so famously changing some guesses made by Newton in such a big way, because it gave people the impression, I think, that other guesses we've made are subject to just as much change. That our understanding is somehow superficial. That might be true in quantum physics, certainly so in some areas of biology, but electricity is a lot different.
Not that electricity and electromagnetism are so simple. A friend of mine specializes in electromagnetic interference effects for multi-gigahertz electronics, and the math he uses is formidable. There's also a lot judgement involved sometimes in product development that makes laymen wonder about "understanding". For example, high-volume production circuit boards are typcially made from a material called "FR-4". It's green, fiberglass, and it's cheap. If you look inside of your PC you'll see a lot of it. Anyway, 10 years ago some of the best analog electrical engineers were of the opinion that for signals with a clock frequency of greater than 500MHz we just might have to drop FR-4, and go to more expensive materials like teflon (due to noise levels, among other things). Anyway, 10 years later we're still using FR-4 for signals well into the multi-gigahertz range. The engineers recommending teflon back then were "wrong". Was this due to a lack of understanding? Did we learn new things about electricity since then?
No, to both questions. Engineers learned more about developing what are called "design rules", that more stringently specified high-speed circuitry to function on FR-4. More was learned about how to manage noise and EMI in physical designs. The engineers were actually correct, using the old rules. So now we have cheap multi-gigahertz circuitry, and nothing I'm aware of was learned about electrical theory. Much was learned about how to engineer products, but it's the same theories, proven over and over again, thousands of times per day, by observations called ultra-precise measurements under controlled conditions. We know how electricity functions because everytime we properly construct a given scenario it works EXACTLY as predicted. Every time.
Do I KNOW that two properly functioning and spec'd power cords are not going to sound audibly different? Anyone who has studied philosophy understands that KNOW is a heavyweight word. I don't KNOW. But if there were audible differences the physical effects that caused the audible differences - that we can't currently explain -would surely show up as anomalies in other areas where low-level currents or signals are incredibly important. (They are not in 120v AC power.) Microchip design, test equipment, 10GHz bit-serial signalling on copper cables... somewhere. And nothing has been detected. Sometimes you need really, really clean power, but you use active devices to achieve it. Our ears are not sensitive devices compared to certain test equipment. Some people don't want to believe it, but it is true.
So in the end, yes, I'm pretty damn certain.