Copper vs. Silver vs. Gold

[rexmerdinus]

There's been a lot of talk about the traditional ratio between the prices of silver and gold, and whether it will ever return to something close those levels. Has anyone addressed the same issue but instead in terms of copper and silver? To state it a different way, let's go back in time, say to 1920--a circulating silver dollar (with 0.7735 troy ounces of silver) is worth a dollar, and a penny is worth .01 times that dollar in terms of commerce. Fast-forward to today, when silver is worth about $30 per ounce, making that silver dollar's metal content worth about $23.20 of today's dollar. Following the ratio of yesteryear, that would make a single 95% Cu penny worth about 23 cents.

Obviously I'm not taking metal supply and demand into account here, but we are certainly relegating some of our copper supply to landfills in one form or another, just like with silver. I'm interested in hearing everyone's thoughts (particularly those who understand the markets better than I do!), on whether we are likely ever to see price levels between copper and silver come back to anything close to these levels. Or the levels associated with 90% silver coinage (.7234 ounces per face dollar, or about $21.70 in today's dollars)?
Thanks!