wow. reading this again was a blast from the past. I swear I have no recollection making that Disco post at all!
Anyway, it seems we dont have any consensus as to when the Copper Age began, or ended, but there does seem to be agreement that it does exist. Thats a start. after all, its only after a distance of years that we can and feel the need to denote a new era. As we enter the end of the decade with no name (oughts? nobody is even talking about it anymore) the 80s are far enough away (28 years ago already!) to be coalescing into an Age of their own.
So, when everyone agrees on Day One, let me know so I can update my database!