  00-00-0000, 00:00 AM  I fail to see how it became set in stone that Mirror worlds cannot be used to give visions of the past. If anything, I'd argue Mirror Worlds are the simplest way for the Rhuidean columns to work. If you can scan the Mirror Worlds , then you can see everything that didn't happen. So if you know all the probable events that didn't end up occurring, you're left with the only true events, which the ter'angreal shows the Aiel.  