. I was purely addressing the theory that Aviendha tampered with the device.  If Aviendha "Tampered" with the columns, she still did not change the physical hardware that read the past. Whether it read Blood and Bone" or tea leaves, it didn't suddenly gain the ability to read the New York Times.  Assuming they manufactured the Column Ter'angreal in Rhuidean, and we know they had the Testing Rings, why not believe that they would take what they understand from the Testing Rings as far as showing futures and then adding a blood component so they have two useful Ter'angreal instead of just one?  Because hybrid machines almost never work as well as dedicated machines for a single function.  Adding "a blood component" to a mirror-world viewer would require additional components and generally complicate the design. People are versatile enough that they can change modes at the drop of a hat, but machines are stupid -- even magical machines that do things impossible in the real world. :D  If the Rhuidean Aes Sedai did manufacture the Columns -- which I personally believe they did -- then how likely would it be that two master ter'angreal makers would survive the Breaking and find their way to Rhuidean to build a multi-mode ter'angreal with one mode locked out for a couple of thousand years?  I think the Rhuidean AS had just enough skill and knowledge to build a way to preserve the Aeil's history and mark the Clan Cheifs and Car'a'Carn. For them to have more than the minimum ter'angreal building skill smacks of deux ex machina.  I doubt the Columns need data from Mirror Worlds to generate a past, beyond any cultural type data that might be useful to craft a reliable setting outside of the blood-memories, but not completely necessary.  Everything needed is contained in the Blood; just as Mat experienced Aemon's life during his Healing, the Columns simply bring the applicable Old Blood Memories to the surface and allow the candidate to experience them; including any and all cultural baggage  