This is one that can emphasize a point about the Kryptos material that is essential to understanding the quagmire of inactivity that surrounds the installed sculpture.  Some intellectuals would argue that everything is relative and who would presume to assign a value/definition/or significance?  The line must be drawn, the meaning established even if only to be proven vastly incorrect at a later date.  We need the confidence and ability to make assertions and make assumptions about the material we have in front of us otherwise it is rapidly impossible to make forward progress.  It becomes less a presumption of authority we are not entitled to but rather a more deliberate and practical resistance to philosophical sophistry and an aknowledgement of our intent: to solve Kryptos.  One cannot approach the ciphers and codes of any cryptological challenge with anything less than the clear intent to make multiple and repeated efforts to solve it.  At the same time and throughout our efforts we must realize that it is very possible to be wrong and make a misinterpretation.  We must have the arrogance to try and the humility to accept our defeats as they occur.  I’ll get off my soapbox…

Have any of us ever thought about what something like “Virtually Invisible” means?  In modern contexts, one would take it to mean a technological invisibility, in other words – an online invisibility.  This is a product of our networked lifestyles. 

Literally taken?  It becomes a figure of speech. 

“It was virtually impossible to finish my paper before the deadline.”

“The differences between our subcultures are virtually nonexistent but their marketing depends on our ability to recognize those differences.”

“Steganography renders the message virtually invisible as it hides in plain sight.”

So something is virtually invisible because it’s not actually invisible, it might as well be but it is in-point-of-fact, not.

So we haven’t seen it because we don’t know where to look.

Time is your position as the shadow forces the virtually invisible…