We're delving into the philosophical here. What is real? If I am facing you and perceiving you, you are real to my perceptions. But if I turn my back and am no longer perceiving you, do you exist? According to the Copenhagen Interpretation of Quantum Mechanics, you do not exist until I, say, turn around and perceive you, in which case what has happened is that the wave function has collapsed and you have come to exist. If I turn back around, it starts all over again. Of course, even if you make a sound and I hear you, the wave function has collapsed as I now perceive you.
The building may or may not exist. Even if I smack my head into it repeatedly, I could be merely responding to what my mind genuinely believes would happen if I were to come into such violent contact with an edifice. At this point, it becomes a matter of interpretting the perception, as the very perception itself has collapsed the wave function. If I don't look at the building, I can claim that it doesn't exist at all, until I walk into it and perceive it, collapsing the wave function.
But getting back to the original gist of this topic, I believe Reed saw something, which in my opinion was nothing more than a cardboard (or some such material) construct. I just don't believe it was what he was claiming it to be.
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I may not agree with what you have to say, but I will fight, kill, and die for your right to say it.