ABSTRACT
Imagine that you are standing at the site of an archeological dig. On your left, you see a large rock with a dent in the middle. Next to it you see a pile of smaller stones. Aside from this, all you see is sand. An archeologist soon appears at the site. What looked like just a rock to you, he recognizes as the base of a column; the small stones, a set of architectural fragments. And where you saw only sand, he begins to visualize the structure that stood here years before.
