If one were to tell you of a particular room, modestly furnished with a table, a chair, a lamp offering some scant lighting, you would think little of such a place. Surely, you would not. Even with much of the room draped in deep shadows, such that the concrete walls, the concrete floor, the concrete ceiling, each can hardly be seen at all, you would think little of it. Even with one whole side a deep abyss, impenetrable, you might not think twice...