Despite these difficulties, we can use the very limitations of modern science to vaguely identify the beginning of our present Age. We can do this by marking the point at which those methods of measurement break down. The physical and spiritual shifts marking the transition from one age to another will erect a ‘wall’ beyond which our historians will be unable to see. If we can identify such a wall, we can approximate the genesis of our era. And indeed we do find such a wall situated somewhere near the 6th century B.C. It is here, according to our enlightened experts, that ‘pre-history’ ends and ‘history’ begins, which is a way of saying that, although history existed for thousands of years before, it is here that it finally becomes observable to us. We do, of course, know something about much older civilizations like Egypt, India, and China, but our understanding of those peoples are so far removed that our experts are wise not to include them in their timeline.