Golden Mean, Base “e” and the Cubit: A Puzzle

In this brief paper, we consider the ancient Egyptian measurement called the cubit. It is the length of a man's forearm. More importantly, when mathematical operations are performed in the 44 cm, the golden mean results. (1.6180). Also, 44cm / 1.618 equals base e. The golden mean and base e are central to Astrotheology Mathematics which indicates the level of sophistication of ancient mathematical physics. The question is: How did the Egyptians know about the centimetre if that SI System was not invented until the 17th Century?