Mezuzah in Three Dimensions

The mezuzah is one of the few mitzvot (divine commandments) for which the Torah states its reward. In this case, the reward is long life for oneself and one's children: And you shall inscribe them on the doorposts ("mezuzot") of your house and on your gates, so that your days and the days of your children may be prolonged upon the land which the Lord swore to give to your fathers for as long as the heavens are above the earth (Deuteronomy 11:20-21). According to the Tosafot and the Shulchan Aruch, the main function of the mezuzah is to protect the house from evil. Because of this attribute, the mezuzah has been called "the coat of arms in the knighthood of G‑d."*  To begin to understand the mechanism of this effect of the mezuzah, [...]