People have not always been buried in graves six feet deep - it has been uncovered that the original standard was twelve feet. Unfortunately the constant thinning of the Earth's crust meant that around 600 AD this practice became dangerous as hazardous magma could boil up from the burial site at any time. Soon the depth will need to be halved again; in fact famous academic Dr. Ispypie has predicted that by the year 2760 AD graves will be only one millimetre deep.