Throughout human history, there are ideas that arise seemingly independently among far-flung cultures — these cultural connections can almost defy belief. The Ancient Greeks, Egyptians, and Norse peoples all held beliefs at one time in their history of a flat world, often envisaged as encircled by an ocean or encased in a larger heavenly sphere. The horizon was a limit on that world — a definite edge from which a person might fall and be lost forever in nothingness.
