The concept of a non-moving flat earth which all the luminaries in the sky rotate around is the traditional way virtually all the people of world understood the universe worked.<br /><br />The idea of a spherical Earth appeared in Greek philosophy with Pythagoras (6th century BC), although most still retained the flat Earth model. Aristotle developed the globe earth theory further around 330 BC. Gradually the Globe Earth theory began to spread from then on.<br /><br />NASA gave the Globe Earth theory a great boost with their Apollo Moon missions when they produced the ‘blue marble’, the first photograph that was claimed to be an actual photograph of the earth taken from space.