They all laughed at Christopher Columbus
When he said the world was round.
They all laughed when Edison recorded sound…
They all said we never would be happy.
Darling let's take a bow.
But ho, ho, ho!
Who's got the last laugh now?

The ancient Greeks noticed five "planets" (or "vagabond stars") which seemed to wander back and forward across the sky. The earth was not assumed to be a "planet". Plato assumed, however, that the earth was a sphere. Eudoxus (c 400-350BC) (who was a teacher in Plato's famous Academy in Athens) was the first to construct a geometric model to predict the positions of planets, using a system of one sphere rotating within another within another and the earth at the centre. A system with just two of these is shown here. Eudoxus used four such spheres for most planets, producing a much more complicated motion.

Aristotle (384-323BC) formulated a whole system of dynamics, biology and other sciences. He also took Eudoxus' system and added more spheres to avoid interaction for the different planets. Cambridge historian Michael Hoskin rightly says of his system: "It is important to recognize that this Aristotelian cosmology drew strength from being an intellectual formulation that reinforced common sense, in contrast to modern science, which contradicts what seems self-evident." Observations of stars, the circular shadow on the moon during a lunar eclipse, and other reasons gave a rational base to believe the earth was a sphere. There was no obvious reason to suppose it moved.

Claudius Ptolemy (c 100-170 AD) extended the earlier Greek work in his own mathematical model to predict the planetary positions. If we imagine one rotating circle with its centre fixed to another rotating circle, Ptolemy used three or four such, each on to of the other, to predict each planet. The whole was centred near the earth, which was a static sphere, and each orbit was going at constant speed an off-centre called the equant. This system was accepted by scholars throughout the middle ages up until the sixteenth century. The earth's radius was taken (fairly accurately) as about 3200 miles, and the size of the universe as being some 65 million miles.

It is difficult to find any church leader in history who did not accept that the earth was comparatively small and spherical, eg Justin, Clement, Origen, Augustine, Boethius, Bede, Aquinas, Isadore, Roger Bacon etc. Some, like Oresme and Nicolas Cusanus, speculated that it was in motion. There was controversy over whether any counties the other side of the earth's sphere (the antiopodes) were inhabited, but belief in a flat earth was very rare for any well educated person.

Columbus (1450-1506) was the self-educated son of a weaver, and argued for an earth smaller than experts knew it to be. The rejection of his scheme in 1486-7 was because such a long voyage was thought impracticable, not because anyone believed the earth was flat. He was lucky the Americas were in the way of his attempt to sail all the way west from Europe to China - otherwise he would have died at sea! His own unreal self-projection of a lonely man of destiny was romanticised further by his American biographer Washington Irving in 1829, with the nonsense about a flat earth that still persists, even though all historians know it to be untrue.