 |
| A mock diagram of Ecphantus' earth rotation theory, according to which the earth rotates like a wagon wheel, and this explains the apparent motion of the stars. |
— Otto Guericke (1672), New Magdeburg Experiments on the Vacuum of Space [1]
“All authorities agree that Heraclides of Pontus affirmed the daily rotation of the earth about its own axis; but the Doxographi associate with this discovery another name, that of ‘Ecphantus the Pythagorean’. Thus, we are told of Ecphantus that he asserted that ‘the earth, being in the centre of the universe, moves about its own centre in an eastward direction’ (Hippolytus, c.210). Again, ‘Heraclides of Pontus and Ecphantus the Pythagorean make the earth move, not in the sense of translation, but by way of turning as on an axle, like a wheel, from west to east, about its own centre’ (Aetius, c.100). Who then is this Ecphantus, described in another place in Aetius as Ecphantus the Syracusan, one of the Pythagoreans? His personality is even more of a mystery than that of Hicetas. The Doxographi, however, tell us of other doctrines of his; Hippolytus devotes a short paragraph to him, between paragraphs about Xenophanes and Hippo, which shows that Theophrastus must have spoken of him at length. Some of his views were quite original, particularly on the subject of atoms. Holding that the universe was made up of indivisible bodies separated by void, he was the first to declare that the monads of Pythagoras were corporeal; he attributed to the atoms, besides size and shape, a ‘motive force’ (δνυαμις); the atoms were moved, not by their weight or by percussion, but by a divine force which he called mind and soul. The universe was a type of this, and accordingly the divine motive force created it spherical.”
— Thomas Hearth (1913), Aristarchus of Samos, the Ancient Copernicus (pg. 251)
