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A Pythagorean. The pythagoreans taught that there were 10 celestial bodies, but they could only observe 9, so they proposed a counter earth that could not be se
by dr_dshiv 2y ago
A Pythagorean. The pythagoreans taught that there were 10 celestial bodies, but they could only observe 9, so they proposed a counter earth that could not be seen — behind the sun. Aristotle mocks them for this idea, but the idea implies rotation around the sun.
- fph 2y agoDoes it? If the sun were rotating around the Earth, there could still be another planet behind it, rotating synchronously with it. At least from the point of view of the Greek, who didn't know how gravitation works in detail.
- dr_dshiv 2y agoPossibly. But I believe the mechanism for the movement of the planets was believed to be crystal spheres. Another possibility is that the Pythagoreans actually described the earth rotating around a central fire or Hestia. If that wasn’t the sun, it might have been the center of the earth — and the counter earth was actually the antipodes. When you see the source texts describing these things, it is terribly vague. Yet, Copernicus described himself as bringing back the Pythagorean ideas—