The planets do not revolve about the Earth. Nor does the Sun or the stars. But if that is your model, you can force-fit the observations to it. In the case of geocentrism, dozens of bizarre adjustments were required to fit the observations. As the figure illustrates, these adjustments added a great deal more complication to the basic geocentric model. Now the planets were not exactly rotating about Earth, but about some nearby point (which could be adjusted as needed). Furthermore, as the planets circle around the Earth or a nearby point, they also travel in smaller circles, or epicycles. And of course these epicycles can be adjusted as needed. The result is a complicated model of celestial motion with a large number of knobs which are adjusted to try to match what we observe from Earth. And it works. If your model has sufficient number of knobs, you can fit any data. Read more