7 ms·
It's not arbitrary. The only two choices that work are the real center of gravity, and the observer's position with the real center of gravity orbiting the obse
by fjsolwmv 7y ago
It's not arbitrary. The only two choices that work are the real center of gravity, and the observer's position with the real center of gravity orbiting the observer and everything else orbiting the real center of gravity. If Tycho chose Jupiter as the center of the orbits, the planetary orbits would have the same problem of epicycles as the older models.
- Armisael16 7y agoWhat precisely do you mean by “the same problem with epicycles”? You can fix Jupiter at the origin. You use exactly the same equations, except that the sun is using the equation that used to describe Jupiter (with an extra negative sign) and the other planets add in the term describing the Sun’s motion. Earth is no different than any other planet (or other celestial body in a stable orbit relative to the solar system) in this respect. Hell, you could make the Moon the center of the solar system - the math works just fine.
- rimliu 7y agoIf observer is on the Earth then equations for Jupiter will not work for describing the apparent motion of the planets.
- goto11 7y agoYou can claim that any arbitrary point is "the center of the universe" if you acknowledge that the planets rotate around the sun, not around the designated "center". If you choose Jupiter as the "center", there would still be no observable difference and you wouldn't need additional epicycles.