From: psperson@old.netcom.invalid   
      
   On Sun, 18 Jan 2026 21:18:47 -0000 (UTC), Lawrence D´Oliveiro   
    wrote:   
      
   >On Sun, 18 Jan 2026 08:56:36 -0800, Paul S Person wrote:   
   >   
   >> On Sat, 17 Jan 2026 22:40:20 -0000 (UTC), Lawrence D´Oliveiro   
   >>  wrote:   
   >>   
   >>> The problem is, he still insisted that the planets moved in perfect   
   >>> circles around the Sun. So it’s hard to see how the calculations   
   >>> could in fact have been any simpler or more accurate.   
   >>   
   >> Every planet (other than the Earth, of course) had one fewer circle   
   >> in Copernicus than in Ptolemy.   
   >>   
   >> The main circle of the Earth made them unnecessary.   
   >   
   >The fact that calculations still didn’t agree with observations of   
   >planetary movements was likely also an obstacle to the adoption of the   
   >Copernican theory.   
      
   The volume I read had some note; IIRC, Ptolemy's explanation of the   
   Sun was so far off that anyone could have seen it was wrong: it was   
   simply far too large (per the theory) when close to the Earth.   
      
   Copernicus was not about actually making the theory fit the   
   appearances. It was about showing that a heliocentric system was   
   mathematically possible -- that it could not just be dismissed as   
   impossible.   
      
   Kepler was the next step: elliptical orbits powered by an unknown   
   force from the Sun.   
      
   Newton provided that force -- gravity. The inverse-square version is   
   the one of three possibles; it prevailed because it matched the data.   
      
   Einstein, of course, produced a better prediction of Mercury's orbit.   
   --    
   "Here lies the Tuscan poet Aretino,   
   Who evil spoke of everyone but God,   
   Giving as his excuse, 'I never knew him.'"   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)