Thursday, November 3, 2011

Copernican Versus Tychonic Solar System Models.

There was a time not long ago where scientists believed the earth was the center of the universe, like Tycho. However, after Copernicus had his revolutionary discoveries we learned that we, and the rest of the solar system, in fact orbit the sun.

This website has a cool demonstration of how the solar-sytem would look under both models. Of course, Copernicus was right, but it is still cool to see what the solar system would look like if Tycho was.   Use the faint buttons in the lower right corner to change between models.

 The other cool thing I like about this animation is that you can see the relative length of orbits for each planet.



  1. Cool post.  The interesting thing about the Tychonic System is that, unlike the earlier Ptolemaic Geocentrism, it is essentially indistinguishable by observations from the Copernican System.  All the relative motions are the same in each.  It really isn't until you invoke Newtonian mechanics, or account for observations of stellar aberrations, that there is a big difference between the two. 

    Anyways, cool demonstration and great post. 

  2. Bill, those are some interesting points.  Thanks for sharing.  

    " It really isn't until you invoke Newtonian mechanics" Ah, so Newtonian Mechanics is the error!  (Just kidding)

  3. "so Newtonian Mechanics is the error!  (Just kidding)" -- You might be kidding, but considering Tycho Brahe died 41 years before Isaac Newton was born (and 128 years before James Bradley observed stellar aberrations), there was plenty of time in which the two systems were essentially indistinguishable from a physics standpoint. 

  4. Very cool.  Would have been interesting to have seen the scientific debates on the matter during that "in between" time period.

  5. Sorry, perhaps I'm just dense, but I don't get it. I'm guessing you're saying that Copernicus was right because rotation is all relative anyway? That's all the Tychonic system is really saying right?

    To be honest, I've always been a little confused at why we teach the Copernican system as if the folks back in the day were stupid for thinking so. I mean, clearly if we assume the stars are an inertial frame, then yeah, we eventually reason that the earth revolves around the sun. But Newtonian mechanics has ruled the day for a long time (hint: it's still taught in aerospace depts. around the world), and according to Newton, rotation is all relative anyway!


To add a link to text:
<a href="URL">Text</a>